1 files changed, 65 insertions, 0 deletions
diff --git a/src/zstd/examples/simple_decompression.c b/src/zstd/examples/simple_decompression.c
new file mode 100644
index 000000000..e108987c6
--- /dev/null
+++ b/src/zstd/examples/simple_decompression.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2016-2020, 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 <stdio.h>     // printf
+#include <stdlib.h>    // free
+#include <zstd.h>      // presumes zstd library is installed
+#include "common.h"    // Helper functions, CHECK(), and CHECK_ZSTD()
+
+static void decompress(const char* fname)
+{
+    size_t cSize;
+    void* const cBuff = mallocAndLoadFile_orDie(fname, &cSize);
+    /* Read the content size from the frame header. For simplicity we require
+     * that it is always present. By default, zstd will write the content size
+     * in the header when it is known. If you can't guarantee that the frame
+     * content size is always written into the header, either use streaming
+     * decompression, or ZSTD_decompressBound().
+     */
+    unsigned long long const rSize = ZSTD_getFrameContentSize(cBuff, cSize);
+    CHECK(rSize != ZSTD_CONTENTSIZE_ERROR, "%s: not compressed by zstd!", fname);
+    CHECK(rSize != ZSTD_CONTENTSIZE_UNKNOWN, "%s: original size unknown!", fname);
+
+    void* const rBuff = malloc_orDie((size_t)rSize);
+
+    /* Decompress.
+     * If you are doing many decompressions, you may want to reuse the context
+     * and use ZSTD_decompressDCtx(). If you want to set advanced parameters,
+     * use ZSTD_DCtx_setParameter().
+     */
+    size_t const dSize = ZSTD_decompress(rBuff, rSize, cBuff, cSize);
+    CHECK_ZSTD(dSize);
+    /* When zstd knows the content size, it will error if it doesn't match. */
+    CHECK(dSize == rSize, "Impossible because zstd will check this condition!");
+
+    /* success */
+    printf("%25s : %6u -> %7u \n", fname, (unsigned)cSize, (unsigned)rSize);
+
+    free(rBuff);
+    free(cBuff);
+}
+
+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;
+    }
+
+    decompress(argv[1]);
+
+    printf("%s correctly decoded (in memory). \n", argv[1]);
+
+    return 0;
+}