update source to Ceph Pacific 16.2.2

[ceph.git] / ceph / src / zstd / contrib / single_file_libs / examples / simple.c

diff --git a/ceph/src/zstd/contrib/single_file_libs/examples/simple.c b/ceph/src/zstd/contrib/single_file_libs/examples/simple.c
new file mode 100644 (file)
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+++ b/ceph/src/zstd/contrib/single_file_libs/examples/simple.c
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+/**
+ * \file simple.c
+ * Simple standalone example of using the single-file \c zstddeclib.
+ * 
+ * \note In this simple example we include the amalgamated source and compile
+ * just this single file, but we could equally (and more conventionally)
+ * include \c zstd.h and compile both this file and \c zstddeclib.c (the
+ * resulting binaries differ slightly in size but perform the same).
+ * 
+ * \author Carl Woffenden, Numfum GmbH (released under a CC0 license)
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../zstddeclib.c"
+
+//************************* Test Data (DXT texture) **************************/
+
+/**
+ * Raw 256x256 DXT1 data (used to compare the result).
+ * \n
+ * See \c testcard.png for the original.
+ */
+static uint8_t const rawDxt1[] = {
+#include "testcard-dxt1.inl"
+};
+
+/**
+ * Zstd compressed version of \c #rawDxt1.
+ * \n
+ * See \c testcard.png for the original.
+ */
+static uint8_t const srcZstd[] = {
+#include "testcard-zstd.inl"
+};
+
+/**
+ * Destination for decoding \c #srcZstd.
+ */
+static uint8_t dstDxt1[sizeof rawDxt1] = {};
+
+#ifndef ZSTD_VERSION_MAJOR
+/**
+ * For the case where the decompression library hasn't been included we add a
+ * dummy function to fake the process and stop the buffers being optimised out.
+ */
+size_t ZSTD_decompress(void* dst, size_t dstLen, const void* src, size_t srcLen) {
+       return (memcmp(dst, src, (srcLen < dstLen) ? srcLen : dstLen)) ? 0 : dstLen;
+}
+#endif
+
+//****************************************************************************/
+
+/**
+ * Simple single-file test to decompress \c #srcZstd into \c # dstDxt1 then
+ * compare the resulting bytes with \c #rawDxt1.
+ * \n
+ * As a (naive) comparison, removing Zstd and building with "-Os -g0 simple.c"
+ * results in a 44kB binary (macOS 10.14, Clang 10); re-adding Zstd increases
+ * the binary by 56kB (after calling \c strip).
+ */
+int main() {
+       size_t size = ZSTD_decompress(dstDxt1, sizeof dstDxt1, srcZstd, sizeof srcZstd);
+       int compare = memcmp(rawDxt1, dstDxt1, sizeof dstDxt1);
+       printf("Decompressed size: %s\n", (size == sizeof dstDxt1) ? "PASSED" : "FAILED");
+       printf("Byte comparison: %s\n", (compare == 0) ? "PASSED" : "FAILED");
+       if (size == sizeof dstDxt1 && compare == 0) {
+               return EXIT_SUCCESS;
+       }
+       return EXIT_FAILURE;
+}