added streaming_compression.c example

diff --git a/examples/.gitignore b/examples/.gitignore
index 9d241dba6ef157871167337a34ea2b771a9a4a8f..3b7352c923bece828a64179646efe0a4c679ce6c 100644 (file)
--- a/examples/.gitignore
+++ b/examples/.gitignore
@@ -3,6 +3,7 @@ simple_compression
 simple_decompression
 dictionary_compression
 dictionary_decompression
+streaming_compression
 
 #test artefact
 tmp*

diff --git a/examples/Makefile b/examples/Makefile
index 6ba8655b41b87cf3bf6d2c37697768c64970ae5c..de1f0d7bbbd10ca048346a9e30b8c8fec549df28 100644 (file)
--- a/examples/Makefile
+++ b/examples/Makefile
@@ -31,7 +31,8 @@ LDFLAGS+= -lzstd
 default: all
 
 all: simple_compression simple_decompression \
-       dictionary_compression dictionary_decompression
+       dictionary_compression dictionary_decompression \
+       streaming_compression
 
 simple_compression : simple_compression.c
        $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
@@ -45,19 +46,24 @@ dictionary_compression : dictionary_compression.c
 dictionary_decompression : dictionary_decompression.c
        $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
 
+streaming_compression : streaming_compression.c
+       $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
+
 clean:
        @rm -f core *.o tmp* result* *.zst \
         simple_compression simple_decompression \
-               dictionary_compression dictionary_decompression
+               dictionary_compression dictionary_decompression \
+               streaming_compression
        @echo Cleaning completed
 
 test: all
        cp README.md tmp
+       @echo starting simple compression
        ./simple_compression tmp
-       @echo starting simple_decompression
        ./simple_decompression tmp.zst
-       @echo dictionary compression
+       @echo starting streaming compression
+       ./streaming_compression tmp
+       @echo starting dictionary compression
        ./dictionary_compression tmp README.md
-       @echo dictionary decompression
        ./dictionary_decompression tmp.zst README.md
        @echo tests completed

diff --git a/examples/streaming_compression.c b/examples/streaming_compression.c
new file mode 100644 (file)
index 0000000..9082e38
--- /dev/null
+++ b/examples/streaming_compression.c
@@ -0,0 +1,143 @@
+/*
+  Streaming compression
+  Educational program using zstd library
+  Copyright (C) Yann Collet 2016
+
+  GPL v2 License
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along
+  with this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+  You can contact the author at :
+  - zstd homepage : http://www.zstd.net/
+*/
+
+#include <stdlib.h>    // malloc, exit
+#include <stdio.h>     // fprintf, perror
+#include <string.h>    // strerror
+#include <errno.h>     // errno
+#define ZSTD_STATIC_LINKING_ONLY  // streaming API defined as "experimental" for the time being
+#include <zstd.h>      // presumes zstd library is installed
+
+
+static void* malloc_orDie(size_t size)
+{
+    void* const buff = malloc(size);
+    if (buff) return buff;
+    /* error */
+    perror(NULL);
+    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)
+{
+    FILE* const fin  = fopen_orDie(fname, "rb");
+    FILE* const fout = fopen_orDie(outName, "wb");
+    size_t const buffInSize = ZSTD_CStreamInSize();;
+    void*  const buffIn  = malloc_orDie(buffInSize);
+    size_t const buffOutSize = ZSTD_CStreamOutSize();;
+    void*  const buffOut = malloc_orDie(buffOutSize);
+    size_t read, toRead = buffInSize;
+
+    ZSTD_CStream* const cstream = ZSTD_createCStream();
+    if (cstream==NULL) { fprintf(stderr, "ZSTD_createCStream() error \n"); exit(10); }
+    size_t const initResult = ZSTD_initCStream(cstream, cLevel);
+    if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_initCStream() error \n"); exit(11); }
+
+    while( (read = fread_orDie(buffIn, toRead, fin)) ) {
+        ZSTD_rCursor cursin = { buffIn, read };
+        while (cursin.size) {
+            ZSTD_wCursor cursout = { buffOut, buffOutSize, 0 };
+            toRead = ZSTD_compressStream(cstream, &cursout , &cursin);
+            fwrite_orDie(buffOut, cursout.nbBytesWritten, fout);
+        }
+    }
+
+    ZSTD_wCursor cursout = { buffOut, buffOutSize, 0 };
+    size_t const remainingToFlush = ZSTD_endStream(cstream, &cursout);
+    if (remainingToFlush) { fprintf(stderr, "not fully flushed"); exit(12); }
+    fwrite_orDie(buffOut, cursout.nbBytesWritten, fout);
+
+    fclose_orDie(fout);
+    fclose_orDie(fin);
+    free(buffIn);
+    free(buffOut);
+}
+
+
+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];
+    const char* const inFilename = argv[1];
+
+    if (argc!=2) {
+        printf("wrong arguments\n");
+        printf("usage:\n");
+        printf("%s FILE\n", exeName);
+        return 1;
+    }
+
+    const char* const outFilename = createOutFilename_orDie(inFilename);
+    compressFile_orDie(inFilename, outFilename, 1);
+
+    return 0;
+}