Merge pull request #2586 from senhuang42/dds_fuzz

Add DDS to oss fuzzer

lib/compress/zstd_compress.c

@@ -3365,7 +3365,7 @@ static U32 ZSTD_resolveRepcodeToRawOffset(const U32 rep[ZSTD_REP_NUM], const U32
  * ZSTD_seqStore_resolveOffCodes() reconciles any possible divergences in offset history that may arise
  * due to emission of RLE/raw blocks that disturb the offset history, and replaces any repcodes within
  * the seqStore that may be invalid.
- * 
+ *
  * dRepcodes are updated as would be on the decompression side. cRepcodes are updated exactly in
  * accordance with the seqStore.
  */
@@ -3555,14 +3555,14 @@ static size_t ZSTD_compressBlock_splitBlock_internal(ZSTD_CCtx* zc, void* dst, s
      * may become invalid. In order to reconcile potentially invalid repcodes, we keep track of two
      * separate repcode histories that simulate repcode history on compression and decompression side,
      * and use the histories to determine whether we must replace a particular repcode with its raw offset.
-     * 
+     *
      * 1) cRep gets updated for each partition, regardless of whether the block was emitted as uncompressed
      *    or RLE. This allows us to retrieve the offset value that an invalid repcode references within
      *    a nocompress/RLE block.
      * 2) dRep gets updated only for compressed partitions, and when a repcode gets replaced, will use
      *    the replacement offset value rather than the original repcode to update the repcode history.
      *    dRep also will be the final repcode history sent to the next block.
-     * 
+     *
      * See ZSTD_seqStore_resolveOffCodes() for more details.
      */
     repcodes_t dRep;
@@ -6192,7 +6192,7 @@ static int ZSTD_dedicatedDictSearch_isSupported(
 {
     return (cParams->strategy >= ZSTD_greedy)
         && (cParams->strategy <= ZSTD_lazy2)
-        && (cParams->hashLog >= cParams->chainLog)
+        && (cParams->hashLog > cParams->chainLog)
         && (cParams->chainLog <= 24);
 }
 
@@ -6211,6 +6211,9 @@ static void ZSTD_dedicatedDictSearch_revertCParams(
         case ZSTD_lazy:
         case ZSTD_lazy2:
             cParams->hashLog -= ZSTD_LAZY_DDSS_BUCKET_LOG;
+            if (cParams->hashLog < ZSTD_HASHLOG_MIN) {
+                cParams->hashLog = ZSTD_HASHLOG_MIN;
+            }
             break;
         case ZSTD_btlazy2:
         case ZSTD_btopt:

lib/compress/zstd_lazy.c

@@ -469,7 +469,7 @@ void ZSTD_dedicatedDictSearch_lazy_loadDictionary(ZSTD_matchState_t* ms, const B
     U32 hashIdx;
 
     assert(ms->cParams.chainLog <= 24);
-    assert(ms->cParams.hashLog >= ms->cParams.chainLog);
+    assert(ms->cParams.hashLog > ms->cParams.chainLog);
     assert(idx != 0);
     assert(tmpMinChain <= minChain);
 
@@ -500,7 +500,7 @@ void ZSTD_dedicatedDictSearch_lazy_loadDictionary(ZSTD_matchState_t* ms, const B
             if (count == cacheSize) {
                 for (count = 0; count < chainLimit;) {
                     if (i < minChain) {
-                        if (!i || countBeyondMinChain++ > cacheSize) {
+                        if (!i || ++countBeyondMinChain > cacheSize) {
                             /* only allow pulling `cacheSize` number of entries
                              * into the cache or chainTable beyond `minChain`,
                              * to replace the entries pulled out of the

tests/fuzz/zstd_helpers.c

@@ -92,6 +92,7 @@ void FUZZ_setRandomParameters(ZSTD_CCtx *cctx, size_t srcSize, FUZZ_dataProducer
     setRand(cctx, ZSTD_c_nbWorkers, 0, 2, producer);
     setRand(cctx, ZSTD_c_rsyncable, 0, 1, producer);
     setRand(cctx, ZSTD_c_useRowMatchFinder, 0, 2, producer);
+    setRand(cctx, ZSTD_c_enableDedicatedDictSearch, 0, 1, producer);
     setRand(cctx, ZSTD_c_forceMaxWindow, 0, 1, producer);
     setRand(cctx, ZSTD_c_literalCompressionMode, 0, 2, producer);
     setRand(cctx, ZSTD_c_forceAttachDict, 0, 2, producer);