Adding upstream version 14.2.21.upstream/14.2.21upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

36 files changed, 4286 insertions, 0 deletions

diff --git a/src/zstd/contrib/pzstd/.gitignore b/src/zstd/contrib/pzstd/.gitignore
new file mode 100644
index 00000000..84e68fb0
--- /dev/null
+++ b/src/zstd/contrib/pzstd/.gitignore
@@ -0,0 +1,2 @@
+# compilation result
+pzstd
diff --git a/src/zstd/contrib/pzstd/BUCK b/src/zstd/contrib/pzstd/BUCK
new file mode 100644
index 00000000..d04eeedd
--- /dev/null
+++ b/src/zstd/contrib/pzstd/BUCK
@@ -0,0 +1,72 @@
+cxx_library(
+    name='libpzstd',
+    visibility=['PUBLIC'],
+    header_namespace='',
+    exported_headers=[
+        'ErrorHolder.h',
+        'Logging.h',
+        'Pzstd.h',
+    ],
+    headers=[
+        'SkippableFrame.h',
+    ],
+    srcs=[
+        'Pzstd.cpp',
+        'SkippableFrame.cpp',
+    ],
+    deps=[
+        ':options',
+        '//contrib/pzstd/utils:utils',
+        '//lib:mem',
+        '//lib:zstd',
+    ],
+)
+
+cxx_library(
+    name='options',
+    visibility=['PUBLIC'],
+    header_namespace='',
+    exported_headers=['Options.h'],
+    srcs=['Options.cpp'],
+    deps=[
+        '//contrib/pzstd/utils:scope_guard',
+        '//lib:zstd',
+        '//programs:util',
+    ],
+)
+
+cxx_binary(
+    name='pzstd',
+    visibility=['PUBLIC'],
+    srcs=['main.cpp'],
+    deps=[
+        ':libpzstd',
+        ':options',
+    ],
+)
+
+# Must run "make googletest" first
+cxx_library(
+    name='gtest',
+    srcs=glob([
+        'googletest/googletest/src/gtest-all.cc',
+        'googletest/googlemock/src/gmock-all.cc',
+        'googletest/googlemock/src/gmock_main.cc',
+    ]),
+    header_namespace='',
+    exported_headers=subdir_glob([
+        ('googletest/googletest/include', '**/*.h'),
+        ('googletest/googlemock/include', '**/*.h'),
+    ]),
+    headers=subdir_glob([
+        ('googletest/googletest', 'src/*.cc'),
+        ('googletest/googletest', 'src/*.h'),
+        ('googletest/googlemock', 'src/*.cc'),
+        ('googletest/googlemock', 'src/*.h'),
+    ]),
+    platform_linker_flags=[
+        ('android', []),
+        ('', ['-lpthread']),
+    ],
+    visibility=['PUBLIC'],
+)
diff --git a/src/zstd/contrib/pzstd/ErrorHolder.h b/src/zstd/contrib/pzstd/ErrorHolder.h
new file mode 100644
index 00000000..829651c5
--- /dev/null
+++ b/src/zstd/contrib/pzstd/ErrorHolder.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include <atomic>
+#include <cassert>
+#include <stdexcept>
+#include <string>
+
+namespace pzstd {
+
+// Coordinates graceful shutdown of the pzstd pipeline
+class ErrorHolder {
+  std::atomic<bool> error_;
+  std::string message_;
+
+ public:
+  ErrorHolder() : error_(false) {}
+
+  bool hasError() noexcept {
+    return error_.load();
+  }
+
+  void setError(std::string message) noexcept {
+    // Given multiple possibly concurrent calls, exactly one will ever succeed.
+    bool expected = false;
+    if (error_.compare_exchange_strong(expected, true)) {
+      message_ = std::move(message);
+    }
+  }
+
+  bool check(bool predicate, std::string message) noexcept {
+    if (!predicate) {
+      setError(std::move(message));
+    }
+    return !hasError();
+  }
+
+  std::string getError() noexcept {
+    error_.store(false);
+    return std::move(message_);
+  }
+
+  ~ErrorHolder() {
+    assert(!hasError());
+  }
+};
+}
diff --git a/src/zstd/contrib/pzstd/Logging.h b/src/zstd/contrib/pzstd/Logging.h
new file mode 100644
index 00000000..16a63932
--- /dev/null
+++ b/src/zstd/contrib/pzstd/Logging.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include <cstdio>
+#include <mutex>
+
+namespace pzstd {
+
+constexpr int ERROR = 1;
+constexpr int INFO = 2;
+constexpr int DEBUG = 3;
+constexpr int VERBOSE = 4;
+
+class Logger {
+  std::mutex mutex_;
+  FILE* out_;
+  const int level_;
+
+  using Clock = std::chrono::system_clock;
+  Clock::time_point lastUpdate_;
+  std::chrono::milliseconds refreshRate_;
+
+ public:
+  explicit Logger(int level, FILE* out = stderr)
+      : out_(out), level_(level), lastUpdate_(Clock::now()),
+        refreshRate_(150) {}
+
+
+  bool logsAt(int level) {
+    return level <= level_;
+  }
+
+  template <typename... Args>
+  void operator()(int level, const char *fmt, Args... args) {
+    if (level > level_) {
+      return;
+    }
+    std::lock_guard<std::mutex> lock(mutex_);
+    std::fprintf(out_, fmt, args...);
+  }
+
+  template <typename... Args>
+  void update(int level, const char *fmt, Args... args) {
+    if (level > level_) {
+      return;
+    }
+    std::lock_guard<std::mutex> lock(mutex_);
+    auto now = Clock::now();
+    if (now - lastUpdate_ > refreshRate_) {
+      lastUpdate_ = now;
+      std::fprintf(out_, "\r");
+      std::fprintf(out_, fmt, args...);
+    }
+  }
+
+  void clear(int level) {
+    if (level > level_) {
+      return;
+    }
+    std::lock_guard<std::mutex> lock(mutex_);
+    std::fprintf(out_, "\r%79s\r", "");
+  }
+};
+
+}
diff --git a/src/zstd/contrib/pzstd/Makefile b/src/zstd/contrib/pzstd/Makefile
new file mode 100644
index 00000000..40531e21
--- /dev/null
+++ b/src/zstd/contrib/pzstd/Makefile
@@ -0,0 +1,269 @@
+# ################################################################
+# Copyright (c) 2016-present, Facebook, Inc.
+# All rights reserved.
+#
+# This source code is licensed under both the BSD-style license (found in the
+# LICENSE file in the root directory of this source tree) and the GPLv2 (found
+# in the COPYING file in the root directory of this source tree).
+# ################################################################
+
+# Standard variables for installation
+DESTDIR ?=
+PREFIX  ?= /usr/local
+BINDIR  := $(DESTDIR)$(PREFIX)/bin
+
+ZSTDDIR = ../../lib
+PROGDIR = ../../programs
+
+# External program to use to run tests, e.g. qemu or valgrind
+TESTPROG  ?=
+# Flags to pass to the tests
+TESTFLAGS ?=
+
+# We use gcc/clang to generate the header dependencies of files
+DEPFLAGS = -MMD -MP -MF $*.Td
+POSTCOMPILE = mv -f $*.Td $*.d
+
+# CFLAGS, CXXFLAGS, CPPFLAGS, and LDFLAGS are for the users to override
+CFLAGS   ?= -O3 -Wall -Wextra
+CXXFLAGS ?= -O3 -Wall -Wextra -pedantic
+CPPFLAGS ?=
+LDFLAGS  ?=
+
+# Include flags
+PZSTD_INC  = -I$(ZSTDDIR) -I$(ZSTDDIR)/common -I$(PROGDIR) -I.
+GTEST_INC  = -isystem googletest/googletest/include
+
+PZSTD_CPPFLAGS  = $(PZSTD_INC)
+PZSTD_CCXXFLAGS =
+PZSTD_CFLAGS    = $(PZSTD_CCXXFLAGS)
+PZSTD_CXXFLAGS  = $(PZSTD_CCXXFLAGS) -std=c++11
+PZSTD_LDFLAGS   =
+EXTRA_FLAGS     =
+ALL_CFLAGS      = $(EXTRA_FLAGS) $(CPPFLAGS) $(PZSTD_CPPFLAGS) $(CFLAGS)   $(PZSTD_CFLAGS)
+ALL_CXXFLAGS    = $(EXTRA_FLAGS) $(CPPFLAGS) $(PZSTD_CPPFLAGS) $(CXXFLAGS) $(PZSTD_CXXFLAGS)
+ALL_LDFLAGS     = $(EXTRA_FLAGS) $(LDFLAGS) $(PZSTD_LDFLAGS)
+
+
+# gtest libraries need to go before "-lpthread" because they depend on it.
+GTEST_LIB  = -L googletest/build/googlemock/gtest
+LIBS       =
+
+# Compilation commands
+LD_COMMAND  = $(CXX) $^          $(ALL_LDFLAGS) $(LIBS) -lpthread -o $@
+CC_COMMAND  = $(CC)  $(DEPFLAGS) $(ALL_CFLAGS)   -c $<  -o $@
+CXX_COMMAND = $(CXX) $(DEPFLAGS) $(ALL_CXXFLAGS) -c $<  -o $@
+
+# Get a list of all zstd files so we rebuild the static library when we need to
+ZSTDCOMMON_FILES := $(wildcard $(ZSTDDIR)/common/*.c) \
+                    $(wildcard $(ZSTDDIR)/common/*.h)
+ZSTDCOMP_FILES   := $(wildcard $(ZSTDDIR)/compress/*.c) \
+                    $(wildcard $(ZSTDDIR)/compress/*.h)
+ZSTDDECOMP_FILES := $(wildcard $(ZSTDDIR)/decompress/*.c) \
+                    $(wildcard $(ZSTDDIR)/decompress/*.h)
+ZSTDPROG_FILES   := $(wildcard $(PROGDIR)/*.c) \
+                    $(wildcard $(PROGDIR)/*.h)
+ZSTD_FILES       := $(wildcard $(ZSTDDIR)/*.h) \
+                    $(ZSTDDECOMP_FILES) $(ZSTDCOMMON_FILES) $(ZSTDCOMP_FILES) \
+                    $(ZSTDPROG_FILES)
+
+# List all the pzstd source files so we can determine their dependencies
+PZSTD_SRCS  := $(wildcard *.cpp)
+PZSTD_TESTS := $(wildcard test/*.cpp)
+UTILS_TESTS := $(wildcard utils/test/*.cpp)
+ALL_SRCS    := $(PZSTD_SRCS) $(PZSTD_TESTS) $(UTILS_TESTS)
+
+
+# Define *.exe as extension for Windows systems
+ifneq (,$(filter Windows%,$(OS)))
+EXT =.exe
+else
+EXT =
+endif
+
+# Standard targets
+.PHONY: default
+default: all
+
+.PHONY: test-pzstd
+test-pzstd: TESTFLAGS=--gtest_filter=-*ExtremelyLarge*
+test-pzstd: clean googletest pzstd tests check
+
+.PHONY: test-pzstd32
+test-pzstd32: clean googletest32 all32 check
+
+.PHONY: test-pzstd-tsan
+test-pzstd-tsan: LDFLAGS=-fuse-ld=gold
+test-pzstd-tsan: TESTFLAGS=--gtest_filter=-*ExtremelyLarge*
+test-pzstd-tsan: clean googletest tsan check
+
+.PHONY: test-pzstd-asan
+test-pzstd-asan: LDFLAGS=-fuse-ld=gold
+test-pzstd-asan: TESTFLAGS=--gtest_filter=-*ExtremelyLarge*
+test-pzstd-asan: clean asan check
+
+.PHONY: check
+check:
+	$(TESTPROG) ./utils/test/BufferTest$(EXT) $(TESTFLAGS)
+	$(TESTPROG) ./utils/test/RangeTest$(EXT) $(TESTFLAGS)
+	$(TESTPROG) ./utils/test/ResourcePoolTest$(EXT) $(TESTFLAGS)
+	$(TESTPROG) ./utils/test/ScopeGuardTest$(EXT) $(TESTFLAGS)
+	$(TESTPROG) ./utils/test/ThreadPoolTest$(EXT) $(TESTFLAGS)
+	$(TESTPROG) ./utils/test/WorkQueueTest$(EXT) $(TESTFLAGS)
+	$(TESTPROG) ./test/OptionsTest$(EXT) $(TESTFLAGS)
+	$(TESTPROG) ./test/PzstdTest$(EXT) $(TESTFLAGS)
+
+.PHONY: install
+install: PZSTD_CPPFLAGS += -DNDEBUG
+install: pzstd$(EXT)
+	install -d -m 755 $(BINDIR)/
+	install -m 755 pzstd$(EXT) $(BINDIR)/pzstd$(EXT)
+
+.PHONY: uninstall
+uninstall:
+	$(RM) $(BINDIR)/pzstd$(EXT)
+
+# Targets for many different builds
+.PHONY: all
+all: PZSTD_CPPFLAGS += -DNDEBUG
+all: pzstd$(EXT)
+
+.PHONY: debug
+debug: EXTRA_FLAGS += -g
+debug: pzstd$(EXT) tests roundtrip
+
+.PHONY: tsan
+tsan: PZSTD_CCXXFLAGS += -fsanitize=thread -fPIC
+tsan: PZSTD_LDFLAGS   += -fsanitize=thread
+tsan: debug
+
+.PHONY: asan
+asan: EXTRA_FLAGS += -fsanitize=address
+asan: debug
+
+.PHONY: ubsan
+ubsan: EXTRA_FLAGS += -fsanitize=undefined
+ubsan: debug
+
+.PHONY: all32
+all32: EXTRA_FLAGS += -m32
+all32: all tests roundtrip
+
+.PHONY: debug32
+debug32: EXTRA_FLAGS += -m32
+debug32: debug
+
+.PHONY: asan32
+asan32: EXTRA_FLAGS += -m32
+asan32: asan
+
+.PHONY: tsan32
+tsan32: EXTRA_FLAGS += -m32
+tsan32: tsan
+
+.PHONY: ubsan32
+ubsan32: EXTRA_FLAGS += -m32
+ubsan32: ubsan
+
+# Run long round trip tests
+.PHONY: roundtripcheck
+roundtripcheck: roundtrip check
+	$(TESTPROG) ./test/RoundTripTest$(EXT) $(TESTFLAGS)
+
+# Build the main binary
+pzstd$(EXT): main.o Options.o Pzstd.o SkippableFrame.o $(ZSTDDIR)/libzstd.a
+	$(LD_COMMAND)
+
+# Target that depends on all the tests
+.PHONY: tests
+tests: EXTRA_FLAGS += -Wno-deprecated-declarations
+tests: $(patsubst %,%$(EXT),$(basename $(PZSTD_TESTS) $(UTILS_TESTS)))
+
+# Build the round trip tests
+.PHONY: roundtrip
+roundtrip: EXTRA_FLAGS += -Wno-deprecated-declarations
+roundtrip: test/RoundTripTest$(EXT)
+
+# Use the static library that zstd builds for simplicity and
+# so we get the compiler options correct
+$(ZSTDDIR)/libzstd.a: $(ZSTD_FILES)
+	CFLAGS="$(ALL_CFLAGS)" LDFLAGS="$(ALL_LDFLAGS)" $(MAKE) -C $(ZSTDDIR) libzstd.a
+
+# Rules to build the tests
+test/RoundTripTest$(EXT): test/RoundTripTest.o $(PROGDIR)/datagen.o Options.o \
+                          Pzstd.o SkippableFrame.o $(ZSTDDIR)/libzstd.a
+	$(LD_COMMAND)
+
+test/%Test$(EXT): PZSTD_LDFLAGS += $(GTEST_LIB)
+test/%Test$(EXT): LIBS += -lgtest -lgtest_main
+test/%Test$(EXT): test/%Test.o $(PROGDIR)/datagen.o Options.o Pzstd.o  \
+                  SkippableFrame.o $(ZSTDDIR)/libzstd.a
+	$(LD_COMMAND)
+
+utils/test/%Test$(EXT): PZSTD_LDFLAGS += $(GTEST_LIB)
+utils/test/%Test$(EXT): LIBS += -lgtest -lgtest_main
+utils/test/%Test$(EXT): utils/test/%Test.o
+	$(LD_COMMAND)
+
+
+GTEST_CMAKEFLAGS =
+
+# Install googletest
+.PHONY: googletest
+googletest: PZSTD_CCXXFLAGS += -fPIC
+googletest:
+	@$(RM) -rf googletest
+	@git clone https://github.com/google/googletest
+	@mkdir -p googletest/build
+	@cd googletest/build && cmake $(GTEST_CMAKEFLAGS) -DCMAKE_CXX_FLAGS="$(ALL_CXXFLAGS)" .. && $(MAKE)
+
+.PHONY: googletest32
+googletest32: PZSTD_CCXXFLAGS  += -m32
+googletest32: googletest
+
+.PHONY: googletest-mingw64
+googletest-mingw64: GTEST_CMAKEFLAGS += -G "MSYS Makefiles"
+googletest-mingw64: googletest
+
+.PHONY: clean
+clean:
+	$(RM) -f *.o pzstd$(EXT) *.Td *.d
+	$(RM) -f test/*.o test/*Test$(EXT) test/*.Td test/*.d
+	$(RM) -f utils/test/*.o utils/test/*Test$(EXT) utils/test/*.Td utils/test/*.d
+	$(RM) -f $(PROGDIR)/*.o $(PROGDIR)/*.Td $(PROGDIR)/*.d
+	$(MAKE) -C $(ZSTDDIR) clean
+	@echo Cleaning completed
+
+
+# Cancel implicit rules
+%.o: %.c
+%.o: %.cpp
+
+# Object file rules
+%.o: %.c
+	$(CC_COMMAND)
+	$(POSTCOMPILE)
+
+$(PROGDIR)/%.o: $(PROGDIR)/%.c
+	$(CC_COMMAND)
+	$(POSTCOMPILE)
+
+%.o: %.cpp
+	$(CXX_COMMAND)
+	$(POSTCOMPILE)
+
+test/%.o: PZSTD_CPPFLAGS += $(GTEST_INC)
+test/%.o: test/%.cpp
+	$(CXX_COMMAND)
+	$(POSTCOMPILE)
+
+utils/test/%.o: PZSTD_CPPFLAGS += $(GTEST_INC)
+utils/test/%.o: utils/test/%.cpp
+	$(CXX_COMMAND)
+	$(POSTCOMPILE)
+
+# Dependency file stuff
+.PRECIOUS: %.d test/%.d utils/test/%.d
+
+# Include rules that specify header file dependencies
+-include $(patsubst %,%.d,$(basename $(ALL_SRCS)))
diff --git a/src/zstd/contrib/pzstd/Options.cpp b/src/zstd/contrib/pzstd/Options.cpp
new file mode 100644
index 00000000..d9b216b4
--- /dev/null
+++ b/src/zstd/contrib/pzstd/Options.cpp
@@ -0,0 +1,439 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "Options.h"
+#include "util.h"
+#include "utils/ScopeGuard.h"
+
+#include <algorithm>
+#include <cassert>
+#include <cstdio>
+#include <cstring>
+#include <iterator>
+#include <thread>
+#include <vector>
+
+#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32) ||     \
+    defined(__CYGWIN__)
+#include <io.h> /* _isatty */
+#define IS_CONSOLE(stdStream) _isatty(_fileno(stdStream))
+#elif defined(_POSIX_C_SOURCE) || defined(_XOPEN_SOURCE) || defined(_POSIX_SOURCE) || (defined(__APPLE__) && defined(__MACH__)) || \
+      defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)  /* https://sourceforge.net/p/predef/wiki/OperatingSystems/ */
+#include <unistd.h> /* isatty */
+#define IS_CONSOLE(stdStream) isatty(fileno(stdStream))
+#else
+#define IS_CONSOLE(stdStream) 0
+#endif
+
+namespace pzstd {
+
+namespace {
+unsigned defaultNumThreads() {
+#ifdef PZSTD_NUM_THREADS
+  return PZSTD_NUM_THREADS;
+#else
+  return std::thread::hardware_concurrency();
+#endif
+}
+
+unsigned parseUnsigned(const char **arg) {
+  unsigned result = 0;
+  while (**arg >= '0' && **arg <= '9') {
+    result *= 10;
+    result += **arg - '0';
+    ++(*arg);
+  }
+  return result;
+}
+
+const char *getArgument(const char *options, const char **argv, int &i,
+                        int argc) {
+  if (options[1] != 0) {
+    return options + 1;
+  }
+  ++i;
+  if (i == argc) {
+    std::fprintf(stderr, "Option -%c requires an argument, but none provided\n",
+                 *options);
+    return nullptr;
+  }
+  return argv[i];
+}
+
+const std::string kZstdExtension = ".zst";
+constexpr char kStdIn[] = "-";
+constexpr char kStdOut[] = "-";
+constexpr unsigned kDefaultCompressionLevel = 3;
+constexpr unsigned kMaxNonUltraCompressionLevel = 19;
+
+#ifdef _WIN32
+const char nullOutput[] = "nul";
+#else
+const char nullOutput[] = "/dev/null";
+#endif
+
+void notSupported(const char *option) {
+  std::fprintf(stderr, "Operation not supported: %s\n", option);
+}
+
+void usage() {
+  std::fprintf(stderr, "Usage:\n");
+  std::fprintf(stderr, "  pzstd [args] [FILE(s)]\n");
+  std::fprintf(stderr, "Parallel ZSTD options:\n");
+  std::fprintf(stderr, "  -p, --processes   #    : number of threads to use for (de)compression (default:%d)\n", defaultNumThreads());
+
+  std::fprintf(stderr, "ZSTD options:\n");
+  std::fprintf(stderr, "  -#                     : # compression level (1-%d, default:%d)\n", kMaxNonUltraCompressionLevel, kDefaultCompressionLevel);
+  std::fprintf(stderr, "  -d, --decompress       : decompression\n");
+  std::fprintf(stderr, "  -o                file : result stored into `file` (only if 1 input file)\n");
+  std::fprintf(stderr, "  -f, --force            : overwrite output without prompting, (de)compress links\n");
+  std::fprintf(stderr, "      --rm               : remove source file(s) after successful (de)compression\n");
+  std::fprintf(stderr, "  -k, --keep             : preserve source file(s) (default)\n");
+  std::fprintf(stderr, "  -h, --help             : display help and exit\n");
+  std::fprintf(stderr, "  -V, --version          : display version number and exit\n");
+  std::fprintf(stderr, "  -v, --verbose          : verbose mode; specify multiple times to increase log level (default:2)\n");
+  std::fprintf(stderr, "  -q, --quiet            : suppress warnings; specify twice to suppress errors too\n");
+  std::fprintf(stderr, "  -c, --stdout           : force write to standard output, even if it is the console\n");
+#ifdef UTIL_HAS_CREATEFILELIST
+  std::fprintf(stderr, "  -r                     : operate recursively on directories\n");
+#endif
+  std::fprintf(stderr, "      --ultra            : enable levels beyond %i, up to %i (requires more memory)\n", kMaxNonUltraCompressionLevel, ZSTD_maxCLevel());
+  std::fprintf(stderr, "  -C, --check            : integrity check (default)\n");
+  std::fprintf(stderr, "      --no-check         : no integrity check\n");
+  std::fprintf(stderr, "  -t, --test             : test compressed file integrity\n");
+  std::fprintf(stderr, "  --                     : all arguments after \"--\" are treated as files\n");
+}
+} // anonymous namespace
+
+Options::Options()
+    : numThreads(defaultNumThreads()), maxWindowLog(23),
+      compressionLevel(kDefaultCompressionLevel), decompress(false),
+      overwrite(false), keepSource(true), writeMode(WriteMode::Auto),
+      checksum(true), verbosity(2) {}
+
+Options::Status Options::parse(int argc, const char **argv) {
+  bool test = false;
+  bool recursive = false;
+  bool ultra = false;
+  bool forceStdout = false;
+  bool followLinks = false;
+  // Local copy of input files, which are pointers into argv.
+  std::vector<const char *> localInputFiles;
+  for (int i = 1; i < argc; ++i) {
+    const char *arg = argv[i];
+    // Protect against empty arguments
+    if (arg[0] == 0) {
+      continue;
+    }
+    // Everything after "--" is an input file
+    if (!std::strcmp(arg, "--")) {
+      ++i;
+      std::copy(argv + i, argv + argc, std::back_inserter(localInputFiles));
+      break;
+    }
+    // Long arguments that don't have a short option
+    {
+      bool isLongOption = true;
+      if (!std::strcmp(arg, "--rm")) {
+        keepSource = false;
+      } else if (!std::strcmp(arg, "--ultra")) {
+        ultra = true;
+        maxWindowLog = 0;
+      } else if (!std::strcmp(arg, "--no-check")) {
+        checksum = false;
+      } else if (!std::strcmp(arg, "--sparse")) {
+        writeMode = WriteMode::Sparse;
+        notSupported("Sparse mode");
+        return Status::Failure;
+      } else if (!std::strcmp(arg, "--no-sparse")) {
+        writeMode = WriteMode::Regular;
+        notSupported("Sparse mode");
+        return Status::Failure;
+      } else if (!std::strcmp(arg, "--dictID")) {
+        notSupported(arg);
+        return Status::Failure;
+      } else if (!std::strcmp(arg, "--no-dictID")) {
+        notSupported(arg);
+        return Status::Failure;
+      } else {
+        isLongOption = false;
+      }
+      if (isLongOption) {
+        continue;
+      }
+    }
+    // Arguments with a short option simply set their short option.
+    const char *options = nullptr;
+    if (!std::strcmp(arg, "--processes")) {
+      options = "p";
+    } else if (!std::strcmp(arg, "--version")) {
+      options = "V";
+    } else if (!std::strcmp(arg, "--help")) {
+      options = "h";
+    } else if (!std::strcmp(arg, "--decompress")) {
+      options = "d";
+    } else if (!std::strcmp(arg, "--force")) {
+      options = "f";
+    } else if (!std::strcmp(arg, "--stdout")) {
+      options = "c";
+    } else if (!std::strcmp(arg, "--keep")) {
+      options = "k";
+    } else if (!std::strcmp(arg, "--verbose")) {
+      options = "v";
+    } else if (!std::strcmp(arg, "--quiet")) {
+      options = "q";
+    } else if (!std::strcmp(arg, "--check")) {
+      options = "C";
+    } else if (!std::strcmp(arg, "--test")) {
+      options = "t";
+    } else if (arg[0] == '-' && arg[1] != 0) {
+      options = arg + 1;
+    } else {
+      localInputFiles.emplace_back(arg);
+      continue;
+    }
+    assert(options != nullptr);
+
+    bool finished = false;
+    while (!finished && *options != 0) {
+      // Parse the compression level
+      if (*options >= '0' && *options <= '9') {
+        compressionLevel = parseUnsigned(&options);
+        continue;
+      }
+
+      switch (*options) {
+      case 'h':
+      case 'H':
+        usage();
+        return Status::Message;
+      case 'V':
+        std::fprintf(stderr, "PZSTD version: %s.\n", ZSTD_VERSION_STRING);
+        return Status::Message;
+      case 'p': {
+        finished = true;
+        const char *optionArgument = getArgument(options, argv, i, argc);
+        if (optionArgument == nullptr) {
+          return Status::Failure;
+        }
+        if (*optionArgument < '0' || *optionArgument > '9') {
+          std::fprintf(stderr, "Option -p expects a number, but %s provided\n",
+                       optionArgument);
+          return Status::Failure;
+        }
+        numThreads = parseUnsigned(&optionArgument);
+        if (*optionArgument != 0) {
+          std::fprintf(stderr,
+                       "Option -p expects a number, but %u%s provided\n",
+                       numThreads, optionArgument);
+          return Status::Failure;
+        }
+        break;
+      }
+      case 'o': {
+        finished = true;
+        const char *optionArgument = getArgument(options, argv, i, argc);
+        if (optionArgument == nullptr) {
+          return Status::Failure;
+        }
+        outputFile = optionArgument;
+        break;
+      }
+      case 'C':
+        checksum = true;
+        break;
+      case 'k':
+        keepSource = true;
+        break;
+      case 'd':
+        decompress = true;
+        break;
+      case 'f':
+        overwrite = true;
+        forceStdout = true;
+        followLinks = true;
+        break;
+      case 't':
+        test = true;
+        decompress = true;
+        break;
+#ifdef UTIL_HAS_CREATEFILELIST
+      case 'r':
+        recursive = true;
+        break;
+#endif
+      case 'c':
+        outputFile = kStdOut;
+        forceStdout = true;
+        break;
+      case 'v':
+        ++verbosity;
+        break;
+      case 'q':
+        --verbosity;
+        // Ignore them for now
+        break;
+      // Unsupported options from Zstd
+      case 'D':
+      case 's':
+        notSupported("Zstd dictionaries.");
+        return Status::Failure;
+      case 'b':
+      case 'e':
+      case 'i':
+      case 'B':
+        notSupported("Zstd benchmarking options.");
+        return Status::Failure;
+      default:
+        std::fprintf(stderr, "Invalid argument: %s\n", arg);
+        return Status::Failure;
+      }
+      if (!finished) {
+        ++options;
+      }
+    } // while (*options != 0);
+  }   // for (int i = 1; i < argc; ++i);
+
+  // Set options for test mode
+  if (test) {
+    outputFile = nullOutput;
+    keepSource = true;
+  }
+
+  // Input file defaults to standard input if not provided.
+  if (localInputFiles.empty()) {
+    localInputFiles.emplace_back(kStdIn);
+  }
+
+  // Check validity of input files
+  if (localInputFiles.size() > 1) {
+    const auto it = std::find(localInputFiles.begin(), localInputFiles.end(),
+                              std::string{kStdIn});
+    if (it != localInputFiles.end()) {
+      std::fprintf(
+          stderr,
+          "Cannot specify standard input when handling multiple files\n");
+      return Status::Failure;
+    }
+  }
+  if (localInputFiles.size() > 1 || recursive) {
+    if (!outputFile.empty() && outputFile != nullOutput) {
+      std::fprintf(
+          stderr,
+          "Cannot specify an output file when handling multiple inputs\n");
+      return Status::Failure;
+    }
+  }
+
+  g_utilDisplayLevel = verbosity;
+  // Remove local input files that are symbolic links
+  if (!followLinks) {
+      std::remove_if(localInputFiles.begin(), localInputFiles.end(),
+                     [&](const char *path) {
+                        bool isLink = UTIL_isLink(path);
+                        if (isLink && verbosity >= 2) {
+                            std::fprintf(
+                                    stderr,
+                                    "Warning : %s is symbolic link, ignoring\n",
+                                    path);
+                        }
+                        return isLink;
+                    });
+  }
+
+  // Translate input files/directories into files to (de)compress
+  if (recursive) {
+    char *scratchBuffer = nullptr;
+    unsigned numFiles = 0;
+    const char **files =
+        UTIL_createFileList(localInputFiles.data(), localInputFiles.size(),
+                            &scratchBuffer, &numFiles, followLinks);
+    if (files == nullptr) {
+      std::fprintf(stderr, "Error traversing directories\n");
+      return Status::Failure;
+    }
+    auto guard =
+        makeScopeGuard([&] { UTIL_freeFileList(files, scratchBuffer); });
+    if (numFiles == 0) {
+      std::fprintf(stderr, "No files found\n");
+      return Status::Failure;
+    }
+    inputFiles.resize(numFiles);
+    std::copy(files, files + numFiles, inputFiles.begin());
+  } else {
+    inputFiles.resize(localInputFiles.size());
+    std::copy(localInputFiles.begin(), localInputFiles.end(),
+              inputFiles.begin());
+  }
+  localInputFiles.clear();
+  assert(!inputFiles.empty());
+
+  // If reading from standard input, default to standard output
+  if (inputFiles[0] == kStdIn && outputFile.empty()) {
+    assert(inputFiles.size() == 1);
+    outputFile = "-";
+  }
+
+  if (inputFiles[0] == kStdIn && IS_CONSOLE(stdin)) {
+    assert(inputFiles.size() == 1);
+    std::fprintf(stderr, "Cannot read input from interactive console\n");
+    return Status::Failure;
+  }
+  if (outputFile == "-" && IS_CONSOLE(stdout) && !(forceStdout && decompress)) {
+    std::fprintf(stderr, "Will not write to console stdout unless -c or -f is "
+                         "specified and decompressing\n");
+    return Status::Failure;
+  }
+
+  // Check compression level
+  {
+    unsigned maxCLevel =
+        ultra ? ZSTD_maxCLevel() : kMaxNonUltraCompressionLevel;
+    if (compressionLevel > maxCLevel || compressionLevel == 0) {
+      std::fprintf(stderr, "Invalid compression level %u.\n", compressionLevel);
+      return Status::Failure;
+    }
+  }
+
+  // Check that numThreads is set
+  if (numThreads == 0) {
+    std::fprintf(stderr, "Invalid arguments: # of threads not specified "
+                         "and unable to determine hardware concurrency.\n");
+    return Status::Failure;
+  }
+
+  // Modify verbosity
+  // If we are piping input and output, turn off interaction
+  if (inputFiles[0] == kStdIn && outputFile == kStdOut && verbosity == 2) {
+    verbosity = 1;
+  }
+  // If we are in multi-file mode, turn off interaction
+  if (inputFiles.size() > 1 && verbosity == 2) {
+    verbosity = 1;
+  }
+
+  return Status::Success;
+}
+
+std::string Options::getOutputFile(const std::string &inputFile) const {
+  if (!outputFile.empty()) {
+    return outputFile;
+  }
+  // Attempt to add/remove zstd extension from the input file
+  if (decompress) {
+    int stemSize = inputFile.size() - kZstdExtension.size();
+    if (stemSize > 0 && inputFile.substr(stemSize) == kZstdExtension) {
+      return inputFile.substr(0, stemSize);
+    } else {
+      return "";
+    }
+  } else {
+    return inputFile + kZstdExtension;
+  }
+}
+}
diff --git a/src/zstd/contrib/pzstd/Options.h b/src/zstd/contrib/pzstd/Options.h
new file mode 100644
index 00000000..f4f2aaa4
--- /dev/null
+++ b/src/zstd/contrib/pzstd/Options.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#define ZSTD_STATIC_LINKING_ONLY
+#include "zstd.h"
+#undef ZSTD_STATIC_LINKING_ONLY
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace pzstd {
+
+struct Options {
+  enum class WriteMode { Regular, Auto, Sparse };
+
+  unsigned numThreads;
+  unsigned maxWindowLog;
+  unsigned compressionLevel;
+  bool decompress;
+  std::vector<std::string> inputFiles;
+  std::string outputFile;
+  bool overwrite;
+  bool keepSource;
+  WriteMode writeMode;
+  bool checksum;
+  int verbosity;
+
+  enum class Status {
+    Success, // Successfully parsed options
+    Failure, // Failure to parse options
+    Message  // Options specified to print a message (e.g. "-h")
+  };
+
+  Options();
+  Options(unsigned numThreads, unsigned maxWindowLog, unsigned compressionLevel,
+          bool decompress, std::vector<std::string> inputFiles,
+          std::string outputFile, bool overwrite, bool keepSource,
+          WriteMode writeMode, bool checksum, int verbosity)
+      : numThreads(numThreads), maxWindowLog(maxWindowLog),
+        compressionLevel(compressionLevel), decompress(decompress),
+        inputFiles(std::move(inputFiles)), outputFile(std::move(outputFile)),
+        overwrite(overwrite), keepSource(keepSource), writeMode(writeMode),
+        checksum(checksum), verbosity(verbosity) {}
+
+  Status parse(int argc, const char **argv);
+
+  ZSTD_parameters determineParameters() const {
+    ZSTD_parameters params = ZSTD_getParams(compressionLevel, 0, 0);
+    params.fParams.contentSizeFlag = 0;
+    params.fParams.checksumFlag = checksum;
+    if (maxWindowLog != 0 && params.cParams.windowLog > maxWindowLog) {
+      params.cParams.windowLog = maxWindowLog;
+      params.cParams = ZSTD_adjustCParams(params.cParams, 0, 0);
+    }
+    return params;
+  }
+
+  std::string getOutputFile(const std::string &inputFile) const;
+};
+}
diff --git a/src/zstd/contrib/pzstd/Pzstd.cpp b/src/zstd/contrib/pzstd/Pzstd.cpp
new file mode 100644
index 00000000..1eb4ce14
--- /dev/null
+++ b/src/zstd/contrib/pzstd/Pzstd.cpp
@@ -0,0 +1,618 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "Pzstd.h"
+#include "SkippableFrame.h"
+#include "utils/FileSystem.h"
+#include "utils/Range.h"
+#include "utils/ScopeGuard.h"
+#include "utils/ThreadPool.h"
+#include "utils/WorkQueue.h"
+
+#include <chrono>
+#include <cinttypes>
+#include <cstddef>
+#include <cstdio>
+#include <memory>
+#include <string>
+
+#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__)
+#  include <fcntl.h>    /* _O_BINARY */
+#  include <io.h>       /* _setmode, _isatty */
+#  define SET_BINARY_MODE(file) { if (_setmode(_fileno(file), _O_BINARY) == -1) perror("Cannot set _O_BINARY"); }
+#else
+#  include <unistd.h>   /* isatty */
+#  define SET_BINARY_MODE(file)
+#endif
+
+namespace pzstd {
+
+namespace {
+#ifdef _WIN32
+const std::string nullOutput = "nul";
+#else
+const std::string nullOutput = "/dev/null";
+#endif
+}
+
+using std::size_t;
+
+static std::uintmax_t fileSizeOrZero(const std::string &file) {
+  if (file == "-") {
+    return 0;
+  }
+  std::error_code ec;
+  auto size = file_size(file, ec);
+  if (ec) {
+    size = 0;
+  }
+  return size;
+}
+
+static std::uint64_t handleOneInput(const Options &options,
+                             const std::string &inputFile,
+                             FILE* inputFd,
+                             const std::string &outputFile,
+                             FILE* outputFd,
+                             SharedState& state) {
+  auto inputSize = fileSizeOrZero(inputFile);
+  // WorkQueue outlives ThreadPool so in the case of error we are certain
+  // we don't accidently try to call push() on it after it is destroyed
+  WorkQueue<std::shared_ptr<BufferWorkQueue>> outs{options.numThreads + 1};
+  std::uint64_t bytesRead;
+  std::uint64_t bytesWritten;
+  {
+    // Initialize the (de)compression thread pool with numThreads
+    ThreadPool executor(options.numThreads);
+    // Run the reader thread on an extra thread
+    ThreadPool readExecutor(1);
+    if (!options.decompress) {
+      // Add a job that reads the input and starts all the compression jobs
+      readExecutor.add(
+          [&state, &outs, &executor, inputFd, inputSize, &options, &bytesRead] {
+            bytesRead = asyncCompressChunks(
+                state,
+                outs,
+                executor,
+                inputFd,
+                inputSize,
+                options.numThreads,
+                options.determineParameters());
+          });
+      // Start writing
+      bytesWritten = writeFile(state, outs, outputFd, options.decompress);
+    } else {
+      // Add a job that reads the input and starts all the decompression jobs
+      readExecutor.add([&state, &outs, &executor, inputFd, &bytesRead] {
+        bytesRead = asyncDecompressFrames(state, outs, executor, inputFd);
+      });
+      // Start writing
+      bytesWritten = writeFile(state, outs, outputFd, options.decompress);
+    }
+  }
+  if (!state.errorHolder.hasError()) {
+    std::string inputFileName = inputFile == "-" ? "stdin" : inputFile;
+    std::string outputFileName = outputFile == "-" ? "stdout" : outputFile;
+    if (!options.decompress) {
+      double ratio = static_cast<double>(bytesWritten) /
+                     static_cast<double>(bytesRead + !bytesRead);
+      state.log(INFO, "%-20s :%6.2f%%   (%6" PRIu64 " => %6" PRIu64
+                   " bytes, %s)\n",
+                   inputFileName.c_str(), ratio * 100, bytesRead, bytesWritten,
+                   outputFileName.c_str());
+    } else {
+      state.log(INFO, "%-20s: %" PRIu64 " bytes \n",
+                   inputFileName.c_str(),bytesWritten);
+    }
+  }
+  return bytesWritten;
+}
+
+static FILE *openInputFile(const std::string &inputFile,
+                           ErrorHolder &errorHolder) {
+  if (inputFile == "-") {
+    SET_BINARY_MODE(stdin);
+    return stdin;
+  }
+  // Check if input file is a directory
+  {
+    std::error_code ec;
+    if (is_directory(inputFile, ec)) {
+      errorHolder.setError("Output file is a directory -- ignored");
+      return nullptr;
+    }
+  }
+  auto inputFd = std::fopen(inputFile.c_str(), "rb");
+  if (!errorHolder.check(inputFd != nullptr, "Failed to open input file")) {
+    return nullptr;
+  }
+  return inputFd;
+}
+
+static FILE *openOutputFile(const Options &options,
+                            const std::string &outputFile,
+                            SharedState& state) {
+  if (outputFile == "-") {
+    SET_BINARY_MODE(stdout);
+    return stdout;
+  }
+  // Check if the output file exists and then open it
+  if (!options.overwrite && outputFile != nullOutput) {
+    auto outputFd = std::fopen(outputFile.c_str(), "rb");
+    if (outputFd != nullptr) {
+      std::fclose(outputFd);
+      if (!state.log.logsAt(INFO)) {
+        state.errorHolder.setError("Output file exists");
+        return nullptr;
+      }
+      state.log(
+          INFO,
+          "pzstd: %s already exists; do you wish to overwrite (y/n) ? ",
+          outputFile.c_str());
+      int c = getchar();
+      if (c != 'y' && c != 'Y') {
+        state.errorHolder.setError("Not overwritten");
+        return nullptr;
+      }
+    }
+  }
+  auto outputFd = std::fopen(outputFile.c_str(), "wb");
+  if (!state.errorHolder.check(
+          outputFd != nullptr, "Failed to open output file")) {
+    return nullptr;
+  }
+  return outputFd;
+}
+
+int pzstdMain(const Options &options) {
+  int returnCode = 0;
+  SharedState state(options);
+  for (const auto& input : options.inputFiles) {
+    // Setup the shared state
+    auto printErrorGuard = makeScopeGuard([&] {
+      if (state.errorHolder.hasError()) {
+        returnCode = 1;
+        state.log(ERROR, "pzstd: %s: %s.\n", input.c_str(),
+                  state.errorHolder.getError().c_str());
+      }
+    });
+    // Open the input file
+    auto inputFd = openInputFile(input, state.errorHolder);
+    if (inputFd == nullptr) {
+      continue;
+    }
+    auto closeInputGuard = makeScopeGuard([&] { std::fclose(inputFd); });
+    // Open the output file
+    auto outputFile = options.getOutputFile(input);
+    if (!state.errorHolder.check(outputFile != "",
+                           "Input file does not have extension .zst")) {
+      continue;
+    }
+    auto outputFd = openOutputFile(options, outputFile, state);
+    if (outputFd == nullptr) {
+      continue;
+    }
+    auto closeOutputGuard = makeScopeGuard([&] { std::fclose(outputFd); });
+    // (de)compress the file
+    handleOneInput(options, input, inputFd, outputFile, outputFd, state);
+    if (state.errorHolder.hasError()) {
+      continue;
+    }
+    // Delete the input file if necessary
+    if (!options.keepSource) {
+      // Be sure that we are done and have written everything before we delete
+      if (!state.errorHolder.check(std::fclose(inputFd) == 0,
+                             "Failed to close input file")) {
+        continue;
+      }
+      closeInputGuard.dismiss();
+      if (!state.errorHolder.check(std::fclose(outputFd) == 0,
+                             "Failed to close output file")) {
+        continue;
+      }
+      closeOutputGuard.dismiss();
+      if (std::remove(input.c_str()) != 0) {
+        state.errorHolder.setError("Failed to remove input file");
+        continue;
+      }
+    }
+  }
+  // Returns 1 if any of the files failed to (de)compress.
+  return returnCode;
+}
+
+/// Construct a `ZSTD_inBuffer` that points to the data in `buffer`.
+static ZSTD_inBuffer makeZstdInBuffer(const Buffer& buffer) {
+  return ZSTD_inBuffer{buffer.data(), buffer.size(), 0};
+}
+
+/**
+ * Advance `buffer` and `inBuffer` by the amount of data read, as indicated by
+ * `inBuffer.pos`.
+ */
+void advance(Buffer& buffer, ZSTD_inBuffer& inBuffer) {
+  auto pos = inBuffer.pos;
+  inBuffer.src = static_cast<const unsigned char*>(inBuffer.src) + pos;
+  inBuffer.size -= pos;
+  inBuffer.pos = 0;
+  return buffer.advance(pos);
+}
+
+/// Construct a `ZSTD_outBuffer` that points to the data in `buffer`.
+static ZSTD_outBuffer makeZstdOutBuffer(Buffer& buffer) {
+  return ZSTD_outBuffer{buffer.data(), buffer.size(), 0};
+}
+
+/**
+ * Split `buffer` and advance `outBuffer` by the amount of data written, as
+ * indicated by `outBuffer.pos`.
+ */
+Buffer split(Buffer& buffer, ZSTD_outBuffer& outBuffer) {
+  auto pos = outBuffer.pos;
+  outBuffer.dst = static_cast<unsigned char*>(outBuffer.dst) + pos;
+  outBuffer.size -= pos;
+  outBuffer.pos = 0;
+  return buffer.splitAt(pos);
+}
+
+/**
+ * Stream chunks of input from `in`, compress it, and stream it out to `out`.
+ *
+ * @param state        The shared state
+ * @param in           Queue that we `pop()` input buffers from
+ * @param out          Queue that we `push()` compressed output buffers to
+ * @param maxInputSize An upper bound on the size of the input
+ */
+static void compress(
+    SharedState& state,
+    std::shared_ptr<BufferWorkQueue> in,
+    std::shared_ptr<BufferWorkQueue> out,
+    size_t maxInputSize) {
+  auto& errorHolder = state.errorHolder;
+  auto guard = makeScopeGuard([&] { out->finish(); });
+  // Initialize the CCtx
+  auto ctx = state.cStreamPool->get();
+  if (!errorHolder.check(ctx != nullptr, "Failed to allocate ZSTD_CStream")) {
+    return;
+  }
+  {
+    auto err = ZSTD_resetCStream(ctx.get(), 0);
+    if (!errorHolder.check(!ZSTD_isError(err), ZSTD_getErrorName(err))) {
+      return;
+    }
+  }
+
+  // Allocate space for the result
+  auto outBuffer = Buffer(ZSTD_compressBound(maxInputSize));
+  auto zstdOutBuffer = makeZstdOutBuffer(outBuffer);
+  {
+    Buffer inBuffer;
+    // Read a buffer in from the input queue
+    while (in->pop(inBuffer) && !errorHolder.hasError()) {
+      auto zstdInBuffer = makeZstdInBuffer(inBuffer);
+      // Compress the whole buffer and send it to the output queue
+      while (!inBuffer.empty() && !errorHolder.hasError()) {
+        if (!errorHolder.check(
+                !outBuffer.empty(), "ZSTD_compressBound() was too small")) {
+          return;
+        }
+        // Compress
+        auto err =
+            ZSTD_compressStream(ctx.get(), &zstdOutBuffer, &zstdInBuffer);
+        if (!errorHolder.check(!ZSTD_isError(err), ZSTD_getErrorName(err))) {
+          return;
+        }
+        // Split the compressed data off outBuffer and pass to the output queue
+        out->push(split(outBuffer, zstdOutBuffer));
+        // Forget about the data we already compressed
+        advance(inBuffer, zstdInBuffer);
+      }
+    }
+  }
+  // Write the epilog
+  size_t bytesLeft;
+  do {
+    if (!errorHolder.check(
+            !outBuffer.empty(), "ZSTD_compressBound() was too small")) {
+      return;
+    }
+    bytesLeft = ZSTD_endStream(ctx.get(), &zstdOutBuffer);
+    if (!errorHolder.check(
+            !ZSTD_isError(bytesLeft), ZSTD_getErrorName(bytesLeft))) {
+      return;
+    }
+    out->push(split(outBuffer, zstdOutBuffer));
+  } while (bytesLeft != 0 && !errorHolder.hasError());
+}
+
+/**
+ * Calculates how large each independently compressed frame should be.
+ *
+ * @param size       The size of the source if known, 0 otherwise
+ * @param numThreads The number of threads available to run compression jobs on
+ * @param params     The zstd parameters to be used for compression
+ */
+static size_t calculateStep(
+    std::uintmax_t size,
+    size_t numThreads,
+    const ZSTD_parameters &params) {
+  (void)size;
+  (void)numThreads;
+  return size_t{1} << (params.cParams.windowLog + 2);
+}
+
+namespace {
+enum class FileStatus { Continue, Done, Error };
+/// Determines the status of the file descriptor `fd`.
+FileStatus fileStatus(FILE* fd) {
+  if (std::feof(fd)) {
+    return FileStatus::Done;
+  } else if (std::ferror(fd)) {
+    return FileStatus::Error;
+  }
+  return FileStatus::Continue;
+}
+} // anonymous namespace
+
+/**
+ * Reads `size` data in chunks of `chunkSize` and puts it into `queue`.
+ * Will read less if an error or EOF occurs.
+ * Returns the status of the file after all of the reads have occurred.
+ */
+static FileStatus
+readData(BufferWorkQueue& queue, size_t chunkSize, size_t size, FILE* fd,
+         std::uint64_t *totalBytesRead) {
+  Buffer buffer(size);
+  while (!buffer.empty()) {
+    auto bytesRead =
+        std::fread(buffer.data(), 1, std::min(chunkSize, buffer.size()), fd);
+    *totalBytesRead += bytesRead;
+    queue.push(buffer.splitAt(bytesRead));
+    auto status = fileStatus(fd);
+    if (status != FileStatus::Continue) {
+      return status;
+    }
+  }
+  return FileStatus::Continue;
+}
+
+std::uint64_t asyncCompressChunks(
+    SharedState& state,
+    WorkQueue<std::shared_ptr<BufferWorkQueue>>& chunks,
+    ThreadPool& executor,
+    FILE* fd,
+    std::uintmax_t size,
+    size_t numThreads,
+    ZSTD_parameters params) {
+  auto chunksGuard = makeScopeGuard([&] { chunks.finish(); });
+  std::uint64_t bytesRead = 0;
+
+  // Break the input up into chunks of size `step` and compress each chunk
+  // independently.
+  size_t step = calculateStep(size, numThreads, params);
+  state.log(DEBUG, "Chosen frame size: %zu\n", step);
+  auto status = FileStatus::Continue;
+  while (status == FileStatus::Continue && !state.errorHolder.hasError()) {
+    // Make a new input queue that we will put the chunk's input data into.
+    auto in = std::make_shared<BufferWorkQueue>();
+    auto inGuard = makeScopeGuard([&] { in->finish(); });
+    // Make a new output queue that compress will put the compressed data into.
+    auto out = std::make_shared<BufferWorkQueue>();
+    // Start compression in the thread pool
+    executor.add([&state, in, out, step] {
+      return compress(
+          state, std::move(in), std::move(out), step);
+    });
+    // Pass the output queue to the writer thread.
+    chunks.push(std::move(out));
+    state.log(VERBOSE, "%s\n", "Starting a new frame");
+    // Fill the input queue for the compression job we just started
+    status = readData(*in, ZSTD_CStreamInSize(), step, fd, &bytesRead);
+  }
+  state.errorHolder.check(status != FileStatus::Error, "Error reading input");
+  return bytesRead;
+}
+
+/**
+ * Decompress a frame, whose data is streamed into `in`, and stream the output
+ * to `out`.
+ *
+ * @param state        The shared state
+ * @param in           Queue that we `pop()` input buffers from. It contains
+ *                      exactly one compressed frame.
+ * @param out          Queue that we `push()` decompressed output buffers to
+ */
+static void decompress(
+    SharedState& state,
+    std::shared_ptr<BufferWorkQueue> in,
+    std::shared_ptr<BufferWorkQueue> out) {
+  auto& errorHolder = state.errorHolder;
+  auto guard = makeScopeGuard([&] { out->finish(); });
+  // Initialize the DCtx
+  auto ctx = state.dStreamPool->get();
+  if (!errorHolder.check(ctx != nullptr, "Failed to allocate ZSTD_DStream")) {
+    return;
+  }
+  {
+    auto err = ZSTD_resetDStream(ctx.get());
+    if (!errorHolder.check(!ZSTD_isError(err), ZSTD_getErrorName(err))) {
+      return;
+    }
+  }
+
+  const size_t outSize = ZSTD_DStreamOutSize();
+  Buffer inBuffer;
+  size_t returnCode = 0;
+  // Read a buffer in from the input queue
+  while (in->pop(inBuffer) && !errorHolder.hasError()) {
+    auto zstdInBuffer = makeZstdInBuffer(inBuffer);
+    // Decompress the whole buffer and send it to the output queue
+    while (!inBuffer.empty() && !errorHolder.hasError()) {
+      // Allocate a buffer with at least outSize bytes.
+      Buffer outBuffer(outSize);
+      auto zstdOutBuffer = makeZstdOutBuffer(outBuffer);
+      // Decompress
+      returnCode =
+          ZSTD_decompressStream(ctx.get(), &zstdOutBuffer, &zstdInBuffer);
+      if (!errorHolder.check(
+              !ZSTD_isError(returnCode), ZSTD_getErrorName(returnCode))) {
+        return;
+      }
+      // Pass the buffer with the decompressed data to the output queue
+      out->push(split(outBuffer, zstdOutBuffer));
+      // Advance past the input we already read
+      advance(inBuffer, zstdInBuffer);
+      if (returnCode == 0) {
+        // The frame is over, prepare to (maybe) start a new frame
+        ZSTD_initDStream(ctx.get());
+      }
+    }
+  }
+  if (!errorHolder.check(returnCode <= 1, "Incomplete block")) {
+    return;
+  }
+  // We've given ZSTD_decompressStream all of our data, but there may still
+  // be data to read.
+  while (returnCode == 1) {
+    // Allocate a buffer with at least outSize bytes.
+    Buffer outBuffer(outSize);
+    auto zstdOutBuffer = makeZstdOutBuffer(outBuffer);
+    // Pass in no input.
+    ZSTD_inBuffer zstdInBuffer{nullptr, 0, 0};
+    // Decompress
+    returnCode =
+        ZSTD_decompressStream(ctx.get(), &zstdOutBuffer, &zstdInBuffer);
+    if (!errorHolder.check(
+            !ZSTD_isError(returnCode), ZSTD_getErrorName(returnCode))) {
+      return;
+    }
+    // Pass the buffer with the decompressed data to the output queue
+    out->push(split(outBuffer, zstdOutBuffer));
+  }
+}
+
+std::uint64_t asyncDecompressFrames(
+    SharedState& state,
+    WorkQueue<std::shared_ptr<BufferWorkQueue>>& frames,
+    ThreadPool& executor,
+    FILE* fd) {
+  auto framesGuard = makeScopeGuard([&] { frames.finish(); });
+  std::uint64_t totalBytesRead = 0;
+
+  // Split the source up into its component frames.
+  // If we find our recognized skippable frame we know the next frames size
+  // which means that we can decompress each standard frame in independently.
+  // Otherwise, we will decompress using only one decompression task.
+  const size_t chunkSize = ZSTD_DStreamInSize();
+  auto status = FileStatus::Continue;
+  while (status == FileStatus::Continue && !state.errorHolder.hasError()) {
+    // Make a new input queue that we will put the frames's bytes into.
+    auto in = std::make_shared<BufferWorkQueue>();
+    auto inGuard = makeScopeGuard([&] { in->finish(); });
+    // Make a output queue that decompress will put the decompressed data into
+    auto out = std::make_shared<BufferWorkQueue>();
+
+    size_t frameSize;
+    {
+      // Calculate the size of the next frame.
+      // frameSize is 0 if the frame info can't be decoded.
+      Buffer buffer(SkippableFrame::kSize);
+      auto bytesRead = std::fread(buffer.data(), 1, buffer.size(), fd);
+      totalBytesRead += bytesRead;
+      status = fileStatus(fd);
+      if (bytesRead == 0 && status != FileStatus::Continue) {
+        break;
+      }
+      buffer.subtract(buffer.size() - bytesRead);
+      frameSize = SkippableFrame::tryRead(buffer.range());
+      in->push(std::move(buffer));
+    }
+    if (frameSize == 0) {
+      // We hit a non SkippableFrame, so this will be the last job.
+      // Make sure that we don't use too much memory
+      in->setMaxSize(64);
+      out->setMaxSize(64);
+    }
+    // Start decompression in the thread pool
+    executor.add([&state, in, out] {
+      return decompress(state, std::move(in), std::move(out));
+    });
+    // Pass the output queue to the writer thread
+    frames.push(std::move(out));
+    if (frameSize == 0) {
+      // We hit a non SkippableFrame ==> not compressed by pzstd or corrupted
+      // Pass the rest of the source to this decompression task
+      state.log(VERBOSE, "%s\n",
+          "Input not in pzstd format, falling back to serial decompression");
+      while (status == FileStatus::Continue && !state.errorHolder.hasError()) {
+        status = readData(*in, chunkSize, chunkSize, fd, &totalBytesRead);
+      }
+      break;
+    }
+    state.log(VERBOSE, "Decompressing a frame of size %zu", frameSize);
+    // Fill the input queue for the decompression job we just started
+    status = readData(*in, chunkSize, frameSize, fd, &totalBytesRead);
+  }
+  state.errorHolder.check(status != FileStatus::Error, "Error reading input");
+  return totalBytesRead;
+}
+
+/// Write `data` to `fd`, returns true iff success.
+static bool writeData(ByteRange data, FILE* fd) {
+  while (!data.empty()) {
+    data.advance(std::fwrite(data.begin(), 1, data.size(), fd));
+    if (std::ferror(fd)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+std::uint64_t writeFile(
+    SharedState& state,
+    WorkQueue<std::shared_ptr<BufferWorkQueue>>& outs,
+    FILE* outputFd,
+    bool decompress) {
+  auto& errorHolder = state.errorHolder;
+  auto lineClearGuard = makeScopeGuard([&state] {
+    state.log.clear(INFO);
+  });
+  std::uint64_t bytesWritten = 0;
+  std::shared_ptr<BufferWorkQueue> out;
+  // Grab the output queue for each decompression job (in order).
+  while (outs.pop(out)) {
+    if (errorHolder.hasError()) {
+      continue;
+    }
+    if (!decompress) {
+      // If we are compressing and want to write skippable frames we can't
+      // start writing before compression is done because we need to know the
+      // compressed size.
+      // Wait for the compressed size to be available and write skippable frame
+      SkippableFrame frame(out->size());
+      if (!writeData(frame.data(), outputFd)) {
+        errorHolder.setError("Failed to write output");
+        return bytesWritten;
+      }
+      bytesWritten += frame.kSize;
+    }
+    // For each chunk of the frame: Pop it from the queue and write it
+    Buffer buffer;
+    while (out->pop(buffer) && !errorHolder.hasError()) {
+      if (!writeData(buffer.range(), outputFd)) {
+        errorHolder.setError("Failed to write output");
+        return bytesWritten;
+      }
+      bytesWritten += buffer.size();
+      state.log.update(INFO, "Written: %u MB   ",
+                static_cast<std::uint32_t>(bytesWritten >> 20));
+    }
+  }
+  return bytesWritten;
+}
+}
diff --git a/src/zstd/contrib/pzstd/Pzstd.h b/src/zstd/contrib/pzstd/Pzstd.h
new file mode 100644
index 00000000..79d1fcca
--- /dev/null
+++ b/src/zstd/contrib/pzstd/Pzstd.h
@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "ErrorHolder.h"
+#include "Logging.h"
+#include "Options.h"
+#include "utils/Buffer.h"
+#include "utils/Range.h"
+#include "utils/ResourcePool.h"
+#include "utils/ThreadPool.h"
+#include "utils/WorkQueue.h"
+#define ZSTD_STATIC_LINKING_ONLY
+#include "zstd.h"
+#undef ZSTD_STATIC_LINKING_ONLY
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+
+namespace pzstd {
+/**
+ * Runs pzstd with `options` and returns the number of bytes written.
+ * An error occurred if `errorHandler.hasError()`.
+ *
+ * @param options      The pzstd options to use for (de)compression
+ * @returns            0 upon success and non-zero on failure.
+ */
+int pzstdMain(const Options& options);
+
+class SharedState {
+ public:
+  SharedState(const Options& options) : log(options.verbosity) {
+    if (!options.decompress) {
+      auto parameters = options.determineParameters();
+      cStreamPool.reset(new ResourcePool<ZSTD_CStream>{
+          [this, parameters]() -> ZSTD_CStream* {
+            this->log(VERBOSE, "%s\n", "Creating new ZSTD_CStream");
+            auto zcs = ZSTD_createCStream();
+            if (zcs) {
+              auto err = ZSTD_initCStream_advanced(
+                  zcs, nullptr, 0, parameters, 0);
+              if (ZSTD_isError(err)) {
+                ZSTD_freeCStream(zcs);
+                return nullptr;
+              }
+            }
+            return zcs;
+          },
+          [](ZSTD_CStream *zcs) {
+            ZSTD_freeCStream(zcs);
+          }});
+    } else {
+      dStreamPool.reset(new ResourcePool<ZSTD_DStream>{
+          [this]() -> ZSTD_DStream* {
+            this->log(VERBOSE, "%s\n", "Creating new ZSTD_DStream");
+            auto zds = ZSTD_createDStream();
+            if (zds) {
+              auto err = ZSTD_initDStream(zds);
+              if (ZSTD_isError(err)) {
+                ZSTD_freeDStream(zds);
+                return nullptr;
+              }
+            }
+            return zds;
+          },
+          [](ZSTD_DStream *zds) {
+            ZSTD_freeDStream(zds);
+          }});
+    }
+  }
+
+  ~SharedState() {
+    // The resource pools have references to this, so destroy them first.
+    cStreamPool.reset();
+    dStreamPool.reset();
+  }
+
+  Logger log;
+  ErrorHolder errorHolder;
+  std::unique_ptr<ResourcePool<ZSTD_CStream>> cStreamPool;
+  std::unique_ptr<ResourcePool<ZSTD_DStream>> dStreamPool;
+};
+
+/**
+ * Streams input from `fd`, breaks input up into chunks, and compresses each
+ * chunk independently.  Output of each chunk gets streamed to a queue, and
+ * the output queues get put into `chunks` in order.
+ *
+ * @param state        The shared state
+ * @param chunks       Each compression jobs output queue gets `pushed()` here
+ *                      as soon as it is available
+ * @param executor     The thread pool to run compression jobs in
+ * @param fd           The input file descriptor
+ * @param size         The size of the input file if known, 0 otherwise
+ * @param numThreads   The number of threads in the thread pool
+ * @param parameters   The zstd parameters to use for compression
+ * @returns            The number of bytes read from the file
+ */
+std::uint64_t asyncCompressChunks(
+    SharedState& state,
+    WorkQueue<std::shared_ptr<BufferWorkQueue>>& chunks,
+    ThreadPool& executor,
+    FILE* fd,
+    std::uintmax_t size,
+    std::size_t numThreads,
+    ZSTD_parameters parameters);
+
+/**
+ * Streams input from `fd`.  If pzstd headers are available it breaks the input
+ * up into independent frames.  It sends each frame to an independent
+ * decompression job.  Output of each frame gets streamed to a queue, and
+ * the output queues get put into `frames` in order.
+ *
+ * @param state        The shared state
+ * @param frames       Each decompression jobs output queue gets `pushed()` here
+ *                      as soon as it is available
+ * @param executor     The thread pool to run compression jobs in
+ * @param fd           The input file descriptor
+ * @returns            The number of bytes read from the file
+ */
+std::uint64_t asyncDecompressFrames(
+    SharedState& state,
+    WorkQueue<std::shared_ptr<BufferWorkQueue>>& frames,
+    ThreadPool& executor,
+    FILE* fd);
+
+/**
+ * Streams input in from each queue in `outs` in order, and writes the data to
+ * `outputFd`.
+ *
+ * @param state        The shared state
+ * @param outs         A queue of output queues, one for each
+ *                      (de)compression job.
+ * @param outputFd     The file descriptor to write to
+ * @param decompress   Are we decompressing?
+ * @returns            The number of bytes written
+ */
+std::uint64_t writeFile(
+    SharedState& state,
+    WorkQueue<std::shared_ptr<BufferWorkQueue>>& outs,
+    FILE* outputFd,
+    bool decompress);
+}
diff --git a/src/zstd/contrib/pzstd/README.md b/src/zstd/contrib/pzstd/README.md
new file mode 100644
index 00000000..84d94581
--- /dev/null
+++ b/src/zstd/contrib/pzstd/README.md
@@ -0,0 +1,56 @@
+# Parallel Zstandard (PZstandard)
+
+Parallel Zstandard is a Pigz-like tool for Zstandard.
+It provides Zstandard format compatible compression and decompression that is able to utilize multiple cores.
+It breaks the input up into equal sized chunks and compresses each chunk independently into a Zstandard frame.
+It then concatenates the frames together to produce the final compressed output.
+Pzstandard will write a 12 byte header for each frame that is a skippable frame in the Zstandard format, which tells PZstandard the size of the next compressed frame.
+PZstandard supports parallel decompression of files compressed with PZstandard.
+When decompressing files compressed with Zstandard, PZstandard does IO in one thread, and decompression in another.
+
+## Usage
+
+PZstandard supports the same command line interface as Zstandard, but also provides the `-p` option to specify the number of threads.
+Dictionary mode is not currently supported.
+
+Basic usage
+
+    pzstd input-file -o output-file -p num-threads -#          # Compression
+    pzstd -d input-file -o output-file -p num-threads          # Decompression
+
+PZstandard also supports piping and fifo pipes
+
+    cat input-file | pzstd -p num-threads -# -c > /dev/null
+
+For more options
+
+    pzstd --help
+
+PZstandard tries to pick a smart default number of threads if not specified (displayed in `pzstd --help`).
+If this number is not suitable, during compilation you can define `PZSTD_NUM_THREADS` to the number of threads you prefer.
+
+## Benchmarks
+
+As a reference, PZstandard and Pigz were compared on an Intel Core i7 @ 3.1 GHz, each using 4 threads, with the [Silesia compression corpus](http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia).
+
+Compression Speed vs Ratio with 4 Threads | Decompression Speed with 4 Threads
+------------------------------------------|-----------------------------------
+![Compression Speed vs Ratio](images/Cspeed.png "Compression Speed vs Ratio") | ![Decompression Speed](images/Dspeed.png "Decompression Speed")
+
+The test procedure was to run each of the following commands 2 times for each compression level, and take the minimum time.
+
+    time pzstd -# -p 4    -c silesia.tar     > silesia.tar.zst
+    time pzstd -d -p 4    -c silesia.tar.zst > /dev/null
+
+    time pigz  -# -p 4 -k -c silesia.tar     > silesia.tar.gz
+    time pigz  -d -p 4 -k -c silesia.tar.gz  > /dev/null
+
+PZstandard was tested using compression levels 1-19, and Pigz was tested using compression levels 1-9.
+Pigz cannot do parallel decompression, it simply does each of reading, decompression, and writing on separate threads.
+
+## Tests
+
+Tests require that you have [gtest](https://github.com/google/googletest) installed.
+Set `GTEST_INC` and `GTEST_LIB` in `Makefile` to specify the location of the gtest headers and libraries.
+Alternatively, run `make googletest`, which will clone googletest and build it.
+Run `make tests && make check` to run tests.
diff --git a/src/zstd/contrib/pzstd/SkippableFrame.cpp b/src/zstd/contrib/pzstd/SkippableFrame.cpp
new file mode 100644
index 00000000..769866df
--- /dev/null
+++ b/src/zstd/contrib/pzstd/SkippableFrame.cpp
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "SkippableFrame.h"
+#include "mem.h"
+#include "utils/Range.h"
+
+#include <cstdio>
+
+using namespace pzstd;
+
+SkippableFrame::SkippableFrame(std::uint32_t size) : frameSize_(size) {
+  MEM_writeLE32(data_.data(), kSkippableFrameMagicNumber);
+  MEM_writeLE32(data_.data() + 4, kFrameContentsSize);
+  MEM_writeLE32(data_.data() + 8, frameSize_);
+}
+
+/* static */ std::size_t SkippableFrame::tryRead(ByteRange bytes) {
+  if (bytes.size() < SkippableFrame::kSize ||
+      MEM_readLE32(bytes.begin()) != kSkippableFrameMagicNumber ||
+      MEM_readLE32(bytes.begin() + 4) != kFrameContentsSize) {
+    return 0;
+  }
+  return MEM_readLE32(bytes.begin() + 8);
+}
diff --git a/src/zstd/contrib/pzstd/SkippableFrame.h b/src/zstd/contrib/pzstd/SkippableFrame.h
new file mode 100644
index 00000000..60deed04
--- /dev/null
+++ b/src/zstd/contrib/pzstd/SkippableFrame.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "utils/Range.h"
+
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+
+namespace pzstd {
+/**
+ * We put a skippable frame before each frame.
+ * It contains a skippable frame magic number, the size of the skippable frame,
+ * and the size of the next frame.
+ * Each skippable frame is exactly 12 bytes in little endian format.
+ * The first 8 bytes are for compatibility with the ZSTD format.
+ * If we have N threads, the output will look like
+ *
+ * [0x184D2A50|4|size1] [frame1 of size size1]
+ * [0x184D2A50|4|size2] [frame2 of size size2]
+ * ...
+ * [0x184D2A50|4|sizeN] [frameN of size sizeN]
+ *
+ * Each sizeX is 4 bytes.
+ *
+ * These skippable frames should allow us to skip through the compressed file
+ * and only load at most N pages.
+ */
+class SkippableFrame {
+ public:
+  static constexpr std::size_t kSize = 12;
+
+ private:
+  std::uint32_t frameSize_;
+  std::array<std::uint8_t, kSize> data_;
+  static constexpr std::uint32_t kSkippableFrameMagicNumber = 0x184D2A50;
+  // Could be improved if the size fits in less bytes
+  static constexpr std::uint32_t kFrameContentsSize = kSize - 8;
+
+ public:
+   // Write the skippable frame to data_ in LE format.
+  explicit SkippableFrame(std::uint32_t size);
+
+  // Read the skippable frame from bytes in LE format.
+  static std::size_t tryRead(ByteRange bytes);
+
+  ByteRange data() const {
+    return {data_.data(), data_.size()};
+  }
+
+  // Size of the next frame.
+  std::size_t frameSize() const {
+    return frameSize_;
+  }
+};
+}
diff --git a/src/zstd/contrib/pzstd/images/Cspeed.png b/src/zstd/contrib/pzstd/images/Cspeed.png
new file mode 100644
index 00000000..aca4f663
--- /dev/null
+++ b/src/zstd/contrib/pzstd/images/Cspeed.png
diff --git a/src/zstd/contrib/pzstd/images/Dspeed.png b/src/zstd/contrib/pzstd/images/Dspeed.png
new file mode 100644
index 00000000..e48881bc
--- /dev/null
+++ b/src/zstd/contrib/pzstd/images/Dspeed.png
diff --git a/src/zstd/contrib/pzstd/main.cpp b/src/zstd/contrib/pzstd/main.cpp
new file mode 100644
index 00000000..b93f043b
--- /dev/null
+++ b/src/zstd/contrib/pzstd/main.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "ErrorHolder.h"
+#include "Options.h"
+#include "Pzstd.h"
+
+using namespace pzstd;
+
+int main(int argc, const char** argv) {
+  Options options;
+  switch (options.parse(argc, argv)) {
+  case Options::Status::Failure:
+    return 1;
+  case Options::Status::Message:
+    return 0;
+  default:
+    break;
+  }
+
+  return pzstdMain(options);
+}
diff --git a/src/zstd/contrib/pzstd/test/BUCK b/src/zstd/contrib/pzstd/test/BUCK
new file mode 100644
index 00000000..6d3fdd3c
--- /dev/null
+++ b/src/zstd/contrib/pzstd/test/BUCK
@@ -0,0 +1,37 @@
+cxx_test(
+    name='options_test',
+    srcs=['OptionsTest.cpp'],
+    deps=['//contrib/pzstd:options'],
+)
+
+cxx_test(
+    name='pzstd_test',
+    srcs=['PzstdTest.cpp'],
+    deps=[
+        ':round_trip',
+        '//contrib/pzstd:libpzstd',
+        '//contrib/pzstd/utils:scope_guard',
+        '//programs:datagen',
+    ],
+)
+
+cxx_binary(
+    name='round_trip_test',
+    srcs=['RoundTripTest.cpp'],
+    deps=[
+        ':round_trip',
+        '//contrib/pzstd/utils:scope_guard',
+        '//programs:datagen',
+    ]
+)
+
+cxx_library(
+    name='round_trip',
+    header_namespace='test',
+    exported_headers=['RoundTrip.h'],
+    deps=[
+        '//contrib/pzstd:libpzstd',
+        '//contrib/pzstd:options',
+        '//contrib/pzstd/utils:scope_guard',
+    ]
+)
diff --git a/src/zstd/contrib/pzstd/test/OptionsTest.cpp b/src/zstd/contrib/pzstd/test/OptionsTest.cpp
new file mode 100644
index 00000000..e6011482
--- /dev/null
+++ b/src/zstd/contrib/pzstd/test/OptionsTest.cpp
@@ -0,0 +1,536 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "Options.h"
+
+#include <array>
+#include <gtest/gtest.h>
+
+using namespace pzstd;
+
+namespace pzstd {
+bool operator==(const Options &lhs, const Options &rhs) {
+  return lhs.numThreads == rhs.numThreads &&
+         lhs.maxWindowLog == rhs.maxWindowLog &&
+         lhs.compressionLevel == rhs.compressionLevel &&
+         lhs.decompress == rhs.decompress && lhs.inputFiles == rhs.inputFiles &&
+         lhs.outputFile == rhs.outputFile && lhs.overwrite == rhs.overwrite &&
+         lhs.keepSource == rhs.keepSource && lhs.writeMode == rhs.writeMode &&
+         lhs.checksum == rhs.checksum && lhs.verbosity == rhs.verbosity;
+}
+
+std::ostream &operator<<(std::ostream &out, const Options &opt) {
+  out << "{";
+  {
+    out << "\n\t"
+        << "numThreads: " << opt.numThreads;
+    out << ",\n\t"
+        << "maxWindowLog: " << opt.maxWindowLog;
+    out << ",\n\t"
+        << "compressionLevel: " << opt.compressionLevel;
+    out << ",\n\t"
+        << "decompress: " << opt.decompress;
+    out << ",\n\t"
+        << "inputFiles: {";
+    {
+      bool first = true;
+      for (const auto &file : opt.inputFiles) {
+        if (!first) {
+          out << ",";
+        }
+        first = false;
+        out << "\n\t\t" << file;
+      }
+    }
+    out << "\n\t}";
+    out << ",\n\t"
+        << "outputFile: " << opt.outputFile;
+    out << ",\n\t"
+        << "overwrite: " << opt.overwrite;
+    out << ",\n\t"
+        << "keepSource: " << opt.keepSource;
+    out << ",\n\t"
+        << "writeMode: " << static_cast<int>(opt.writeMode);
+    out << ",\n\t"
+        << "checksum: " << opt.checksum;
+    out << ",\n\t"
+        << "verbosity: " << opt.verbosity;
+  }
+  out << "\n}";
+  return out;
+}
+}
+
+namespace {
+#ifdef _WIN32
+const char nullOutput[] = "nul";
+#else
+const char nullOutput[] = "/dev/null";
+#endif
+
+constexpr auto autoMode = Options::WriteMode::Auto;
+} // anonymous namespace
+
+#define EXPECT_SUCCESS(...) EXPECT_EQ(Options::Status::Success, __VA_ARGS__)
+#define EXPECT_FAILURE(...) EXPECT_EQ(Options::Status::Failure, __VA_ARGS__)
+#define EXPECT_MESSAGE(...) EXPECT_EQ(Options::Status::Message, __VA_ARGS__)
+
+template <typename... Args>
+std::array<const char *, sizeof...(Args) + 1> makeArray(Args... args) {
+  return {{nullptr, args...}};
+}
+
+TEST(Options, ValidInputs) {
+  {
+    Options options;
+    auto args = makeArray("--processes", "5", "-o", "x", "y", "-f");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {5,    23,   3,        false, {"y"}, "x",
+                        true, true, autoMode, true,  2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("-p", "1", "input", "-19");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {1,     23,   19,       false, {"input"}, "",
+                        false, true, autoMode, true,  2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args =
+        makeArray("--ultra", "-22", "-p", "1", "-o", "x", "-d", "x.zst", "-f");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {1,    0,    22,       true, {"x.zst"}, "x",
+                        true, true, autoMode, true, 2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("--processes", "100", "hello.zst", "--decompress",
+                          "--force");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {100,  23,       3,    true, {"hello.zst"}, "", true,
+                        true, autoMode, true, 2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-dp", "1", "-c");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {1,     23,   3,        true, {"x"}, "-",
+                        false, true, autoMode, true, 2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-dp", "1", "--stdout");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {1,     23,   3,        true, {"x"}, "-",
+                        false, true, autoMode, true, 2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("-p", "1", "x", "-5", "-fo", "-", "--ultra", "-d");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {1,    0,    5,        true, {"x"}, "-",
+                        true, true, autoMode, true, 2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("silesia.tar", "-o", "silesia.tar.pzstd", "-p", "2");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {2,
+                        23,
+                        3,
+                        false,
+                        {"silesia.tar"},
+                        "silesia.tar.pzstd",
+                        false,
+                        true,
+                        autoMode,
+                        true,
+                        2};
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-p", "1");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-p", "1");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+  }
+}
+
+TEST(Options, GetOutputFile) {
+  {
+    Options options;
+    auto args = makeArray("x");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ("x.zst", options.getOutputFile(options.inputFiles[0]));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "y", "-o", nullOutput);
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(nullOutput, options.getOutputFile(options.inputFiles[0]));
+  }
+  {
+    Options options;
+    auto args = makeArray("x.zst", "-do", nullOutput);
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(nullOutput, options.getOutputFile(options.inputFiles[0]));
+  }
+  {
+    Options options;
+    auto args = makeArray("x.zst", "-d");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ("x", options.getOutputFile(options.inputFiles[0]));
+  }
+  {
+    Options options;
+    auto args = makeArray("xzst", "-d");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ("", options.getOutputFile(options.inputFiles[0]));
+  }
+  {
+    Options options;
+    auto args = makeArray("xzst", "-doxx");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ("xx", options.getOutputFile(options.inputFiles[0]));
+  }
+}
+
+TEST(Options, MultipleFiles) {
+  {
+    Options options;
+    auto args = makeArray("x", "y", "z");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected;
+    expected.inputFiles = {"x", "y", "z"};
+    expected.verbosity = 1;
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "y", "z", "-o", nullOutput);
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected;
+    expected.inputFiles = {"x", "y", "z"};
+    expected.outputFile = nullOutput;
+    expected.verbosity = 1;
+    EXPECT_EQ(expected, options);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "y", "-o-");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "y", "-o", "file");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("-qqvd12qp4", "-f", "x", "--", "--rm", "-c");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    Options expected = {4,  23,   12,   true,     {"x", "--rm", "-c"},
+                        "", true, true, autoMode, true,
+                        0};
+    EXPECT_EQ(expected, options);
+  }
+}
+
+TEST(Options, NumThreads) {
+  {
+    Options options;
+    auto args = makeArray("x", "-dfo", "-");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-p", "0", "-fo", "-");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("-f", "-p", "-o", "-");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+}
+
+TEST(Options, BadCompressionLevel) {
+  {
+    Options options;
+    auto args = makeArray("x", "-20");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "--ultra", "-23");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "--1"); // negative 1?
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+}
+
+TEST(Options, InvalidOption) {
+  {
+    Options options;
+    auto args = makeArray("x", "-x");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+}
+
+TEST(Options, BadOutputFile) {
+  {
+    Options options;
+    auto args = makeArray("notzst", "-d", "-p", "1");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ("", options.getOutputFile(options.inputFiles.front()));
+  }
+}
+
+TEST(Options, BadOptionsWithArguments) {
+  {
+    Options options;
+    auto args = makeArray("x", "-pf");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-p", "10f");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-p");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-o");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-o");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+}
+
+TEST(Options, KeepSource) {
+  {
+    Options options;
+    auto args = makeArray("x", "--rm", "-k");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.keepSource);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "--rm", "--keep");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.keepSource);
+  }
+  {
+    Options options;
+    auto args = makeArray("x");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.keepSource);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "--rm");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(false, options.keepSource);
+  }
+}
+
+TEST(Options, Verbosity) {
+  {
+    Options options;
+    auto args = makeArray("x");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(2, options.verbosity);
+  }
+  {
+    Options options;
+    auto args = makeArray("--quiet", "-qq", "x");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(-1, options.verbosity);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "y");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(1, options.verbosity);
+  }
+  {
+    Options options;
+    auto args = makeArray("--", "x", "y");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(1, options.verbosity);
+  }
+  {
+    Options options;
+    auto args = makeArray("-qv", "x", "y");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(1, options.verbosity);
+  }
+  {
+    Options options;
+    auto args = makeArray("-v", "x", "y");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(3, options.verbosity);
+  }
+  {
+    Options options;
+    auto args = makeArray("-v", "x");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(3, options.verbosity);
+  }
+}
+
+TEST(Options, TestMode) {
+  {
+    Options options;
+    auto args = makeArray("x", "-t");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.keepSource);
+    EXPECT_EQ(true, options.decompress);
+    EXPECT_EQ(nullOutput, options.outputFile);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "--test", "--rm", "-ohello");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.keepSource);
+    EXPECT_EQ(true, options.decompress);
+    EXPECT_EQ(nullOutput, options.outputFile);
+  }
+}
+
+TEST(Options, Checksum) {
+  {
+    Options options;
+    auto args = makeArray("x.zst", "--no-check", "-Cd");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.checksum);
+  }
+  {
+    Options options;
+    auto args = makeArray("x");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.checksum);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "--no-check", "--check");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(true, options.checksum);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "--no-check");
+    EXPECT_SUCCESS(options.parse(args.size(), args.data()));
+    EXPECT_EQ(false, options.checksum);
+  }
+}
+
+TEST(Options, InputFiles) {
+  {
+    Options options;
+    auto args = makeArray("-cd");
+    options.parse(args.size(), args.data());
+    EXPECT_EQ(1, options.inputFiles.size());
+    EXPECT_EQ("-", options.inputFiles[0]);
+    EXPECT_EQ("-", options.outputFile);
+  }
+  {
+    Options options;
+    auto args = makeArray();
+    options.parse(args.size(), args.data());
+    EXPECT_EQ(1, options.inputFiles.size());
+    EXPECT_EQ("-", options.inputFiles[0]);
+    EXPECT_EQ("-", options.outputFile);
+  }
+  {
+    Options options;
+    auto args = makeArray("-d");
+    options.parse(args.size(), args.data());
+    EXPECT_EQ(1, options.inputFiles.size());
+    EXPECT_EQ("-", options.inputFiles[0]);
+    EXPECT_EQ("-", options.outputFile);
+  }
+  {
+    Options options;
+    auto args = makeArray("x", "-");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+}
+
+TEST(Options, InvalidOptions) {
+  {
+    Options options;
+    auto args = makeArray("-ibasdf");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("- ");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("-n15");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("-0", "x");
+    EXPECT_FAILURE(options.parse(args.size(), args.data()));
+  }
+}
+
+TEST(Options, Extras) {
+  {
+    Options options;
+    auto args = makeArray("-h");
+    EXPECT_MESSAGE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("-H");
+    EXPECT_MESSAGE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("-V");
+    EXPECT_MESSAGE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("--help");
+    EXPECT_MESSAGE(options.parse(args.size(), args.data()));
+  }
+  {
+    Options options;
+    auto args = makeArray("--version");
+    EXPECT_MESSAGE(options.parse(args.size(), args.data()));
+  }
+}
diff --git a/src/zstd/contrib/pzstd/test/PzstdTest.cpp b/src/zstd/contrib/pzstd/test/PzstdTest.cpp
new file mode 100644
index 00000000..5c7d6631
--- /dev/null
+++ b/src/zstd/contrib/pzstd/test/PzstdTest.cpp
@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "Pzstd.h"
+extern "C" {
+#include "datagen.h"
+}
+#include "test/RoundTrip.h"
+#include "utils/ScopeGuard.h"
+
+#include <cstddef>
+#include <cstdio>
+#include <gtest/gtest.h>
+#include <memory>
+#include <random>
+
+using namespace std;
+using namespace pzstd;
+
+TEST(Pzstd, SmallSizes) {
+  unsigned seed = std::random_device{}();
+  std::fprintf(stderr, "Pzstd.SmallSizes seed: %u\n", seed);
+  std::mt19937 gen(seed);
+
+  for (unsigned len = 1; len < 256; ++len) {
+    if (len % 16 == 0) {
+      std::fprintf(stderr, "%u / 16\n", len / 16);
+    }
+    std::string inputFile = std::tmpnam(nullptr);
+    auto guard = makeScopeGuard([&] { std::remove(inputFile.c_str()); });
+    {
+      static uint8_t buf[256];
+      RDG_genBuffer(buf, len, 0.5, 0.0, gen());
+      auto fd = std::fopen(inputFile.c_str(), "wb");
+      auto written = std::fwrite(buf, 1, len, fd);
+      std::fclose(fd);
+      ASSERT_EQ(written, len);
+    }
+    for (unsigned numThreads = 1; numThreads <= 2; ++numThreads) {
+      for (unsigned level = 1; level <= 4; level *= 4) {
+        auto errorGuard = makeScopeGuard([&] {
+          std::fprintf(stderr, "# threads: %u\n", numThreads);
+          std::fprintf(stderr, "compression level: %u\n", level);
+        });
+        Options options;
+        options.overwrite = true;
+        options.inputFiles = {inputFile};
+        options.numThreads = numThreads;
+        options.compressionLevel = level;
+        options.verbosity = 1;
+        ASSERT_TRUE(roundTrip(options));
+        errorGuard.dismiss();
+      }
+    }
+  }
+}
+
+TEST(Pzstd, LargeSizes) {
+  unsigned seed = std::random_device{}();
+  std::fprintf(stderr, "Pzstd.LargeSizes seed: %u\n", seed);
+  std::mt19937 gen(seed);
+
+  for (unsigned len = 1 << 20; len <= (1 << 24); len *= 2) {
+    std::string inputFile = std::tmpnam(nullptr);
+    auto guard = makeScopeGuard([&] { std::remove(inputFile.c_str()); });
+    {
+      std::unique_ptr<uint8_t[]> buf(new uint8_t[len]);
+      RDG_genBuffer(buf.get(), len, 0.5, 0.0, gen());
+      auto fd = std::fopen(inputFile.c_str(), "wb");
+      auto written = std::fwrite(buf.get(), 1, len, fd);
+      std::fclose(fd);
+      ASSERT_EQ(written, len);
+    }
+    for (unsigned numThreads = 1; numThreads <= 16; numThreads *= 4) {
+      for (unsigned level = 1; level <= 4; level *= 4) {
+        auto errorGuard = makeScopeGuard([&] {
+          std::fprintf(stderr, "# threads: %u\n", numThreads);
+          std::fprintf(stderr, "compression level: %u\n", level);
+        });
+        Options options;
+        options.overwrite = true;
+        options.inputFiles = {inputFile};
+        options.numThreads = std::min(numThreads, options.numThreads);
+        options.compressionLevel = level;
+        options.verbosity = 1;
+        ASSERT_TRUE(roundTrip(options));
+        errorGuard.dismiss();
+      }
+    }
+  }
+}
+
+TEST(Pzstd, DISABLED_ExtremelyLargeSize) {
+  unsigned seed = std::random_device{}();
+  std::fprintf(stderr, "Pzstd.ExtremelyLargeSize seed: %u\n", seed);
+  std::mt19937 gen(seed);
+
+  std::string inputFile = std::tmpnam(nullptr);
+  auto guard = makeScopeGuard([&] { std::remove(inputFile.c_str()); });
+
+  {
+    // Write 4GB + 64 MB
+    constexpr size_t kLength = 1 << 26;
+    std::unique_ptr<uint8_t[]> buf(new uint8_t[kLength]);
+    auto fd = std::fopen(inputFile.c_str(), "wb");
+    auto closeGuard = makeScopeGuard([&] { std::fclose(fd); });
+    for (size_t i = 0; i < (1 << 6) + 1; ++i) {
+      RDG_genBuffer(buf.get(), kLength, 0.5, 0.0, gen());
+      auto written = std::fwrite(buf.get(), 1, kLength, fd);
+      if (written != kLength) {
+        std::fprintf(stderr, "Failed to write file, skipping test\n");
+        return;
+      }
+    }
+  }
+
+  Options options;
+  options.overwrite = true;
+  options.inputFiles = {inputFile};
+  options.compressionLevel = 1;
+  if (options.numThreads == 0) {
+    options.numThreads = 1;
+  }
+  ASSERT_TRUE(roundTrip(options));
+}
+
+TEST(Pzstd, ExtremelyCompressible) {
+  std::string inputFile = std::tmpnam(nullptr);
+  auto guard = makeScopeGuard([&] { std::remove(inputFile.c_str()); });
+  {
+    std::unique_ptr<uint8_t[]> buf(new uint8_t[10000]);
+    std::memset(buf.get(), 'a', 10000);
+    auto fd = std::fopen(inputFile.c_str(), "wb");
+    auto written = std::fwrite(buf.get(), 1, 10000, fd);
+    std::fclose(fd);
+    ASSERT_EQ(written, 10000);
+  }
+  Options options;
+  options.overwrite = true;
+  options.inputFiles = {inputFile};
+  options.numThreads = 1;
+  options.compressionLevel = 1;
+  ASSERT_TRUE(roundTrip(options));
+}
diff --git a/src/zstd/contrib/pzstd/test/RoundTrip.h b/src/zstd/contrib/pzstd/test/RoundTrip.h
new file mode 100644
index 00000000..c6364ecb
--- /dev/null
+++ b/src/zstd/contrib/pzstd/test/RoundTrip.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "Options.h"
+#include "Pzstd.h"
+#include "utils/ScopeGuard.h"
+
+#include <cstdio>
+#include <string>
+#include <cstdint>
+#include <memory>
+
+namespace pzstd {
+
+inline bool check(std::string source, std::string decompressed) {
+  std::unique_ptr<std::uint8_t[]> sBuf(new std::uint8_t[1024]);
+  std::unique_ptr<std::uint8_t[]> dBuf(new std::uint8_t[1024]);
+
+  auto sFd = std::fopen(source.c_str(), "rb");
+  auto dFd = std::fopen(decompressed.c_str(), "rb");
+  auto guard = makeScopeGuard([&] {
+    std::fclose(sFd);
+    std::fclose(dFd);
+  });
+
+  size_t sRead, dRead;
+
+  do {
+    sRead = std::fread(sBuf.get(), 1, 1024, sFd);
+    dRead = std::fread(dBuf.get(), 1, 1024, dFd);
+    if (std::ferror(sFd) || std::ferror(dFd)) {
+      return false;
+    }
+    if (sRead != dRead) {
+      return false;
+    }
+
+    for (size_t i = 0; i < sRead; ++i) {
+      if (sBuf.get()[i] != dBuf.get()[i]) {
+        return false;
+      }
+    }
+  } while (sRead == 1024);
+  if (!std::feof(sFd) || !std::feof(dFd)) {
+    return false;
+  }
+  return true;
+}
+
+inline bool roundTrip(Options& options) {
+  if (options.inputFiles.size() != 1) {
+    return false;
+  }
+  std::string source = options.inputFiles.front();
+  std::string compressedFile = std::tmpnam(nullptr);
+  std::string decompressedFile = std::tmpnam(nullptr);
+  auto guard = makeScopeGuard([&] {
+    std::remove(compressedFile.c_str());
+    std::remove(decompressedFile.c_str());
+  });
+
+  {
+    options.outputFile = compressedFile;
+    options.decompress = false;
+    if (pzstdMain(options) != 0) {
+      return false;
+    }
+  }
+  {
+    options.decompress = true;
+    options.inputFiles.front() = compressedFile;
+    options.outputFile = decompressedFile;
+    if (pzstdMain(options) != 0) {
+      return false;
+    }
+  }
+  return check(source, decompressedFile);
+}
+}
diff --git a/src/zstd/contrib/pzstd/test/RoundTripTest.cpp b/src/zstd/contrib/pzstd/test/RoundTripTest.cpp
new file mode 100644
index 00000000..36af0673
--- /dev/null
+++ b/src/zstd/contrib/pzstd/test/RoundTripTest.cpp
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+extern "C" {
+#include "datagen.h"
+}
+#include "Options.h"
+#include "test/RoundTrip.h"
+#include "utils/ScopeGuard.h"
+
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <memory>
+#include <random>
+
+using namespace std;
+using namespace pzstd;
+
+namespace {
+string
+writeData(size_t size, double matchProba, double litProba, unsigned seed) {
+  std::unique_ptr<uint8_t[]> buf(new uint8_t[size]);
+  RDG_genBuffer(buf.get(), size, matchProba, litProba, seed);
+  string file = tmpnam(nullptr);
+  auto fd = std::fopen(file.c_str(), "wb");
+  auto guard = makeScopeGuard([&] { std::fclose(fd); });
+  auto bytesWritten = std::fwrite(buf.get(), 1, size, fd);
+  if (bytesWritten != size) {
+    std::abort();
+  }
+  return file;
+}
+
+template <typename Generator>
+string generateInputFile(Generator& gen) {
+  // Use inputs ranging from 1 Byte to 2^16 Bytes
+  std::uniform_int_distribution<size_t> size{1, 1 << 16};
+  std::uniform_real_distribution<> prob{0, 1};
+  return writeData(size(gen), prob(gen), prob(gen), gen());
+}
+
+template <typename Generator>
+Options generateOptions(Generator& gen, const string& inputFile) {
+  Options options;
+  options.inputFiles = {inputFile};
+  options.overwrite = true;
+
+  std::uniform_int_distribution<unsigned> numThreads{1, 32};
+  std::uniform_int_distribution<unsigned> compressionLevel{1, 10};
+
+  options.numThreads = numThreads(gen);
+  options.compressionLevel = compressionLevel(gen);
+
+  return options;
+}
+}
+
+int main() {
+  std::mt19937 gen(std::random_device{}());
+
+  auto newlineGuard = makeScopeGuard([] { std::fprintf(stderr, "\n"); });
+  for (unsigned i = 0; i < 10000; ++i) {
+    if (i % 100 == 0) {
+      std::fprintf(stderr, "Progress: %u%%\r", i / 100);
+    }
+    auto inputFile = generateInputFile(gen);
+    auto inputGuard = makeScopeGuard([&] { std::remove(inputFile.c_str()); });
+    for (unsigned i = 0; i < 10; ++i) {
+      auto options = generateOptions(gen, inputFile);
+      if (!roundTrip(options)) {
+        std::fprintf(stderr, "numThreads: %u\n", options.numThreads);
+        std::fprintf(stderr, "level: %u\n", options.compressionLevel);
+        std::fprintf(stderr, "decompress? %u\n", (unsigned)options.decompress);
+        std::fprintf(stderr, "file: %s\n", inputFile.c_str());
+        return 1;
+      }
+    }
+  }
+  return 0;
+}
diff --git a/src/zstd/contrib/pzstd/utils/BUCK b/src/zstd/contrib/pzstd/utils/BUCK
new file mode 100644
index 00000000..e757f412
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/BUCK
@@ -0,0 +1,75 @@
+cxx_library(
+    name='buffer',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['Buffer.h'],
+    deps=[':range'],
+)
+
+cxx_library(
+    name='file_system',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['FileSystem.h'],
+    deps=[':range'],
+)
+
+cxx_library(
+    name='likely',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['Likely.h'],
+)
+
+cxx_library(
+    name='range',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['Range.h'],
+    deps=[':likely'],
+)
+
+cxx_library(
+    name='resource_pool',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['ResourcePool.h'],
+)
+
+cxx_library(
+    name='scope_guard',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['ScopeGuard.h'],
+)
+
+cxx_library(
+    name='thread_pool',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['ThreadPool.h'],
+    deps=[':work_queue'],
+)
+
+cxx_library(
+    name='work_queue',
+    visibility=['PUBLIC'],
+    header_namespace='utils',
+    exported_headers=['WorkQueue.h'],
+    deps=[':buffer'],
+)
+
+cxx_library(
+    name='utils',
+    visibility=['PUBLIC'],
+    deps=[
+        ':buffer',
+        ':file_system',
+        ':likely',
+        ':range',
+        ':resource_pool',
+        ':scope_guard',
+        ':thread_pool',
+        ':work_queue',
+    ],
+)
diff --git a/src/zstd/contrib/pzstd/utils/Buffer.h b/src/zstd/contrib/pzstd/utils/Buffer.h
new file mode 100644
index 00000000..f69c3b4d
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/Buffer.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "utils/Range.h"
+
+#include <array>
+#include <cstddef>
+#include <memory>
+
+namespace pzstd {
+
+/**
+ * A `Buffer` has a pointer to a shared buffer, and a range of the buffer that
+ * it owns.
+ * The idea is that you can allocate one buffer, and write chunks into it
+ * and break off those chunks.
+ * The underlying buffer is reference counted, and will be destroyed when all
+ * `Buffer`s that reference it are destroyed.
+ */
+class Buffer {
+  std::shared_ptr<unsigned char> buffer_;
+  MutableByteRange range_;
+
+  static void delete_buffer(unsigned char* buffer) {
+    delete[] buffer;
+  }
+
+ public:
+  /// Construct an empty buffer that owns no data.
+  explicit Buffer() {}
+
+  /// Construct a `Buffer` that owns a new underlying buffer of size `size`.
+  explicit Buffer(std::size_t size)
+      : buffer_(new unsigned char[size], delete_buffer),
+        range_(buffer_.get(), buffer_.get() + size) {}
+
+  explicit Buffer(std::shared_ptr<unsigned char> buffer, MutableByteRange data)
+      : buffer_(buffer), range_(data) {}
+
+  Buffer(Buffer&&) = default;
+  Buffer& operator=(Buffer&&) & = default;
+
+  /**
+   * Splits the data into two pieces: [begin, begin + n), [begin + n, end).
+   * Their data both points into the same underlying buffer.
+   * Modifies the original `Buffer` to point to only [begin + n, end).
+   *
+   * @param n  The offset to split at.
+   * @returns  A buffer that owns the data [begin, begin + n).
+   */
+  Buffer splitAt(std::size_t n) {
+    auto firstPiece = range_.subpiece(0, n);
+    range_.advance(n);
+    return Buffer(buffer_, firstPiece);
+  }
+
+  /// Modifies the buffer to point to the range [begin + n, end).
+  void advance(std::size_t n) {
+    range_.advance(n);
+  }
+
+  /// Modifies the buffer to point to the range [begin, end - n).
+  void subtract(std::size_t n) {
+    range_.subtract(n);
+  }
+
+  /// Returns a read only `Range` pointing to the `Buffer`s data.
+  ByteRange range() const {
+    return range_;
+  }
+  /// Returns a mutable `Range` pointing to the `Buffer`s data.
+  MutableByteRange range() {
+    return range_;
+  }
+
+  const unsigned char* data() const {
+    return range_.data();
+  }
+
+  unsigned char* data() {
+    return range_.data();
+  }
+
+  std::size_t size() const {
+    return range_.size();
+  }
+
+  bool empty() const {
+    return range_.empty();
+  }
+};
+}
diff --git a/src/zstd/contrib/pzstd/utils/FileSystem.h b/src/zstd/contrib/pzstd/utils/FileSystem.h
new file mode 100644
index 00000000..3cfbe86e
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/FileSystem.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "utils/Range.h"
+
+#include <sys/stat.h>
+#include <cerrno>
+#include <cstdint>
+#include <system_error>
+
+// A small subset of `std::filesystem`.
+// `std::filesystem` should be a drop in replacement.
+// See http://en.cppreference.com/w/cpp/filesystem for documentation.
+
+namespace pzstd {
+
+// using file_status = ... causes gcc to emit a false positive warning
+#if defined(_MSC_VER)
+typedef struct ::_stat64 file_status;
+#else
+typedef struct ::stat file_status;
+#endif
+
+/// http://en.cppreference.com/w/cpp/filesystem/status
+inline file_status status(StringPiece path, std::error_code& ec) noexcept {
+  file_status status;
+#if defined(_MSC_VER)
+  const auto error = ::_stat64(path.data(), &status);
+#else
+  const auto error = ::stat(path.data(), &status);
+#endif
+  if (error) {
+    ec.assign(errno, std::generic_category());
+  } else {
+    ec.clear();
+  }
+  return status;
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_regular_file
+inline bool is_regular_file(file_status status) noexcept {
+#if defined(S_ISREG)
+  return S_ISREG(status.st_mode);
+#elif !defined(S_ISREG) && defined(S_IFMT) && defined(S_IFREG)
+  return (status.st_mode & S_IFMT) == S_IFREG;
+#else
+  static_assert(false, "No POSIX stat() support.");
+#endif
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_regular_file
+inline bool is_regular_file(StringPiece path, std::error_code& ec) noexcept {
+  return is_regular_file(status(path, ec));
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_directory
+inline bool is_directory(file_status status) noexcept {
+#if defined(S_ISDIR)
+  return S_ISDIR(status.st_mode);
+#elif !defined(S_ISDIR) && defined(S_IFMT) && defined(S_IFDIR)
+  return (status.st_mode & S_IFMT) == S_IFDIR;
+#else
+  static_assert(false, "NO POSIX stat() support.");
+#endif
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/is_directory
+inline bool is_directory(StringPiece path, std::error_code& ec) noexcept {
+  return is_directory(status(path, ec));
+}
+
+/// http://en.cppreference.com/w/cpp/filesystem/file_size
+inline std::uintmax_t file_size(
+    StringPiece path,
+    std::error_code& ec) noexcept {
+  auto stat = status(path, ec);
+  if (ec) {
+    return -1;
+  }
+  if (!is_regular_file(stat)) {
+    ec.assign(ENOTSUP, std::generic_category());
+    return -1;
+  }
+  ec.clear();
+  return stat.st_size;
+}
+}
diff --git a/src/zstd/contrib/pzstd/utils/Likely.h b/src/zstd/contrib/pzstd/utils/Likely.h
new file mode 100644
index 00000000..7cea8da2
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/Likely.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+ 
+/**
+ * Compiler hints to indicate the fast path of an "if" branch: whether
+ * the if condition is likely to be true or false.
+ *
+ * @author Tudor Bosman (tudorb@fb.com)
+ */
+
+#pragma once
+
+#undef LIKELY
+#undef UNLIKELY
+
+#if defined(__GNUC__) && __GNUC__ >= 4
+#define LIKELY(x) (__builtin_expect((x), 1))
+#define UNLIKELY(x) (__builtin_expect((x), 0))
+#else
+#define LIKELY(x) (x)
+#define UNLIKELY(x) (x)
+#endif
diff --git a/src/zstd/contrib/pzstd/utils/Range.h b/src/zstd/contrib/pzstd/utils/Range.h
new file mode 100644
index 00000000..7e2559cc
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/Range.h
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+ 
+/**
+ * A subset of `folly/Range.h`.
+ * All code copied verbatiam modulo formatting
+ */
+#pragma once
+
+#include "utils/Likely.h"
+
+#include <cstddef>
+#include <cstring>
+#include <stdexcept>
+#include <string>
+#include <type_traits>
+
+namespace pzstd {
+
+namespace detail {
+/*
+ *Use IsCharPointer<T>::type to enable const char* or char*.
+ *Use IsCharPointer<T>::const_type to enable only const char*.
+*/
+template <class T>
+struct IsCharPointer {};
+
+template <>
+struct IsCharPointer<char*> {
+  typedef int type;
+};
+
+template <>
+struct IsCharPointer<const char*> {
+  typedef int const_type;
+  typedef int type;
+};
+
+} // namespace detail
+
+template <typename Iter>
+class Range {
+  Iter b_;
+  Iter e_;
+
+ public:
+  using size_type = std::size_t;
+  using iterator = Iter;
+  using const_iterator = Iter;
+  using value_type = typename std::remove_reference<
+      typename std::iterator_traits<Iter>::reference>::type;
+  using reference = typename std::iterator_traits<Iter>::reference;
+
+  constexpr Range() : b_(), e_() {}
+  constexpr Range(Iter begin, Iter end) : b_(begin), e_(end) {}
+
+  constexpr Range(Iter begin, size_type size) : b_(begin), e_(begin + size) {}
+
+  template <class T = Iter, typename detail::IsCharPointer<T>::type = 0>
+  /* implicit */ Range(Iter str) : b_(str), e_(str + std::strlen(str)) {}
+
+  template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
+  /* implicit */ Range(const std::string& str)
+      : b_(str.data()), e_(b_ + str.size()) {}
+
+  // Allow implicit conversion from Range<From> to Range<To> if From is
+  // implicitly convertible to To.
+  template <
+      class OtherIter,
+      typename std::enable_if<
+          (!std::is_same<Iter, OtherIter>::value &&
+           std::is_convertible<OtherIter, Iter>::value),
+          int>::type = 0>
+  constexpr /* implicit */ Range(const Range<OtherIter>& other)
+      : b_(other.begin()), e_(other.end()) {}
+
+  Range(const Range&) = default;
+  Range(Range&&) = default;
+
+  Range& operator=(const Range&) & = default;
+  Range& operator=(Range&&) & = default;
+
+  constexpr size_type size() const {
+    return e_ - b_;
+  }
+  bool empty() const {
+    return b_ == e_;
+  }
+  Iter data() const {
+    return b_;
+  }
+  Iter begin() const {
+    return b_;
+  }
+  Iter end() const {
+    return e_;
+  }
+
+  void advance(size_type n) {
+    if (UNLIKELY(n > size())) {
+      throw std::out_of_range("index out of range");
+    }
+    b_ += n;
+  }
+
+  void subtract(size_type n) {
+    if (UNLIKELY(n > size())) {
+      throw std::out_of_range("index out of range");
+    }
+    e_ -= n;
+  }
+
+  Range subpiece(size_type first, size_type length = std::string::npos) const {
+    if (UNLIKELY(first > size())) {
+      throw std::out_of_range("index out of range");
+    }
+
+    return Range(b_ + first, std::min(length, size() - first));
+  }
+};
+
+using ByteRange = Range<const unsigned char*>;
+using MutableByteRange = Range<unsigned char*>;
+using StringPiece = Range<const char*>;
+}
diff --git a/src/zstd/contrib/pzstd/utils/ResourcePool.h b/src/zstd/contrib/pzstd/utils/ResourcePool.h
new file mode 100644
index 00000000..a6ff5ffc
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/ResourcePool.h
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include <cassert>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <vector>
+
+namespace pzstd {
+
+/**
+ * An unbounded pool of resources.
+ * A `ResourcePool<T>` requires a factory function that takes allocates `T*` and
+ * a free function that frees a `T*`.
+ * Calling `ResourcePool::get()` will give you a new `ResourcePool::UniquePtr`
+ * to a `T`, and when it goes out of scope the resource will be returned to the
+ * pool.
+ * The `ResourcePool<T>` *must* survive longer than any resources it hands out.
+ * Remember that `ResourcePool<T>` hands out mutable `T`s, so make sure to clean
+ * up the resource before or after every use.
+ */
+template <typename T>
+class ResourcePool {
+ public:
+  class Deleter;
+  using Factory = std::function<T*()>;
+  using Free = std::function<void(T*)>;
+  using UniquePtr = std::unique_ptr<T, Deleter>;
+
+ private:
+  std::mutex mutex_;
+  Factory factory_;
+  Free free_;
+  std::vector<T*> resources_;
+  unsigned inUse_;
+
+ public:
+  /**
+   * Creates a `ResourcePool`.
+   *
+   * @param factory  The function to use to create new resources.
+   * @param free     The function to use to free resources created by `factory`.
+   */
+  ResourcePool(Factory factory, Free free)
+      : factory_(std::move(factory)), free_(std::move(free)), inUse_(0) {}
+
+  /**
+   * @returns  A unique pointer to a resource.  The resource is null iff
+   *           there are no avaiable resources and `factory()` returns null.
+   */
+  UniquePtr get() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    if (!resources_.empty()) {
+      UniquePtr resource{resources_.back(), Deleter{*this}};
+      resources_.pop_back();
+      ++inUse_;
+      return resource;
+    }
+    UniquePtr resource{factory_(), Deleter{*this}};
+    ++inUse_;
+    return resource;
+  }
+
+  ~ResourcePool() noexcept {
+    assert(inUse_ == 0);
+    for (const auto resource : resources_) {
+      free_(resource);
+    }
+  }
+
+  class Deleter {
+    ResourcePool *pool_;
+  public:
+    explicit Deleter(ResourcePool &pool) : pool_(&pool) {}
+
+    void operator() (T *resource) {
+      std::lock_guard<std::mutex> lock(pool_->mutex_);
+      // Make sure we don't put null resources into the pool
+      if (resource) {
+        pool_->resources_.push_back(resource);
+      }
+      assert(pool_->inUse_ > 0);
+      --pool_->inUse_;
+    }
+  };
+};
+
+}
diff --git a/src/zstd/contrib/pzstd/utils/ScopeGuard.h b/src/zstd/contrib/pzstd/utils/ScopeGuard.h
new file mode 100644
index 00000000..31768f43
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/ScopeGuard.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include <utility>
+
+namespace pzstd {
+
+/**
+ * Dismissable scope guard.
+ * `Function` must be callable and take no parameters.
+ * Unless `dissmiss()` is called, the callable is executed upon destruction of
+ * `ScopeGuard`.
+ *
+ * Example:
+ *
+ *   auto guard = makeScopeGuard([&] { cleanup(); });
+ */
+template <typename Function>
+class ScopeGuard {
+  Function function;
+  bool dismissed;
+
+ public:
+  explicit ScopeGuard(Function&& function)
+      : function(std::move(function)), dismissed(false) {}
+
+  void dismiss() {
+    dismissed = true;
+  }
+
+  ~ScopeGuard() noexcept {
+    if (!dismissed) {
+      function();
+    }
+  }
+};
+
+/// Creates a scope guard from `function`.
+template <typename Function>
+ScopeGuard<Function> makeScopeGuard(Function&& function) {
+  return ScopeGuard<Function>(std::forward<Function>(function));
+}
+}
diff --git a/src/zstd/contrib/pzstd/utils/ThreadPool.h b/src/zstd/contrib/pzstd/utils/ThreadPool.h
new file mode 100644
index 00000000..8ece8e0d
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/ThreadPool.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "utils/WorkQueue.h"
+
+#include <cstddef>
+#include <functional>
+#include <thread>
+#include <vector>
+
+namespace pzstd {
+/// A simple thread pool that pulls tasks off its queue in FIFO order.
+class ThreadPool {
+  std::vector<std::thread> threads_;
+
+  WorkQueue<std::function<void()>> tasks_;
+
+ public:
+  /// Constructs a thread pool with `numThreads` threads.
+  explicit ThreadPool(std::size_t numThreads) {
+    threads_.reserve(numThreads);
+    for (std::size_t i = 0; i < numThreads; ++i) {
+      threads_.emplace_back([this] {
+        std::function<void()> task;
+        while (tasks_.pop(task)) {
+          task();
+        }
+      });
+    }
+  }
+
+  /// Finishes all tasks currently in the queue.
+  ~ThreadPool() {
+    tasks_.finish();
+    for (auto& thread : threads_) {
+      thread.join();
+    }
+  }
+
+  /**
+   * Adds `task` to the queue of tasks to execute. Since `task` is a
+   * `std::function<>`, it cannot be a move only type. So any lambda passed must
+   * not capture move only types (like `std::unique_ptr`).
+   *
+   * @param task  The task to execute.
+   */
+  void add(std::function<void()> task) {
+    tasks_.push(std::move(task));
+  }
+};
+}
diff --git a/src/zstd/contrib/pzstd/utils/WorkQueue.h b/src/zstd/contrib/pzstd/utils/WorkQueue.h
new file mode 100644
index 00000000..1d14d922
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/WorkQueue.h
@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#pragma once
+
+#include "utils/Buffer.h"
+
+#include <atomic>
+#include <cassert>
+#include <cstddef>
+#include <condition_variable>
+#include <cstddef>
+#include <functional>
+#include <mutex>
+#include <queue>
+
+namespace pzstd {
+
+/// Unbounded thread-safe work queue.
+template <typename T>
+class WorkQueue {
+  // Protects all member variable access
+  std::mutex mutex_;
+  std::condition_variable readerCv_;
+  std::condition_variable writerCv_;
+  std::condition_variable finishCv_;
+
+  std::queue<T> queue_;
+  bool done_;
+  std::size_t maxSize_;
+
+  // Must have lock to call this function
+  bool full() const {
+    if (maxSize_ == 0) {
+      return false;
+    }
+    return queue_.size() >= maxSize_;
+  }
+
+ public:
+  /**
+   * Constructs an empty work queue with an optional max size.
+   * If `maxSize == 0` the queue size is unbounded.
+   *
+   * @param maxSize The maximum allowed size of the work queue.
+   */
+  WorkQueue(std::size_t maxSize = 0) : done_(false), maxSize_(maxSize) {}
+
+  /**
+   * Push an item onto the work queue.  Notify a single thread that work is
+   * available.  If `finish()` has been called, do nothing and return false.
+   * If `push()` returns false, then `item` has not been moved from.
+   *
+   * @param item  Item to push onto the queue.
+   * @returns     True upon success, false if `finish()` has been called.  An
+   *               item was pushed iff `push()` returns true.
+   */
+  bool push(T&& item) {
+    {
+      std::unique_lock<std::mutex> lock(mutex_);
+      while (full() && !done_) {
+        writerCv_.wait(lock);
+      }
+      if (done_) {
+        return false;
+      }
+      queue_.push(std::move(item));
+    }
+    readerCv_.notify_one();
+    return true;
+  }
+
+  /**
+   * Attempts to pop an item off the work queue.  It will block until data is
+   * available or `finish()` has been called.
+   *
+   * @param[out] item  If `pop` returns `true`, it contains the popped item.
+   *                    If `pop` returns `false`, it is unmodified.
+   * @returns          True upon success.  False if the queue is empty and
+   *                    `finish()` has been called.
+   */
+  bool pop(T& item) {
+    {
+      std::unique_lock<std::mutex> lock(mutex_);
+      while (queue_.empty() && !done_) {
+        readerCv_.wait(lock);
+      }
+      if (queue_.empty()) {
+        assert(done_);
+        return false;
+      }
+      item = std::move(queue_.front());
+      queue_.pop();
+    }
+    writerCv_.notify_one();
+    return true;
+  }
+
+  /**
+   * Sets the maximum queue size.  If `maxSize == 0` then it is unbounded.
+   *
+   * @param maxSize The new maximum queue size.
+   */
+  void setMaxSize(std::size_t maxSize) {
+    {
+      std::lock_guard<std::mutex> lock(mutex_);
+      maxSize_ = maxSize;
+    }
+    writerCv_.notify_all();
+  }
+
+  /**
+   * Promise that `push()` won't be called again, so once the queue is empty
+   * there will never any more work.
+   */
+  void finish() {
+    {
+      std::lock_guard<std::mutex> lock(mutex_);
+      assert(!done_);
+      done_ = true;
+    }
+    readerCv_.notify_all();
+    writerCv_.notify_all();
+    finishCv_.notify_all();
+  }
+
+  /// Blocks until `finish()` has been called (but the queue may not be empty).
+  void waitUntilFinished() {
+    std::unique_lock<std::mutex> lock(mutex_);
+    while (!done_) {
+      finishCv_.wait(lock);
+    }
+  }
+};
+
+/// Work queue for `Buffer`s that knows the total number of bytes in the queue.
+class BufferWorkQueue {
+  WorkQueue<Buffer> queue_;
+  std::atomic<std::size_t> size_;
+
+ public:
+  BufferWorkQueue(std::size_t maxSize = 0) : queue_(maxSize), size_(0) {}
+
+  void push(Buffer buffer) {
+    size_.fetch_add(buffer.size());
+    queue_.push(std::move(buffer));
+  }
+
+  bool pop(Buffer& buffer) {
+    bool result = queue_.pop(buffer);
+    if (result) {
+      size_.fetch_sub(buffer.size());
+    }
+    return result;
+  }
+
+  void setMaxSize(std::size_t maxSize) {
+    queue_.setMaxSize(maxSize);
+  }
+
+  void finish() {
+    queue_.finish();
+  }
+
+  /**
+   * Blocks until `finish()` has been called.
+   *
+   * @returns The total number of bytes of all the `Buffer`s currently in the
+   *           queue.
+   */
+  std::size_t size() {
+    queue_.waitUntilFinished();
+    return size_.load();
+  }
+};
+}
diff --git a/src/zstd/contrib/pzstd/utils/test/BUCK b/src/zstd/contrib/pzstd/utils/test/BUCK
new file mode 100644
index 00000000..a5113cab
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/test/BUCK
@@ -0,0 +1,35 @@
+cxx_test(
+    name='buffer_test',
+    srcs=['BufferTest.cpp'],
+    deps=['//contrib/pzstd/utils:buffer'],
+)
+
+cxx_test(
+    name='range_test',
+    srcs=['RangeTest.cpp'],
+    deps=['//contrib/pzstd/utils:range'],
+)
+
+cxx_test(
+    name='resource_pool_test',
+    srcs=['ResourcePoolTest.cpp'],
+    deps=['//contrib/pzstd/utils:resource_pool'],
+)
+
+cxx_test(
+    name='scope_guard_test',
+    srcs=['ScopeGuardTest.cpp'],
+    deps=['//contrib/pzstd/utils:scope_guard'],
+)
+
+cxx_test(
+    name='thread_pool_test',
+    srcs=['ThreadPoolTest.cpp'],
+    deps=['//contrib/pzstd/utils:thread_pool'],
+)
+
+cxx_test(
+    name='work_queue_test',
+    srcs=['RangeTest.cpp'],
+    deps=['//contrib/pzstd/utils:work_queue'],
+)
diff --git a/src/zstd/contrib/pzstd/utils/test/BufferTest.cpp b/src/zstd/contrib/pzstd/utils/test/BufferTest.cpp
new file mode 100644
index 00000000..fbba74e8
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/test/BufferTest.cpp
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "utils/Buffer.h"
+#include "utils/Range.h"
+
+#include <gtest/gtest.h>
+#include <memory>
+
+using namespace pzstd;
+
+namespace {
+void deleter(const unsigned char* buf) {
+  delete[] buf;
+}
+}
+
+TEST(Buffer, Constructors) {
+  Buffer empty;
+  EXPECT_TRUE(empty.empty());
+  EXPECT_EQ(0, empty.size());
+
+  Buffer sized(5);
+  EXPECT_FALSE(sized.empty());
+  EXPECT_EQ(5, sized.size());
+
+  Buffer moved(std::move(sized));
+  EXPECT_FALSE(sized.empty());
+  EXPECT_EQ(5, sized.size());
+
+  Buffer assigned;
+  assigned = std::move(moved);
+  EXPECT_FALSE(sized.empty());
+  EXPECT_EQ(5, sized.size());
+}
+
+TEST(Buffer, BufferManagement) {
+  std::shared_ptr<unsigned char> buf(new unsigned char[10], deleter);
+  {
+    Buffer acquired(buf, MutableByteRange(buf.get(), buf.get() + 10));
+    EXPECT_EQ(2, buf.use_count());
+    Buffer moved(std::move(acquired));
+    EXPECT_EQ(2, buf.use_count());
+    Buffer assigned;
+    assigned = std::move(moved);
+    EXPECT_EQ(2, buf.use_count());
+
+    Buffer split = assigned.splitAt(5);
+    EXPECT_EQ(3, buf.use_count());
+
+    split.advance(1);
+    assigned.subtract(1);
+    EXPECT_EQ(3, buf.use_count());
+  }
+  EXPECT_EQ(1, buf.use_count());
+}
+
+TEST(Buffer, Modifiers) {
+  Buffer buf(10);
+  {
+    unsigned char i = 0;
+    for (auto& byte : buf.range()) {
+      byte = i++;
+    }
+  }
+
+  auto prefix = buf.splitAt(2);
+
+  ASSERT_EQ(2, prefix.size());
+  EXPECT_EQ(0, *prefix.data());
+
+  ASSERT_EQ(8, buf.size());
+  EXPECT_EQ(2, *buf.data());
+
+  buf.advance(2);
+  EXPECT_EQ(4, *buf.data());
+
+  EXPECT_EQ(9, *(buf.range().end() - 1));
+
+  buf.subtract(2);
+  EXPECT_EQ(7, *(buf.range().end() - 1));
+
+  EXPECT_EQ(4, buf.size());
+}
diff --git a/src/zstd/contrib/pzstd/utils/test/RangeTest.cpp b/src/zstd/contrib/pzstd/utils/test/RangeTest.cpp
new file mode 100644
index 00000000..755b50fa
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/test/RangeTest.cpp
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "utils/Range.h"
+
+#include <gtest/gtest.h>
+#include <string>
+
+using namespace pzstd;
+
+// Range is directly copied from folly.
+// Just some sanity tests to make sure everything seems to work.
+
+TEST(Range, Constructors) {
+  StringPiece empty;
+  EXPECT_TRUE(empty.empty());
+  EXPECT_EQ(0, empty.size());
+
+  std::string str = "hello";
+  {
+    Range<std::string::const_iterator> piece(str.begin(), str.end());
+    EXPECT_EQ(5, piece.size());
+    EXPECT_EQ('h', *piece.data());
+    EXPECT_EQ('o', *(piece.end() - 1));
+  }
+
+  {
+    StringPiece piece(str.data(), str.size());
+    EXPECT_EQ(5, piece.size());
+    EXPECT_EQ('h', *piece.data());
+    EXPECT_EQ('o', *(piece.end() - 1));
+  }
+
+  {
+    StringPiece piece(str);
+    EXPECT_EQ(5, piece.size());
+    EXPECT_EQ('h', *piece.data());
+    EXPECT_EQ('o', *(piece.end() - 1));
+  }
+
+  {
+    StringPiece piece(str.c_str());
+    EXPECT_EQ(5, piece.size());
+    EXPECT_EQ('h', *piece.data());
+    EXPECT_EQ('o', *(piece.end() - 1));
+  }
+}
+
+TEST(Range, Modifiers) {
+  StringPiece range("hello world");
+  ASSERT_EQ(11, range.size());
+
+  {
+    auto hello = range.subpiece(0, 5);
+    EXPECT_EQ(5, hello.size());
+    EXPECT_EQ('h', *hello.data());
+    EXPECT_EQ('o', *(hello.end() - 1));
+  }
+  {
+    auto hello = range;
+    hello.subtract(6);
+    EXPECT_EQ(5, hello.size());
+    EXPECT_EQ('h', *hello.data());
+    EXPECT_EQ('o', *(hello.end() - 1));
+  }
+  {
+    auto world = range;
+    world.advance(6);
+    EXPECT_EQ(5, world.size());
+    EXPECT_EQ('w', *world.data());
+    EXPECT_EQ('d', *(world.end() - 1));
+  }
+
+  std::string expected = "hello world";
+  EXPECT_EQ(expected, std::string(range.begin(), range.end()));
+  EXPECT_EQ(expected, std::string(range.data(), range.size()));
+}
diff --git a/src/zstd/contrib/pzstd/utils/test/ResourcePoolTest.cpp b/src/zstd/contrib/pzstd/utils/test/ResourcePoolTest.cpp
new file mode 100644
index 00000000..6fe14518
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/test/ResourcePoolTest.cpp
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "utils/ResourcePool.h"
+
+#include <gtest/gtest.h>
+#include <atomic>
+#include <thread>
+
+using namespace pzstd;
+
+TEST(ResourcePool, FullTest) {
+  unsigned numCreated = 0;
+  unsigned numDeleted = 0;
+  {
+    ResourcePool<int> pool(
+      [&numCreated] { ++numCreated; return new int{5}; },
+      [&numDeleted](int *x) { ++numDeleted; delete x; });
+
+    {
+      auto i = pool.get();
+      EXPECT_EQ(5, *i);
+      *i = 6;
+    }
+    {
+      auto i = pool.get();
+      EXPECT_EQ(6, *i);
+      auto j = pool.get();
+      EXPECT_EQ(5, *j);
+      *j = 7;
+    }
+    {
+      auto i = pool.get();
+      EXPECT_EQ(6, *i);
+      auto j = pool.get();
+      EXPECT_EQ(7, *j);
+    }
+  }
+  EXPECT_EQ(2, numCreated);
+  EXPECT_EQ(numCreated, numDeleted);
+}
+
+TEST(ResourcePool, ThreadSafe) {
+  std::atomic<unsigned> numCreated{0};
+  std::atomic<unsigned> numDeleted{0};
+  {
+    ResourcePool<int> pool(
+      [&numCreated] { ++numCreated; return new int{0}; },
+      [&numDeleted](int *x) { ++numDeleted; delete x; });
+    auto push = [&pool] {
+      for (int i = 0; i < 100; ++i) {
+        auto x = pool.get();
+        ++*x;
+      }
+    };
+    std::thread t1{push};
+    std::thread t2{push};
+    t1.join();
+    t2.join();
+
+    auto x = pool.get();
+    auto y = pool.get();
+    EXPECT_EQ(200, *x + *y);
+  }
+  EXPECT_GE(2, numCreated);
+  EXPECT_EQ(numCreated, numDeleted);
+}
diff --git a/src/zstd/contrib/pzstd/utils/test/ScopeGuardTest.cpp b/src/zstd/contrib/pzstd/utils/test/ScopeGuardTest.cpp
new file mode 100644
index 00000000..7bc624da
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/test/ScopeGuardTest.cpp
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "utils/ScopeGuard.h"
+
+#include <gtest/gtest.h>
+
+using namespace pzstd;
+
+TEST(ScopeGuard, Dismiss) {
+  {
+    auto guard = makeScopeGuard([&] { EXPECT_TRUE(false); });
+    guard.dismiss();
+  }
+}
+
+TEST(ScopeGuard, Executes) {
+  bool executed = false;
+  {
+    auto guard = makeScopeGuard([&] { executed = true; });
+  }
+  EXPECT_TRUE(executed);
+}
diff --git a/src/zstd/contrib/pzstd/utils/test/ThreadPoolTest.cpp b/src/zstd/contrib/pzstd/utils/test/ThreadPoolTest.cpp
new file mode 100644
index 00000000..703fd4c9
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/test/ThreadPoolTest.cpp
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "utils/ThreadPool.h"
+
+#include <gtest/gtest.h>
+#include <atomic>
+#include <iostream>
+#include <thread>
+#include <vector>
+
+using namespace pzstd;
+
+TEST(ThreadPool, Ordering) {
+  std::vector<int> results;
+
+  {
+    ThreadPool executor(1);
+    for (int i = 0; i < 10; ++i) {
+      executor.add([ &results, i ] { results.push_back(i); });
+    }
+  }
+
+  for (int i = 0; i < 10; ++i) {
+    EXPECT_EQ(i, results[i]);
+  }
+}
+
+TEST(ThreadPool, AllJobsFinished) {
+  std::atomic<unsigned> numFinished{0};
+  std::atomic<bool> start{false};
+  {
+    std::cerr << "Creating executor" << std::endl;
+    ThreadPool executor(5);
+    for (int i = 0; i < 10; ++i) {
+      executor.add([ &numFinished, &start ] {
+        while (!start.load()) {
+          std::this_thread::yield();
+        }
+        ++numFinished;
+      });
+    }
+    std::cerr << "Starting" << std::endl;
+    start.store(true);
+    std::cerr << "Finishing" << std::endl;
+  }
+  EXPECT_EQ(10, numFinished.load());
+}
+
+TEST(ThreadPool, AddJobWhileJoining) {
+  std::atomic<bool> done{false};
+  {
+    ThreadPool executor(1);
+    executor.add([&executor, &done] {
+      while (!done.load()) {
+        std::this_thread::yield();
+      }
+      // Sleep for a second to be sure that we are joining
+      std::this_thread::sleep_for(std::chrono::seconds(1));
+      executor.add([] {
+        EXPECT_TRUE(false);
+      });
+    });
+    done.store(true);
+  }
+}
diff --git a/src/zstd/contrib/pzstd/utils/test/WorkQueueTest.cpp b/src/zstd/contrib/pzstd/utils/test/WorkQueueTest.cpp
new file mode 100644
index 00000000..14cf7730
--- /dev/null
+++ b/src/zstd/contrib/pzstd/utils/test/WorkQueueTest.cpp
@@ -0,0 +1,282 @@
+/*
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ */
+#include "utils/Buffer.h"
+#include "utils/WorkQueue.h"
+
+#include <gtest/gtest.h>
+#include <iostream>
+#include <memory>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+using namespace pzstd;
+
+namespace {
+struct Popper {
+  WorkQueue<int>* queue;
+  int* results;
+  std::mutex* mutex;
+
+  void operator()() {
+    int result;
+    while (queue->pop(result)) {
+      std::lock_guard<std::mutex> lock(*mutex);
+      results[result] = result;
+    }
+  }
+};
+}
+
+TEST(WorkQueue, SingleThreaded) {
+  WorkQueue<int> queue;
+  int result;
+
+  queue.push(5);
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(5, result);
+
+  queue.push(1);
+  queue.push(2);
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(1, result);
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(2, result);
+
+  queue.push(1);
+  queue.push(2);
+  queue.finish();
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(1, result);
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(2, result);
+  EXPECT_FALSE(queue.pop(result));
+
+  queue.waitUntilFinished();
+}
+
+TEST(WorkQueue, SPSC) {
+  WorkQueue<int> queue;
+  const int max = 100;
+
+  for (int i = 0; i < 10; ++i) {
+    queue.push(int{i});
+  }
+
+  std::thread thread([ &queue, max ] {
+    int result;
+    for (int i = 0;; ++i) {
+      if (!queue.pop(result)) {
+        EXPECT_EQ(i, max);
+        break;
+      }
+      EXPECT_EQ(i, result);
+    }
+  });
+
+  std::this_thread::yield();
+  for (int i = 10; i < max; ++i) {
+    queue.push(int{i});
+  }
+  queue.finish();
+
+  thread.join();
+}
+
+TEST(WorkQueue, SPMC) {
+  WorkQueue<int> queue;
+  std::vector<int> results(50, -1);
+  std::mutex mutex;
+  std::vector<std::thread> threads;
+  for (int i = 0; i < 5; ++i) {
+    threads.emplace_back(Popper{&queue, results.data(), &mutex});
+  }
+
+  for (int i = 0; i < 50; ++i) {
+    queue.push(int{i});
+  }
+  queue.finish();
+
+  for (auto& thread : threads) {
+    thread.join();
+  }
+
+  for (int i = 0; i < 50; ++i) {
+    EXPECT_EQ(i, results[i]);
+  }
+}
+
+TEST(WorkQueue, MPMC) {
+  WorkQueue<int> queue;
+  std::vector<int> results(100, -1);
+  std::mutex mutex;
+  std::vector<std::thread> popperThreads;
+  for (int i = 0; i < 4; ++i) {
+    popperThreads.emplace_back(Popper{&queue, results.data(), &mutex});
+  }
+
+  std::vector<std::thread> pusherThreads;
+  for (int i = 0; i < 2; ++i) {
+    auto min = i * 50;
+    auto max = (i + 1) * 50;
+    pusherThreads.emplace_back(
+        [ &queue, min, max ] {
+          for (int i = min; i < max; ++i) {
+            queue.push(int{i});
+          }
+        });
+  }
+
+  for (auto& thread : pusherThreads) {
+    thread.join();
+  }
+  queue.finish();
+
+  for (auto& thread : popperThreads) {
+    thread.join();
+  }
+
+  for (int i = 0; i < 100; ++i) {
+    EXPECT_EQ(i, results[i]);
+  }
+}
+
+TEST(WorkQueue, BoundedSizeWorks) {
+  WorkQueue<int> queue(1);
+  int result;
+  queue.push(5);
+  queue.pop(result);
+  queue.push(5);
+  queue.pop(result);
+  queue.push(5);
+  queue.finish();
+  queue.pop(result);
+  EXPECT_EQ(5, result);
+}
+
+TEST(WorkQueue, BoundedSizePushAfterFinish) {
+  WorkQueue<int> queue(1);
+  int result;
+  queue.push(5);
+  std::thread pusher([&queue] {
+    queue.push(6);
+  });
+  // Dirtily try and make sure that pusher has run.
+  std::this_thread::sleep_for(std::chrono::seconds(1));
+  queue.finish();
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(5, result);
+  EXPECT_FALSE(queue.pop(result));
+
+  pusher.join();
+}
+
+TEST(WorkQueue, SetMaxSize) {
+  WorkQueue<int> queue(2);
+  int result;
+  queue.push(5);
+  queue.push(6);
+  queue.setMaxSize(1);
+  std::thread pusher([&queue] {
+    queue.push(7);
+  });
+  // Dirtily try and make sure that pusher has run.
+  std::this_thread::sleep_for(std::chrono::seconds(1));
+  queue.finish();
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(5, result);
+  EXPECT_TRUE(queue.pop(result));
+  EXPECT_EQ(6, result);
+  EXPECT_FALSE(queue.pop(result));
+
+  pusher.join();
+}
+
+TEST(WorkQueue, BoundedSizeMPMC) {
+  WorkQueue<int> queue(10);
+  std::vector<int> results(200, -1);
+  std::mutex mutex;
+  std::cerr << "Creating popperThreads" << std::endl;
+  std::vector<std::thread> popperThreads;
+  for (int i = 0; i < 4; ++i) {
+    popperThreads.emplace_back(Popper{&queue, results.data(), &mutex});
+  }
+
+  std::cerr << "Creating pusherThreads" << std::endl;
+  std::vector<std::thread> pusherThreads;
+  for (int i = 0; i < 2; ++i) {
+    auto min = i * 100;
+    auto max = (i + 1) * 100;
+    pusherThreads.emplace_back(
+        [ &queue, min, max ] {
+          for (int i = min; i < max; ++i) {
+            queue.push(int{i});
+          }
+        });
+  }
+
+  std::cerr << "Joining pusherThreads" << std::endl;
+  for (auto& thread : pusherThreads) {
+    thread.join();
+  }
+  std::cerr << "Finishing queue" << std::endl;
+  queue.finish();
+
+  std::cerr << "Joining popperThreads" << std::endl;
+  for (auto& thread : popperThreads) {
+    thread.join();
+  }
+
+  std::cerr << "Inspecting results" << std::endl;
+  for (int i = 0; i < 200; ++i) {
+    EXPECT_EQ(i, results[i]);
+  }
+}
+
+TEST(WorkQueue, FailedPush) {
+  WorkQueue<std::unique_ptr<int>> queue;
+  std::unique_ptr<int> x(new int{5});
+  EXPECT_TRUE(queue.push(std::move(x)));
+  EXPECT_EQ(nullptr, x);
+  queue.finish();
+  x.reset(new int{6});
+  EXPECT_FALSE(queue.push(std::move(x)));
+  EXPECT_NE(nullptr, x);
+  EXPECT_EQ(6, *x);
+}
+
+TEST(BufferWorkQueue, SizeCalculatedCorrectly) {
+  {
+    BufferWorkQueue queue;
+    queue.finish();
+    EXPECT_EQ(0, queue.size());
+  }
+  {
+    BufferWorkQueue queue;
+    queue.push(Buffer(10));
+    queue.finish();
+    EXPECT_EQ(10, queue.size());
+  }
+  {
+    BufferWorkQueue queue;
+    queue.push(Buffer(10));
+    queue.push(Buffer(5));
+    queue.finish();
+    EXPECT_EQ(15, queue.size());
+  }
+  {
+    BufferWorkQueue queue;
+    queue.push(Buffer(10));
+    queue.push(Buffer(5));
+    queue.finish();
+    Buffer buffer;
+    queue.pop(buffer);
+    EXPECT_EQ(5, queue.size());
+  }
+}