Adding upstream version 0.8.0.upstream/0.8.0upstream

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

12 files changed, 1124 insertions, 0 deletions

diff --git a/examples/.gitignore b/examples/.gitignore
new file mode 100644
index 0000000..20a9df3
--- /dev/null
+++ b/examples/.gitignore
@@ -0,0 +1 @@
+/qpack
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
new file mode 100644
index 0000000..31ec1aa
--- /dev/null
+++ b/examples/CMakeLists.txt
@@ -0,0 +1,50 @@
+# ngtcp3
+#
+# Copyright (c) 2019 nghttp3 contributors
+# Copyright (c) 2017 ngtcp2 contributors
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+if(ENABLE_EXAMPLES)
+  include_directories(
+    ${CMAKE_SOURCE_DIR}/lib/includes
+    ${CMAKE_BINARY_DIR}/lib/includes
+  )
+
+  link_libraries(
+    nghttp3
+  )
+
+  set(qpack_SOURCES
+    qpack.cc
+    qpack_encode.cc
+    qpack_decode.cc
+    util.cc
+  )
+
+  add_executable(qpack ${qpack_SOURCES})
+  set_target_properties(qpack PROPERTIES
+    COMPILE_FLAGS "${WARNCXXFLAGS}"
+    CXX_STANDARD 17
+    CXX_STANDARD_REQUIRED ON
+  )
+
+  # TODO prevent qpack example from being installed?
+endif()
diff --git a/examples/Makefile.am b/examples/Makefile.am
new file mode 100644
index 0000000..8c90892
--- /dev/null
+++ b/examples/Makefile.am
@@ -0,0 +1,46 @@
+# ngtcp3
+#
+# Copyright (c) 2019 nghttp3 contributors
+# Copyright (c) 2017 ngtcp2 contributors
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+EXTRA_DIST = CMakeLists.txt
+
+if ENABLE_EXAMPLES
+
+AM_CFLAGS = $(WARNCFLAGS) $(DEBUGCFLAGS)
+AM_CXXFLAGS = $(WARNCXXFLAGS) $(DEBUGCFLAGS)
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/lib/includes \
+	-I$(top_builddir)/lib/includes \
+	@DEFS@
+AM_LDFLAGS = -no-install
+LDADD = $(top_builddir)/lib/libnghttp3.la
+
+noinst_PROGRAMS = qpack
+
+qpack_SOURCES = \
+	qpack.cc qpack.h \
+	qpack_encode.cc qpack_encode.h \
+	qpack_decode.cc qpack_decode.h \
+	template.h \
+	util.cc util.h
+
+endif # ENABLE_EXAMPLES
diff --git a/examples/qpack.cc b/examples/qpack.cc
new file mode 100644
index 0000000..1353ad9
--- /dev/null
+++ b/examples/qpack.cc
@@ -0,0 +1,143 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "qpack.h"
+
+#include <cstring>
+#include <iostream>
+#include <string>
+
+#include <getopt.h>
+
+#include "qpack_encode.h"
+#include "qpack_decode.h"
+
+namespace nghttp3 {
+
+Config config{};
+
+namespace {
+void print_usage() {
+  std::cerr << "Usage: qpack [OPTIONS] <COMMAND> <INFILE> <OUTFILE>"
+            << std::endl;
+}
+} // namespace
+
+namespace {
+void print_help() {
+  print_usage();
+
+  std::cerr << R"(
+  <COMMAND>   "encode" or "decode"
+  <INFILE>    Path to an input file
+  <OUTFILE>   Path to an output file
+Options:
+  -h, --help  Display this help and exit.
+  -m, --max-blocked=<N>
+              The maximum number of streams which are permitted to be blocked.
+  -s, --max-dtable-size=<N>
+              The maximum size of dynamic table.
+  -a, --immediate-ack
+              Turn on immediate acknowlegement.
+)";
+}
+} // namespace
+
+int main(int argc, char **argv) {
+  for (;;) {
+    static int flag = 0;
+    (void)flag;
+    constexpr static option long_opts[] = {
+        {"help", no_argument, nullptr, 'h'},
+        {"max-blocked", required_argument, nullptr, 'm'},
+        {"max-dtable-size", required_argument, nullptr, 's'},
+        {"immediate-ack", no_argument, nullptr, 'a'},
+        {nullptr, 0, nullptr, 0},
+    };
+
+    auto optidx = 0;
+    auto c = getopt_long(argc, argv, "hm:s:a", long_opts, &optidx);
+    if (c == -1) {
+      break;
+    }
+    switch (c) {
+    case 'h':
+      // --help
+      print_help();
+      exit(EXIT_SUCCESS);
+    case 'm': {
+      // --max-blocked
+      config.max_blocked = strtoul(optarg, nullptr, 10);
+      break;
+    }
+    case 's': {
+      // --max-dtable-size
+      config.max_dtable_size = strtoul(optarg, nullptr, 10);
+      break;
+    }
+    case 'a':
+      // --immediate-ack
+      config.immediate_ack = true;
+      break;
+    case '?':
+      print_usage();
+      exit(EXIT_FAILURE);
+    case 0:
+      break;
+    default:
+      break;
+    };
+  }
+
+  if (argc - optind < 3) {
+    std::cerr << "Too few arguments" << std::endl;
+    print_usage();
+    exit(EXIT_FAILURE);
+  }
+
+  auto command = std::string_view(argv[optind++]);
+  auto infile = std::string_view(argv[optind++]);
+  auto outfile = std::string_view(argv[optind++]);
+
+  int rv;
+  if (command == "encode") {
+    rv = encode(outfile, infile);
+  } else if (command == "decode") {
+    rv = decode(outfile, infile);
+  } else {
+    std::cerr << "Unrecognized command: " << command << std::endl;
+    print_usage();
+    exit(EXIT_FAILURE);
+  }
+
+  if (rv != 0) {
+    exit(EXIT_FAILURE);
+  }
+
+  return 0;
+}
+
+} // namespace nghttp3
+
+int main(int argc, char **argv) { return nghttp3::main(argc, argv); }
diff --git a/examples/qpack.h b/examples/qpack.h
new file mode 100644
index 0000000..d0b0ce6
--- /dev/null
+++ b/examples/qpack.h
@@ -0,0 +1,44 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef QPACK_H
+#define QPACK_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <nghttp3/nghttp3.h>
+
+namespace nghttp3 {
+
+struct Config {
+  size_t max_blocked;
+  size_t max_dtable_size;
+  bool immediate_ack;
+};
+
+} // namespace nghttp3
+
+#endif // QPACK_H
diff --git a/examples/qpack_decode.cc b/examples/qpack_decode.cc
new file mode 100644
index 0000000..22e44c8
--- /dev/null
+++ b/examples/qpack_decode.cc
@@ -0,0 +1,299 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "qpack_decode.h"
+
+#include <arpa/inet.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include <cassert>
+#include <cstring>
+#include <cerrno>
+#include <iostream>
+#include <fstream>
+
+#include "qpack.h"
+#include "template.h"
+#include "util.h"
+
+namespace nghttp3 {
+
+extern Config config;
+
+Request::Request(int64_t stream_id, const nghttp3_buf *buf)
+    : buf(*buf), stream_id(stream_id) {
+  auto mem = nghttp3_mem_default();
+  nghttp3_qpack_stream_context_new(&sctx, stream_id, mem);
+}
+
+Request::~Request() { nghttp3_qpack_stream_context_del(sctx); }
+
+Decoder::Decoder(size_t max_dtable_size, size_t max_blocked)
+    : mem_(nghttp3_mem_default()),
+      dec_(nullptr),
+      max_dtable_size_(max_dtable_size),
+      max_blocked_(max_blocked) {}
+
+Decoder::~Decoder() { nghttp3_qpack_decoder_del(dec_); }
+
+int Decoder::init() {
+  if (auto rv = nghttp3_qpack_decoder_new(&dec_, max_dtable_size_, max_blocked_,
+                                          mem_);
+      rv != 0) {
+    std::cerr << "nghttp3_qpack_decoder_new: " << nghttp3_strerror(rv)
+              << std::endl;
+    return -1;
+  }
+
+  if (auto rv =
+          nghttp3_qpack_decoder_set_max_dtable_capacity(dec_, max_dtable_size_);
+      rv != 0) {
+    std::cerr << "nghttp3_qpack_decoder_set_max_dtable_capacity: "
+              << nghttp3_strerror(rv) << std::endl;
+    return -1;
+  }
+
+  return 0;
+}
+
+int Decoder::read_encoder(nghttp3_buf *buf) {
+  auto nread =
+      nghttp3_qpack_decoder_read_encoder(dec_, buf->pos, nghttp3_buf_len(buf));
+  if (nread < 0) {
+    std::cerr << "nghttp3_qpack_decoder_read_encoder: "
+              << nghttp3_strerror(nread) << std::endl;
+    return -1;
+  }
+
+  assert(static_cast<size_t>(nread) == nghttp3_buf_len(buf));
+
+  return 0;
+}
+
+std::tuple<Headers, int> Decoder::read_request(nghttp3_buf *buf,
+                                               int64_t stream_id) {
+  auto req = std::make_shared<Request>(stream_id, buf);
+
+  auto [headers, rv] = read_request(*req);
+  if (rv == -1) {
+    return {Headers{}, -1};
+  }
+  if (rv == 1) {
+    if (blocked_reqs_.size() >= max_blocked_) {
+      std::cerr << "Too many blocked streams: max_blocked=" << max_blocked_
+                << std::endl;
+      return {Headers{}, -1};
+    }
+    blocked_reqs_.emplace(std::move(req));
+    return {Headers{}, 1};
+  }
+  return {headers, 0};
+}
+
+std::tuple<Headers, int> Decoder::read_request(Request &req) {
+  nghttp3_qpack_nv nv;
+  uint8_t flags;
+  Headers headers;
+
+  for (;;) {
+    auto nread = nghttp3_qpack_decoder_read_request(
+        dec_, req.sctx, &nv, &flags, req.buf.pos, nghttp3_buf_len(&req.buf), 1);
+    if (nread < 0) {
+      std::cerr << "nghttp3_qpack_decoder_read_request: "
+                << nghttp3_strerror(nread) << std::endl;
+      return {Headers{}, -1};
+    }
+
+    req.buf.pos += nread;
+
+    if (flags & NGHTTP3_QPACK_DECODE_FLAG_FINAL) {
+      break;
+    }
+    if (flags & NGHTTP3_QPACK_DECODE_FLAG_BLOCKED) {
+      return {Headers{}, 1};
+    }
+    if (flags & NGHTTP3_QPACK_DECODE_FLAG_EMIT) {
+      auto name = nghttp3_rcbuf_get_buf(nv.name);
+      auto value = nghttp3_rcbuf_get_buf(nv.value);
+      headers.emplace_back(std::string{name.base, name.base + name.len},
+                           std::string{value.base, value.base + value.len});
+      nghttp3_rcbuf_decref(nv.name);
+      nghttp3_rcbuf_decref(nv.value);
+    }
+  }
+
+  return {headers, 0};
+}
+
+std::tuple<int64_t, Headers, int> Decoder::process_blocked() {
+  if (!blocked_reqs_.empty()) {
+    auto &top = blocked_reqs_.top();
+    if (nghttp3_qpack_stream_context_get_ricnt(top->sctx) >
+        nghttp3_qpack_decoder_get_icnt(dec_)) {
+      return {-1, {}, 0};
+    }
+
+    auto req = top;
+    blocked_reqs_.pop();
+
+    auto [headers, rv] = read_request(*req);
+    if (rv < 0) {
+      return {-1, {}, -1};
+    }
+    assert(rv == 0);
+
+    return {req->stream_id, headers, 0};
+  }
+  return {-1, {}, 0};
+}
+
+size_t Decoder::get_num_blocked() const { return blocked_reqs_.size(); }
+
+namespace {
+void write_header(
+    std::ostream &out,
+    const std::vector<std::pair<std::string, std::string>> &headers) {
+  for (auto &nv : headers) {
+    out.write(nv.first.c_str(), nv.first.size());
+    out.put('\t');
+    out.write(nv.second.c_str(), nv.second.size());
+    out.put('\n');
+  }
+  out.put('\n');
+}
+} // namespace
+
+int decode(const std::string_view &outfile, const std::string_view &infile) {
+  auto fd = open(infile.data(), O_RDONLY);
+  if (fd == -1) {
+    std::cerr << "Could not open " << infile << ": " << strerror(errno)
+              << std::endl;
+    return -1;
+  }
+
+  auto fd_closer = defer(close, fd);
+
+  struct stat st;
+  if (fstat(fd, &st) == -1) {
+    std::cerr << "fstat: " << strerror(errno) << std::endl;
+    return -1;
+  }
+
+  auto out = std::ofstream(outfile.data(), std::ios::trunc | std::ios::binary);
+  if (!out) {
+    std::cerr << "Could not open file " << outfile << ": " << strerror(errno)
+              << std::endl;
+    return -1;
+  }
+
+  auto in = reinterpret_cast<uint8_t *>(
+      mmap(nullptr, st.st_size, PROT_READ, MAP_SHARED, fd, 0));
+  if (in == MAP_FAILED) {
+    std::cerr << "mmap: " << strerror(errno) << std::endl;
+    return -1;
+  }
+
+  auto unmapper = defer(munmap, in, st.st_size);
+
+  auto dec = Decoder(config.max_dtable_size, config.max_blocked);
+  if (auto rv = dec.init(); rv != 0) {
+    return rv;
+  }
+
+  for (auto p = in, end = in + st.st_size; p != end;) {
+    int64_t stream_id;
+    uint32_t size;
+
+    if (static_cast<size_t>(end - p) < sizeof(stream_id) + sizeof(size)) {
+      std::cerr << "Could not read stream ID and size" << std::endl;
+      return -1;
+    }
+
+    memcpy(&stream_id, p, sizeof(stream_id));
+    stream_id = nghttp3_ntohl64(stream_id);
+    p += sizeof(stream_id);
+
+    memcpy(&size, p, sizeof(size));
+    size = ntohl(size);
+    p += sizeof(size);
+
+    if ((size_t)(end - p) < size) {
+      std::cerr << "Insufficient input: require " << size << " but "
+                << (end - p) << " is available" << std::endl;
+      return -1;
+    }
+
+    nghttp3_buf buf;
+    buf.begin = buf.pos = p;
+    buf.end = buf.last = p + size;
+
+    p += size;
+
+    if (stream_id == 0) {
+      if (auto rv = dec.read_encoder(&buf); rv != 0) {
+        return rv;
+      }
+
+      for (;;) {
+        auto [stream_id, headers, rv] = dec.process_blocked();
+        if (rv != 0) {
+          return rv;
+        }
+
+        if (stream_id == -1) {
+          break;
+        }
+
+        write_header(out, headers);
+      }
+
+      continue;
+    }
+
+    auto [headers, rv] = dec.read_request(&buf, stream_id);
+    if (rv == -1) {
+      return rv;
+    }
+    if (rv == 1) {
+      // Stream blocked
+      continue;
+    }
+
+    write_header(out, headers);
+  }
+
+  if (auto n = dec.get_num_blocked(); n) {
+    std::cerr << "Still " << n << " stream(s) blocked" << std::endl;
+    return -1;
+  }
+
+  return 0;
+}
+
+} // namespace nghttp3
diff --git a/examples/qpack_decode.h b/examples/qpack_decode.h
new file mode 100644
index 0000000..8641b3a
--- /dev/null
+++ b/examples/qpack_decode.h
@@ -0,0 +1,93 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef QPACK_DECODE_H
+#define QPACK_DECODE_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <nghttp3/nghttp3.h>
+
+#include <vector>
+#include <queue>
+#include <functional>
+#include <utility>
+#include <memory>
+#include <string>
+
+namespace nghttp3 {
+struct Request {
+  Request(int64_t stream_id, const nghttp3_buf *buf);
+  ~Request();
+
+  nghttp3_buf buf;
+  nghttp3_qpack_stream_context *sctx;
+  int64_t stream_id;
+};
+} // namespace nghttp3
+
+namespace std {
+template <> struct greater<std::shared_ptr<nghttp3::Request>> {
+  bool operator()(const std::shared_ptr<nghttp3::Request> &lhs,
+                  const std::shared_ptr<nghttp3::Request> &rhs) const {
+    return nghttp3_qpack_stream_context_get_ricnt(lhs->sctx) >
+           nghttp3_qpack_stream_context_get_ricnt(rhs->sctx);
+  }
+};
+} // namespace std
+
+namespace nghttp3 {
+
+using Headers = std::vector<std::pair<std::string, std::string>>;
+
+class Decoder {
+public:
+  Decoder(size_t max_dtable_size, size_t max_blocked);
+  ~Decoder();
+
+  int init();
+  int read_encoder(nghttp3_buf *buf);
+  std::tuple<Headers, int> read_request(nghttp3_buf *buf, int64_t stream_id);
+  std::tuple<Headers, int> read_request(Request &req);
+  std::tuple<int64_t, Headers, int> process_blocked();
+  size_t get_num_blocked() const;
+
+private:
+  const nghttp3_mem *mem_;
+  nghttp3_qpack_decoder *dec_;
+  std::priority_queue<std::shared_ptr<Request>,
+                      std::vector<std::shared_ptr<Request>>,
+                      std::greater<std::shared_ptr<Request>>>
+      blocked_reqs_;
+  size_t max_dtable_size_;
+  size_t max_blocked_;
+};
+
+int decode(const std::string_view &outfile, const std::string_view &infile);
+
+} // namespace nghttp3
+
+#endif // QPACK_ENCODE_H
diff --git a/examples/qpack_encode.cc b/examples/qpack_encode.cc
new file mode 100644
index 0000000..867a085
--- /dev/null
+++ b/examples/qpack_encode.cc
@@ -0,0 +1,221 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "qpack_encode.h"
+
+#include <arpa/inet.h>
+
+#include <cerrno>
+#include <cstring>
+#include <cassert>
+#include <iostream>
+#include <fstream>
+#include <algorithm>
+#include <array>
+#include <iomanip>
+#include <vector>
+
+#include "qpack.h"
+#include "template.h"
+#include "util.h"
+
+namespace nghttp3 {
+
+extern Config config;
+
+Encoder::Encoder(size_t max_dtable_size, size_t max_blocked, bool immediate_ack)
+    : mem_(nghttp3_mem_default()),
+      enc_(nullptr),
+      max_dtable_size_(max_dtable_size),
+      max_blocked_(max_blocked),
+      immediate_ack_(immediate_ack) {}
+
+Encoder::~Encoder() { nghttp3_qpack_encoder_del(enc_); }
+
+int Encoder::init() {
+  int rv;
+
+  rv = nghttp3_qpack_encoder_new(&enc_, max_dtable_size_, mem_);
+  if (rv != 0) {
+    std::cerr << "nghttp3_qpack_encoder_new: " << nghttp3_strerror(rv)
+              << std::endl;
+    return -1;
+  }
+
+  nghttp3_qpack_encoder_set_max_dtable_capacity(enc_, max_dtable_size_);
+  nghttp3_qpack_encoder_set_max_blocked_streams(enc_, max_blocked_);
+
+  return 0;
+}
+
+int Encoder::encode(nghttp3_buf *pbuf, nghttp3_buf *rbuf, nghttp3_buf *ebuf,
+                    int64_t stream_id, const nghttp3_nv *nva, size_t len) {
+  auto rv =
+      nghttp3_qpack_encoder_encode(enc_, pbuf, rbuf, ebuf, stream_id, nva, len);
+  if (rv != 0) {
+    std::cerr << "nghttp3_qpack_encoder_encode: " << nghttp3_strerror(rv)
+              << std::endl;
+    return -1;
+  }
+  if (immediate_ack_) {
+    nghttp3_qpack_encoder_ack_everything(enc_);
+  }
+  return 0;
+}
+
+namespace {
+void write_encoder_stream(std::ostream &out, nghttp3_buf *ebuf) {
+  uint64_t stream_id = 0;
+  out.write(reinterpret_cast<char *>(&stream_id), sizeof(stream_id));
+  uint32_t size = htonl(nghttp3_buf_len(ebuf));
+  out.write(reinterpret_cast<char *>(&size), sizeof(size));
+  out.write(reinterpret_cast<char *>(ebuf->pos), nghttp3_buf_len(ebuf));
+}
+} // namespace
+
+namespace {
+void write_request_stream(std::ostream &out, int64_t stream_id,
+                          nghttp3_buf *pbuf, nghttp3_buf *rbuf) {
+  stream_id = nghttp3_htonl64(stream_id);
+  out.write(reinterpret_cast<char *>(&stream_id), sizeof(stream_id));
+  uint32_t size = htonl(nghttp3_buf_len(pbuf) + nghttp3_buf_len(rbuf));
+  out.write(reinterpret_cast<char *>(&size), sizeof(size));
+  out.write(reinterpret_cast<char *>(pbuf->pos), nghttp3_buf_len(pbuf));
+  out.write(reinterpret_cast<char *>(rbuf->pos), nghttp3_buf_len(rbuf));
+}
+} // namespace
+
+int encode(const std::string_view &outfile, const std::string_view &infile) {
+  auto in = std::ifstream(infile.data(), std::ios::binary);
+
+  if (!in) {
+    std::cerr << "Could not open file " << infile << ": " << strerror(errno)
+              << std::endl;
+    return -1;
+  }
+
+  auto out = std::ofstream(outfile.data(), std::ios::trunc | std::ios::binary);
+  if (!out) {
+    std::cerr << "Could not open file " << outfile << ": " << strerror(errno)
+              << std::endl;
+    return -1;
+  }
+
+  auto enc =
+      Encoder(config.max_dtable_size, config.max_blocked, config.immediate_ack);
+  if (enc.init() != 0) {
+    return -1;
+  }
+
+  nghttp3_buf pbuf, rbuf, ebuf;
+  nghttp3_buf_init(&pbuf);
+  nghttp3_buf_init(&rbuf);
+  nghttp3_buf_init(&ebuf);
+
+  auto mem = nghttp3_mem_default();
+  auto pbufd = defer(nghttp3_buf_free, &pbuf, mem);
+  auto rbufd = defer(nghttp3_buf_free, &rbuf, mem);
+  auto ebufd = defer(nghttp3_buf_free, &ebuf, mem);
+
+  int64_t stream_id = 1;
+  std::array<std::string, 1024> sarray;
+
+  size_t srclen = 0;
+  size_t enclen = 0;
+  size_t rslen = 0;
+  size_t eslen = 0;
+
+  for (; in;) {
+    auto nva = std::vector<nghttp3_nv>();
+    for (std::string line; std::getline(in, line);) {
+      if (line == "") {
+        break;
+      }
+
+      if (sarray.size() == nva.size()) {
+        std::cerr << "Too many headers: " << nva.size() << std::endl;
+        return -1;
+      }
+
+      sarray[nva.size()] = line;
+      const auto &s = sarray[nva.size()];
+
+      auto d = s.find('\t');
+      if (d == std::string_view::npos) {
+        std::cerr << "Could not find TAB in " << s << std::endl;
+        return -1;
+      }
+      auto name = std::string_view(s.c_str(), d);
+      auto value = std::string_view(s.c_str() + d + 1, s.size() - d - 1);
+      value.remove_prefix(std::min(value.find_first_not_of(" "), value.size()));
+
+      srclen += name.size() + value.size();
+
+      nva.emplace_back(nghttp3_nv{
+          const_cast<uint8_t *>(reinterpret_cast<const uint8_t *>(name.data())),
+          const_cast<uint8_t *>(
+              reinterpret_cast<const uint8_t *>(value.data())),
+          name.size(), value.size()});
+    }
+
+    if (nva.empty()) {
+      break;
+    }
+
+    if (auto rv =
+            enc.encode(&pbuf, &rbuf, &ebuf, stream_id, nva.data(), nva.size());
+        rv != 0) {
+      return -1;
+    }
+
+    enclen += nghttp3_buf_len(&pbuf) + nghttp3_buf_len(&rbuf) +
+              nghttp3_buf_len(&ebuf);
+
+    if (nghttp3_buf_len(&ebuf)) {
+      write_encoder_stream(out, &ebuf);
+    }
+    write_request_stream(out, stream_id, &pbuf, &rbuf);
+
+    rslen += nghttp3_buf_len(&pbuf) + nghttp3_buf_len(&rbuf);
+    eslen += nghttp3_buf_len(&ebuf);
+
+    nghttp3_buf_reset(&pbuf);
+    nghttp3_buf_reset(&rbuf);
+    nghttp3_buf_reset(&ebuf);
+
+    ++stream_id;
+  }
+
+  if (srclen == 0) {
+    std::cerr << "No header field processed" << std::endl;
+  } else {
+    std::cerr << srclen << " -> " << enclen << " (r:" << rslen
+              << " + e:" << eslen << ") " << std::fixed << std::setprecision(2)
+              << (1. - (static_cast<double>(enclen) / srclen)) * 100
+              << "% compressed" << std::endl;
+  }
+  return 0;
+}
+
+} // namespace nghttp3
diff --git a/examples/qpack_encode.h b/examples/qpack_encode.h
new file mode 100644
index 0000000..b310ecd
--- /dev/null
+++ b/examples/qpack_encode.h
@@ -0,0 +1,59 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef QPACK_ENCODE_H
+#define QPACK_ENCODE_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <nghttp3/nghttp3.h>
+
+#include <string>
+
+namespace nghttp3 {
+
+class Encoder {
+public:
+  Encoder(size_t max_dtable_size, size_t max_blocked, bool immediate_ack);
+  ~Encoder();
+
+  int init();
+  int encode(nghttp3_buf *pbuf, nghttp3_buf *rbuf, nghttp3_buf *ebuf,
+             int64_t stream_id, const nghttp3_nv *nva, size_t len);
+
+private:
+  const nghttp3_mem *mem_;
+  nghttp3_qpack_encoder *enc_;
+  size_t max_dtable_size_;
+  size_t max_blocked_;
+  bool immediate_ack_;
+};
+
+int encode(const std::string_view &outfile, const std::string_view &infile);
+
+} // namespace nghttp3
+
+#endif // QPACK_ENCODE_H
diff --git a/examples/template.h b/examples/template.h
new file mode 100644
index 0000000..1f758b4
--- /dev/null
+++ b/examples/template.h
@@ -0,0 +1,77 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ * Copyright (c) 2017 ngtcp2 contributors
+ * Copyright (c) 2015 ngttp2 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef TEMPLATE_H
+#define TEMPLATE_H
+
+#include <functional>
+#include <utility>
+#include <type_traits>
+
+namespace nghttp3 {
+
+// inspired by <http://blog.korfuri.fr/post/go-defer-in-cpp/>, but our
+// template can take functions returning other than void.
+template <typename F, typename... T> struct Defer {
+  Defer(F &&f, T &&...t)
+      : f(std::bind(std::forward<F>(f), std::forward<T>(t)...)) {}
+  Defer(Defer &&o) noexcept : f(std::move(o.f)) {}
+  ~Defer() { f(); }
+
+  using ResultType = typename std::result_of<typename std::decay<F>::type(
+      typename std::decay<T>::type...)>::type;
+  std::function<ResultType()> f;
+};
+
+template <typename F, typename... T> Defer<F, T...> defer(F &&f, T &&...t) {
+  return Defer<F, T...>(std::forward<F>(f), std::forward<T>(t)...);
+}
+
+template <typename T, size_t N> constexpr size_t array_size(T (&)[N]) {
+  return N;
+}
+
+template <typename T, size_t N> constexpr size_t str_size(T (&)[N]) {
+  return N - 1;
+}
+
+// User-defined literals for K, M, and G (powers of 1024)
+
+constexpr unsigned long long operator"" _k(unsigned long long k) {
+  return k * 1024;
+}
+
+constexpr unsigned long long operator"" _m(unsigned long long m) {
+  return m * 1024 * 1024;
+}
+
+constexpr unsigned long long operator"" _g(unsigned long long g) {
+  return g * 1024 * 1024 * 1024;
+}
+
+} // namespace nghttp3
+
+#endif // TEMPLATE_H
diff --git a/examples/util.cc b/examples/util.cc
new file mode 100644
index 0000000..8973825
--- /dev/null
+++ b/examples/util.cc
@@ -0,0 +1,27 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "util.h"
+
+namespace nghttp3 {} // namespace nghttp3
diff --git a/examples/util.h b/examples/util.h
new file mode 100644
index 0000000..8e06086
--- /dev/null
+++ b/examples/util.h
@@ -0,0 +1,64 @@
+/*
+ * nghttp3
+ *
+ * Copyright (c) 2019 nghttp3 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef UTIL_H
+#define UTIL_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <stdint.h>
+
+#ifdef HAVE_ARPA_INET_H
+#  include <arpa/inet.h>
+#endif /* HAVE_ARPA_INET_H */
+
+#ifdef HAVE_NETINET_IN_H
+#  include <netinet/in.h>
+#endif /* HAVE_NETINET_IN_H */
+
+#ifdef HAVE_ENDIAN_H
+#  include <endian.h>
+#endif /* HAVE_ENDIAN_H */
+
+#ifdef HAVE_SYS_ENDIAN_H
+#  include <sys/endian.h>
+#endif /* HAVE_SYS_ENDIAN_H */
+
+namespace nghttp3 {
+
+#if defined HAVE_BE64TOH || HAVE_DECL_BE64TOH
+#  define nghttp3_ntohl64(N) be64toh(N)
+#  define nghttp3_htonl64(N) htobe64(N)
+#else /* !HAVE_BE64TOH */
+#  define nghttp3_bswap64(N)                                                   \
+    ((uint64_t)(ntohl((uint32_t)(N))) << 32 | ntohl((uint32_t)((N) >> 32)))
+#  define nghttp3_ntohl64(N) nghttp3_bswap64(N)
+#  define nghttp3_htonl64(N) nghttp3_bswap64(N)
+#endif /* !HAVE_BE64TOH */
+
+} // namespace nghttp3
+
+#endif // UTIL_H