Adding information about dirty context for _HC_ family of functions

3 files changed, 58 insertions, 22 deletions

diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 714ab62..d4180e3 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -744,16 +744,22 @@ LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal (
     cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel);
     {   cParams_t const cParam = clTable[cLevel];
         HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio;
-        if (cParam.strat == lz4hc)
-            return LZ4HC_compress_hashChain(ctx,
+        int result;
+
+        if (cParam.strat == lz4hc) {
+            result = LZ4HC_compress_hashChain(ctx,
                                 src, dst, srcSizePtr, dstCapacity,
                                 cParam.nbSearches, limit, dict);
-        assert(cParam.strat == lz4opt);
-        return LZ4HC_compress_optimal(ctx,
-                            src, dst, srcSizePtr, dstCapacity,
-                            cParam.nbSearches, cParam.targetLength, limit,
-                            cLevel == LZ4HC_CLEVEL_MAX,   /* ultra mode */
-                            dict, favor);
+        } else {
+            assert(cParam.strat == lz4opt);
+            result = LZ4HC_compress_optimal(ctx,
+                                src, dst, srcSizePtr, dstCapacity,
+                                cParam.nbSearches, cParam.targetLength, limit,
+                                cLevel == LZ4HC_CLEVEL_MAX,   /* ultra mode */
+                                dict, favor);
+        }
+        if (result <= 0) ctx->dirty = 1;
+        return result;
     }
 }
 
@@ -892,16 +898,21 @@ void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
     LZ4_streamHCPtr->internal_donotuse.base = NULL;
     LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
     LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0;
+    LZ4_streamHCPtr->internal_donotuse.dirty = 0;
     LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
 }
 
 void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
 {
     DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel);
-    LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base;
-    LZ4_streamHCPtr->internal_donotuse.base = NULL;
-    LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
-    LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
+    if (LZ4_streamHCPtr->internal_donotuse.dirty) {
+        LZ4_resetStreamHC(LZ4_streamHCPtr, compressionLevel);
+    } else {
+        LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base;
+        LZ4_streamHCPtr->internal_donotuse.base = NULL;
+        LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
+        LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
+    }
 }
 
 void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
diff --git a/lib/lz4hc.h b/lib/lz4hc.h
index 4c7ba5a..26919af 100644
--- a/lib/lz4hc.h
+++ b/lib/lz4hc.h
@@ -161,7 +161,9 @@ struct LZ4HC_CCtx_internal
     uint32_t   lowLimit;        /* below that point, no more dict */
     uint32_t   nextToUpdate;    /* index from which to continue dictionary update */
     short      compressionLevel;
-    short      favorDecSpeed;
+    int8_t     favorDecSpeed;   /* favor decompression speed if this flag set,
+                                   otherwise, favor compression ratio */
+    int8_t     dirty;           /* stream has to be fully reset if this flag is set */
     const LZ4HC_CCtx_internal* dictCtx;
 };
 
@@ -179,7 +181,9 @@ struct LZ4HC_CCtx_internal
     unsigned int   lowLimit;         /* below that point, no more dict */
     unsigned int   nextToUpdate;     /* index from which to continue dictionary update */
     short          compressionLevel;
-    short          favorDecSpeed;
+    char           favorDecSpeed;    /* favor decompression speed if this flag set,
+                                        otherwise, favor compression ratio */
+    char           dirty;            /* stream has to be fully reset if this flag is set */
     const LZ4HC_CCtx_internal* dictCtx;
 };
 
@@ -314,6 +318,11 @@ void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor);
  *  - the stream was in an indeterminate state and was used in a compression
  *    call that fully reset the state (LZ4_compress_HC_extStateHC()) and that
  *    returned success
+ *
+ *  Note:
+ *  A stream that was last used in a compression call that returned an error
+ *  may be passed to this function. However, it will be fully reset, which will
+ *  clear any existing history and settings from the context.
  */
 void LZ4_resetStreamHC_fast(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
 
diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index 95cb092..1d23e1a 100644
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -832,17 +832,20 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
         LZ4_setCompressionLevel(&LZ4dictHC, compressionLevel-1);
         blockContinueCompressedSize = LZ4_compress_HC_continue(&LZ4dictHC, block, compressedBuffer, blockSize, (int)compressedBufferSize);
         FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compress_HC_continue failed");
+        FUZ_CHECKTEST(LZ4dictHC.internal_donotuse.dirty, "Context should be clean");
 
         FUZ_DISPLAYTEST();
         LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
         ret = LZ4_compress_HC_continue(&LZ4dictHC, block, compressedBuffer, blockSize, blockContinueCompressedSize-1);
         FUZ_CHECKTEST(ret>0, "LZ4_compress_HC_continue using ExtDict should fail : one missing byte for output buffer (%i != %i)", ret, blockContinueCompressedSize);
+        FUZ_CHECKTEST(!LZ4dictHC.internal_donotuse.dirty, "Context should be dirty");
 
         FUZ_DISPLAYTEST();
         LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
         ret = LZ4_compress_HC_continue(&LZ4dictHC, block, compressedBuffer, blockSize, blockContinueCompressedSize);
         FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_compress_HC_continue size is different (%i != %i)", ret, blockContinueCompressedSize);
         FUZ_CHECKTEST(ret<=0, "LZ4_compress_HC_continue should work : enough size available within output buffer");
+        FUZ_CHECKTEST(LZ4dictHC.internal_donotuse.dirty, "Context should be clean");
 
         FUZ_DISPLAYTEST();
         decodedBuffer[blockSize] = 0;
@@ -865,19 +868,22 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
             LZ4_attach_HC_dictionary(&LZ4_streamHC, &LZ4dictHC);
             blockContinueCompressedSize = LZ4_compress_HC_continue(&LZ4_streamHC, block, compressedBuffer, blockSize, (int)compressedBufferSize);
             FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compress_HC_continue with ExtDictCtx failed");
+            FUZ_CHECKTEST(LZ4_streamHC.internal_donotuse.dirty, "Context should be clean");
 
             FUZ_DISPLAYTEST();
-            LZ4_resetStreamHC (&LZ4_streamHC, compressionLevel);
+            LZ4_resetStreamHC_fast (&LZ4_streamHC, compressionLevel);
             LZ4_attach_HC_dictionary(&LZ4_streamHC, &LZ4dictHC);
             ret = LZ4_compress_HC_continue(&LZ4_streamHC, block, compressedBuffer, blockSize, blockContinueCompressedSize-1);
             FUZ_CHECKTEST(ret>0, "LZ4_compress_HC_continue using ExtDictCtx should fail : one missing byte for output buffer (%i != %i)", ret, blockContinueCompressedSize);
+            FUZ_CHECKTEST(!LZ4_streamHC.internal_donotuse.dirty, "Context should be dirty");
 
             FUZ_DISPLAYTEST();
-            LZ4_resetStreamHC (&LZ4_streamHC, compressionLevel);
+            LZ4_resetStreamHC_fast (&LZ4_streamHC, compressionLevel);
             LZ4_attach_HC_dictionary(&LZ4_streamHC, &LZ4dictHC);
             ret = LZ4_compress_HC_continue(&LZ4_streamHC, block, compressedBuffer, blockSize, blockContinueCompressedSize);
             FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_compress_HC_continue using ExtDictCtx size is different (%i != %i)", ret, blockContinueCompressedSize);
             FUZ_CHECKTEST(ret<=0, "LZ4_compress_HC_continue using ExtDictCtx should work : enough size available within output buffer");
+            FUZ_CHECKTEST(LZ4_streamHC.internal_donotuse.dirty, "Context should be clean");
 
             FUZ_DISPLAYTEST();
             LZ4_resetStreamHC_fast (&LZ4_streamHC, compressionLevel);
@@ -885,6 +891,7 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
             ret = LZ4_compress_HC_continue(&LZ4_streamHC, block, compressedBuffer, blockSize, blockContinueCompressedSize);
             FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_compress_HC_continue using ExtDictCtx and fast reset size is different (%i != %i)", ret, blockContinueCompressedSize);
             FUZ_CHECKTEST(ret<=0, "LZ4_compress_HC_continue using ExtDictCtx and fast reset should work : enough size available within output buffer");
+            FUZ_CHECKTEST(LZ4_streamHC.internal_donotuse.dirty, "Context should be clean");
 
             FUZ_DISPLAYTEST();
             decodedBuffer[blockSize] = 0;
@@ -1070,6 +1077,7 @@ static void FUZ_unitTests(int compressionLevel)
         LZ4_resetStreamHC(&sHC, compressionLevel);
         result = LZ4_compress_HC_continue(&sHC, testInput, testCompressed, testCompressedSize, testCompressedSize-1);
         FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() compression failed");
+        FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
 
         result = LZ4_decompress_safe(testCompressed, testVerify, result, testCompressedSize);
         FUZ_CHECKTEST(result!=(int)testCompressedSize, "LZ4_decompress_safe() decompression failed");
@@ -1078,10 +1086,11 @@ static void FUZ_unitTests(int compressionLevel)
 
         /* simple dictionary HC compression test */
         crcOrig = XXH64(testInput + 64 KB, testCompressedSize, 0);
-        LZ4_resetStreamHC(&sHC, compressionLevel);
+        LZ4_resetStreamHC_fast(&sHC, compressionLevel);
         LZ4_loadDictHC(&sHC, testInput, 64 KB);
         result = LZ4_compress_HC_continue(&sHC, testInput + 64 KB, testCompressed, testCompressedSize, testCompressedSize-1);
         FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result);
+        FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
 
         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");
@@ -1092,12 +1101,14 @@ static void FUZ_unitTests(int compressionLevel)
         {   int result1, result2;
             int segSize = testCompressedSize / 2;
             crcOrig = XXH64(testInput + segSize, testCompressedSize, 0);
-            LZ4_resetStreamHC(&sHC, compressionLevel);
+            LZ4_resetStreamHC_fast(&sHC, compressionLevel);
             LZ4_loadDictHC(&sHC, testInput, segSize);
             result1 = LZ4_compress_HC_continue(&sHC, testInput + segSize, testCompressed, segSize, segSize -1);
             FUZ_CHECKTEST(result1==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result1);
+            FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
             result2 = LZ4_compress_HC_continue(&sHC, testInput + 2*segSize, testCompressed+result1, segSize, segSize-1);
             FUZ_CHECKTEST(result2==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result2);
+            FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
 
             result = LZ4_decompress_safe_usingDict(testCompressed, testVerify, result1, segSize, testInput, segSize);
             FUZ_CHECKTEST(result!=segSize, "LZ4_decompress_safe() dictionary decompression part 1 failed");
@@ -1109,10 +1120,11 @@ static void FUZ_unitTests(int compressionLevel)
 
         /* remote dictionary HC compression test */
         crcOrig = XXH64(testInput + 64 KB, testCompressedSize, 0);
-        LZ4_resetStreamHC(&sHC, compressionLevel);
+        LZ4_resetStreamHC_fast(&sHC, compressionLevel);
         LZ4_loadDictHC(&sHC, testInput, 32 KB);
         result = LZ4_compress_HC_continue(&sHC, testInput + 64 KB, testCompressed, testCompressedSize, testCompressedSize-1);
         FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() remote dictionary failed : result = %i", result);
+        FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
 
         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");
@@ -1130,7 +1142,7 @@ static void FUZ_unitTests(int compressionLevel)
             int segSize = (FUZ_rand(&randState) & 8191);
             int segNb = 1;
 
-            LZ4_resetStreamHC(&sHC, compressionLevel);
+            LZ4_resetStreamHC_fast(&sHC, compressionLevel);
             LZ4_loadDictHC(&sHC, dict, dictSize);
 
             XXH64_reset(&crcOrigState, 0);
@@ -1141,6 +1153,7 @@ static void FUZ_unitTests(int compressionLevel)
                 crcOrig = XXH64_digest(&crcOrigState);
                 result = LZ4_compress_HC_continue(&sHC, testInput + segStart, testCompressed, segSize, LZ4_compressBound(segSize));
                 FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() dictionary compression failed : result = %i", result);
+                FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
 
                 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);
@@ -1177,7 +1190,7 @@ static void FUZ_unitTests(int compressionLevel)
             XXH64_reset(&xxhOrig, 0);
             XXH64_reset(&xxhNewSafe, 0);
             XXH64_reset(&xxhNewFast, 0);
-            LZ4_resetStreamHC(&sHC, compressionLevel);
+            LZ4_resetStreamHC_fast(&sHC, compressionLevel);
             LZ4_setStreamDecode(&decodeStateSafe, NULL, 0);
             LZ4_setStreamDecode(&decodeStateFast, NULL, 0);
 
@@ -1188,6 +1201,7 @@ static void FUZ_unitTests(int compressionLevel)
                 memcpy (ringBuffer + rNext, testInput + iNext, messageSize);
                 compressedSize = LZ4_compress_HC_continue(&sHC, ringBuffer + rNext, testCompressed, messageSize, testCompressedSize-ringBufferSize);
                 FUZ_CHECKTEST(compressedSize==0, "LZ4_compress_HC_continue() compression failed");
+                FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
 
                 result = LZ4_decompress_safe_continue(&decodeStateSafe, testCompressed, testVerify + dNext, compressedSize, messageSize);
                 FUZ_CHECKTEST(result!=(int)messageSize, "ringBuffer : LZ4_decompress_safe_continue() test failed");
@@ -1238,7 +1252,7 @@ static void FUZ_unitTests(int compressionLevel)
             XXH64_reset(&xxhOrig, 0);
             XXH64_reset(&xxhNewSafe, 0);
             XXH64_reset(&xxhNewFast, 0);
-            LZ4_resetStreamHC(&sHC, compressionLevel);
+            LZ4_resetStreamHC_fast(&sHC, compressionLevel);
             LZ4_setStreamDecode(&decodeStateSafe, NULL, 0);
             LZ4_setStreamDecode(&decodeStateFast, NULL, 0);
 
@@ -1251,6 +1265,7 @@ static void FUZ_unitTests(int compressionLevel)
 
             compressedSize = LZ4_compress_HC_continue(&sHC, testInput + iNext, testCompressed, messageSize, testCompressedSize-ringBufferSize);
             FUZ_CHECKTEST(compressedSize==0, "LZ4_compress_HC_continue() compression failed");
+            FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
 
             result = LZ4_decompress_safe_continue(&decodeStateSafe, testCompressed, ringBufferSafe + dNext, compressedSize, messageSize);
             FUZ_CHECKTEST(result!=messageSize, "64K D.ringBuffer : LZ4_decompress_safe_continue() test failed");
@@ -1282,6 +1297,7 @@ static void FUZ_unitTests(int compressionLevel)
 
                 compressedSize = LZ4_compress_HC_continue(&sHC, testInput + iNext, testCompressed, messageSize, testCompressedSize-ringBufferSize);
                 FUZ_CHECKTEST(compressedSize==0, "LZ4_compress_HC_continue() compression failed");
+                FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
                 DISPLAYLEVEL(5, "compressed %i bytes to %i bytes \n", messageSize, compressedSize);
 
                 /* test LZ4_decompress_safe_continue */