examples/frameCompress.c - lz4 - Rivoreo Source Code Repositories

 /* LZ4frame API example : compress a file
  * Modified from an example code by Zbigniew Jędrzejewski-Szmek
  *
  * This example streams an input file into an output file
  * using a bounded memory budget.
  * Input is read in chunks of IN_CHUNK_SIZE */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 #include <assert.h>

 #include <lz4frame.h>


 #define IN_CHUNK_SIZE  (16*1024)

 static const LZ4F_preferences_t kPrefs = {
     { LZ4F_max256KB, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame,
       0 /* unknown content size */, 0 /* no dictID */ , LZ4F_noBlockChecksum },
     0,   /* compression level; 0 == default */
     0,   /* autoflush */
     { 0, 0, 0, 0 },  /* reserved, must be set to 0 */
 };


 /* safe_fwrite() :
  * performs fwrite(), ensure operation success, or immediately exit() */
 static void safe_fwrite(void* buf, size_t eltSize, size_t nbElt, FILE* f)
 {
     size_t const writtenSize = fwrite(buf, eltSize, nbElt, f);
     size_t const expectedSize = eltSize * nbElt;   /* note : should check for overflow */
     if (writtenSize < expectedSize) {
         if (ferror(f))  /* note : ferror() must follow fwrite */
             printf("Write failed\n");
         else
             printf("Short write\n");
         exit(1);
     }
 }


 /* ================================================= */
 /*     Streaming Compression example               */
 /* ================================================= */

 typedef struct {
     int error;
     unsigned long long size_in;
     unsigned long long size_out;
 } compressResult_t;

 static compressResult_t
 compress_file_internal(FILE* f_in, FILE* f_out,
                     LZ4F_compressionContext_t ctx,
                     void* inBuff, size_t inChunkSize,
                     void* outBuff, size_t outCapacity)
 {
     compressResult_t result = { 1, 0, 0 };  /* result for an error */
     unsigned long long count_in = 0, count_out;

     assert(f_in != NULL); assert(f_out != NULL);
     assert(ctx != NULL);
     assert(outCapacity >= LZ4F_HEADER_SIZE_MAX);
     assert(outCapacity >= LZ4F_compressBound(inChunkSize, &kPrefs));

     /* write frame header */
     {   size_t const headerSize = LZ4F_compressBegin(ctx, outBuff, outCapacity, &kPrefs);
         if (LZ4F_isError(headerSize)) {
             printf("Failed to start compression: error %zu\n", headerSize);
             return result;
         }
         count_out = headerSize;
         printf("Buffer size is %zu bytes, header size %zu bytes\n", outCapacity, headerSize);
         safe_fwrite(outBuff, 1, headerSize, f_out);
     }

     /* stream file */
     for (;;) {
         size_t const readSize = fread(inBuff, 1, IN_CHUNK_SIZE, f_in);
         if (readSize == 0) break; /* nothing left to read from input file */
         count_in += readSize;

         size_t const compressedSize = LZ4F_compressUpdate(ctx,
                                                 outBuff, outCapacity,
                                                 inBuff, readSize,
                                                 NULL);
         if (LZ4F_isError(compressedSize)) {
             printf("Compression failed: error %zu\n", compressedSize);
             return result;
         }

         printf("Writing %zu bytes\n", compressedSize);
         safe_fwrite(outBuff, 1, compressedSize, f_out);
         count_out += compressedSize;
     }

     /* flush whatever remains within internal buffers */
     {   size_t const compressedSize = LZ4F_compressEnd(ctx,
                                                 outBuff, outCapacity,
                                                 NULL);
         if (LZ4F_isError(compressedSize)) {
             printf("Failed to end compression: error %zu\n", compressedSize);
             return result;
         }

         printf("Writing %zu bytes\n", compressedSize);
         safe_fwrite(outBuff, 1, compressedSize, f_out);
         count_out += compressedSize;
     }

     result.size_in = count_in;
     result.size_out = count_out;
     result.error = 0;
     return result;
 }

 static compressResult_t
 compress_file(FILE* f_in, FILE* f_out)
 {
     assert(f_in != NULL);
     assert(f_out != NULL);

     /* ressource allocation */
     LZ4F_compressionContext_t ctx;
     size_t const ctxCreation = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION);
     void* const src = malloc(IN_CHUNK_SIZE);
     size_t const outbufCapacity = LZ4F_compressBound(IN_CHUNK_SIZE, &kPrefs);   /* large enough for any input <= IN_CHUNK_SIZE */
     void* const outbuff = malloc(outbufCapacity);

     compressResult_t result = { 1, 0, 0 };  /* == error (default) */
     if (!LZ4F_isError(ctxCreation) && src && outbuff) {
         result = compress_file_internal(f_in, f_out,
                                         ctx,
                                         src, IN_CHUNK_SIZE,
                                         outbuff, outbufCapacity);
     } else {
         printf("error : ressource allocation failed \n");
     }

     LZ4F_freeCompressionContext(ctx);   /* supports free on NULL */
     free(src);
     free(outbuff);
     return result;
 }


 /* ================================================= */
 /*     Streaming decompression example               */
 /* ================================================= */

 static size_t get_block_size(const LZ4F_frameInfo_t* info) {
     switch (info->blockSizeID) {
         case LZ4F_default:
         case LZ4F_max64KB:  return 1 << 16;
         case LZ4F_max256KB: return 1 << 18;
         case LZ4F_max1MB:   return 1 << 20;
         case LZ4F_max4MB:   return 1 << 22;
         default:
             printf("Impossible with expected frame specification (<=v1.6.1)\n");
             exit(1);
     }
 }

 /* @return : 1==error, 0==success */
 static int
 decompress_file_internal(FILE* f_in, FILE* f_out,
                         LZ4F_dctx* dctx,
                         void* src, size_t srcCapacity, size_t filled, size_t alreadyConsumed,
                         void* dst, size_t dstCapacity)
 {
     int firstChunk = 1;
     size_t ret = 1;

     assert(f_in != NULL); assert(f_out != NULL);
     assert(dctx != NULL);
     assert(src != NULL); assert(srcCapacity > 0); assert(filled <= srcCapacity); assert(alreadyConsumed <= filled);
     assert(dst != NULL); assert(dstCapacity > 0);

     /* Decompression */
     while (ret != 0) {
         /* Load more input */
         size_t readSize = firstChunk ? filled : fread(src, 1, srcCapacity, f_in); firstChunk=0;
         const void* srcPtr = src + alreadyConsumed; alreadyConsumed=0;
         const void* const srcEnd = srcPtr + readSize;
         if (readSize == 0 || ferror(f_in)) {
             printf("Decompress: not enough input or error reading file\n");
             return 1;
         }

         /* Decompress:
          * Continue while there is more input to read (srcPtr != srcEnd)
          * and the frame isn't over (ret != 0)
          */
         while (srcPtr != srcEnd && ret != 0) {
             /* Any data within dst has been flushed at this stage */
             size_t dstSize = dstCapacity;
             size_t srcSize = srcEnd - srcPtr;
             ret = LZ4F_decompress(dctx, dst, &dstSize, srcPtr, &srcSize, /* LZ4F_decompressOptions_t */ NULL);
             if (LZ4F_isError(ret)) {
                 printf("Decompression error: %s\n", LZ4F_getErrorName(ret));
                 return 1;
             }
             /* Flush output */
             if (dstSize != 0) safe_fwrite(dst, 1, dstSize, f_out);
             /* Update input */
             srcPtr += srcSize;
         }
     }

     /* Check that there isn't trailing input data after the frame.
      * It is valid to have multiple frames in the same file,
      * but this example only supports one frame.
      */
     {   size_t const readSize = fread(src, 1, 1, f_in);
         if (readSize != 0 || !feof(f_in)) {
             printf("Decompress: Trailing data left in file after frame\n");
             return 1;
     }   }

     return 0;
 }


 /* @return : 1==error, 0==completed */
 static int
 decompress_file_allocDst(FILE* f_in, FILE* f_out,
                         LZ4F_dctx* dctx,
                         void* src, size_t srcCapacity)
 {
     assert(f_in != NULL); assert(f_out != NULL);
     assert(dctx != NULL);
     assert(src != NULL);
     assert(srcCapacity >= LZ4F_HEADER_SIZE_MAX);  /* ensure LZ4F_getFrameInfo() can read enough data */

     /* Read Frame header */
     size_t const readSize = fread(src, 1, srcCapacity, f_in);
     if (readSize == 0 || ferror(f_in)) {
         printf("Decompress: not enough input or error reading file\n");
         return 1;
     }

     LZ4F_frameInfo_t info;
     size_t consumedSize = readSize;
     {   size_t const fires = LZ4F_getFrameInfo(dctx, &info, src, &consumedSize);
         if (LZ4F_isError(fires)) {
             printf("LZ4F_getFrameInfo error: %s\n", LZ4F_getErrorName(fires));
             return 1;
     }   }

     /* Allocating enough space for an entire block isn't necessary for
      * correctness, but it allows some memcpy's to be elided.
      */
     size_t const dstCapacity = get_block_size(&info);
     void* const dst = malloc(dstCapacity);
     if (!dst) { perror("decompress_file(dst)"); return 1; }

     int const decompressionResult = decompress_file_internal(
                         f_in, f_out,
                         dctx,
                         src, srcCapacity, readSize, consumedSize,
                         dst, dstCapacity);

     free(dst);
     return decompressionResult;
 }


 /* @result : 1==error, 0==success */
 static int decompress_file(FILE* f_in, FILE* f_out)
 {
     assert(f_in != NULL); assert(f_out != NULL);

     /* Ressource allocation */
     void* const src = malloc(IN_CHUNK_SIZE);
     if (!src) { perror("decompress_file(src)"); return 1; }

     LZ4F_dctx* dctx;
     {   size_t const dctxStatus = LZ4F_createDecompressionContext(&dctx, 100);
         if (LZ4F_isError(dctxStatus)) {
             printf("LZ4F_dctx creation error: %s\n", LZ4F_getErrorName(dctxStatus));
     }   }

     int const result = !dctx ? 1 /* error */ :
                        decompress_file_allocDst(f_in, f_out, dctx, src, IN_CHUNK_SIZE);

     free(src);
     LZ4F_freeDecompressionContext(dctx);   /* note : free works on NULL */
     return result;
 }


 int compareFiles(FILE* fp0, FILE* fp1)
 {
     int result = 0;

     while (result==0) {
         char b0[1024];
         char b1[1024];
         size_t const r0 = fread(b0, 1, sizeof(b0), fp0);
         size_t const r1 = fread(b1, 1, sizeof(b1), fp1);

         result = (r0 != r1);
         if (!r0 || !r1) break;
         if (!result) result = memcmp(b0, b1, r0);
     }

     return result;
 }


 int main(int argc, const 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.lz4", argv[1]);
     snprintf(decFilename, 256, "%s.lz4.dec", argv[1]);

     printf("inp = [%s]\n", inpFilename);
     printf("lz4 = [%s]\n", lz4Filename);
     printf("dec = [%s]\n", decFilename);

     /* compress */
     {   FILE* const inpFp = fopen(inpFilename, "rb");
         FILE* const outFp = fopen(lz4Filename, "wb");

         printf("compress : %s -> %s\n", inpFilename, lz4Filename);
         compressResult_t const ret = compress_file(inpFp, outFp);

         fclose(outFp);
         fclose(inpFp);

         if (ret.error) {
             printf("compress : failed with code %i\n", ret.error);
             return ret.error;
         }
         printf("%s: %zu → %zu bytes, %.1f%%\n",
             inpFilename,
             (size_t)ret.size_in, (size_t)ret.size_out,  /* might overflow is size_t is 32 bits and size_{in,out} > 4 GB */
             (double)ret.size_out / ret.size_in * 100);
         printf("compress : done\n");
     }

     /* decompress */
     {   FILE* const inpFp = fopen(lz4Filename, "rb");
         FILE* const outFp = fopen(decFilename, "wb");

         printf("decompress : %s -> %s\n", lz4Filename, decFilename);
         int const ret = decompress_file(inpFp, outFp);

         fclose(outFp);
         fclose(inpFp);

         if (ret) {
             printf("decompress : failed with code %i\n", ret);
             return ret;
         }
         printf("decompress : done\n");
     }

     /* verify */
     {   FILE* const inpFp = fopen(inpFilename, "rb");
         FILE* const decFp = fopen(decFilename, "rb");

         printf("verify : %s <-> %s\n", inpFilename, decFilename);
         int const cmp = compareFiles(inpFp, decFp);

         fclose(decFp);
         fclose(inpFp);

         if (cmp) {
             printf("corruption detected : decompressed file differs from original\n");
             return cmp;
         }
         printf("verify : OK\n");
     }

     return 0;
 }
	/* LZ4frame API example : compress a file
	* Modified from an example code by Zbigniew Jędrzejewski-Szmek
	*
	* This example streams an input file into an output file
	* using a bounded memory budget.
	* Input is read in chunks of IN_CHUNK_SIZE */

	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <errno.h>
	#include <assert.h>

	#include <lz4frame.h>


	#define IN_CHUNK_SIZE (16*1024)

	static const LZ4F_preferences_t kPrefs = {
	{ LZ4F_max256KB, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame,
	0 /* unknown content size /, 0 / no dictID */ , LZ4F_noBlockChecksum },
	0, /* compression level; 0 == default */
	0, /* autoflush */
	{ 0, 0, 0, 0 }, /* reserved, must be set to 0 */
	};


	/* safe_fwrite() :
	* performs fwrite(), ensure operation success, or immediately exit() */
	static void safe_fwrite(void* buf, size_t eltSize, size_t nbElt, FILE* f)
	{
	size_t const writtenSize = fwrite(buf, eltSize, nbElt, f);
	size_t const expectedSize = eltSize * nbElt; /* note : should check for overflow */
	if (writtenSize < expectedSize) {
	if (ferror(f)) /* note : ferror() must follow fwrite */
	printf("Write failed\n");
	else
	printf("Short write\n");
	exit(1);
	}
	}


	/* ================================================= */
	/* Streaming Compression example */
	/* ================================================= */

	typedef struct {
	int error;
	unsigned long long size_in;
	unsigned long long size_out;
	} compressResult_t;

	static compressResult_t
	compress_file_internal(FILE* f_in, FILE* f_out,
	LZ4F_compressionContext_t ctx,
	void* inBuff, size_t inChunkSize,
	void* outBuff, size_t outCapacity)
	{
	compressResult_t result = { 1, 0, 0 }; /* result for an error */
	unsigned long long count_in = 0, count_out;

	assert(f_in != NULL); assert(f_out != NULL);
	assert(ctx != NULL);
	assert(outCapacity >= LZ4F_HEADER_SIZE_MAX);
	assert(outCapacity >= LZ4F_compressBound(inChunkSize, &kPrefs));

	/* write frame header */
	{ size_t const headerSize = LZ4F_compressBegin(ctx, outBuff, outCapacity, &kPrefs);
	if (LZ4F_isError(headerSize)) {
	printf("Failed to start compression: error %zu\n", headerSize);
	return result;
	}
	count_out = headerSize;
	printf("Buffer size is %zu bytes, header size %zu bytes\n", outCapacity, headerSize);
	safe_fwrite(outBuff, 1, headerSize, f_out);
	}

	/* stream file */
	for (;;) {
	size_t const readSize = fread(inBuff, 1, IN_CHUNK_SIZE, f_in);
	if (readSize == 0) break; /* nothing left to read from input file */
	count_in += readSize;

	size_t const compressedSize = LZ4F_compressUpdate(ctx,
	outBuff, outCapacity,
	inBuff, readSize,
	NULL);
	if (LZ4F_isError(compressedSize)) {
	printf("Compression failed: error %zu\n", compressedSize);
	return result;
	}

	printf("Writing %zu bytes\n", compressedSize);
	safe_fwrite(outBuff, 1, compressedSize, f_out);
	count_out += compressedSize;
	}

	/* flush whatever remains within internal buffers */
	{ size_t const compressedSize = LZ4F_compressEnd(ctx,
	outBuff, outCapacity,
	NULL);
	if (LZ4F_isError(compressedSize)) {
	printf("Failed to end compression: error %zu\n", compressedSize);
	return result;
	}

	printf("Writing %zu bytes\n", compressedSize);
	safe_fwrite(outBuff, 1, compressedSize, f_out);
	count_out += compressedSize;
	}

	result.size_in = count_in;
	result.size_out = count_out;
	result.error = 0;
	return result;
	}

	static compressResult_t
	compress_file(FILE* f_in, FILE* f_out)
	{
	assert(f_in != NULL);
	assert(f_out != NULL);

	/* ressource allocation */
	LZ4F_compressionContext_t ctx;
	size_t const ctxCreation = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION);
	void* const src = malloc(IN_CHUNK_SIZE);
	size_t const outbufCapacity = LZ4F_compressBound(IN_CHUNK_SIZE, &kPrefs); /* large enough for any input <= IN_CHUNK_SIZE */
	void* const outbuff = malloc(outbufCapacity);

	compressResult_t result = { 1, 0, 0 }; /* == error (default) */
	if (!LZ4F_isError(ctxCreation) && src && outbuff) {
	result = compress_file_internal(f_in, f_out,
	ctx,
	src, IN_CHUNK_SIZE,
	outbuff, outbufCapacity);
	} else {
	printf("error : ressource allocation failed \n");
	}

	LZ4F_freeCompressionContext(ctx); /* supports free on NULL */
	free(src);
	free(outbuff);
	return result;
	}


	/* ================================================= */
	/* Streaming decompression example */
	/* ================================================= */

	static size_t get_block_size(const LZ4F_frameInfo_t* info) {
	switch (info->blockSizeID) {
	case LZ4F_default:
	case LZ4F_max64KB: return 1 << 16;
	case LZ4F_max256KB: return 1 << 18;
	case LZ4F_max1MB: return 1 << 20;
	case LZ4F_max4MB: return 1 << 22;
	default:
	printf("Impossible with expected frame specification (<=v1.6.1)\n");
	exit(1);
	}
	}

	/* @return : 1==error, 0==success */
	static int
	decompress_file_internal(FILE* f_in, FILE* f_out,
	LZ4F_dctx* dctx,
	void* src, size_t srcCapacity, size_t filled, size_t alreadyConsumed,
	void* dst, size_t dstCapacity)
	{
	int firstChunk = 1;
	size_t ret = 1;

	assert(f_in != NULL); assert(f_out != NULL);
	assert(dctx != NULL);
	assert(src != NULL); assert(srcCapacity > 0); assert(filled <= srcCapacity); assert(alreadyConsumed <= filled);
	assert(dst != NULL); assert(dstCapacity > 0);

	/* Decompression */
	while (ret != 0) {
	/* Load more input */
	size_t readSize = firstChunk ? filled : fread(src, 1, srcCapacity, f_in); firstChunk=0;
	const void* srcPtr = src + alreadyConsumed; alreadyConsumed=0;
	const void* const srcEnd = srcPtr + readSize;
	if (readSize == 0 \|\| ferror(f_in)) {
	printf("Decompress: not enough input or error reading file\n");
	return 1;
	}

	/* Decompress:
	* Continue while there is more input to read (srcPtr != srcEnd)
	* and the frame isn't over (ret != 0)
	*/
	while (srcPtr != srcEnd && ret != 0) {
	/* Any data within dst has been flushed at this stage */
	size_t dstSize = dstCapacity;
	size_t srcSize = srcEnd - srcPtr;
	ret = LZ4F_decompress(dctx, dst, &dstSize, srcPtr, &srcSize, /* LZ4F_decompressOptions_t */ NULL);
	if (LZ4F_isError(ret)) {
	printf("Decompression error: %s\n", LZ4F_getErrorName(ret));
	return 1;
	}
	/* Flush output */
	if (dstSize != 0) safe_fwrite(dst, 1, dstSize, f_out);
	/* Update input */
	srcPtr += srcSize;
	}
	}

	/* Check that there isn't trailing input data after the frame.
	* It is valid to have multiple frames in the same file,
	* but this example only supports one frame.
	*/
	{ size_t const readSize = fread(src, 1, 1, f_in);
	if (readSize != 0 \|\| !feof(f_in)) {
	printf("Decompress: Trailing data left in file after frame\n");
	return 1;
	} }

	return 0;
	}


	/* @return : 1==error, 0==completed */
	static int
	decompress_file_allocDst(FILE* f_in, FILE* f_out,
	LZ4F_dctx* dctx,
	void* src, size_t srcCapacity)
	{
	assert(f_in != NULL); assert(f_out != NULL);
	assert(dctx != NULL);
	assert(src != NULL);
	assert(srcCapacity >= LZ4F_HEADER_SIZE_MAX); /* ensure LZ4F_getFrameInfo() can read enough data */

	/* Read Frame header */
	size_t const readSize = fread(src, 1, srcCapacity, f_in);
	if (readSize == 0 \|\| ferror(f_in)) {
	printf("Decompress: not enough input or error reading file\n");
	return 1;
	}

	LZ4F_frameInfo_t info;
	size_t consumedSize = readSize;
	{ size_t const fires = LZ4F_getFrameInfo(dctx, &info, src, &consumedSize);
	if (LZ4F_isError(fires)) {
	printf("LZ4F_getFrameInfo error: %s\n", LZ4F_getErrorName(fires));
	return 1;
	} }

	/* Allocating enough space for an entire block isn't necessary for
	* correctness, but it allows some memcpy's to be elided.
	*/
	size_t const dstCapacity = get_block_size(&info);
	void* const dst = malloc(dstCapacity);
	if (!dst) { perror("decompress_file(dst)"); return 1; }

	int const decompressionResult = decompress_file_internal(
	f_in, f_out,
	dctx,
	src, srcCapacity, readSize, consumedSize,
	dst, dstCapacity);

	free(dst);
	return decompressionResult;
	}


	/* @result : 1==error, 0==success */
	static int decompress_file(FILE* f_in, FILE* f_out)
	{
	assert(f_in != NULL); assert(f_out != NULL);

	/* Ressource allocation */
	void* const src = malloc(IN_CHUNK_SIZE);
	if (!src) { perror("decompress_file(src)"); return 1; }

	LZ4F_dctx* dctx;
	{ size_t const dctxStatus = LZ4F_createDecompressionContext(&dctx, 100);
	if (LZ4F_isError(dctxStatus)) {
	printf("LZ4F_dctx creation error: %s\n", LZ4F_getErrorName(dctxStatus));
	} }

	int const result = !dctx ? 1 /* error */ :
	decompress_file_allocDst(f_in, f_out, dctx, src, IN_CHUNK_SIZE);

	free(src);
	LZ4F_freeDecompressionContext(dctx); /* note : free works on NULL */
	return result;
	}


	int compareFiles(FILE* fp0, FILE* fp1)
	{
	int result = 0;

	while (result==0) {
	char b0[1024];
	char b1[1024];
	size_t const r0 = fread(b0, 1, sizeof(b0), fp0);
	size_t const r1 = fread(b1, 1, sizeof(b1), fp1);

	result = (r0 != r1);
	if (!r0 \|\| !r1) break;
	if (!result) result = memcmp(b0, b1, r0);
	}

	return result;
	}


	int main(int argc, const 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.lz4", argv[1]);
	snprintf(decFilename, 256, "%s.lz4.dec", argv[1]);

	printf("inp = [%s]\n", inpFilename);
	printf("lz4 = [%s]\n", lz4Filename);
	printf("dec = [%s]\n", decFilename);

	/* compress */
	{ FILE* const inpFp = fopen(inpFilename, "rb");
	FILE* const outFp = fopen(lz4Filename, "wb");

	printf("compress : %s -> %s\n", inpFilename, lz4Filename);
	compressResult_t const ret = compress_file(inpFp, outFp);

	fclose(outFp);
	fclose(inpFp);

	if (ret.error) {
	printf("compress : failed with code %i\n", ret.error);
	return ret.error;
	}
	printf("%s: %zu → %zu bytes, %.1f%%\n",
	inpFilename,
	(size_t)ret.size_in, (size_t)ret.size_out, /* might overflow is size_t is 32 bits and size_{in,out} > 4 GB */
	(double)ret.size_out / ret.size_in * 100);
	printf("compress : done\n");
	}

	/* decompress */
	{ FILE* const inpFp = fopen(lz4Filename, "rb");
	FILE* const outFp = fopen(decFilename, "wb");

	printf("decompress : %s -> %s\n", lz4Filename, decFilename);
	int const ret = decompress_file(inpFp, outFp);

	fclose(outFp);
	fclose(inpFp);

	if (ret) {
	printf("decompress : failed with code %i\n", ret);
	return ret;
	}
	printf("decompress : done\n");
	}

	/* verify */
	{ FILE* const inpFp = fopen(inpFilename, "rb");
	FILE* const decFp = fopen(decFilename, "rb");

	printf("verify : %s <-> %s\n", inpFilename, decFilename);
	int const cmp = compareFiles(inpFp, decFp);

	fclose(decFp);
	fclose(inpFp);

	if (cmp) {
	printf("corruption detected : decompressed file differs from original\n");
	return cmp;
	}
	printf("verify : OK\n");
	}

	return 0;
	}