Merge branch 'dev' into oss

.gitignore

@@ -31,6 +31,7 @@ projects/
 bin/
 .buckd/
 buck-out/
+build-*
 
 # Other files
 .directory
@@ -43,3 +44,5 @@ _zstdbench/
 googletest/
 *.d
 *.vscode
+compile_commands.json
+.clangd

build/cmake/tests/CMakeLists.txt

@@ -49,6 +49,9 @@ target_link_libraries(fullbench libzstd_static)
 add_executable(fuzzer ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/util.c ${PROGRAMS_DIR}/timefn.c ${TESTS_DIR}/fuzzer.c)
 target_link_libraries(fuzzer libzstd_static)
 
+add_executable(zstreamtest ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/util.c ${PROGRAMS_DIR}/timefn.c ${TESTS_DIR}/seqgen.c ${TESTS_DIR}/zstreamtest.c)
+target_link_libraries(zstreamtest libzstd_static)
+
 if (UNIX)
     add_executable(paramgrill ${PROGRAMS_DIR}/benchfn.c ${PROGRAMS_DIR}/benchzstd.c ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/util.c ${PROGRAMS_DIR}/timefn.c ${TESTS_DIR}/paramgrill.c)
     target_link_libraries(paramgrill libzstd_static m) #m is math library

lib/Makefile

@@ -161,7 +161,7 @@ ifneq (,$(filter Windows%,$(OS)))
 LIBZSTD = dll\libzstd.dll
 $(LIBZSTD): $(ZSTD_FILES)
 	@echo compiling dynamic library $(LIBVER)
-	$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -Wl,--out-implib,dll\libzstd.lib -shared $^ -o $@
+	$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -Wl,--out-implib,dll\libzstd.dll.a -shared $^ -o $@
 
 else
 

lib/compress/zstd_compress.c

@@ -1336,10 +1336,7 @@ ZSTD_reset_matchState(ZSTD_matchState_t* ms,
 
     DEBUGLOG(4, "reset indices : %u", forceResetIndex == ZSTDirp_reset);
     if (forceResetIndex == ZSTDirp_reset) {
-        memset(&ms->window, 0, sizeof(ms->window));
+        ZSTD_window_init(&ms->window);
-        ms->window.dictLimit = 1;    /* start from 1, so that 1st position is valid */
-        ms->window.lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
-        ms->window.nextSrc = ms->window.base + 1;   /* see issue #1241 */
         ZSTD_cwksp_mark_tables_dirty(ws);
     }
 
@@ -1432,7 +1429,7 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
         size_t const matchStateSize = ZSTD_sizeof_matchState(&params.cParams, /* forCCtx */ 1);
         size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(params.ldmParams, blockSize);
 
-        ZSTD_indexResetPolicy_e needsIndexReset = ZSTDirp_continue;
+        ZSTD_indexResetPolicy_e needsIndexReset = zc->initialized ? ZSTDirp_continue : ZSTDirp_reset;
 
         if (ZSTD_indexTooCloseToMax(zc->blockState.matchState.window)) {
             needsIndexReset = ZSTDirp_reset;
@@ -1557,11 +1554,12 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
             zc->ldmSequences = (rawSeq*)ZSTD_cwksp_reserve_aligned(ws, maxNbLdmSeq * sizeof(rawSeq));
             zc->maxNbLdmSequences = maxNbLdmSeq;
 
-            memset(&zc->ldmState.window, 0, sizeof(zc->ldmState.window));
+            ZSTD_window_init(&zc->ldmState.window);
             ZSTD_window_clear(&zc->ldmState.window);
         }
 
         DEBUGLOG(3, "wksp: finished allocating, %zd bytes remain available", ZSTD_cwksp_available_space(ws));
+        zc->initialized = 1;
 
         return 0;
     }
@@ -2593,23 +2591,25 @@ static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
         /* Ensure hash/chain table insertion resumes no sooner than lowlimit */
         if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
 
-        {   int useTargetCBlockSize = ZSTD_useTargetCBlockSize(&cctx->appliedParams);
+        {   size_t cSize;
-            size_t cSize = 0;
+            int useTargetCBlockSize = ZSTD_useTargetCBlockSize(&cctx->appliedParams);
             if (useTargetCBlockSize) {
                 cSize = ZSTD_compressBlock_targetCBlockSize(cctx, op, dstCapacity, ip, blockSize, lastBlock);
                 FORWARD_IF_ERROR(cSize);
             } else {
                 cSize = ZSTD_compressBlock_internal(cctx,
                                         op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize,
-                                        ip, blockSize, 0 /* frame */);
+                                        ip, blockSize, 1 /* frame */);
                 FORWARD_IF_ERROR(cSize);
 
                 if (cSize == 0) {  /* block is not compressible */
                     cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
                     FORWARD_IF_ERROR(cSize);
                 } else {
-                    U32 const cBlockHeader24 = lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
+                    U32 const cBlockHeader = cSize == 1 ?
-                    MEM_writeLE24(op, cBlockHeader24);
+                        lastBlock + (((U32)bt_rle)<<1) + (U32)(blockSize << 3) :
+                        lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
+                    MEM_writeLE24(op, cBlockHeader);
                     cSize += ZSTD_blockHeaderSize;
                 }
             }
@@ -3767,11 +3767,11 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                           ZSTD_EndDirective const flushMode)
 {
     const char* const istart = (const char*)input->src;
-    const char* const iend = istart + input->size;
+    const char* const iend = input->size != 0 ? istart + input->size : istart;
-    const char* ip = istart + input->pos;
+    const char* ip = input->pos != 0 ? istart + input->pos : istart;
     char* const ostart = (char*)output->dst;
-    char* const oend = ostart + output->size;
+    char* const oend = output->size != 0 ? ostart + output->size : ostart;
-    char* op = ostart + output->pos;
+    char* op = output->pos != 0 ? ostart + output->pos : ostart;
     U32 someMoreWork = 1;
 
     /* check expectations */
@@ -3810,7 +3810,8 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                         zcs->inBuff + zcs->inBuffPos, toLoad,
                                         ip, iend-ip);
                 zcs->inBuffPos += loaded;
-                ip += loaded;
+                if (loaded != 0)
+                    ip += loaded;
                 if ( (flushMode == ZSTD_e_continue)
                   && (zcs->inBuffPos < zcs->inBuffTarget) ) {
                     /* not enough input to fill full block : stop here */
@@ -3870,7 +3871,8 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                             zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
                 DEBUGLOG(5, "toFlush: %u into %u ==> flushed: %u",
                             (unsigned)toFlush, (unsigned)(oend-op), (unsigned)flushed);
-                op += flushed;
+                if (flushed)
+                    op += flushed;
                 zcs->outBuffFlushedSize += flushed;
                 if (toFlush!=flushed) {
                     /* flush not fully completed, presumably because dst is too small */

lib/compress/zstd_compress_internal.h

@@ -249,6 +249,7 @@ struct ZSTD_CCtx_s {
     size_t staticSize;
     SeqCollector seqCollector;
     int isFirstBlock;
+    int initialized;
 
     seqStore_t seqStore;      /* sequences storage ptrs */
     ldmState_t ldmState;      /* long distance matching state */
@@ -858,6 +859,15 @@ ZSTD_checkDictValidity(const ZSTD_window_t* window,
     }   }   }
 }
 
+MEM_STATIC void ZSTD_window_init(ZSTD_window_t* window) {
+    memset(window, 0, sizeof(*window));
+    window->base = (BYTE const*)"";
+    window->dictBase = (BYTE const*)"";
+    window->dictLimit = 1;    /* start from 1, so that 1st position is valid */
+    window->lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
+    window->nextSrc = window->base + 1;   /* see issue #1241 */
+}
+
 /**
  * ZSTD_window_update():
  * Updates the window by appending [src, src + srcSize) to the window.
@@ -871,6 +881,10 @@ MEM_STATIC U32 ZSTD_window_update(ZSTD_window_t* window,
     BYTE const* const ip = (BYTE const*)src;
     U32 contiguous = 1;
     DEBUGLOG(5, "ZSTD_window_update");
+    if (srcSize == 0)
+        return contiguous;
+    assert(window->base != NULL);
+    assert(window->dictBase != NULL);
     /* Check if blocks follow each other */
     if (src != window->nextSrc) {
         /* not contiguous */

lib/compress/zstd_double_fast.c

@@ -96,7 +96,7 @@ size_t ZSTD_compressBlock_doubleFast_generic(
                                      dictCParams->hashLog : hBitsL;
     const U32 dictHBitsS           = dictMode == ZSTD_dictMatchState ?
                                      dictCParams->chainLog : hBitsS;
-    const U32 dictAndPrefixLength  = (U32)(ip - prefixLowest + dictEnd - dictStart);
+    const U32 dictAndPrefixLength  = (U32)((ip - prefixLowest) + (dictEnd - dictStart));
 
     DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_generic");
 
@@ -271,7 +271,7 @@ _match_stored:
                     U32 const repIndex2 = current2 - offset_2;
                     const BYTE* repMatch2 = dictMode == ZSTD_dictMatchState
                         && repIndex2 < prefixLowestIndex ?
-                            dictBase - dictIndexDelta + repIndex2 :
+                            dictBase + repIndex2 - dictIndexDelta :
                             base + repIndex2;
                     if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
                        && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {

lib/compress/zstd_lazy.c

@@ -660,7 +660,7 @@ ZSTD_compressBlock_lazy_generic(
     const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
                                      prefixLowestIndex - (U32)(dictEnd - dictBase) :
                                      0;
-    const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
+    const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictLowest));
 
     /* init */
     ip += (dictAndPrefixLength == 0);

lib/compress/zstdmt_compress.c

@@ -490,7 +490,7 @@ static int ZSTDMT_serialState_reset(serialState_t* serialState, ZSTDMT_seqPool*
         /* Size the seq pool tables */
         ZSTDMT_setNbSeq(seqPool, ZSTD_ldm_getMaxNbSeq(params.ldmParams, jobSize));
         /* Reset the window */
-        ZSTD_window_clear(&serialState->ldmState.window);
+        ZSTD_window_init(&serialState->ldmState.window);
         serialState->ldmWindow = serialState->ldmState.window;
         /* Resize tables and output space if necessary. */
         if (serialState->ldmState.hashTable == NULL || serialState->params.ldmParams.hashLog < hashLog) {
@@ -1786,7 +1786,7 @@ static int ZSTDMT_isOverlapped(buffer_t buffer, range_t range)
     BYTE const* const bufferStart = (BYTE const*)buffer.start;
     BYTE const* const bufferEnd = bufferStart + buffer.capacity;
     BYTE const* const rangeStart = (BYTE const*)range.start;
-    BYTE const* const rangeEnd = rangeStart + range.size;
+    BYTE const* const rangeEnd = range.size != 0 ? rangeStart + range.size : rangeStart;
 
     if (rangeStart == NULL || bufferStart == NULL)
         return 0;

lib/decompress/huf_decompress.c

@@ -181,17 +181,29 @@ size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize
 
     /* fill DTable */
     {   U32 n;
-        for (n=0; n<nbSymbols; n++) {
+        size_t const nEnd = nbSymbols;
-            U32 const w = huffWeight[n];
+        for (n=0; n<nEnd; n++) {
-            U32 const length = (1 << w) >> 1;
+            size_t const w = huffWeight[n];
-            U32 u;
+            size_t const length = (1 << w) >> 1;
+            size_t const uStart = rankVal[w];
+            size_t const uEnd = uStart + length;
+            size_t u;
             HUF_DEltX1 D;
-            D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
+            D.byte = (BYTE)n;
-            for (u = rankVal[w]; u < rankVal[w] + length; u++)
+            D.nbBits = (BYTE)(tableLog + 1 - w);
-                dt[u] = D;
+            rankVal[w] = (U32)uEnd;
-            rankVal[w] += length;
+            if (length < 4) {
-    }   }
+                /* Use length in the loop bound so the compiler knows it is short. */
-
+                for (u = 0; u < length; ++u)
+                    dt[uStart + u] = D;
+            } else {
+                /* Unroll the loop 4 times, we know it is a power of 2. */
+                for (u = uStart; u < uEnd; u += 4) {
+                    dt[u + 0] = D;
+                    dt[u + 1] = D;
+                    dt[u + 2] = D;
+                    dt[u + 3] = D;
+    }   }   }   }
     return iSize;
 }
 

lib/decompress/zstd_decompress.c

@@ -618,7 +618,7 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
 {
     const BYTE* ip = (const BYTE*)(*srcPtr);
     BYTE* const ostart = (BYTE* const)dst;
-    BYTE* const oend = ostart + dstCapacity;
+    BYTE* const oend = dstCapacity != 0 ? ostart + dstCapacity : ostart;
     BYTE* op = ostart;
     size_t remainingSrcSize = *srcSizePtr;
 
@@ -669,7 +669,9 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
         if (ZSTD_isError(decodedSize)) return decodedSize;
         if (dctx->fParams.checksumFlag)
             XXH64_update(&dctx->xxhState, op, decodedSize);
-        op += decodedSize;
+        if (decodedSize != 0)
+            op += decodedSize;
+        assert(ip != NULL);
         ip += cBlockSize;
         remainingSrcSize -= cBlockSize;
         if (blockProperties.lastBlock) break;
@@ -776,7 +778,8 @@ static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
                 "error.");
             if (ZSTD_isError(res)) return res;
             assert(res <= dstCapacity);
-            dst = (BYTE*)dst + res;
+            if (res != 0)
+                dst = (BYTE*)dst + res;
             dstCapacity -= res;
         }
         moreThan1Frame = 1;
@@ -1486,11 +1489,13 @@ MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src,
 
 size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
-    const char* const istart = (const char*)(input->src) + input->pos;
+    const char* const src = (const char*)input->src;
-    const char* const iend = (const char*)(input->src) + input->size;
+    const char* const istart = input->pos != 0 ? src + input->pos : src;
+    const char* const iend = input->size != 0 ? src + input->size : src;
     const char* ip = istart;
-    char* const ostart = (char*)(output->dst) + output->pos;
+    char* const dst = (char*)output->dst;
-    char* const oend = (char*)(output->dst) + output->size;
+    char* const ostart = output->pos != 0 ? dst + output->pos : dst;
+    char* const oend = output->size != 0 ? dst + output->size : dst;
     char* op = ostart;
     U32 someMoreWork = 1;
 

lib/zstd.h

@@ -763,7 +763,7 @@ ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);
 
 /* This function is redundant with the advanced API and equivalent to:
  *
- *     ZSTD_DCtx_reset(zds);
+ *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
  *     ZSTD_DCtx_refDDict(zds, NULL);
  */
 ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds);

programs/util.c

@@ -73,7 +73,7 @@ int UTIL_setFileStat(const char *filename, stat_t *statbuf)
     {
         /* (atime, mtime) */
         struct timespec timebuf[2] = { {0, UTIME_NOW} };
-        timebuf[1] = statbuf->st_mtim;
+        timebuf[1].tv_sec = statbuf->st_mtime;
         res += utimensat(AT_FDCWD, filename, timebuf, 0);
     }
 #endif

programs/zstd.1.md

@@ -402,7 +402,7 @@ The list of available _options_:
     Bigger hash tables cause less collisions which usually makes compression
     faster, but requires more memory during compression.
 
-    The minimum _hlog_ is 6 (64 B) and the maximum is 26 (128 MiB).
+    The minimum _hlog_ is 6 (64 B) and the maximum is 30 (1 GiB).
 
 - `chainLog`=_clog_, `clog`=_clog_:
     Specify the maximum number of bits for a hash chain or a binary tree.
@@ -413,7 +413,8 @@ The list of available _options_:
     compression.
     This option is ignored for the ZSTD_fast strategy.
 
-    The minimum _clog_ is 6 (64 B) and the maximum is 28 (256 MiB).
+    The minimum _clog_ is 6 (64 B) and the maximum is 29 (524 Mib) on 32-bit platforms
+    and 30 (1 Gib) on 64-bit platforms.
 
 - `searchLog`=_slog_, `slog`=_slog_:
     Specify the maximum number of searches in a hash chain or a binary tree
@@ -422,7 +423,7 @@ The list of available _options_:
     More searches increases the chance to find a match which usually increases
     compression ratio but decreases compression speed.
 
-    The minimum _slog_ is 1 and the maximum is 26.
+    The minimum _slog_ is 1 and the maximum is 'windowLog' - 1.
 
 - `minMatch`=_mml_, `mml`=_mml_:
     Specify the minimum searched length of a match in a hash table.
@@ -447,7 +448,7 @@ The list of available _options_:
 
     For all other strategies, this field has no impact.
 
-    The minimum _tlen_ is 0 and the maximum is 999.
+    The minimum _tlen_ is 0 and the maximum is 128 Kib.
 
 - `overlapLog`=_ovlog_,  `ovlog`=_ovlog_:
     Determine `overlapSize`, amount of data reloaded from previous job.
@@ -470,7 +471,7 @@ The list of available _options_:
     Bigger hash tables usually improve compression ratio at the expense of more
     memory during compression and a decrease in compression speed.
 
-    The minimum _lhlog_ is 6 and the maximum is 26 (default: 20).
+    The minimum _lhlog_ is 6 and the maximum is 30 (default: 20).
 
 - `ldmMinMatch`=_lmml_, `lmml`=_lmml_:
     Specify the minimum searched length of a match for long distance matching.
@@ -490,7 +491,7 @@ The list of available _options_:
     Larger bucket sizes improve collision resolution but decrease compression
     speed.
 
-    The minimum _lblog_ is 0 and the maximum is 8 (default: 3).
+    The minimum _lblog_ is 1 and the maximum is 8 (default: 3).
 
 - `ldmHashRateLog`=_lhrlog_, `lhrlog`=_lhrlog_:
     Specify the frequency of inserting entries into the long distance matching

tests/fuzz/.gitignore

@@ -2,7 +2,13 @@
 corpora
 block_decompress
 block_round_trip
+dictionary_decompress
+dictionary_loader
+dictionary_round_trip
+simple_compress
 simple_decompress
 simple_round_trip
 stream_decompress
 stream_round_trip
+zstd_frame_info
+fuzz-*.log

tests/fuzzer.c

@@ -502,6 +502,19 @@ static int basicUnitTests(U32 const seed, double compressibility)
     }
     DISPLAYLEVEL(3, "OK \n");
   
+    DISPLAYLEVEL(3, "test%3i : compress a NULL input with each level : ", testNb++);
+    {   int level = -1;
+        ZSTD_CCtx* cctx = ZSTD_createCCtx();
+        if (!cctx) goto _output_error;
+        for (level = -1; level <= ZSTD_maxCLevel(); ++level) {
+          CHECK_Z( ZSTD_compress(compressedBuffer, compressedBufferSize, NULL, 0, level) );
+          CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, level) );
+          CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, NULL, 0) );
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
     DISPLAYLEVEL(3, "test%3d : check CCtx size after compressing empty input : ", testNb++);
     {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
         size_t const r = ZSTD_compressCCtx(cctx, compressedBuffer, compressedBufferSize, NULL, 0, 19);
@@ -2057,14 +2070,14 @@ static int basicUnitTests(U32 const seed, double compressibility)
 
     /* long rle test */
     {   size_t sampleSize = 0;
+        size_t expectedCompressedSize = 39; /* block 1, 2: compressed, block 3: RLE, zstd 1.4.4 */
         DISPLAYLEVEL(3, "test%3i : Long RLE test : ", testNb++);
-        RDG_genBuffer(CNBuffer, sampleSize, compressibility, 0., seed+1);
         memset((char*)CNBuffer+sampleSize, 'B', 256 KB - 1);
         sampleSize += 256 KB - 1;
-        RDG_genBuffer((char*)CNBuffer+sampleSize, 96 KB, compressibility, 0., seed+2);
+        memset((char*)CNBuffer+sampleSize, 'A', 96 KB);
         sampleSize += 96 KB;
         cSize = ZSTD_compress(compressedBuffer, ZSTD_compressBound(sampleSize), CNBuffer, sampleSize, 1);
-        if (ZSTD_isError(cSize)) goto _output_error;
+        if (ZSTD_isError(cSize) || cSize > expectedCompressedSize) goto _output_error;
         { CHECK_NEWV(regenSize, ZSTD_decompress(decodedBuffer, sampleSize, compressedBuffer, cSize));
           if (regenSize!=sampleSize) goto _output_error; }
         DISPLAYLEVEL(3, "OK \n");

tests/zstreamtest.c

@@ -509,6 +509,33 @@ static int basicUnitTests(U32 seed, double compressibility)
     }
     DISPLAYLEVEL(3, "OK \n");
 
+    DISPLAYLEVEL(3, "test%3i : NULL buffers : ", testNb++);
+    inBuff.src = NULL;
+    inBuff.size = 0;
+    inBuff.pos = 0;
+    outBuff.dst = NULL;
+    outBuff.size = 0;
+    outBuff.pos = 0;
+    CHECK_Z( ZSTD_compressStream(zc, &outBuff, &inBuff) );
+    CHECK(inBuff.pos != inBuff.size, "Entire input should be consumed");
+    CHECK_Z( ZSTD_endStream(zc, &outBuff) );
+    outBuff.dst = (char*)(compressedBuffer);
+    outBuff.size = compressedBufferSize;
+    outBuff.pos = 0;
+    {   size_t const r = ZSTD_endStream(zc, &outBuff);
+        CHECK(r != 0, "Error or some data not flushed (ret=%zu)", r);
+    }
+    inBuff.src = outBuff.dst;
+    inBuff.size = outBuff.pos;
+    inBuff.pos = 0;
+    outBuff.dst = NULL;
+    outBuff.size = 0;
+    outBuff.pos = 0;
+    CHECK_Z( ZSTD_initDStream(zd) );
+    {   size_t const ret = ZSTD_decompressStream(zd, &outBuff, &inBuff);
+        if (ret != 0) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK\n");
     /* _srcSize compression test */
     DISPLAYLEVEL(3, "test%3i : compress_srcSize %u bytes : ", testNb++, COMPRESSIBLE_NOISE_LENGTH);
     CHECK_Z( ZSTD_initCStream_srcSize(zc, 1, CNBufferSize) );