githubmirror/lz4 | Gitverse

programs/fuzzer.c
1 167 строк50 KB
Yann Collet
Fixed : LZ4_compress_limitedOutput() bug, as reported by Christopher Speller
10 дек 2014, 19:58
10 дек 2014, 19:58e68d7dc
/*
    fuzzer.c - Fuzzer test tool for LZ4
    Copyright (C) Yann Collet 2012-2015

    GPL v2 License

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

    You can contact the author at :
    - LZ4 source repository : http://code.google.com/p/lz4
    - LZ4 source mirror : https://github.com/Cyan4973/lz4
    - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
*/

/**************************************
* Remove Visual warning messages
**************************************/
#ifdef _MSC_VER    /* Visual Studio */
#  define _CRT_SECURE_NO_WARNINGS    /* fgets */
#  pragma warning(disable : 4127)    /* disable: C4127: conditional expression is constant */
#  pragma warning(disable : 4146)    /* disable: C4146: minus unsigned expression */
#  pragma warning(disable : 4310)    /* disable: C4310: constant char value > 127 */
#endif


/**************************************
* Includes
**************************************/
#include <stdlib.h>
#include <stdio.h>      /* fgets, sscanf */
#include <sys/timeb.h>  /* timeb */
#include <string.h>     /* strcmp */
#include "lz4.h"
#include "lz4hc.h"
#include "xxhash.h"


/**************************************
* Basic Types
**************************************/
#if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)   /* C99 */
# include <stdint.h>
typedef  uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
typedef  int32_t S32;
typedef uint64_t U64;
#else
typedef unsigned char       BYTE;
typedef unsigned short      U16;
typedef unsigned int        U32;
typedef   signed int        S32;
typedef unsigned long long  U64;
#endif


/**************************************
* Constants
**************************************/
#ifndef LZ4_VERSION
#  define LZ4_VERSION ""
#endif

#define NB_ATTEMPTS (1<<16)
#define COMPRESSIBLE_NOISE_LENGTH (1 << 21)
#define FUZ_MAX_BLOCK_SIZE (1 << 17)
#define FUZ_MAX_DICT_SIZE  (1 << 15)
#define FUZ_COMPRESSIBILITY_DEFAULT 60
#define PRIME1   2654435761U
#define PRIME2   2246822519U
#define PRIME3   3266489917U

#define KB *(1U<<10)
#define MB *(1U<<20)
#define GB *(1U<<30)


/*****************************************
* Macros
*****************************************/
#define DISPLAY(...)         fprintf(stderr, __VA_ARGS__)
#define DISPLAYLEVEL(l, ...) if (g_displayLevel>=l) { DISPLAY(__VA_ARGS__); }
static int g_displayLevel = 2;
static const U32 g_refreshRate = 250;
static U32 g_time = 0;


/*********************************************************
  Fuzzer functions
*********************************************************/
static U32 FUZ_GetMilliStart(void)
{
    struct timeb tb;
    U32 nCount;
    ftime( &tb );
    nCount = (U32) (((tb.time & 0xFFFFF) * 1000) +  tb.millitm);
    return nCount;
}

static U32 FUZ_GetMilliSpan(U32 nTimeStart)
{
    U32 nCurrent = FUZ_GetMilliStart();
    U32 nSpan = nCurrent - nTimeStart;
    if (nTimeStart > nCurrent)
        nSpan += 0x100000 * 1000;
    return nSpan;
}

static U32 FUZ_rotl32(U32 u32, U32 nbBits)
{
    return ((u32 << nbBits) | (u32 >> (32 - nbBits)));
}

static U32 FUZ_rand(U32* src)
{
    U32 rand32 = *src;
    rand32 *= PRIME1;
    rand32 += PRIME2;
    rand32  = FUZ_rotl32(rand32, 13);
    *src = rand32;
    return rand32 >> 3;
}


#define FUZ_RAND15BITS  ((FUZ_rand(seed) >> 3) & 32767)
#define FUZ_RANDLENGTH  ( ((FUZ_rand(seed) >> 7) & 3) ? (FUZ_rand(seed) % 15) : (FUZ_rand(seed) % 510) + 15)
static void FUZ_fillCompressibleNoiseBuffer(void* buffer, size_t bufferSize, double proba, U32* seed)
{
    BYTE* BBuffer = (BYTE*)buffer;
    size_t pos = 0;
    U32 P32 = (U32)(32768 * proba);

    // First Byte
    BBuffer[pos++] = (BYTE)(FUZ_rand(seed));

    while (pos < bufferSize)
    {
        // Select : Literal (noise) or copy (within 64K)
        if (FUZ_RAND15BITS < P32)
        {
            // Copy (within 64K)
            size_t match, d;
            size_t length = FUZ_RANDLENGTH + 4;
            size_t offset = FUZ_RAND15BITS + 1;
            if (offset > pos) offset = pos;
            d = pos + length;
            if (d > bufferSize) d = bufferSize;
            match = pos - offset;
            while (pos < d) BBuffer[pos++] = BBuffer[match++];
        }
        else
        {
            // Literal (noise)
            size_t d;
            size_t length = FUZ_RANDLENGTH;
            d = pos + length;
            if (d > bufferSize) d = bufferSize;
            while (pos < d) BBuffer[pos++] = (BYTE)(FUZ_rand(seed) >> 5);
        }
    }
}


#define MAX_NB_BUFF_I134 150
#define BLOCKSIZE_I134   (32 MB)
static int FUZ_AddressOverflow(void)
{
    char* buffers[MAX_NB_BUFF_I134+1] = {0};
    int i, nbBuff=0;
    int highAddress = 0;

    printf("Overflow tests : ");

    // Only possible in 32-bits
    if (sizeof(void*)==8)
    {
        printf("64 bits mode : no overflow \n");
        fflush(stdout);
        return 0;
    }

    buffers[0] = (char*)malloc(BLOCKSIZE_I134);
    buffers[1] = (char*)malloc(BLOCKSIZE_I134);
    if ((!buffers[0]) || (!buffers[1]))
    {
        printf("not enough memory for tests \n");
        return 0;
    }
    for (nbBuff=2; nbBuff < MAX_NB_BUFF_I134; nbBuff++)
    {
        printf("%3i \b\b\b\b", nbBuff);
        buffers[nbBuff] = (char*)malloc(BLOCKSIZE_I134);
        //printf("%08X ", (U32)(size_t)(buffers[nbBuff]));
        fflush(stdout);

        if (((size_t)buffers[nbBuff] > (size_t)0x80000000) && (!highAddress))
        {
            printf("high address detected : ");
            fflush(stdout);
            highAddress=1;
        }
        if (buffers[nbBuff]==NULL) goto _endOfTests;

        {
            size_t sizeToGenerateOverflow = (size_t)(- ((size_t)buffers[nbBuff-1]) + 512);
            int nbOf255 = (int)((sizeToGenerateOverflow / 255) + 1);
            char* input = buffers[nbBuff-1];
            char* output = buffers[nbBuff];
            int r;
            input[0] = (char)0xF0;   // Literal length overflow
            input[1] = (char)0xFF;
            input[2] = (char)0xFF;
            input[3] = (char)0xFF;
            for(i = 4; i <= nbOf255+4; i++) input[i] = (char)0xff;
            r = LZ4_decompress_safe(input, output, nbOf255+64, BLOCKSIZE_I134);
            if (r>0) goto _overflowError;
            input[0] = (char)0x1F;   // Match length overflow
            input[1] = (char)0x01;
            input[2] = (char)0x01;
            input[3] = (char)0x00;
            r = LZ4_decompress_safe(input, output, nbOf255+64, BLOCKSIZE_I134);
            if (r>0) goto _overflowError;

            output = buffers[nbBuff-2];   // Reverse in/out pointer order
            input[0] = (char)0xF0;   // Literal length overflow
            input[1] = (char)0xFF;
            input[2] = (char)0xFF;
            input[3] = (char)0xFF;
            r = LZ4_decompress_safe(input, output, nbOf255+64, BLOCKSIZE_I134);
            if (r>0) goto _overflowError;
            input[0] = (char)0x1F;   // Match length overflow
            input[1] = (char)0x01;
            input[2] = (char)0x01;
            input[3] = (char)0x00;
            r = LZ4_decompress_safe(input, output, nbOf255+64, BLOCKSIZE_I134);
            if (r>0) goto _overflowError;
        }
    }

    nbBuff++;
_endOfTests:
    for (i=0 ; i<nbBuff; i++) free(buffers[i]);
    if (!highAddress) printf("high address not possible \n");
    else printf("all overflows correctly detected \n");
    return 0;

_overflowError:
    printf("Address space overflow error !! \n");
    exit(1);
}


static void FUZ_displayUpdate(unsigned testNb)
{
    if ((FUZ_GetMilliSpan(g_time) > g_refreshRate) || (g_displayLevel>=3))
    {
        g_time = FUZ_GetMilliStart();
        DISPLAY("\r%5u   ", testNb);
        if (g_displayLevel>=3) fflush(stdout);
    }
}


static int FUZ_test(U32 seed, const U32 nbCycles, const U32 startCycle, const double compressibility)
{
    unsigned long long bytes = 0;
    unsigned long long cbytes = 0;
    unsigned long long hcbytes = 0;
    unsigned long long ccbytes = 0;
    void* CNBuffer;
    char* compressedBuffer;
    char* decodedBuffer;
#   define FUZ_max   LZ4_COMPRESSBOUND(LEN)
    int ret;
    unsigned cycleNb;
#   define FUZ_CHECKTEST(cond, ...) if (cond) { printf("Test %u : ", testNb); printf(__VA_ARGS__); \
    printf(" (seed %u, cycle %u) \n", seed, cycleNb); goto _output_error; }
#   define FUZ_DISPLAYTEST          { testNb++; g_displayLevel<3 ? 0 : printf("%2u\b\b", testNb); if (g_displayLevel==4) fflush(stdout); }
    void* stateLZ4   = malloc(LZ4_sizeofState());
    void* stateLZ4HC = malloc(LZ4_sizeofStateHC());
    void* LZ4continue;
    LZ4_stream_t LZ4dict;
    LZ4_streamHC_t LZ4dictHC;
    U32 crcOrig, crcCheck;
    U32 coreRandState = seed;
    U32 randState = coreRandState ^ PRIME3;


    // init
    memset(&LZ4dict, 0, sizeof(LZ4dict));

    // Create compressible test buffer
    CNBuffer = malloc(COMPRESSIBLE_NOISE_LENGTH);
    FUZ_fillCompressibleNoiseBuffer(CNBuffer, COMPRESSIBLE_NOISE_LENGTH, compressibility, &randState);
    compressedBuffer = (char*)malloc(LZ4_compressBound(FUZ_MAX_BLOCK_SIZE));
    decodedBuffer = (char*)malloc(FUZ_MAX_DICT_SIZE + FUZ_MAX_BLOCK_SIZE);

    // move to startCycle
    for (cycleNb = 0; cycleNb < startCycle; cycleNb++)
    {
        (void)FUZ_rand(&coreRandState);

        if (0)   // some problems related to dictionary re-use; in this case, enable this loop
        {
            int dictSize, blockSize, blockStart;
            char* dict;
            char* block;
            FUZ_displayUpdate(cycleNb);
            randState = coreRandState ^ PRIME3;
            blockSize  = FUZ_rand(&randState) % FUZ_MAX_BLOCK_SIZE;
            blockStart = FUZ_rand(&randState) % (COMPRESSIBLE_NOISE_LENGTH - blockSize);
            dictSize   = FUZ_rand(&randState) % FUZ_MAX_DICT_SIZE;
            if (dictSize > blockStart) dictSize = blockStart;
            block = ((char*)CNBuffer) + blockStart;
            dict = block - dictSize;
            LZ4_loadDict(&LZ4dict, dict, dictSize);
            LZ4_compress_continue(&LZ4dict, block, compressedBuffer, blockSize);
            LZ4_loadDict(&LZ4dict, dict, dictSize);
            LZ4_compress_continue(&LZ4dict, block, compressedBuffer, blockSize);
            LZ4_loadDict(&LZ4dict, dict, dictSize);
            LZ4_compress_continue(&LZ4dict, block, compressedBuffer, blockSize);
        }
    }

    // Test loop
    for (cycleNb = startCycle; cycleNb < nbCycles; cycleNb++)
    {
        U32 testNb = 0;
        char* dict;
        char* block;
        int dictSize, blockSize, blockStart, compressedSize, HCcompressedSize;
        int blockContinueCompressedSize;

        FUZ_displayUpdate(cycleNb);
        (void)FUZ_rand(&coreRandState);
        randState = coreRandState ^ PRIME3;

        // Select block to test
        blockSize  = FUZ_rand(&randState) % FUZ_MAX_BLOCK_SIZE;
        blockStart = FUZ_rand(&randState) % (COMPRESSIBLE_NOISE_LENGTH - blockSize);
        dictSize   = FUZ_rand(&randState) % FUZ_MAX_DICT_SIZE;
        if (dictSize > blockStart) dictSize = blockStart;
        block = ((char*)CNBuffer) + blockStart;
        dict = block - dictSize;

        /* Compression tests */

        // Test compression HC
        FUZ_DISPLAYTEST;
        ret = LZ4_compressHC(block, compressedBuffer, blockSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compressHC() failed");
        HCcompressedSize = ret;

        // Test compression HC using external state
        FUZ_DISPLAYTEST;
        ret = LZ4_compressHC_withStateHC(stateLZ4HC, block, compressedBuffer, blockSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compressHC_withStateHC() failed");

        // Test compression using external state
        FUZ_DISPLAYTEST;
        ret = LZ4_compress_withState(stateLZ4, block, compressedBuffer, blockSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compress_withState() failed");

        // Test compression
        FUZ_DISPLAYTEST;
        ret = LZ4_compress(block, compressedBuffer, blockSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compress() failed");
        compressedSize = ret;

        /* Decompression tests */

        crcOrig = XXH32(block, blockSize, 0);

        // Test decoding with output size being exactly what's necessary => must work
        FUZ_DISPLAYTEST;
        ret = LZ4_decompress_fast(compressedBuffer, decodedBuffer, blockSize);
        FUZ_CHECKTEST(ret<0, "LZ4_decompress_fast failed despite correct space");
        FUZ_CHECKTEST(ret!=compressedSize, "LZ4_decompress_fast failed : did not fully read compressed data");
        crcCheck = XXH32(decodedBuffer, blockSize, 0);
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_fast corrupted decoded data");

        // Test decoding with one byte missing => must fail
        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize-1] = 0;
        ret = LZ4_decompress_fast(compressedBuffer, decodedBuffer, blockSize-1);
        FUZ_CHECKTEST(ret>=0, "LZ4_decompress_fast should have failed, due to Output Size being too small");
        FUZ_CHECKTEST(decodedBuffer[blockSize-1], "LZ4_decompress_fast overrun specified output buffer");

        // Test decoding with one byte too much => must fail
        FUZ_DISPLAYTEST;
        ret = LZ4_decompress_fast(compressedBuffer, decodedBuffer, blockSize+1);
        FUZ_CHECKTEST(ret>=0, "LZ4_decompress_fast should have failed, due to Output Size being too large");

        // Test decoding with output size exactly what's necessary => must work
        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize] = 0;
        ret = LZ4_decompress_safe(compressedBuffer, decodedBuffer, compressedSize, blockSize);
        FUZ_CHECKTEST(ret<0, "LZ4_decompress_safe failed despite sufficient space");
        FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe did not regenerate original data");
        FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe overrun specified output buffer size");
        crcCheck = XXH32(decodedBuffer, blockSize, 0);
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe corrupted decoded data");

        // Test decoding with more than enough output size => must work
        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize] = 0;
        decodedBuffer[blockSize+1] = 0;
        ret = LZ4_decompress_safe(compressedBuffer, decodedBuffer, compressedSize, blockSize+1);
        FUZ_CHECKTEST(ret<0, "LZ4_decompress_safe failed despite amply sufficient space");
        FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe did not regenerate original data");
        //FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe wrote more than (unknown) target size");   // well, is that an issue ?
        FUZ_CHECKTEST(decodedBuffer[blockSize+1], "LZ4_decompress_safe overrun specified output buffer size");
        crcCheck = XXH32(decodedBuffer, blockSize, 0);
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe corrupted decoded data");

        // Test decoding with output size being one byte too short => must fail
        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize-1] = 0;
        ret = LZ4_decompress_safe(compressedBuffer, decodedBuffer, compressedSize, blockSize-1);
        FUZ_CHECKTEST(ret>=0, "LZ4_decompress_safe should have failed, due to Output Size being one byte too short");
        FUZ_CHECKTEST(decodedBuffer[blockSize-1], "LZ4_decompress_safe overrun specified output buffer size");

        // Test decoding with output size being 10 bytes too short => must fail
        FUZ_DISPLAYTEST;
        if (blockSize>10)
        {
            decodedBuffer[blockSize-10] = 0;
            ret = LZ4_decompress_safe(compressedBuffer, decodedBuffer, compressedSize, blockSize-10);
            FUZ_CHECKTEST(ret>=0, "LZ4_decompress_safe should have failed, due to Output Size being 10 bytes too short");
            FUZ_CHECKTEST(decodedBuffer[blockSize-10], "LZ4_decompress_safe overrun specified output buffer size");
        }

        // Test decoding with input size being one byte too short => must fail
        FUZ_DISPLAYTEST;
        ret = LZ4_decompress_safe(compressedBuffer, decodedBuffer, compressedSize-1, blockSize);
        FUZ_CHECKTEST(ret>=0, "LZ4_decompress_safe should have failed, due to input size being one byte too short (blockSize=%i, ret=%i, compressedSize=%i)", blockSize, ret, compressedSize);

        // Test decoding with input size being one byte too large => must fail
        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize] = 0;
        ret = LZ4_decompress_safe(compressedBuffer, decodedBuffer, compressedSize+1, blockSize);
        FUZ_CHECKTEST(ret>=0, "LZ4_decompress_safe should have failed, due to input size being too large");
        FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe overrun specified output buffer size");

        // Test partial decoding with target output size being max/2 => must work
        FUZ_DISPLAYTEST;
        ret = LZ4_decompress_safe_partial(compressedBuffer, decodedBuffer, compressedSize, blockSize/2, blockSize);
        FUZ_CHECKTEST(ret<0, "LZ4_decompress_safe_partial failed despite sufficient space");

        // Test partial decoding with target output size being just below max => must work
        FUZ_DISPLAYTEST;
        ret = LZ4_decompress_safe_partial(compressedBuffer, decodedBuffer, compressedSize, blockSize-3, blockSize);
        FUZ_CHECKTEST(ret<0, "LZ4_decompress_safe_partial failed despite sufficient space");

        /* Test Compression with limited output size */

        /* Test compression with output size being exactly what's necessary (should work) */
        FUZ_DISPLAYTEST;
        ret = LZ4_compress_limitedOutput(block, compressedBuffer, blockSize, compressedSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compress_limitedOutput() failed despite sufficient space");

        /* Test compression with output size being exactly what's necessary and external state (should work) */
        FUZ_DISPLAYTEST;
        ret = LZ4_compress_limitedOutput_withState(stateLZ4, block, compressedBuffer, blockSize, compressedSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compress_limitedOutput_withState() failed despite sufficient space");

        /* Test HC compression with output size being exactly what's necessary (should work) */
        FUZ_DISPLAYTEST;
        ret = LZ4_compressHC_limitedOutput(block, compressedBuffer, blockSize, HCcompressedSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compressHC_limitedOutput() failed despite sufficient space");

        /* Test HC compression with output size being exactly what's necessary (should work) */
        FUZ_DISPLAYTEST;
        ret = LZ4_compressHC_limitedOutput_withStateHC(stateLZ4HC, block, compressedBuffer, blockSize, HCcompressedSize);
        FUZ_CHECKTEST(ret==0, "LZ4_compressHC_limitedOutput_withStateHC() failed despite sufficient space");

        /* Test compression with missing bytes into output buffer => must fail */
        FUZ_DISPLAYTEST;
        {
            int missingBytes = (FUZ_rand(&randState) % 0x3F) + 1;
            if (missingBytes >= compressedSize) missingBytes = compressedSize-1;
            missingBytes += !missingBytes;   /* avoid special case missingBytes==0 */
            compressedBuffer[compressedSize-missingBytes] = 0;
            ret = LZ4_compress_limitedOutput(block, compressedBuffer, blockSize, compressedSize-missingBytes);
            FUZ_CHECKTEST(ret, "LZ4_compress_limitedOutput should have failed (output buffer too small by %i byte)", missingBytes);
            FUZ_CHECKTEST(compressedBuffer[compressedSize-missingBytes], "LZ4_compress_limitedOutput overran output buffer ! (%i missingBytes)", missingBytes)
        }

        /* Test HC compression with missing bytes into output buffer => must fail */
        FUZ_DISPLAYTEST;
        {
            int missingBytes = (FUZ_rand(&randState) % 0x3F) + 1;
            if (missingBytes >= HCcompressedSize) missingBytes = HCcompressedSize-1;
            missingBytes += !missingBytes;   /* avoid special case missingBytes==0 */
            compressedBuffer[HCcompressedSize-missingBytes] = 0;
            ret = LZ4_compressHC_limitedOutput(block, compressedBuffer, blockSize, HCcompressedSize-missingBytes);
            FUZ_CHECKTEST(ret, "LZ4_compressHC_limitedOutput should have failed (output buffer too small by %i byte)", missingBytes);
            FUZ_CHECKTEST(compressedBuffer[HCcompressedSize-missingBytes], "LZ4_compressHC_limitedOutput overran output buffer ! (%i missingBytes)", missingBytes)
        }


        /********************/
        /* Dictionary tests */
        /********************/

        /* Compress using dictionary */
        FUZ_DISPLAYTEST;
        LZ4continue = LZ4_create (dict);
        LZ4_compress_continue ((LZ4_stream_t*)LZ4continue, dict, compressedBuffer, dictSize);   // Just to fill hash tables
        blockContinueCompressedSize = LZ4_compress_continue ((LZ4_stream_t*)LZ4continue, block, compressedBuffer, blockSize);
        FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compress_continue failed");
        free (LZ4continue);

        /* Decompress with dictionary as prefix */
        FUZ_DISPLAYTEST;
        memcpy(decodedBuffer, dict, dictSize);
        ret = LZ4_decompress_fast_withPrefix64k(compressedBuffer, decodedBuffer+dictSize, blockSize);
        FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_decompress_fast_withPrefix64k did not read all compressed block input");
        crcCheck = XXH32(decodedBuffer+dictSize, blockSize, 0);
        if (crcCheck!=crcOrig)
        {
            int i=0;
            while (block[i]==decodedBuffer[i]) i++;
            printf("Wrong Byte at position %i/%i\n", i, blockSize);

        }
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_fast_withPrefix64k corrupted decoded data (dict %i)", dictSize);

        FUZ_DISPLAYTEST;
        ret = LZ4_decompress_safe_withPrefix64k(compressedBuffer, decodedBuffer+dictSize, blockContinueCompressedSize, blockSize);
        FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe_withPrefix64k did not regenerate original data");
        crcCheck = XXH32(decodedBuffer+dictSize, blockSize, 0);
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe_withPrefix64k corrupted decoded data");

        // Compress using External dictionary
        FUZ_DISPLAYTEST;
        dict -= (FUZ_rand(&randState) & 0xF) + 1;   // Separation, so it is an ExtDict
        if (dict < (char*)CNBuffer) dict = (char*)CNBuffer;
        LZ4_loadDict(&LZ4dict, dict, dictSize);
        blockContinueCompressedSize = LZ4_compress_continue(&LZ4dict, block, compressedBuffer, blockSize);
        FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compress_continue failed");

        FUZ_DISPLAYTEST;
        LZ4_loadDict(&LZ4dict, dict, dictSize);
        ret = LZ4_compress_limitedOutput_continue(&LZ4dict, block, compressedBuffer, blockSize, blockContinueCompressedSize-1);
        FUZ_CHECKTEST(ret>0, "LZ4_compress_limitedOutput_continue using ExtDict should fail : one missing byte for output buffer");

        FUZ_DISPLAYTEST;
        LZ4_loadDict(&LZ4dict, dict, dictSize);
        ret = LZ4_compress_limitedOutput_continue(&LZ4dict, block, compressedBuffer, blockSize, blockContinueCompressedSize);
        FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_compress_limitedOutput_compressed size is different (%i != %i)", ret, blockContinueCompressedSize);
        FUZ_CHECKTEST(ret<=0, "LZ4_compress_limitedOutput_continue should work : enough size available within output buffer");

        // Decompress with dictionary as external
        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize] = 0;
        ret = LZ4_decompress_fast_usingDict(compressedBuffer, decodedBuffer, blockSize, dict, dictSize);
        FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_decompress_fast_usingDict did not read all compressed block input");
        FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_fast_usingDict overrun specified output buffer size")
            crcCheck = XXH32(decodedBuffer, blockSize, 0);
        if (crcCheck!=crcOrig)
        {
            int i=0;
            while (block[i]==decodedBuffer[i]) i++;
            printf("Wrong Byte at position %i/%i\n", i, blockSize);
        }
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_fast_usingDict corrupted decoded data (dict %i)", dictSize);

        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize] = 0;
        ret = LZ4_decompress_safe_usingDict(compressedBuffer, decodedBuffer, blockContinueCompressedSize, blockSize, dict, dictSize);
        FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe_usingDict did not regenerate original data");
        FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe_usingDict overrun specified output buffer size")
            crcCheck = XXH32(decodedBuffer, blockSize, 0);
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe_usingDict corrupted decoded data");

        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize-1] = 0;
        ret = LZ4_decompress_fast_usingDict(compressedBuffer, decodedBuffer, blockSize-1, dict, dictSize);
        FUZ_CHECKTEST(ret>=0, "LZ4_decompress_fast_withDict should have failed : wrong original size (-1 byte)");
        FUZ_CHECKTEST(decodedBuffer[blockSize-1], "LZ4_decompress_fast_usingDict overrun specified output buffer size");

        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize-1] = 0;
        ret = LZ4_decompress_safe_usingDict(compressedBuffer, decodedBuffer, blockContinueCompressedSize, blockSize-1, dict, dictSize);
        FUZ_CHECKTEST(ret>=0, "LZ4_decompress_safe_usingDict should have failed : not enough output size (-1 byte)");
        FUZ_CHECKTEST(decodedBuffer[blockSize-1], "LZ4_decompress_safe_usingDict overrun specified output buffer size");

        FUZ_DISPLAYTEST;
        {
            U32 missingBytes = (FUZ_rand(&randState) & 0xF) + 2;
            if ((U32)blockSize > missingBytes)
            {
                decodedBuffer[blockSize-missingBytes] = 0;
                ret = LZ4_decompress_safe_usingDict(compressedBuffer, decodedBuffer, blockContinueCompressedSize, blockSize-missingBytes, dict, dictSize);
                FUZ_CHECKTEST(ret>=0, "LZ4_decompress_safe_usingDict should have failed : output buffer too small (-%u byte)", missingBytes);
                FUZ_CHECKTEST(decodedBuffer[blockSize-missingBytes], "LZ4_decompress_safe_usingDict overrun specified output buffer size (-%u byte) (blockSize=%i)", missingBytes, blockSize);
            }
        }

        // Compress HC using External dictionary
        FUZ_DISPLAYTEST;
        dict -= (FUZ_rand(&randState) & 7);    // even bigger separation
        if (dict < (char*)CNBuffer) dict = (char*)CNBuffer;
        LZ4_resetStreamHC (&LZ4dictHC, FUZ_rand(&randState) & 0x7);
        LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
        blockContinueCompressedSize = LZ4_compressHC_continue(&LZ4dictHC, block, compressedBuffer, blockSize);
        FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compressHC_continue failed");

        FUZ_DISPLAYTEST;
        LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
        ret = LZ4_compressHC_limitedOutput_continue(&LZ4dictHC, block, compressedBuffer, blockSize, blockContinueCompressedSize-1);
        FUZ_CHECKTEST(ret>0, "LZ4_compressHC_limitedOutput_continue using ExtDict should fail : one missing byte for output buffer");

        FUZ_DISPLAYTEST;
        LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
        ret = LZ4_compressHC_limitedOutput_continue(&LZ4dictHC, block, compressedBuffer, blockSize, blockContinueCompressedSize);
        FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_compress_limitedOutput_compressed size is different (%i != %i)", ret, blockContinueCompressedSize);
        FUZ_CHECKTEST(ret<=0, "LZ4_compress_limitedOutput_continue should work : enough size available within output buffer");

        FUZ_DISPLAYTEST;
        decodedBuffer[blockSize] = 0;
        ret = LZ4_decompress_safe_usingDict(compressedBuffer, decodedBuffer, blockContinueCompressedSize, blockSize, dict, dictSize);
        FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe_usingDict did not regenerate original data");
        FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe_usingDict overrun specified output buffer size")
            crcCheck = XXH32(decodedBuffer, blockSize, 0);
        if (crcCheck!=crcOrig)
        {
            int i=0;
            while (block[i]==decodedBuffer[i]) i++;
            printf("Wrong Byte at position %i/%i\n", i, blockSize);
        }
        FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe_usingDict corrupted decoded data");


        // ***** End of tests *** //
        // Fill stats
        bytes += blockSize;
        cbytes += compressedSize;
        hcbytes += HCcompressedSize;
        ccbytes += blockContinueCompressedSize;
    }

    printf("\r%7u /%7u   - ", cycleNb, nbCycles);
    printf("all tests completed successfully \n");
    printf("compression ratio: %0.3f%%\n", (double)cbytes/bytes*100);
    printf("HC compression ratio: %0.3f%%\n", (double)hcbytes/bytes*100);
    printf("ratio with dict: %0.3f%%\n", (double)ccbytes/bytes*100);

    // unalloc
    {
        int result = 0;
_exit:
        free(CNBuffer);
        free(compressedBuffer);
        free(decodedBuffer);
        free(stateLZ4);
        free(stateLZ4HC);
        return result;

_output_error:
        result = 1;
        goto _exit;
    }
}


#define testInputSize (192 KB)
#define testCompressedSize (128 KB)
#define ringBufferSize (8 KB)

static void FUZ_unitTests(void)
{
    const unsigned testNb = 0;
    const unsigned seed   = 0;
    const unsigned cycleNb= 0;
    char testInput[testInputSize];
    char testCompressed[testCompressedSize];
    char testVerify[testInputSize];
    char ringBuffer[ringBufferSize];
    U32 randState = 1;

    // Init
    FUZ_fillCompressibleNoiseBuffer(testInput, testInputSize, 0.50, &randState);

    // 32-bits address space overflow test
    FUZ_AddressOverflow();

    // LZ4 streaming tests
    {
        LZ4_stream_t* statePtr;
        LZ4_stream_t  streamingState;
        U64 crcOrig;
        U64 crcNew;
        int result;

        // Allocation test
        statePtr = LZ4_createStream();
        FUZ_CHECKTEST(statePtr==NULL, "LZ4_createStream() allocation failed");
        LZ4_freeStream(statePtr);

        // simple compression test
        crcOrig = XXH64(testInput, testCompressedSize, 0);
        LZ4_resetStream(&streamingState);
        result = LZ4_compress_limitedOutput_continue(&streamingState, testInput, testCompressed, testCompressedSize, testCompressedSize-1);
        FUZ_CHECKTEST(result==0, "LZ4_compress_limitedOutput_continue() compression failed");

        result = LZ4_decompress_safe(testCompressed, testVerify, result, testCompressedSize);
        FUZ_CHECKTEST(result!=(int)testCompressedSize, "LZ4_decompress_safe() decompression failed");
        crcNew = XXH64(testVerify, testCompressedSize, 0);
        FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe() decompression corruption");

        // ring buffer test
        {
            XXH64_state_t xxhOrig;
            XXH64_state_t xxhNew;
            LZ4_streamDecode_t decodeState;
            const U32 maxMessageSizeLog = 10;
            const U32 maxMessageSizeMask = (1<<maxMessageSizeLog) - 1;
            U32 messageSize = (FUZ_rand(&randState) & maxMessageSizeMask) + 1;
            U32 iNext = 0;
            U32 rNext = 0;
            U32 dNext = 0;
            const U32 dBufferSize = ringBufferSize + maxMessageSizeMask;

            XXH64_reset(&xxhOrig, 0);
            XXH64_reset(&xxhNew, 0);
            LZ4_resetStream(&streamingState);
            LZ4_setStreamDecode(&decodeState, NULL, 0);

            while (iNext + messageSize < testCompressedSize)
            {
                XXH64_update(&xxhOrig, testInput + iNext, messageSize);
                crcOrig = XXH64_digest(&xxhOrig);

                memcpy (ringBuffer + rNext, testInput + iNext, messageSize);
                result = LZ4_compress_limitedOutput_continue(&streamingState, ringBuffer + rNext, testCompressed, messageSize, testCompressedSize-ringBufferSize);
                FUZ_CHECKTEST(result==0, "LZ4_compress_limitedOutput_continue() compression failed");

                result = LZ4_decompress_safe_continue(&decodeState, testCompressed, testVerify + dNext, result, messageSize);
                FUZ_CHECKTEST(result!=(int)messageSize, "ringBuffer : LZ4_decompress_safe() test failed");

                XXH64_update(&xxhNew, testVerify + dNext, messageSize);
                crcNew = crcOrig = XXH64_digest(&xxhNew);
                FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe() decompression corruption");

                // prepare next message
                iNext += messageSize;
                rNext += messageSize;
                dNext += messageSize;
                messageSize = (FUZ_rand(&randState) & maxMessageSizeMask) + 1;
                if (rNext + messageSize > ringBufferSize) rNext = 0;
                if (dNext + messageSize > dBufferSize) dNext = 0;
            }
        }
    }

    // LZ4 HC streaming tests
    {
        LZ4_streamHC_t* sp;
        LZ4_streamHC_t  sHC;
        //XXH64_state_t xxh;
        U64 crcOrig;
        U64 crcNew;
        int result;

        // Allocation test
        sp = LZ4_createStreamHC();
        FUZ_CHECKTEST(sp==NULL, "LZ4_createStreamHC() allocation failed");
        LZ4_freeStreamHC(sp);

        // simple compression test
        crcOrig = XXH64(testInput, testCompressedSize, 0);
        LZ4_resetStreamHC(&sHC, 0);
        result = LZ4_compressHC_limitedOutput_continue(&sHC, testInput, testCompressed, testCompressedSize, testCompressedSize-1);
        FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() compression failed");

        result = LZ4_decompress_safe(testCompressed, testVerify, result, testCompressedSize);
        FUZ_CHECKTEST(result!=(int)testCompressedSize, "LZ4_decompress_safe() decompression failed");
        crcNew = XXH64(testVerify, testCompressedSize, 0);
        FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe() decompression corruption");

        // simple dictionary compression test
        crcOrig = XXH64(testInput + 64 KB, testCompressedSize, 0);
        LZ4_resetStreamHC(&sHC, 0);
        LZ4_loadDictHC(&sHC, testInput, 64 KB);
        result = LZ4_compressHC_limitedOutput_continue(&sHC, testInput + 64 KB, testCompressed, testCompressedSize, testCompressedSize-1);
        FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result);

        result = LZ4_decompress_safe_usingDict(testCompressed, testVerify, result, testCompressedSize, testInput, 64 KB);
        FUZ_CHECKTEST(result!=(int)testCompressedSize, "LZ4_decompress_safe() simple dictionary decompression test failed");
        crcNew = XXH64(testVerify, testCompressedSize, 0);
        FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe() simple dictionary decompression test : corruption");

        // multiple HC compression test with dictionary
        {
            int result1, result2;
            int segSize = testCompressedSize / 2;
            crcOrig = XXH64(testInput + segSize, testCompressedSize, 0);
            LZ4_resetStreamHC(&sHC, 0);
            LZ4_loadDictHC(&sHC, testInput, segSize);
            result1 = LZ4_compressHC_limitedOutput_continue(&sHC, testInput + segSize, testCompressed, segSize, segSize -1);
            FUZ_CHECKTEST(result1==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result1);
            result2 = LZ4_compressHC_limitedOutput_continue(&sHC, testInput + 2*segSize, testCompressed+result1, segSize, segSize-1);
            FUZ_CHECKTEST(result2==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result2);

            result = LZ4_decompress_safe_usingDict(testCompressed, testVerify, result1, segSize, testInput, segSize);
            FUZ_CHECKTEST(result!=segSize, "LZ4_decompress_safe() dictionary decompression part 1 failed");
            result = LZ4_decompress_safe_usingDict(testCompressed+result1, testVerify+segSize, result2, segSize, testInput, 2*segSize);
            FUZ_CHECKTEST(result!=segSize, "LZ4_decompress_safe() dictionary decompression part 2 failed");
            crcNew = XXH64(testVerify, testCompressedSize, 0);
            FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe() dictionary decompression corruption");
        }

        // remote dictionary HC compression test
        crcOrig = XXH64(testInput + 64 KB, testCompressedSize, 0);
        LZ4_resetStreamHC(&sHC, 0);
        LZ4_loadDictHC(&sHC, testInput, 32 KB);
        result = LZ4_compressHC_limitedOutput_continue(&sHC, testInput + 64 KB, testCompressed, testCompressedSize, testCompressedSize-1);
        FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() remote dictionary failed : result = %i", result);

        result = LZ4_decompress_safe_usingDict(testCompressed, testVerify, result, testCompressedSize, testInput, 32 KB);
        FUZ_CHECKTEST(result!=(int)testCompressedSize, "LZ4_decompress_safe_usingDict() decompression failed following remote dictionary HC compression test");
        crcNew = XXH64(testVerify, testCompressedSize, 0);
        FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe_usingDict() decompression corruption");

        // multiple HC compression with ext. dictionary
        {
            XXH64_state_t crcOrigState;
            XXH64_state_t crcNewState;
            const char* dict = testInput + 3;
            int dictSize = (FUZ_rand(&randState) & 8191);
            char* dst = testVerify;

            size_t segStart = dictSize + 7;
            int segSize = (FUZ_rand(&randState) & 8191);
            int segNb = 1;

            LZ4_resetStreamHC(&sHC, 0);
            LZ4_loadDictHC(&sHC, dict, dictSize);

            XXH64_reset(&crcOrigState, 0);
            XXH64_reset(&crcNewState, 0);

            while (segStart + segSize < testInputSize)
            {
                XXH64_update(&crcOrigState, testInput + segStart, segSize);
                crcOrig = XXH64_digest(&crcOrigState);
                result = LZ4_compressHC_limitedOutput_continue(&sHC, testInput + segStart, testCompressed, segSize, LZ4_compressBound(segSize));
                FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result);

                result = LZ4_decompress_safe_usingDict(testCompressed, dst, result, segSize, dict, dictSize);
                FUZ_CHECKTEST(result!=segSize, "LZ4_decompress_safe_usingDict() dictionary decompression part %i failed", segNb);
                XXH64_update(&crcNewState, dst, segSize);
                crcNew = XXH64_digest(&crcNewState);
                if (crcOrig!=crcNew)
                {
                    size_t c=0;
                    while (dst[c] == testInput[segStart+c]) c++;
                    DISPLAY("Bad decompression at %u / %u \n", (U32)c, (U32)segSize);
                }
                FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe_usingDict() part %i corruption", segNb);

                dict = dst;
                //dict = testInput + segStart;
                dictSize = segSize;

                dst += segSize + 1;
                segNb ++;

                segStart += segSize + (FUZ_rand(&randState) & 0xF) + 1;
                segSize = (FUZ_rand(&randState) & 8191);
            }
        }

        // ring buffer test
        {
            XXH64_state_t xxhOrig;
            XXH64_state_t xxhNew;
            LZ4_streamDecode_t decodeState;
            const U32 maxMessageSizeLog = 10;
            const U32 maxMessageSizeMask = (1<<maxMessageSizeLog) - 1;
            U32 messageSize = (FUZ_rand(&randState) & maxMessageSizeMask) + 1;
            U32 iNext = 0;
            U32 rNext = 0;
            U32 dNext = 0;
            const U32 dBufferSize = ringBufferSize + maxMessageSizeMask;

            XXH64_reset(&xxhOrig, 0);
            XXH64_reset(&xxhNew, 0);
            LZ4_resetStreamHC(&sHC, 0);
            LZ4_setStreamDecode(&decodeState, NULL, 0);

            while (iNext + messageSize < testCompressedSize)
            {
                XXH64_update(&xxhOrig, testInput + iNext, messageSize);
                crcOrig = XXH64_digest(&xxhOrig);

                memcpy (ringBuffer + rNext, testInput + iNext, messageSize);
                result = LZ4_compressHC_limitedOutput_continue(&sHC, ringBuffer + rNext, testCompressed, messageSize, testCompressedSize-ringBufferSize);
                FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() compression failed");

                result = LZ4_decompress_safe_continue(&decodeState, testCompressed, testVerify + dNext, result, messageSize);
                FUZ_CHECKTEST(result!=(int)messageSize, "ringBuffer : LZ4_decompress_safe() test failed");

                XXH64_update(&xxhNew, testVerify + dNext, messageSize);
                crcNew = crcOrig = XXH64_digest(&xxhNew);
                FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe() decompression corruption");

                // prepare next message
                iNext += messageSize;
                rNext += messageSize;
                dNext += messageSize;
                messageSize = (FUZ_rand(&randState) & maxMessageSizeMask) + 1;
                if (rNext + messageSize > ringBufferSize) rNext = 0;
                if (dNext + messageSize > dBufferSize) dNext = 0;
            }
        }

        // small decoder-side ring buffer test
        {
            XXH64_state_t xxhOrig;
            XXH64_state_t xxhNew;
            LZ4_streamDecode_t decodeState;
            const U32 maxMessageSizeLog = 10;
            const U32 maxMessageSizeMask = (1<<maxMessageSizeLog) - 1;
            U32 messageSize = (FUZ_rand(&randState) & maxMessageSizeMask) + 1;
            U32 totalMessageSize = 0;
            U32 iNext = 0;
            U32 dNext = 0;
            const U32 dBufferSize = 64 KB + maxMessageSizeMask;

            XXH64_reset(&xxhOrig, 0);
            XXH64_reset(&xxhNew, 0);
            LZ4_resetStreamHC(&sHC, 0);
            LZ4_setStreamDecode(&decodeState, NULL, 0);

            while (totalMessageSize < 9 MB)
            {
                XXH64_update(&xxhOrig, testInput + iNext, messageSize);
                crcOrig = XXH64_digest(&xxhOrig);

                result = LZ4_compressHC_limitedOutput_continue(&sHC, testInput + iNext, testCompressed, messageSize, testCompressedSize-ringBufferSize);
                FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() compression failed");

                result = LZ4_decompress_safe_continue(&decodeState, testCompressed, testVerify + dNext, result, messageSize);
                FUZ_CHECKTEST(result!=(int)messageSize, "ringBuffer : LZ4_decompress_safe() test failed");

                XXH64_update(&xxhNew, testVerify + dNext, messageSize);
                crcNew = crcOrig = XXH64_digest(&xxhNew);
                FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe() decompression corruption");

                // prepare next message
                dNext += messageSize;
                totalMessageSize += messageSize;
                messageSize = (FUZ_rand(&randState) & maxMessageSizeMask) + 1;
                iNext = (FUZ_rand(&randState) & 65535);
                if (dNext + messageSize > dBufferSize) dNext = 0;
            }
        }

        // long stream test ; Warning : very long test !
        if (1)
        {
            XXH64_state_t crcOrigState;
            XXH64_state_t crcNewState;
            const U64 totalTestSize = 6ULL << 30;
            U64 totalTestDone = 0;
            size_t oldStart = 0;
            size_t oldSize  = 0;
            U32 segNb = 1;

            DISPLAY("Long HC streaming test (%u MB)\n", (U32)(totalTestSize >> 20));
            LZ4_resetStreamHC(&sHC, 0);

            XXH64_reset(&crcOrigState, 0);
            XXH64_reset(&crcNewState, 0);

            while (totalTestDone < totalTestSize)
            {
                size_t testSize = (FUZ_rand(&randState) & 65535) + 1;
                size_t testStart = FUZ_rand(&randState) & 65535;

                FUZ_displayUpdate((U32)(totalTestDone >> 20));

                if (testStart == oldStart + oldSize)   // Corner case not covered by this test (LZ4_decompress_safe_usingDict() limitation)
                    testStart++;

                XXH64_update(&crcOrigState, testInput + testStart, testSize);
                crcOrig = XXH64_digest(&crcOrigState);

                result = LZ4_compressHC_limitedOutput_continue(&sHC, testInput + testStart, testCompressed, (int)testSize, LZ4_compressBound((int)testSize));
                FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result);

                result = LZ4_decompress_safe_usingDict(testCompressed, testVerify, result, (int)testSize, testInput + oldStart, (int)oldSize);
                FUZ_CHECKTEST(result!=(int)testSize, "LZ4_decompress_safe_usingDict() dictionary decompression part %u failed", segNb);

                XXH64_update(&crcNewState, testVerify, testSize);
                crcNew = XXH64_digest(&crcNewState);
                if (crcOrig!=crcNew)
                {
                    size_t c=0;
                    while (testVerify[c] == testInput[testStart+c]) c++;
                    DISPLAY("Bad decompression at %u / %u \n", (U32)c, (U32)testSize);
                }
                FUZ_CHECKTEST(crcOrig!=crcNew, "LZ4_decompress_safe_usingDict() part %u corruption", segNb);

                oldStart = testStart;
                oldSize = testSize;
                totalTestDone += testSize;

                segNb ++;
            }

            DISPLAY("\r");
        }
    }

    printf("All unit tests completed successfully \n");
    return;
_output_error:
    exit(1);
}


static int FUZ_usage(char* programName)
{
    DISPLAY( "Usage :\n");
    DISPLAY( "      %s [args]\n", programName);
    DISPLAY( "\n");
    DISPLAY( "Arguments :\n");
    DISPLAY( " -i#    : Nb of tests (default:%i) \n", NB_ATTEMPTS);
    DISPLAY( " -s#    : Select seed (default:prompt user)\n");
    DISPLAY( " -t#    : Select starting test number (default:0)\n");
    DISPLAY( " -P#    : Select compressibility in %% (default:%i%%)\n", FUZ_COMPRESSIBILITY_DEFAULT);
    DISPLAY( " -v     : verbose\n");
    DISPLAY( " -p     : pause at the end\n");
    DISPLAY( " -h     : display help and exit\n");
    return 0;
}


int main(int argc, char** argv)
{
    U32 seed=0;
    int seedset=0;
    int argNb;
    int nbTests = NB_ATTEMPTS;
    int testNb = 0;
    int proba = FUZ_COMPRESSIBILITY_DEFAULT;
    int pause = 0;
    char* programName = argv[0];

    // Check command line
    for(argNb=1; argNb<argc; argNb++)
    {
        char* argument = argv[argNb];

        if(!argument) continue;   // Protection if argument empty

        // Decode command (note : aggregated commands are allowed)
        if (argument[0]=='-')
        {
            if (!strcmp(argument, "--no-prompt")) { pause=0; seedset=1; g_displayLevel=1; continue; }
            argument++;

            while (*argument!=0)
            {
                switch(*argument)
                {
                case 'h':   /* display help */
                    return FUZ_usage(programName);

                case 'v':   /* verbose mode */
                    argument++;
                    g_displayLevel=4;
                    break;

                case 'p':   /* pause at the end */
                    argument++;
                    pause=1;
                    break;

                case 'i':
                    argument++;
                    nbTests=0;
                    while ((*argument>='0') && (*argument<='9'))
                    {
                        nbTests *= 10;
                        nbTests += *argument - '0';
                        argument++;
                    }
                    break;

                case 's':
                    argument++;
                    seed=0; seedset=1;
                    while ((*argument>='0') && (*argument<='9'))
                    {
                        seed *= 10;
                        seed += *argument - '0';
                        argument++;
                    }
                    break;

                case 't':   /* select starting test nb */
                    argument++;
                    testNb=0;
                    while ((*argument>='0') && (*argument<='9'))
                    {
                        testNb *= 10;
                        testNb += *argument - '0';
                        argument++;
                    }
                    break;

                case 'P':  /* change probability */
                    argument++;
                    proba=0;
                    while ((*argument>='0') && (*argument<='9'))
                    {
                        proba *= 10;
                        proba += *argument - '0';
                        argument++;
                    }
                    if (proba<0) proba=0;
                    if (proba>100) proba=100;
                    break;
                default: ;
                }
            }
        }
    }

    // Get Seed
    printf("Starting LZ4 fuzzer (%i-bits, %s)\n", (int)(sizeof(size_t)*8), LZ4_VERSION);

    if (!seedset) seed = FUZ_GetMilliStart() % 10000;
    printf("Seed = %u\n", seed);
    if (proba!=FUZ_COMPRESSIBILITY_DEFAULT) printf("Compressibility : %i%%\n", proba);

    if ((seedset==0) && (testNb==0)) FUZ_unitTests();

    if (nbTests<=0) nbTests=1;

    {
        int result = FUZ_test(seed, nbTests, testNb, ((double)proba) / 100);
        if (pause)
        {
            DISPLAY("press enter ... \n");
            getchar();
        }
        return result;
    }
}