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-rw-r--r--src/zstd/examples/streaming_compression.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/src/zstd/examples/streaming_compression.c b/src/zstd/examples/streaming_compression.c
new file mode 100644
index 00000000..f76364d8
--- /dev/null
+++ b/src/zstd/examples/streaming_compression.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2016-present, Yann Collet, 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).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+
+#include <stdlib.h> // malloc, free, exit
+#include <stdio.h> // fprintf, perror, feof, fopen, etc.
+#include <string.h> // strlen, memset, strcat
+#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("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)
+{
+ 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_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 : %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_compressStream(cstream, &output , &input); /* toRead is guaranteed to be <= ZSTD_CStreamInSize() */
+ if (ZSTD_isError(toRead)) { fprintf(stderr, "ZSTD_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);
+ }
+ }
+
+ ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
+ size_t const remainingToFlush = ZSTD_endStream(cstream, &output); /* close frame */
+ if (remainingToFlush) { fprintf(stderr, "not fully flushed"); exit(13); }
+ fwrite_orDie(buffOut, output.pos, fout);
+
+ ZSTD_freeCStream(cstream);
+ 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];
+
+ if (argc!=2) {
+ printf("wrong arguments\n");
+ printf("usage:\n");
+ printf("%s FILE\n", exeName);
+ return 1;
+ }
+
+ const char* const inFilename = argv[1];
+
+ const char* const outFilename = createOutFilename_orDie(inFilename);
+ compressFile_orDie(inFilename, outFilename, 1);
+
+ return 0;
+}