vendor/zstd/1.3.4

1 files changed, 179 insertions, 79 deletions

diff --git a/tests/zstreamtest.c b/tests/zstreamtest.c
index 5590c9af15f8..b94f282f5802 100644
--- a/tests/zstreamtest.c
+++ b/tests/zstreamtest.c
@@ -99,7 +99,7 @@ unsigned int FUZ_rand(unsigned int* seedPtr)
     if (cond) {                                              \
         DISPLAY("Error => ");                                \
         DISPLAY(__VA_ARGS__);                                \
-        DISPLAY(" (seed %u, test nb %u, line %u)  \n",       \
+        DISPLAY(" (seed %u, test nb %u, line %u) \n",        \
                 seed, testNb, __LINE__);                     \
         goto _output_error;                                  \
 }   }
@@ -219,6 +219,7 @@ static int basicUnitTests(U32 seed, double compressibility)
     size_t cSize;
     int testResult = 0;
     U32 testNb = 1;
+    U32 coreSeed = 0;  /* this name to conform with CHECK_Z macro display */
     ZSTD_CStream* zc = ZSTD_createCStream();
     ZSTD_DStream* zd = ZSTD_createDStream();
     ZSTDMT_CCtx* mtctx = ZSTDMT_createCCtx(2);
@@ -238,7 +239,7 @@ static int basicUnitTests(U32 seed, double compressibility)
 
     /* Create dictionary */
     DISPLAYLEVEL(3, "creating dictionary for unit tests \n");
-    dictionary = FUZ_createDictionary(CNBuffer, CNBufferSize / 2, 8 KB, 40 KB);
+    dictionary = FUZ_createDictionary(CNBuffer, CNBufferSize / 3, 16 KB, 48 KB);
     if (!dictionary.start) {
         DISPLAY("Error creating dictionary, aborting \n");
         goto _output_error;
@@ -372,7 +373,7 @@ static int basicUnitTests(U32 seed, double compressibility)
       DISPLAYLEVEL(3, "OK (%u bytes) \n", (U32)s);
     }
 
-    /* Byte-by-byte decompression test */
+    /* Decompression by small increment */
     DISPLAYLEVEL(3, "test%3i : decompress byte-by-byte : ", testNb++);
     {   /* skippable frame */
         size_t r = 1;
@@ -382,8 +383,10 @@ static int basicUnitTests(U32 seed, double compressibility)
         inBuff.pos = 0;
         outBuff.pos = 0;
         while (r) {   /* skippable frame */
-            inBuff.size = inBuff.pos + 1;
-            outBuff.size = outBuff.pos + 1;
+            size_t const inSize = FUZ_rand(&coreSeed) & 15;
+            size_t const outSize = FUZ_rand(&coreSeed) & 15;
+            inBuff.size = inBuff.pos + inSize;
+            outBuff.size = outBuff.pos + outSize;
             r = ZSTD_decompressStream(zd, &outBuff, &inBuff);
             if (ZSTD_isError(r)) goto _output_error;
         }
@@ -391,8 +394,10 @@ static int basicUnitTests(U32 seed, double compressibility)
         ZSTD_initDStream_usingDict(zd, CNBuffer, dictSize);
         r=1;
         while (r) {
-            inBuff.size = inBuff.pos + 1;
-            outBuff.size = outBuff.pos + 1;
+            size_t const inSize = FUZ_rand(&coreSeed) & 15;
+            size_t const outSize = FUZ_rand(&coreSeed) & 15;
+            inBuff.size = inBuff.pos + inSize;
+            outBuff.size = outBuff.pos + outSize;
             r = ZSTD_decompressStream(zd, &outBuff, &inBuff);
             if (ZSTD_isError(r)) goto _output_error;
         }
@@ -427,8 +432,8 @@ static int basicUnitTests(U32 seed, double compressibility)
     DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (U32)cSize, (double)cSize/COMPRESSIBLE_NOISE_LENGTH*100);
 
     /* wrong _srcSize compression test */
-    DISPLAYLEVEL(3, "test%3i : wrong srcSize : %u bytes : ", testNb++, COMPRESSIBLE_NOISE_LENGTH-1);
-    ZSTD_initCStream_srcSize(zc, 1, CNBufferSize-1);
+    DISPLAYLEVEL(3, "test%3i : too large srcSize : %u bytes : ", testNb++, COMPRESSIBLE_NOISE_LENGTH-1);
+    ZSTD_initCStream_srcSize(zc, 1, CNBufferSize+1);
     outBuff.dst = (char*)(compressedBuffer);
     outBuff.size = compressedBufferSize;
     outBuff.pos = 0;
@@ -441,6 +446,20 @@ static int basicUnitTests(U32 seed, double compressibility)
       if (ZSTD_getErrorCode(r) != ZSTD_error_srcSize_wrong) goto _output_error;    /* must fail : wrong srcSize */
       DISPLAYLEVEL(3, "OK (error detected : %s) \n", ZSTD_getErrorName(r)); }
 
+    /* wrong _srcSize compression test */
+    DISPLAYLEVEL(3, "test%3i : too small srcSize : %u bytes : ", testNb++, COMPRESSIBLE_NOISE_LENGTH-1);
+    ZSTD_initCStream_srcSize(zc, 1, CNBufferSize-1);
+    outBuff.dst = (char*)(compressedBuffer);
+    outBuff.size = compressedBufferSize;
+    outBuff.pos = 0;
+    inBuff.src = CNBuffer;
+    inBuff.size = CNBufferSize;
+    inBuff.pos = 0;
+    {   size_t const r = ZSTD_compressStream(zc, &outBuff, &inBuff);
+        if (ZSTD_getErrorCode(r) != ZSTD_error_srcSize_wrong) goto _output_error;    /* must fail : wrong srcSize */
+        DISPLAYLEVEL(3, "OK (error detected : %s) \n", ZSTD_getErrorName(r));
+    }
+
     /* Complex context re-use scenario */
     DISPLAYLEVEL(3, "test%3i : context re-use : ", testNb++);
     ZSTD_freeCStream(zc);
@@ -557,11 +576,50 @@ static int basicUnitTests(U32 seed, double compressibility)
     { size_t const r = ZSTD_decompressStream(zd, &outBuff, &inBuff);
       if (!ZSTD_isError(r)) goto _output_error;  /* must fail : frame requires > 100 bytes */
       DISPLAYLEVEL(3, "OK (%s)\n", ZSTD_getErrorName(r)); }
+    ZSTD_DCtx_reset(zd);   /* leave zd in good shape for next tests */
+
+    DISPLAYLEVEL(3, "test%3i : dictionary source size and level : ", testNb++);
+    {   ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        int const maxLevel = 16;   /* first level with zstd_opt */
+        int level;
+        assert(maxLevel < ZSTD_maxCLevel());
+        CHECK_Z( ZSTD_DCtx_loadDictionary_byReference(dctx, dictionary.start, dictionary.filled) );
+        for (level = 1; level <= maxLevel; ++level) {
+            ZSTD_CDict* const cdict = ZSTD_createCDict(dictionary.start, dictionary.filled, level);
+            size_t const maxSize = MIN(1 MB, CNBufferSize);
+            size_t size;
+            for (size = 512; size <= maxSize; size <<= 1) {
+                U64 const crcOrig = XXH64(CNBuffer, size, 0);
+                ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+                outBuff.dst = compressedBuffer;
+                outBuff.size = compressedBufferSize;
+                outBuff.pos = 0;
+                inBuff.src = CNBuffer;
+                inBuff.size = size;
+                inBuff.pos = 0;
+                CHECK_Z(ZSTD_CCtx_refCDict(cctx, cdict));
+                CHECK_Z(ZSTD_compress_generic(cctx, &outBuff, &inBuff, ZSTD_e_end));
+                if (inBuff.pos != inBuff.size) goto _output_error;
+                {   ZSTD_outBuffer decOut = {decodedBuffer, size, 0};
+                    ZSTD_inBuffer decIn = {outBuff.dst, outBuff.pos, 0};
+                    CHECK_Z( ZSTD_decompress_generic(dctx, &decOut, &decIn) );
+                    if (decIn.pos != decIn.size) goto _output_error;
+                    if (decOut.pos != size) goto _output_error;
+                    {   U64 const crcDec = XXH64(decOut.dst, decOut.pos, 0);
+                        if (crcDec != crcOrig) goto _output_error;
+                }   }
+                ZSTD_freeCCtx(cctx);
+            }
+            ZSTD_freeCDict(cdict);
+        }
+        ZSTD_freeDCtx(dctx);
+    }
+    DISPLAYLEVEL(3, "OK\n");
 
     DISPLAYLEVEL(3, "test%3i : ZSTD_initCStream_usingCDict_advanced with masked dictID : ", testNb++);
     {   ZSTD_compressionParameters const cParams = ZSTD_getCParams(1, CNBufferSize, dictionary.filled);
         ZSTD_frameParameters const fParams = { 1 /* contentSize */, 1 /* checksum */, 1 /* noDictID */};
-        ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictionary.start, dictionary.filled, ZSTD_dlm_byRef, ZSTD_dm_auto, cParams, ZSTD_defaultCMem);
+        ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictionary.start, dictionary.filled, ZSTD_dlm_byRef, ZSTD_dct_auto, cParams, ZSTD_defaultCMem);
         size_t const initError = ZSTD_initCStream_usingCDict_advanced(zc, cdict, fParams, CNBufferSize);
         if (ZSTD_isError(initError)) goto _output_error;
         cSize = 0;
@@ -605,14 +663,18 @@ static int basicUnitTests(U32 seed, double compressibility)
     cSize = outBuff.pos;
     DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (U32)cSize, (double)cSize/CNBufferSize*100);
 
-    DISPLAYLEVEL(3, "test%3i : decompress with dictionary : ", testNb++);
-    {   size_t const r = ZSTD_decompress_usingDict(zd,
-                                        decodedBuffer, CNBufferSize,
-                                        compressedBuffer, cSize,
-                                        dictionary.start, dictionary.filled);
-        if (ZSTD_isError(r)) goto _output_error;  /* must fail : dictionary not used */
-        DISPLAYLEVEL(3, "OK \n");
-    }
+    DISPLAYLEVEL(3, "test%3i : decompress with ZSTD_DCtx_refPrefix : ", testNb++);
+    CHECK_Z( ZSTD_DCtx_refPrefix(zd, dictionary.start, dictionary.filled) );
+    outBuff.dst = decodedBuffer;
+    outBuff.size = CNBufferSize;
+    outBuff.pos = 0;
+    inBuff.src = compressedBuffer;
+    inBuff.size = cSize;
+    inBuff.pos = 0;
+    CHECK_Z( ZSTD_decompress_generic(zd, &outBuff, &inBuff) );
+    if (inBuff.pos != inBuff.size) goto _output_error;  /* entire input should be consumed */
+    if (outBuff.pos != CNBufferSize) goto _output_error;  /* must regenerate whole input */
+    DISPLAYLEVEL(3, "OK \n");
 
     DISPLAYLEVEL(3, "test%3i : decompress without dictionary (should fail): ", testNb++);
     {   size_t const r = ZSTD_decompress(decodedBuffer, CNBufferSize, compressedBuffer, cSize);
@@ -694,16 +756,19 @@ static int basicUnitTests(U32 seed, double compressibility)
     inBuff.src = CNBuffer;
     inBuff.size = CNBufferSize;
     inBuff.pos = 0;
-    CHECK_Z( ZSTDMT_compressStream_generic(mtctx, &outBuff, &inBuff, ZSTD_e_end) );
+    {   size_t const compressResult = ZSTDMT_compressStream_generic(mtctx, &outBuff, &inBuff, ZSTD_e_end);
+        if (compressResult != 0) goto _output_error;  /* compression must be completed in a single round */
+    }
     if (inBuff.pos != inBuff.size) goto _output_error;   /* entire input should be consumed */
-    { size_t const r = ZSTDMT_endStream(mtctx, &outBuff);
-      if (r != 0) goto _output_error; }  /* error, or some data not flushed */
+    {   size_t const compressedSize = ZSTD_findFrameCompressedSize(compressedBuffer, outBuff.pos);
+        if (compressedSize != outBuff.pos) goto _output_error;  /* must be a full valid frame */
+    }
     DISPLAYLEVEL(3, "OK \n");
 
     /* Complex multithreading + dictionary test */
-    {   U32 const nbThreads = 2;
+    {   U32 const nbWorkers = 2;
         size_t const jobSize = 4 * 1 MB;
-        size_t const srcSize = jobSize * nbThreads;  /* we want each job to have predictable size */
+        size_t const srcSize = jobSize * nbWorkers;  /* we want each job to have predictable size */
         size_t const segLength = 2 KB;
         size_t const offset = 600 KB;   /* must be larger than window defined in cdict */
         size_t const start = jobSize + (offset-1);
@@ -711,7 +776,7 @@ static int basicUnitTests(U32 seed, double compressibility)
         BYTE* const dst = (BYTE*)CNBuffer + start - offset;
         DISPLAYLEVEL(3, "test%3i : compress %u bytes with multiple threads + dictionary : ", testNb++, (U32)srcSize);
         CHECK_Z( ZSTD_CCtx_setParameter(zc, ZSTD_p_compressionLevel, 3) );
-        CHECK_Z( ZSTD_CCtx_setParameter(zc, ZSTD_p_nbThreads, 2) );
+        CHECK_Z( ZSTD_CCtx_setParameter(zc, ZSTD_p_nbWorkers, nbWorkers) );
         CHECK_Z( ZSTD_CCtx_setParameter(zc, ZSTD_p_jobSize, jobSize) );
         assert(start > offset);
         assert(start + segLength < COMPRESSIBLE_NOISE_LENGTH);
@@ -724,7 +789,7 @@ static int basicUnitTests(U32 seed, double compressibility)
         inBuff.pos = 0;
     }
     {   ZSTD_compressionParameters const cParams = ZSTD_getCParams(1, 4 KB, dictionary.filled);   /* intentionnally lies on estimatedSrcSize, to push cdict into targeting a small window size */
-        ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictionary.start, dictionary.filled, ZSTD_dlm_byRef, ZSTD_dm_fullDict, cParams, ZSTD_defaultCMem);
+        ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictionary.start, dictionary.filled, ZSTD_dlm_byRef, ZSTD_dct_fullDict, cParams, ZSTD_defaultCMem);
         DISPLAYLEVEL(5, "cParams.windowLog = %u : ", cParams.windowLog);
         CHECK_Z( ZSTD_CCtx_refCDict(zc, cdict) );
         CHECK_Z( ZSTD_compress_generic(zc, &outBuff, &inBuff, ZSTD_e_end) );
@@ -767,7 +832,7 @@ static int basicUnitTests(U32 seed, double compressibility)
 
         XXH64_reset(&xxh, 0);
         cParams.windowLog = kMaxWindowLog;
-        cdict = ZSTD_createCDict_advanced(dictionary.start, dictionary.filled, ZSTD_dlm_byRef, ZSTD_dm_fullDict, cParams, ZSTD_defaultCMem);
+        cdict = ZSTD_createCDict_advanced(dictionary.start, dictionary.filled, ZSTD_dlm_byRef, ZSTD_dct_fullDict, cParams, ZSTD_defaultCMem);
         ddict = ZSTD_createDDict(dictionary.start, dictionary.filled);
 
         if (!cdict || !ddict) goto _output_error;
@@ -863,11 +928,21 @@ static size_t findDiff(const void* buf1, const void* buf2, size_t max)
     for (u=0; u<max; u++) {
         if (b1[u] != b2[u]) break;
     }
+    if (u==max) {
+        DISPLAY("=> No difference detected within %u bytes \n", (U32)max);
+        return u;
+    }
     DISPLAY("Error at position %u / %u \n", (U32)u, (U32)max);
-    DISPLAY(" %02X %02X %02X  :%02X:  %02X %02X %02X %02X %02X \n",
-            b1[u-3], b1[u-2], b1[u-1], b1[u-0], b1[u+1], b1[u+2], b1[u+3], b1[u+4], b1[u+5]);
-    DISPLAY(" %02X %02X %02X  :%02X:  %02X %02X %02X %02X %02X \n",
-            b2[u-3], b2[u-2], b2[u-1], b2[u-0], b2[u+1], b2[u+2], b2[u+3], b2[u+4], b2[u+5]);
+    if (u>=3)
+        DISPLAY(" %02X %02X %02X ",
+                b1[u-3], b1[u-2], b1[u-1]);
+    DISPLAY(" :%02X:  %02X %02X %02X %02X %02X \n",
+            b1[u], b1[u+1], b1[u+2], b1[u+3], b1[u+4], b1[u+5]);
+    if (u>=3)
+        DISPLAY(" %02X %02X %02X ",
+                b2[u-3], b2[u-2], b2[u-1]);
+    DISPLAY(" :%02X:  %02X %02X %02X %02X %02X \n",
+            b2[u], b2[u+1], b2[u+2], b2[u+3], b2[u+4], b2[u+5]);
     return u;
 }
 
@@ -948,10 +1023,13 @@ static int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compres
         size_t maxTestSize;
 
         /* init */
-        if (nbTests >= testNb) { DISPLAYUPDATE(2, "\r%6u/%6u    ", testNb, nbTests); }
-        else { DISPLAYUPDATE(2, "\r%6u          ", testNb); }
         FUZ_rand(&coreSeed);
         lseed = coreSeed ^ prime32;
+        if (nbTests >= testNb) {
+            DISPLAYUPDATE(2, "\r%6u/%6u    ", testNb, nbTests);
+        } else {
+            DISPLAYUPDATE(2, "\r%6u        ", testNb);
+        }
 
         /* states full reset (deliberately not synchronized) */
         /* some issues can only happen when reusing states */
@@ -1161,7 +1239,6 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
     UTIL_time_t const startClock = UTIL_getTime();
     const BYTE* dict=NULL;   /* can keep same dict on 2 consecutive tests */
     size_t dictSize = 0;
-    U32 oldTestLog = 0;
     int const cLevelMax = bigTests ? (U32)ZSTD_maxCLevel()-1 : g_cLevelMax_smallTests;
     U32 const nbThreadsMax = bigTests ? 4 : 2;
 
@@ -1183,6 +1260,7 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
     RDG_genBuffer(cNoiseBuffer[4], srcBufferSize, 1.00, 0., coreSeed);    /* sparse content */
     memset(copyBuffer, 0x65, copyBufferSize);                             /* make copyBuffer considered initialized */
     ZSTD_initDStream_usingDict(zd, NULL, 0);  /* ensure at least one init */
+    DISPLAYLEVEL(6, "Creating initial context with %u threads \n", nbThreads);
 
     /* catch up testNb */
     for (testNb=1; testNb < startTest; testNb++)
@@ -1195,14 +1273,14 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
         size_t totalTestSize, totalGenSize, cSize;
         XXH64_state_t xxhState;
         U64 crcOrig;
-        U32 resetAllowed = 1;
         size_t maxTestSize;
 
-        /* init */
-        if (testNb < nbTests) {
-            DISPLAYUPDATE(2, "\r%6u/%6u    ", testNb, nbTests);
-        } else { DISPLAYUPDATE(2, "\r%6u          ", testNb); }
         FUZ_rand(&coreSeed);
+        if (nbTests >= testNb) {
+            DISPLAYUPDATE(2, "\r%6u/%6u    ", testNb, nbTests);
+        } else {
+            DISPLAYUPDATE(2, "\r%6u         ", testNb);
+        }
         lseed = coreSeed ^ prime32;
 
         /* states full reset (deliberately not synchronized) */
@@ -1213,7 +1291,6 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
             ZSTDMT_freeCCtx(zc);
             zc = ZSTDMT_createCCtx(nbThreads);
             CHECK(zc==NULL, "ZSTDMT_createCCtx allocation error")
-            resetAllowed=0;
         }
         if ((FUZ_rand(&lseed) & 0xFF) == 132) {
             ZSTD_freeDStream(zd);
@@ -1238,15 +1315,7 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
         }
 
         /* compression init */
-        if ((FUZ_rand(&lseed)&1) /* at beginning, to keep same nb of rand */
-            && oldTestLog /* at least one test happened */ && resetAllowed) {
-            maxTestSize = FUZ_randomLength(&lseed, oldTestLog+2);
-            if (maxTestSize >= srcBufferSize) maxTestSize = srcBufferSize-1;
-            {   int const compressionLevel = (FUZ_rand(&lseed) % 5) + 1;
-                CHECK_Z( ZSTDMT_initCStream(zc, compressionLevel) );
-            }
-        } else {
-            U32 const testLog = FUZ_rand(&lseed) % maxSrcLog;
+        {   U32 const testLog = FUZ_rand(&lseed) % maxSrcLog;
             U32 const dictLog = FUZ_rand(&lseed) % maxSrcLog;
             int const cLevelCandidate = ( FUZ_rand(&lseed)
                             % (ZSTD_maxCLevel() - (MAX(testLog, dictLog) / 2)) )
@@ -1255,24 +1324,29 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
             int const cLevelMin = MAX(cLevelThreadAdjusted, 1);  /* no negative cLevel yet */
             int const cLevel = MIN(cLevelMin, cLevelMax);
             maxTestSize = FUZ_rLogLength(&lseed, testLog);
-            oldTestLog = testLog;
-            /* random dictionary selection */
-            dictSize  = ((FUZ_rand(&lseed)&63)==1) ? FUZ_rLogLength(&lseed, dictLog) : 0;
-            {   size_t const dictStart = FUZ_rand(&lseed) % (srcBufferSize - dictSize);
-                dict = srcBuffer + dictStart;
-            }
-            {   U64 const pledgedSrcSize = (FUZ_rand(&lseed) & 3) ? ZSTD_CONTENTSIZE_UNKNOWN : maxTestSize;
-                ZSTD_parameters params = ZSTD_getParams(cLevel, pledgedSrcSize, dictSize);
-                DISPLAYLEVEL(5, "Init with windowLog = %u, pledgedSrcSize = %u, dictSize = %u \n",
-                    params.cParams.windowLog, (U32)pledgedSrcSize, (U32)dictSize);
-                params.fParams.checksumFlag = FUZ_rand(&lseed) & 1;
-                params.fParams.noDictIDFlag = FUZ_rand(&lseed) & 1;
-                params.fParams.contentSizeFlag = FUZ_rand(&lseed) & 1;
-                DISPLAYLEVEL(5, "checksumFlag : %u \n", params.fParams.checksumFlag);
-                CHECK_Z( ZSTDMT_setMTCtxParameter(zc, ZSTDMT_p_overlapSectionLog, FUZ_rand(&lseed) % 12) );
-                CHECK_Z( ZSTDMT_setMTCtxParameter(zc, ZSTDMT_p_jobSize, FUZ_rand(&lseed) % (2*maxTestSize+1)) );   /* custome job size */
-                CHECK_Z( ZSTDMT_initCStream_advanced(zc, dict, dictSize, params, pledgedSrcSize) );
-        }   }
+
+            if (FUZ_rand(&lseed)&1) {   /* simple init */
+                int const compressionLevel = (FUZ_rand(&lseed) % 5) + 1;
+                DISPLAYLEVEL(5, "Init with compression level = %i \n", compressionLevel);
+                CHECK_Z( ZSTDMT_initCStream(zc, compressionLevel) );
+            } else {   /* advanced init */
+                /* random dictionary selection */
+                dictSize  = ((FUZ_rand(&lseed)&63)==1) ? FUZ_rLogLength(&lseed, dictLog) : 0;
+                {   size_t const dictStart = FUZ_rand(&lseed) % (srcBufferSize - dictSize);
+                    dict = srcBuffer + dictStart;
+                }
+                {   U64 const pledgedSrcSize = (FUZ_rand(&lseed) & 3) ? ZSTD_CONTENTSIZE_UNKNOWN : maxTestSize;
+                    ZSTD_parameters params = ZSTD_getParams(cLevel, pledgedSrcSize, dictSize);
+                    DISPLAYLEVEL(5, "Init with windowLog = %u, pledgedSrcSize = %u, dictSize = %u \n",
+                        params.cParams.windowLog, (U32)pledgedSrcSize, (U32)dictSize);
+                    params.fParams.checksumFlag = FUZ_rand(&lseed) & 1;
+                    params.fParams.noDictIDFlag = FUZ_rand(&lseed) & 1;
+                    params.fParams.contentSizeFlag = FUZ_rand(&lseed) & 1;
+                    DISPLAYLEVEL(5, "checksumFlag : %u \n", params.fParams.checksumFlag);
+                    CHECK_Z( ZSTDMT_setMTCtxParameter(zc, ZSTDMT_p_overlapSectionLog, FUZ_rand(&lseed) % 12) );
+                    CHECK_Z( ZSTDMT_setMTCtxParameter(zc, ZSTDMT_p_jobSize, FUZ_rand(&lseed) % (2*maxTestSize+1)) );   /* custome job size */
+                    CHECK_Z( ZSTDMT_initCStream_advanced(zc, dict, dictSize, params, pledgedSrcSize) );
+        }   }   }
 
         /* multi-segments compression test */
         XXH64_reset(&xxhState, 0);
@@ -1301,9 +1375,12 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
                 if ((FUZ_rand(&lseed) & 15) == 0) {
                     size_t const randomDstSize = FUZ_randomLength(&lseed, maxSampleLog);
                     size_t const adjustedDstSize = MIN(cBufferSize - cSize, randomDstSize);
+                    size_t const previousPos = outBuff.pos;
                     outBuff.size = outBuff.pos + adjustedDstSize;
                     DISPLAYLEVEL(5, "Flushing into dst buffer of size %u \n", (U32)adjustedDstSize);
                     CHECK_Z( ZSTDMT_flushStream(zc, &outBuff) );
+                    assert(outBuff.pos >= previousPos);
+                    DISPLAYLEVEL(6, "%u bytes flushed by ZSTDMT_flushStream \n", (U32)(outBuff.pos-previousPos));
             }   }
 
             /* final frame epilogue */
@@ -1311,18 +1388,24 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
                 while (remainingToFlush) {
                     size_t const randomDstSize = FUZ_randomLength(&lseed, maxSampleLog);
                     size_t const adjustedDstSize = MIN(cBufferSize - cSize, randomDstSize);
+                    size_t const previousPos = outBuff.pos;
                     outBuff.size = outBuff.pos + adjustedDstSize;
                     DISPLAYLEVEL(5, "Ending into dst buffer of size %u \n", (U32)adjustedDstSize);
                     remainingToFlush = ZSTDMT_endStream(zc, &outBuff);
                     CHECK (ZSTD_isError(remainingToFlush), "ZSTDMT_endStream error : %s", ZSTD_getErrorName(remainingToFlush));
+                    assert(outBuff.pos >= previousPos);
+                    DISPLAYLEVEL(6, "%u bytes flushed by ZSTDMT_endStream \n", (U32)(outBuff.pos-previousPos));
                     DISPLAYLEVEL(5, "endStream : remainingToFlush : %u \n", (U32)remainingToFlush);
             }   }
             crcOrig = XXH64_digest(&xxhState);
             cSize = outBuff.pos;
-            DISPLAYLEVEL(5, "Frame completed : %u bytes \n", (U32)cSize);
+            DISPLAYLEVEL(5, "Frame completed : %u bytes compressed into %u bytes \n",
+                            (U32)totalTestSize, (U32)cSize);
         }
 
         /* multi - fragments decompression test */
+        assert(totalTestSize < dstBufferSize);
+        memset(dstBuffer, 170, totalTestSize);   /* init dest area */
         if (!dictSize /* don't reset if dictionary : could be different */ && (FUZ_rand(&lseed) & 1)) {
             CHECK_Z( ZSTD_resetDStream(zd) );
         } else {
@@ -1337,10 +1420,16 @@ static int fuzzerTests_MT(U32 seed, U32 nbTests, unsigned startTest, double comp
                 size_t const dstBuffSize = MIN(dstBufferSize - totalGenSize, randomDstSize);
                 inBuff.size = inBuff.pos + readCSrcSize;
                 outBuff.size = outBuff.pos + dstBuffSize;
-                DISPLAYLEVEL(6, "ZSTD_decompressStream input %u bytes \n", (U32)readCSrcSize);
+                DISPLAYLEVEL(6, "ZSTD_decompressStream input %u bytes into outBuff %u bytes \n",
+                                (U32)readCSrcSize, (U32)dstBuffSize);
                 decompressionResult = ZSTD_decompressStream(zd, &outBuff, &inBuff);
+                if (ZSTD_isError(decompressionResult)) {
+                    DISPLAY("ZSTD_decompressStream error : %s \n", ZSTD_getErrorName(decompressionResult));
+                    findDiff(copyBuffer, dstBuffer, totalTestSize);
+                }
                 CHECK (ZSTD_isError(decompressionResult), "decompression error : %s", ZSTD_getErrorName(decompressionResult));
-                DISPLAYLEVEL(6, "inBuff.pos = %u \n", (U32)readCSrcSize);
+                DISPLAYLEVEL(6, "total ingested (inBuff.pos) = %u and produced (outBuff.pos) = %u \n",
+                                (U32)inBuff.pos, (U32)outBuff.pos);
             }
             CHECK (outBuff.pos != totalTestSize, "decompressed data : wrong size (%u != %u)", (U32)outBuff.pos, (U32)totalTestSize);
             CHECK (inBuff.pos != cSize, "compressed data should be fully read (%u != %u)", (U32)inBuff.pos, (U32)cSize);
@@ -1579,7 +1668,11 @@ static int fuzzerTests_newAPI(U32 seed, U32 nbTests, unsigned startTest, double
                 }
 
                 /* mess with frame parameters */
-                if (FUZ_rand(&lseed) & 1) CHECK_Z( setCCtxParameter(zc, cctxParams, ZSTD_p_checksumFlag, FUZ_rand(&lseed) & 1, useOpaqueAPI) );
+                if (FUZ_rand(&lseed) & 1) {
+                    U32 const checksumFlag = FUZ_rand(&lseed) & 1;
+                    DISPLAYLEVEL(5, "t%u: frame checksum : %u \n", testNb, checksumFlag);
+                    CHECK_Z( setCCtxParameter(zc, cctxParams, ZSTD_p_checksumFlag, checksumFlag, useOpaqueAPI) );
+                }
                 if (FUZ_rand(&lseed) & 1) CHECK_Z( setCCtxParameter(zc, cctxParams, ZSTD_p_dictIDFlag, FUZ_rand(&lseed) & 1, useOpaqueAPI) );
                 if (FUZ_rand(&lseed) & 1) CHECK_Z( setCCtxParameter(zc, cctxParams, ZSTD_p_contentSizeFlag, FUZ_rand(&lseed) & 1, useOpaqueAPI) );
                 if (FUZ_rand(&lseed) & 1) {
@@ -1592,7 +1685,7 @@ static int fuzzerTests_newAPI(U32 seed, U32 nbTests, unsigned startTest, double
                     U32 const nbThreadsAdjusted = (windowLogMalus < nbThreadsCandidate) ? nbThreadsCandidate - windowLogMalus : 1;
                     U32 const nbThreads = MIN(nbThreadsAdjusted, nbThreadsMax);
                     DISPLAYLEVEL(5, "t%u: nbThreads : %u \n", testNb, nbThreads);
-                    CHECK_Z( setCCtxParameter(zc, cctxParams, ZSTD_p_nbThreads, nbThreads, useOpaqueAPI) );
+                    CHECK_Z( setCCtxParameter(zc, cctxParams, ZSTD_p_nbWorkers, nbThreads, useOpaqueAPI) );
                     if (nbThreads > 1) {
                         U32 const jobLog = FUZ_rand(&lseed) % (testLog+1);
                         CHECK_Z( setCCtxParameter(zc, cctxParams, ZSTD_p_overlapSizeLog, FUZ_rand(&lseed) % 10, useOpaqueAPI) );
@@ -1644,8 +1737,8 @@ static int fuzzerTests_newAPI(U32 seed, U32 nbTests, unsigned startTest, double
                 outBuff.size = outBuff.pos + dstBuffSize;
 
                 CHECK_Z( ZSTD_compress_generic(zc, &outBuff, &inBuff, flush) );
-                DISPLAYLEVEL(6, "t%u: compress consumed %u bytes (total : %u) \n",
-                    testNb, (U32)inBuff.pos, (U32)(totalTestSize + inBuff.pos));
+                DISPLAYLEVEL(6, "t%u: compress consumed %u bytes (total : %u) ; flush: %u (total : %u) \n",
+                    testNb, (U32)inBuff.pos, (U32)(totalTestSize + inBuff.pos), (U32)flush, (U32)outBuff.pos);
 
                 XXH64_update(&xxhState, srcBuffer+srcStart, inBuff.pos);
                 memcpy(copyBuffer+totalTestSize, srcBuffer+srcStart, inBuff.pos);
@@ -1653,14 +1746,15 @@ static int fuzzerTests_newAPI(U32 seed, U32 nbTests, unsigned startTest, double
             }
 
             /* final frame epilogue */
-            {   size_t remainingToFlush = (size_t)(-1);
+            {   size_t remainingToFlush = 1;
                 while (remainingToFlush) {
                     ZSTD_inBuffer inBuff = { NULL, 0, 0 };
                     size_t const randomDstSize = FUZ_randomLength(&lseed, maxSampleLog+1);
                     size_t const adjustedDstSize = MIN(cBufferSize - cSize, randomDstSize);
                     outBuff.size = outBuff.pos + adjustedDstSize;
-                    DISPLAYLEVEL(6, "End-flush into dst buffer of size %u \n", (U32)adjustedDstSize);
+                    DISPLAYLEVEL(6, "t%u: End-flush into dst buffer of size %u \n", testNb, (U32)adjustedDstSize);
                     remainingToFlush = ZSTD_compress_generic(zc, &outBuff, &inBuff, ZSTD_e_end);
+                    DISPLAYLEVEL(6, "t%u: Total flushed so far : %u bytes \n", testNb, (U32)outBuff.pos);
                     CHECK( ZSTD_isError(remainingToFlush),
                           "ZSTD_compress_generic w/ ZSTD_e_end error : %s",
                            ZSTD_getErrorName(remainingToFlush) );
@@ -1687,14 +1781,20 @@ static int fuzzerTests_newAPI(U32 seed, U32 nbTests, unsigned startTest, double
                 size_t const dstBuffSize = MIN(dstBufferSize - totalGenSize, randomDstSize);
                 inBuff.size = inBuff.pos + readCSrcSize;
                 outBuff.size = outBuff.pos + dstBuffSize;
-                DISPLAYLEVEL(6, "ZSTD_decompressStream input %u bytes (pos:%u/%u)\n",
-                            (U32)readCSrcSize, (U32)inBuff.pos, (U32)cSize);
+                DISPLAYLEVEL(6, "decompression presented %u new bytes (pos:%u/%u)\n",
+                                (U32)readCSrcSize, (U32)inBuff.pos, (U32)cSize);
                 decompressionResult = ZSTD_decompressStream(zd, &outBuff, &inBuff);
+                DISPLAYLEVEL(6, "so far: consumed = %u, produced = %u \n",
+                                (U32)inBuff.pos, (U32)outBuff.pos);
+                if (ZSTD_isError(decompressionResult)) {
+                    DISPLAY("ZSTD_decompressStream error : %s \n", ZSTD_getErrorName(decompressionResult));
+                    findDiff(copyBuffer, dstBuffer, totalTestSize);
+                }
                 CHECK (ZSTD_isError(decompressionResult), "decompression error : %s", ZSTD_getErrorName(decompressionResult));
-                DISPLAYLEVEL(6, "inBuff.pos = %u \n", (U32)readCSrcSize);
+                CHECK (inBuff.pos > cSize, "ZSTD_decompressStream consumes too much input : %u > %u ", (U32)inBuff.pos, (U32)cSize);
             }
-            CHECK (outBuff.pos != totalTestSize, "decompressed data : wrong size (%u != %u)", (U32)outBuff.pos, (U32)totalTestSize);
             CHECK (inBuff.pos != cSize, "compressed data should be fully read (%u != %u)", (U32)inBuff.pos, (U32)cSize);
+            CHECK (outBuff.pos != totalTestSize, "decompressed data : wrong size (%u != %u)", (U32)outBuff.pos, (U32)totalTestSize);
             {   U64 const crcDest = XXH64(dstBuffer, totalTestSize, 0);
                 if (crcDest!=crcOrig) findDiff(copyBuffer, dstBuffer, totalTestSize);
                 CHECK (crcDest!=crcOrig, "decompressed data corrupted");