Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

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

7 files changed, 882 insertions, 0 deletions

diff --git a/src/zstd/contrib/seekable_format/examples/.gitignore b/src/zstd/contrib/seekable_format/examples/.gitignore
new file mode 100644
index 000000000..0b83f5e11
--- /dev/null
+++ b/src/zstd/contrib/seekable_format/examples/.gitignore
@@ -0,0 +1,5 @@
+seekable_compression
+seekable_decompression
+seekable_decompression_mem
+parallel_processing
+parallel_compression
diff --git a/src/zstd/contrib/seekable_format/examples/Makefile b/src/zstd/contrib/seekable_format/examples/Makefile
new file mode 100644
index 000000000..543780f75
--- /dev/null
+++ b/src/zstd/contrib/seekable_format/examples/Makefile
@@ -0,0 +1,53 @@
+# ################################################################
+# Copyright (c) 2017-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).
+# ################################################################
+
+# This Makefile presumes libzstd is built, using `make` in / or /lib/
+
+ZSTDLIB_PATH = ../../../lib
+ZSTDLIB_NAME = libzstd.a
+ZSTDLIB = $(ZSTDLIB_PATH)/$(ZSTDLIB_NAME)
+
+CPPFLAGS += -I../ -I../../../lib -I../../../lib/common
+
+CFLAGS ?= -O3
+CFLAGS += -g
+
+SEEKABLE_OBJS = ../zstdseek_compress.c ../zstdseek_decompress.c $(ZSTDLIB)
+
+.PHONY: default all clean test
+
+default: all
+
+all: seekable_compression seekable_decompression seekable_decompression_mem \
+	parallel_processing
+
+$(ZSTDLIB):
+	make -C $(ZSTDLIB_PATH) $(ZSTDLIB_NAME)
+
+seekable_compression : seekable_compression.c $(SEEKABLE_OBJS)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
+
+seekable_decompression : seekable_decompression.c $(SEEKABLE_OBJS)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
+
+seekable_decompression_mem : seekable_decompression_mem.c $(SEEKABLE_OBJS)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
+
+parallel_processing : parallel_processing.c $(SEEKABLE_OBJS)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ -pthread
+
+parallel_compression : parallel_compression.c $(SEEKABLE_OBJS)
+	$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ -pthread
+
+clean:
+	@rm -f core *.o tmp* result* *.zst \
+		seekable_compression seekable_decompression \
+		seekable_decompression_mem \
+		parallel_processing parallel_compression
+	@echo Cleaning completed
diff --git a/src/zstd/contrib/seekable_format/examples/parallel_compression.c b/src/zstd/contrib/seekable_format/examples/parallel_compression.c
new file mode 100644
index 000000000..69644d2b3
--- /dev/null
+++ b/src/zstd/contrib/seekable_format/examples/parallel_compression.c
@@ -0,0 +1,215 @@
+/*
+ * Copyright (c) 2017-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 <stdlib.h>    // malloc, free, exit, atoi
+#include <stdio.h>     // fprintf, perror, feof, fopen, etc.
+#include <string.h>    // strlen, memset, strcat
+#define ZSTD_STATIC_LINKING_ONLY
+#include <zstd.h>      // presumes zstd library is installed
+#include <zstd_errors.h>
+#if defined(WIN32) || defined(_WIN32)
+#  include <windows.h>
+#  define SLEEP(x) Sleep(x)
+#else
+#  include <unistd.h>
+#  define SLEEP(x) usleep(x * 1000)
+#endif
+
+#define XXH_NAMESPACE ZSTD_
+#include "xxhash.h"
+
+#include "pool.h"      // use zstd thread pool for demo
+
+#include "zstd_seekable.h"
+
+static void* malloc_orDie(size_t size)
+{
+    void* const buff = malloc(size);
+    if (buff) return buff;
+    /* error */
+    perror("malloc:");
+    exit(1);
+}
+
+static FILE* fopen_orDie(const char *filename, const char *instruction)
+{
+    FILE* const inFile = fopen(filename, instruction);
+    if (inFile) return inFile;
+    /* error */
+    perror(filename);
+    exit(3);
+}
+
+static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
+{
+    size_t const readSize = fread(buffer, 1, sizeToRead, file);
+    if (readSize == sizeToRead) return readSize;   /* good */
+    if (feof(file)) return readSize;   /* good, reached end of file */
+    /* error */
+    perror("fread");
+    exit(4);
+}
+
+static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
+{
+    size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
+    if (writtenSize == sizeToWrite) return sizeToWrite;   /* good */
+    /* error */
+    perror("fwrite");
+    exit(5);
+}
+
+static size_t fclose_orDie(FILE* file)
+{
+    if (!fclose(file)) return 0;
+    /* error */
+    perror("fclose");
+    exit(6);
+}
+
+static void fseek_orDie(FILE* file, long int offset, int origin)
+{
+    if (!fseek(file, offset, origin)) {
+        if (!fflush(file)) return;
+    }
+    /* error */
+    perror("fseek");
+    exit(7);
+}
+
+static long int ftell_orDie(FILE* file)
+{
+    long int off = ftell(file);
+    if (off != -1) return off;
+    /* error */
+    perror("ftell");
+    exit(8);
+}
+
+struct job {
+    const void* src;
+    size_t srcSize;
+    void* dst;
+    size_t dstSize;
+
+    unsigned checksum;
+
+    int compressionLevel;
+    int done;
+};
+
+static void compressFrame(void* opaque)
+{
+    struct job* job = opaque;
+
+    job->checksum = XXH64(job->src, job->srcSize, 0);
+
+    size_t ret = ZSTD_compress(job->dst, job->dstSize, job->src, job->srcSize, job->compressionLevel);
+    if (ZSTD_isError(ret)) {
+        fprintf(stderr, "ZSTD_compress() error : %s \n", ZSTD_getErrorName(ret));
+        exit(20);
+    }
+
+    job->dstSize = ret;
+    job->done = 1;
+}
+
+static void compressFile_orDie(const char* fname, const char* outName, int cLevel, unsigned frameSize, int nbThreads)
+{
+    POOL_ctx* pool = POOL_create(nbThreads, nbThreads);
+    if (pool == NULL) { fprintf(stderr, "POOL_create() error \n"); exit(9); }
+
+    FILE* const fin  = fopen_orDie(fname, "rb");
+    FILE* const fout = fopen_orDie(outName, "wb");
+
+    if (ZSTD_compressBound(frameSize) > 0xFFFFFFFFU) { fprintf(stderr, "Frame size too large \n"); exit(10); }
+    unsigned dstSize = ZSTD_compressBound(frameSize);
+
+
+    fseek_orDie(fin, 0, SEEK_END);
+    long int length = ftell_orDie(fin);
+    fseek_orDie(fin, 0, SEEK_SET);
+
+    size_t numFrames = (length + frameSize - 1) / frameSize;
+
+    struct job* jobs = malloc_orDie(sizeof(struct job) * numFrames);
+
+    size_t i;
+    for(i = 0; i < numFrames; i++) {
+        void* in = malloc_orDie(frameSize);
+        void* out = malloc_orDie(dstSize);
+
+        size_t inSize = fread_orDie(in, frameSize, fin);
+
+        jobs[i].src = in;
+        jobs[i].srcSize = inSize;
+        jobs[i].dst = out;
+        jobs[i].dstSize = dstSize;
+        jobs[i].compressionLevel = cLevel;
+        jobs[i].done = 0;
+        POOL_add(pool, compressFrame, &jobs[i]);
+    }
+
+    ZSTD_frameLog* fl = ZSTD_seekable_createFrameLog(1);
+    if (fl == NULL) { fprintf(stderr, "ZSTD_seekable_createFrameLog() failed \n"); exit(11); }
+    for (i = 0; i < numFrames; i++) {
+        while (!jobs[i].done) SLEEP(5); /* wake up every 5 milliseconds to check */
+        fwrite_orDie(jobs[i].dst, jobs[i].dstSize, fout);
+        free((void*)jobs[i].src);
+        free(jobs[i].dst);
+
+        size_t ret = ZSTD_seekable_logFrame(fl, jobs[i].dstSize, jobs[i].srcSize, jobs[i].checksum);
+        if (ZSTD_isError(ret)) { fprintf(stderr, "ZSTD_seekable_logFrame() error : %s \n", ZSTD_getErrorName(ret)); }
+    }
+
+    {   unsigned char seekTableBuff[1024];
+        ZSTD_outBuffer out = {seekTableBuff, 1024, 0};
+        while (ZSTD_seekable_writeSeekTable(fl, &out) != 0) {
+            fwrite_orDie(seekTableBuff, out.pos, fout);
+            out.pos = 0;
+        }
+        fwrite_orDie(seekTableBuff, out.pos, fout);
+    }
+
+    ZSTD_seekable_freeFrameLog(fl);
+    free(jobs);
+    fclose_orDie(fout);
+    fclose_orDie(fin);
+}
+
+static const char* createOutFilename_orDie(const char* filename)
+{
+    size_t const inL = strlen(filename);
+    size_t const outL = inL + 5;
+    void* outSpace = malloc_orDie(outL);
+    memset(outSpace, 0, outL);
+    strcat(outSpace, filename);
+    strcat(outSpace, ".zst");
+    return (const char*)outSpace;
+}
+
+int main(int argc, const char** argv) {
+    const char* const exeName = argv[0];
+    if (argc!=4) {
+        printf("wrong arguments\n");
+        printf("usage:\n");
+        printf("%s FILE FRAME_SIZE NB_THREADS\n", exeName);
+        return 1;
+    }
+
+    {   const char* const inFileName = argv[1];
+        unsigned const frameSize = (unsigned)atoi(argv[2]);
+        int const nbThreads = atoi(argv[3]);
+
+        const char* const outFileName = createOutFilename_orDie(inFileName);
+        compressFile_orDie(inFileName, outFileName, 5, frameSize, nbThreads);
+    }
+
+    return 0;
+}
diff --git a/src/zstd/contrib/seekable_format/examples/parallel_processing.c b/src/zstd/contrib/seekable_format/examples/parallel_processing.c
new file mode 100644
index 000000000..36226b49f
--- /dev/null
+++ b/src/zstd/contrib/seekable_format/examples/parallel_processing.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (c) 2017-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 simple demo that sums up all the bytes in the file in parallel using
+ * seekable decompression and the zstd thread pool
+ */
+
+#include <stdlib.h>    // malloc, exit
+#include <stdio.h>     // fprintf, perror, feof
+#include <string.h>    // strerror
+#include <errno.h>     // errno
+#define ZSTD_STATIC_LINKING_ONLY
+#include <zstd.h>      // presumes zstd library is installed
+#include <zstd_errors.h>
+#if defined(WIN32) || defined(_WIN32)
+#  include <windows.h>
+#  define SLEEP(x) Sleep(x)
+#else
+#  include <unistd.h>
+#  define SLEEP(x) usleep(x * 1000)
+#endif
+
+#include "pool.h"      // use zstd thread pool for demo
+
+#include "zstd_seekable.h"
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
+static void* malloc_orDie(size_t size)
+{
+    void* const buff = malloc(size);
+    if (buff) return buff;
+    /* error */
+    perror("malloc");
+    exit(1);
+}
+
+static void* realloc_orDie(void* ptr, size_t size)
+{
+    ptr = realloc(ptr, size);
+    if (ptr) return ptr;
+    /* error */
+    perror("realloc");
+    exit(1);
+}
+
+static FILE* fopen_orDie(const char *filename, const char *instruction)
+{
+    FILE* const inFile = fopen(filename, instruction);
+    if (inFile) return inFile;
+    /* error */
+    perror(filename);
+    exit(3);
+}
+
+static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
+{
+    size_t const readSize = fread(buffer, 1, sizeToRead, file);
+    if (readSize == sizeToRead) return readSize;   /* good */
+    if (feof(file)) return readSize;   /* good, reached end of file */
+    /* error */
+    perror("fread");
+    exit(4);
+}
+
+static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
+{
+    size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
+    if (writtenSize == sizeToWrite) return sizeToWrite;   /* good */
+    /* error */
+    perror("fwrite");
+    exit(5);
+}
+
+static size_t fclose_orDie(FILE* file)
+{
+    if (!fclose(file)) return 0;
+    /* error */
+    perror("fclose");
+    exit(6);
+}
+
+static void fseek_orDie(FILE* file, long int offset, int origin) {
+    if (!fseek(file, offset, origin)) {
+        if (!fflush(file)) return;
+    }
+    /* error */
+    perror("fseek");
+    exit(7);
+}
+
+struct sum_job {
+    const char* fname;
+    unsigned long long sum;
+    unsigned frameNb;
+    int done;
+};
+
+static void sumFrame(void* opaque)
+{
+    struct sum_job* job = (struct sum_job*)opaque;
+    job->done = 0;
+
+    FILE* const fin = fopen_orDie(job->fname, "rb");
+
+    ZSTD_seekable* const seekable = ZSTD_seekable_create();
+    if (seekable==NULL) { fprintf(stderr, "ZSTD_seekable_create() error \n"); exit(10); }
+
+    size_t const initResult = ZSTD_seekable_initFile(seekable, fin);
+    if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_init() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
+
+    size_t const frameSize = ZSTD_seekable_getFrameDecompressedSize(seekable, job->frameNb);
+    unsigned char* data = malloc_orDie(frameSize);
+
+    size_t result = ZSTD_seekable_decompressFrame(seekable, data, frameSize, job->frameNb);
+    if (ZSTD_isError(result)) { fprintf(stderr, "ZSTD_seekable_decompressFrame() error : %s \n", ZSTD_getErrorName(result)); exit(12); }
+
+    unsigned long long sum = 0;
+    size_t i;
+    for (i = 0; i < frameSize; i++) {
+        sum += data[i];
+    }
+    job->sum = sum;
+    job->done = 1;
+
+    fclose(fin);
+    ZSTD_seekable_free(seekable);
+    free(data);
+}
+
+static void sumFile_orDie(const char* fname, int nbThreads)
+{
+    POOL_ctx* pool = POOL_create(nbThreads, nbThreads);
+    if (pool == NULL) { fprintf(stderr, "POOL_create() error \n"); exit(9); }
+
+    FILE* const fin = fopen_orDie(fname, "rb");
+
+    ZSTD_seekable* const seekable = ZSTD_seekable_create();
+    if (seekable==NULL) { fprintf(stderr, "ZSTD_seekable_create() error \n"); exit(10); }
+
+    size_t const initResult = ZSTD_seekable_initFile(seekable, fin);
+    if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_init() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
+
+    unsigned const numFrames = ZSTD_seekable_getNumFrames(seekable);
+    struct sum_job* jobs = (struct sum_job*)malloc(numFrames * sizeof(struct sum_job));
+
+    unsigned fnb;
+    for (fnb = 0; fnb < numFrames; fnb++) {
+        jobs[fnb] = (struct sum_job){ fname, 0, fnb, 0 };
+        POOL_add(pool, sumFrame, &jobs[fnb]);
+    }
+
+    unsigned long long total = 0;
+
+    for (fnb = 0; fnb < numFrames; fnb++) {
+        while (!jobs[fnb].done) SLEEP(5); /* wake up every 5 milliseconds to check */
+        total += jobs[fnb].sum;
+    }
+
+    printf("Sum: %llu\n", total);
+
+    POOL_free(pool);
+    ZSTD_seekable_free(seekable);
+    fclose(fin);
+    free(jobs);
+}
+
+
+int main(int argc, const char** argv)
+{
+    const char* const exeName = argv[0];
+
+    if (argc!=3) {
+        fprintf(stderr, "wrong arguments\n");
+        fprintf(stderr, "usage:\n");
+        fprintf(stderr, "%s FILE NB_THREADS\n", exeName);
+        return 1;
+    }
+
+    {
+        const char* const inFilename = argv[1];
+        int const nbThreads = atoi(argv[2]);
+        sumFile_orDie(inFilename, nbThreads);
+    }
+
+    return 0;
+}
diff --git a/src/zstd/contrib/seekable_format/examples/seekable_compression.c b/src/zstd/contrib/seekable_format/examples/seekable_compression.c
new file mode 100644
index 000000000..9a331a895
--- /dev/null
+++ b/src/zstd/contrib/seekable_format/examples/seekable_compression.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2017-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 <stdlib.h>    // malloc, free, exit, atoi
+#include <stdio.h>     // fprintf, perror, feof, fopen, etc.
+#include <string.h>    // strlen, memset, strcat
+#define ZSTD_STATIC_LINKING_ONLY
+#include <zstd.h>      // presumes zstd library is installed
+
+#include "zstd_seekable.h"
+
+static void* malloc_orDie(size_t size)
+{
+    void* const buff = malloc(size);
+    if (buff) return buff;
+    /* error */
+    perror("malloc:");
+    exit(1);
+}
+
+static FILE* fopen_orDie(const char *filename, const char *instruction)
+{
+    FILE* const inFile = fopen(filename, instruction);
+    if (inFile) return inFile;
+    /* error */
+    perror(filename);
+    exit(3);
+}
+
+static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
+{
+    size_t const readSize = fread(buffer, 1, sizeToRead, file);
+    if (readSize == sizeToRead) return readSize;   /* good */
+    if (feof(file)) return readSize;   /* good, reached end of file */
+    /* error */
+    perror("fread");
+    exit(4);
+}
+
+static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
+{
+    size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
+    if (writtenSize == sizeToWrite) return sizeToWrite;   /* good */
+    /* error */
+    perror("fwrite");
+    exit(5);
+}
+
+static size_t fclose_orDie(FILE* file)
+{
+    if (!fclose(file)) return 0;
+    /* error */
+    perror("fclose");
+    exit(6);
+}
+
+static void compressFile_orDie(const char* fname, const char* outName, int cLevel, unsigned frameSize)
+{
+    FILE* const fin  = fopen_orDie(fname, "rb");
+    FILE* const fout = fopen_orDie(outName, "wb");
+    size_t const buffInSize = ZSTD_CStreamInSize();    /* can always read one full block */
+    void*  const buffIn  = malloc_orDie(buffInSize);
+    size_t const buffOutSize = ZSTD_CStreamOutSize();  /* can always flush a full block */
+    void*  const buffOut = malloc_orDie(buffOutSize);
+
+    ZSTD_seekable_CStream* const cstream = ZSTD_seekable_createCStream();
+    if (cstream==NULL) { fprintf(stderr, "ZSTD_seekable_createCStream() error \n"); exit(10); }
+    size_t const initResult = ZSTD_seekable_initCStream(cstream, cLevel, 1, frameSize);
+    if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_initCStream() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
+
+    size_t read, toRead = buffInSize;
+    while( (read = fread_orDie(buffIn, toRead, fin)) ) {
+        ZSTD_inBuffer input = { buffIn, read, 0 };
+        while (input.pos < input.size) {
+            ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
+            toRead = ZSTD_seekable_compressStream(cstream, &output , &input);   /* toRead is guaranteed to be <= ZSTD_CStreamInSize() */
+            if (ZSTD_isError(toRead)) { fprintf(stderr, "ZSTD_seekable_compressStream() error : %s \n", ZSTD_getErrorName(toRead)); exit(12); }
+            if (toRead > buffInSize) toRead = buffInSize;   /* Safely handle case when `buffInSize` is manually changed to a value < ZSTD_CStreamInSize()*/
+            fwrite_orDie(buffOut, output.pos, fout);
+        }
+    }
+
+    while (1) {
+        ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
+        size_t const remainingToFlush = ZSTD_seekable_endStream(cstream, &output);   /* close stream */
+        if (ZSTD_isError(remainingToFlush)) { fprintf(stderr, "ZSTD_seekable_endStream() error : %s \n", ZSTD_getErrorName(remainingToFlush)); exit(13); }
+        fwrite_orDie(buffOut, output.pos, fout);
+        if (!remainingToFlush) break;
+    }
+
+    ZSTD_seekable_freeCStream(cstream);
+    fclose_orDie(fout);
+    fclose_orDie(fin);
+    free(buffIn);
+    free(buffOut);
+}
+
+static char* createOutFilename_orDie(const char* filename)
+{
+    size_t const inL = strlen(filename);
+    size_t const outL = inL + 5;
+    void* outSpace = malloc_orDie(outL);
+    memset(outSpace, 0, outL);
+    strcat(outSpace, filename);
+    strcat(outSpace, ".zst");
+    return (char*)outSpace;
+}
+
+int main(int argc, const char** argv) {
+    const char* const exeName = argv[0];
+    if (argc!=3) {
+        printf("wrong arguments\n");
+        printf("usage:\n");
+        printf("%s FILE FRAME_SIZE\n", exeName);
+        return 1;
+    }
+
+    {   const char* const inFileName = argv[1];
+        unsigned const frameSize = (unsigned)atoi(argv[2]);
+
+        char* const outFileName = createOutFilename_orDie(inFileName);
+        compressFile_orDie(inFileName, outFileName, 5, frameSize);
+        free(outFileName);
+    }
+
+    return 0;
+}
diff --git a/src/zstd/contrib/seekable_format/examples/seekable_decompression.c b/src/zstd/contrib/seekable_format/examples/seekable_decompression.c
new file mode 100644
index 000000000..7050e0fa5
--- /dev/null
+++ b/src/zstd/contrib/seekable_format/examples/seekable_decompression.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2017-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 <stdlib.h>    // malloc, exit
+#include <stdio.h>     // fprintf, perror, feof
+#include <string.h>    // strerror
+#include <errno.h>     // errno
+#define ZSTD_STATIC_LINKING_ONLY
+#include <zstd.h>      // presumes zstd library is installed
+#include <zstd_errors.h>
+
+#include "zstd_seekable.h"
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
+static void* malloc_orDie(size_t size)
+{
+    void* const buff = malloc(size);
+    if (buff) return buff;
+    /* error */
+    perror("malloc");
+    exit(1);
+}
+
+static void* realloc_orDie(void* ptr, size_t size)
+{
+    ptr = realloc(ptr, size);
+    if (ptr) return ptr;
+    /* error */
+    perror("realloc");
+    exit(1);
+}
+
+static FILE* fopen_orDie(const char *filename, const char *instruction)
+{
+    FILE* const inFile = fopen(filename, instruction);
+    if (inFile) return inFile;
+    /* error */
+    perror(filename);
+    exit(3);
+}
+
+static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
+{
+    size_t const readSize = fread(buffer, 1, sizeToRead, file);
+    if (readSize == sizeToRead) return readSize;   /* good */
+    if (feof(file)) return readSize;   /* good, reached end of file */
+    /* error */
+    perror("fread");
+    exit(4);
+}
+
+static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
+{
+    size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
+    if (writtenSize == sizeToWrite) return sizeToWrite;   /* good */
+    /* error */
+    perror("fwrite");
+    exit(5);
+}
+
+static size_t fclose_orDie(FILE* file)
+{
+    if (!fclose(file)) return 0;
+    /* error */
+    perror("fclose");
+    exit(6);
+}
+
+static void fseek_orDie(FILE* file, long int offset, int origin) {
+    if (!fseek(file, offset, origin)) {
+        if (!fflush(file)) return;
+    }
+    /* error */
+    perror("fseek");
+    exit(7);
+}
+
+
+static void decompressFile_orDie(const char* fname, off_t startOffset, off_t endOffset)
+{
+    FILE* const fin  = fopen_orDie(fname, "rb");
+    FILE* const fout = stdout;
+    size_t const buffOutSize = ZSTD_DStreamOutSize();  /* Guarantee to successfully flush at least one complete compressed block in all circumstances. */
+    void*  const buffOut = malloc_orDie(buffOutSize);
+
+    ZSTD_seekable* const seekable = ZSTD_seekable_create();
+    if (seekable==NULL) { fprintf(stderr, "ZSTD_seekable_create() error \n"); exit(10); }
+
+    size_t const initResult = ZSTD_seekable_initFile(seekable, fin);
+    if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_init() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
+
+    while (startOffset < endOffset) {
+        size_t const result = ZSTD_seekable_decompress(seekable, buffOut, MIN(endOffset - startOffset, buffOutSize), startOffset);
+
+        if (ZSTD_isError(result)) {
+            fprintf(stderr, "ZSTD_seekable_decompress() error : %s \n",
+                    ZSTD_getErrorName(result));
+            exit(12);
+        }
+        fwrite_orDie(buffOut, result, fout);
+        startOffset += result;
+    }
+
+    ZSTD_seekable_free(seekable);
+    fclose_orDie(fin);
+    fclose_orDie(fout);
+    free(buffOut);
+}
+
+
+int main(int argc, const char** argv)
+{
+    const char* const exeName = argv[0];
+
+    if (argc!=4) {
+        fprintf(stderr, "wrong arguments\n");
+        fprintf(stderr, "usage:\n");
+        fprintf(stderr, "%s FILE START END\n", exeName);
+        return 1;
+    }
+
+    {
+        const char* const inFilename = argv[1];
+        off_t const startOffset = atoll(argv[2]);
+        off_t const endOffset = atoll(argv[3]);
+        decompressFile_orDie(inFilename, startOffset, endOffset);
+    }
+
+    return 0;
+}
diff --git a/src/zstd/contrib/seekable_format/examples/seekable_decompression_mem.c b/src/zstd/contrib/seekable_format/examples/seekable_decompression_mem.c
new file mode 100644
index 000000000..c36d2221f
--- /dev/null
+++ b/src/zstd/contrib/seekable_format/examples/seekable_decompression_mem.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2017-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 <stdlib.h>    // malloc, exit
+#include <stdio.h>     // fprintf, perror, feof
+#include <string.h>    // strerror
+#include <errno.h>     // errno
+#define ZSTD_STATIC_LINKING_ONLY
+#include <zstd.h>      // presumes zstd library is installed
+#include <zstd_errors.h>
+
+#include "zstd_seekable.h"
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
+#define MAX_FILE_SIZE (8 * 1024 * 1024)
+
+static void* malloc_orDie(size_t size)
+{
+    void* const buff = malloc(size);
+    if (buff) return buff;
+    /* error */
+    perror("malloc");
+    exit(1);
+}
+
+static void* realloc_orDie(void* ptr, size_t size)
+{
+    ptr = realloc(ptr, size);
+    if (ptr) return ptr;
+    /* error */
+    perror("realloc");
+    exit(1);
+}
+
+static FILE* fopen_orDie(const char *filename, const char *instruction)
+{
+    FILE* const inFile = fopen(filename, instruction);
+    if (inFile) return inFile;
+    /* error */
+    perror(filename);
+    exit(3);
+}
+
+static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
+{
+    size_t const readSize = fread(buffer, 1, sizeToRead, file);
+    if (readSize == sizeToRead) return readSize;   /* good */
+    if (feof(file)) return readSize;   /* good, reached end of file */
+    /* error */
+    perror("fread");
+    exit(4);
+}
+
+static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
+{
+    size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
+    if (writtenSize == sizeToWrite) return sizeToWrite;   /* good */
+    /* error */
+    perror("fwrite");
+    exit(5);
+}
+
+static size_t fclose_orDie(FILE* file)
+{
+    if (!fclose(file)) return 0;
+    /* error */
+    perror("fclose");
+    exit(6);
+}
+
+static void fseek_orDie(FILE* file, long int offset, int origin) {
+    if (!fseek(file, offset, origin)) {
+        if (!fflush(file)) return;
+    }
+    /* error */
+    perror("fseek");
+    exit(7);
+}
+
+
+static void decompressFile_orDie(const char* fname, off_t startOffset, off_t endOffset)
+{
+    FILE* const fin  = fopen_orDie(fname, "rb");
+    FILE* const fout = stdout;
+    // Just for demo purposes, assume file is <= MAX_FILE_SIZE
+    void*  const buffIn = malloc_orDie(MAX_FILE_SIZE);
+    size_t const inSize = fread_orDie(buffIn, MAX_FILE_SIZE, fin);
+    size_t const buffOutSize = ZSTD_DStreamOutSize();  /* Guarantee to successfully flush at least one complete compressed block in all circumstances. */
+    void*  const buffOut = malloc_orDie(buffOutSize);
+
+    ZSTD_seekable* const seekable = ZSTD_seekable_create();
+    if (seekable==NULL) { fprintf(stderr, "ZSTD_seekable_create() error \n"); exit(10); }
+
+    size_t const initResult = ZSTD_seekable_initBuff(seekable, buffIn, inSize);
+    if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_init() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
+
+    while (startOffset < endOffset) {
+        size_t const result = ZSTD_seekable_decompress(seekable, buffOut, MIN(endOffset - startOffset, buffOutSize), startOffset);
+
+        if (ZSTD_isError(result)) {
+            fprintf(stderr, "ZSTD_seekable_decompress() error : %s \n",
+                    ZSTD_getErrorName(result));
+            exit(12);
+        }
+        fwrite_orDie(buffOut, result, fout);
+        startOffset += result;
+    }
+
+    ZSTD_seekable_free(seekable);
+    fclose_orDie(fin);
+    fclose_orDie(fout);
+    free(buffIn);
+    free(buffOut);
+}
+
+
+int main(int argc, const char** argv)
+{
+    const char* const exeName = argv[0];
+
+    if (argc!=4) {
+        fprintf(stderr, "wrong arguments\n");
+        fprintf(stderr, "usage:\n");
+        fprintf(stderr, "%s FILE START END\n", exeName);
+        return 1;
+    }
+
+    {
+        const char* const inFilename = argv[1];
+        off_t const startOffset = atoll(argv[2]);
+        off_t const endOffset = atoll(argv[3]);
+        decompressFile_orDie(inFilename, startOffset, endOffset);
+    }
+
+    return 0;
+}