Squashed 'src/lz4/' content from commit e25b51d

git-subtree-dir: src/lz4
git-subtree-split: e25b51de7b51101e04ceea194dd557fcc23c03ca

examples/blockStreaming_ringBuffer.c

@@ -0,0 +1,200 @@
+// LZ4 streaming API example : ring buffer
+// Based on sample code from Takayuki Matsuoka
+
+
+/**************************************
+ * Compiler Options
+ **************************************/
+#ifdef _MSC_VER    /* Visual Studio */
+#  define _CRT_SECURE_NO_WARNINGS // for MSVC
+#  define snprintf sprintf_s
+#endif
+#ifdef __GNUC__
+#  pragma GCC diagnostic ignored "-Wmissing-braces"   /* GCC bug 53119 : doesn't accept { 0 } as initializer (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119) */
+#endif
+
+
+/**************************************
+ * Includes
+ **************************************/
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include "lz4.h"
+
+
+enum {
+    MESSAGE_MAX_BYTES   = 1024,
+    RING_BUFFER_BYTES   = 1024 * 8 + MESSAGE_MAX_BYTES,
+    DECODE_RING_BUFFER  = RING_BUFFER_BYTES + MESSAGE_MAX_BYTES   // Intentionally larger, to test unsynchronized ring buffers
+};
+
+
+size_t write_int32(FILE* fp, int32_t i) {
+    return fwrite(&i, sizeof(i), 1, fp);
+}
+
+size_t write_bin(FILE* fp, const void* array, int arrayBytes) {
+    return fwrite(array, 1, arrayBytes, fp);
+}
+
+size_t read_int32(FILE* fp, int32_t* i) {
+    return fread(i, sizeof(*i), 1, fp);
+}
+
+size_t read_bin(FILE* fp, void* array, int arrayBytes) {
+    return fread(array, 1, arrayBytes, fp);
+}
+
+
+void test_compress(FILE* outFp, FILE* inpFp)
+{
+    LZ4_stream_t lz4Stream_body = { 0 };
+    LZ4_stream_t* lz4Stream = &lz4Stream_body;
+
+    static char inpBuf[RING_BUFFER_BYTES];
+    int inpOffset = 0;
+
+    for(;;) {
+        // Read random length ([1,MESSAGE_MAX_BYTES]) data to the ring buffer.
+        char* const inpPtr = &inpBuf[inpOffset];
+        const int randomLength = (rand() % MESSAGE_MAX_BYTES) + 1;
+        const int inpBytes = (int) read_bin(inpFp, inpPtr, randomLength);
+        if (0 == inpBytes) break;
+
+        {
+            char cmpBuf[LZ4_COMPRESSBOUND(MESSAGE_MAX_BYTES)];
+            const int cmpBytes = LZ4_compress_continue(lz4Stream, inpPtr, cmpBuf, inpBytes);
+            if(cmpBytes <= 0) break;
+            write_int32(outFp, cmpBytes);
+            write_bin(outFp, cmpBuf, cmpBytes);
+
+            inpOffset += inpBytes;
+
+            // Wraparound the ringbuffer offset
+            if(inpOffset >= RING_BUFFER_BYTES - MESSAGE_MAX_BYTES) inpOffset = 0;
+        }
+    }
+
+    write_int32(outFp, 0);
+}
+
+
+void test_decompress(FILE* outFp, FILE* inpFp)
+{
+    static char decBuf[DECODE_RING_BUFFER];
+    int   decOffset    = 0;
+    LZ4_streamDecode_t lz4StreamDecode_body = { 0 };
+    LZ4_streamDecode_t* lz4StreamDecode = &lz4StreamDecode_body;
+
+    for(;;) {
+        int cmpBytes = 0;
+        char cmpBuf[LZ4_COMPRESSBOUND(MESSAGE_MAX_BYTES)];
+
+        {
+            const size_t r0 = read_int32(inpFp, &cmpBytes);
+            if(r0 != 1 || cmpBytes <= 0) break;
+
+            const size_t r1 = read_bin(inpFp, cmpBuf, cmpBytes);
+            if(r1 != (size_t) cmpBytes) break;
+        }
+
+        {
+            char* const decPtr = &decBuf[decOffset];
+            const int decBytes = LZ4_decompress_safe_continue(
+                lz4StreamDecode, cmpBuf, decPtr, cmpBytes, MESSAGE_MAX_BYTES);
+            if(decBytes <= 0) break;
+            decOffset += decBytes;
+            write_bin(outFp, decPtr, decBytes);
+
+            // Wraparound the ringbuffer offset
+            if(decOffset >= DECODE_RING_BUFFER - MESSAGE_MAX_BYTES) decOffset = 0;
+        }
+    }
+}
+
+
+int compare(FILE* f0, FILE* f1)
+{
+    int result = 0;
+
+    while(0 == result) {
+        char b0[65536];
+        char b1[65536];
+        const size_t r0 = fread(b0, 1, sizeof(b0), f0);
+        const size_t r1 = fread(b1, 1, sizeof(b1), f1);
+
+        result = (int) r0 - (int) r1;
+
+        if(0 == r0 || 0 == r1) {
+            break;
+        }
+        if(0 == result) {
+            result = memcmp(b0, b1, r0);
+        }
+    }
+
+    return result;
+}
+
+
+int main(int argc, char** argv)
+{
+    char inpFilename[256] = { 0 };
+    char lz4Filename[256] = { 0 };
+    char decFilename[256] = { 0 };
+
+    if(argc < 2) {
+        printf("Please specify input filename\n");
+        return 0;
+    }
+
+    snprintf(inpFilename, 256, "%s", argv[1]);
+    snprintf(lz4Filename, 256, "%s.lz4s-%d", argv[1], 0);
+    snprintf(decFilename, 256, "%s.lz4s-%d.dec", argv[1], 0);
+
+    printf("inp = [%s]\n", inpFilename);
+    printf("lz4 = [%s]\n", lz4Filename);
+    printf("dec = [%s]\n", decFilename);
+
+    // compress
+    {
+        FILE* inpFp = fopen(inpFilename, "rb");
+        FILE* outFp = fopen(lz4Filename, "wb");
+
+        test_compress(outFp, inpFp);
+
+        fclose(outFp);
+        fclose(inpFp);
+    }
+
+    // decompress
+    {
+        FILE* inpFp = fopen(lz4Filename, "rb");
+        FILE* outFp = fopen(decFilename, "wb");
+
+        test_decompress(outFp, inpFp);
+
+        fclose(outFp);
+        fclose(inpFp);
+    }
+
+    // verify
+    {
+        FILE* inpFp = fopen(inpFilename, "rb");
+        FILE* decFp = fopen(decFilename, "rb");
+
+        const int cmp = compare(inpFp, decFp);
+        if(0 == cmp) {
+            printf("Verify : OK\n");
+        } else {
+            printf("Verify : NG\n");
+        }
+
+        fclose(decFp);
+        fclose(inpFp);
+    }
+
+    return 0;
+}