Merge pull request #65 from Cyan4973/dev

Dev

Makefile

@@ -32,7 +32,7 @@
 # ################################################################
 
 # Version number
-export VERSION := 0.3.0
+export VERSION := 0.3.3
 
 PRGDIR  = programs
 ZSTDDIR = lib

NEWS

@@ -1,3 +1,12 @@
+v0.3.3
+Small compression ratio improvement
+
+v0.3.2
+Fixed Visual Studio
+
+v0.3.1 :
+Small compression ratio improvement
+
 v0.3
 HC mode : compression levels 2-26
 

README.md

@@ -13,36 +13,32 @@ For a taste of its performance, here are a few benchmark numbers from a number o
 |-----------------|-------|--------:|--------:|
 |                 |       |   MB/s  |  MB/s   |
 | **zstd 0.3**    |**2.858**|**280**| **670** |
-| [zlib 1.2.8] -1 | 2.730 |    70   |   300   | 
+| [zlib] 1.2.8 -1 | 2.730 |    70   |   300   | 
 | QuickLZ 1.5.1b6 | 2.237 |   370   |   415   |
 | LZO 2.06        | 2.106 |   400   |   580   |
 | [LZ4] r131      | 2.101 |   450   |  2100   |
 | Snappy 1.1.0    | 2.091 |   330   |  1100   |
 | LZF 3.6         | 2.077 |   200   |   560   |
 
-[zlib 1.2.8]:http://www.zlib.net/
+[zlib]:http://www.zlib.net/
 [LZ4]:http://www.lz4.org/
 
-Zstd can also offer stronger compression ratio at the cost of compression speed, but preserving its decompression speed. In the following test, a few compressors suitable for this scenario are selected (they offer very asymetric performance, useful when compression time has little importance). The test was completed on a Core i7-5600U @ 2.6 GHz, using [benchmark 0.6.1](http://encode.ru/threads/1266-In-memory-benchmark-with-fastest-LZSS-(QuickLZ-Snappy)-compressors?p=45217&viewfull=1#post45217), an open-source benchmark program by inikep.
+Zstd can also offer stronger compression ratio at the cost of compression speed. Speed / Ratio trade-off is configurable by small increment, to fit different situations. Note however that decompression speed is preserved and remain roughly the same at all settings, a property shared by most LZ compression algorithms, such as [zlib]. The following test is run on a Core i7-3930K CPU @ 4.5GHz, using [lzbench], an open-source in-memory benchmark by inikep, on the [Silesia compression corpus](http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia)
 
-|Name             | Ratio | C.speed | D.speed |
-|-----------------|-------|--------:|--------:|
-|                 |       |   MB/s  |  MB/s   |
-| brotli -9       | 3.729 |     4   |   340   |
-| **zstd 0.3 -9** |**3.447**|**30** | **640** |
-| [zlib 1.2.8] -9 | 3.133 |    10   |   300   | 
-| LZO 2.06 -999   | 2.790 |     1   |   560   |
-| [LZ4] r131 -9   | 2.720 |    25   |  2100   |
+[lzbench]:https://github.com/inikep/lzbench
 
-[lzma]:http://www.7-zip.org/
+Compression Speed vs Ratio | Decompression Speed
+---------------------------|--------------------
+![Compression Speed vs Ratio](images/CSpeed.png "Compression Speed vs Ratio") | ![Decompression Speed](images/DSpeed.png "Decompression Speed")
 
-Zstd compression speed is highly configurable, by small increment, to fit different situations. Its memory requirement can also be configured to fit into low-memory hardware configurations, or servers handling multiple connections/contexts in parallel.
 
 Zstd entropy stage is provided by [Huff0 and FSE, from Finite State Entrop library](https://github.com/Cyan4973/FiniteStateEntropy).
 
-Zstd has not yet reached "stable" status. Specifically, it doesn't guarantee yet that its current compressed format will remain stable and supported in future versions. It may still change to adapt further optimizations still being investigated. That being said, the library is now pretty robust, able to withstand hazards situations, including invalid input. The library reliability has been tested using [Fuzz Testing](https://en.wikipedia.org/wiki/Fuzz_testing), with both [internal tools](programs/fuzzer.c) and [external ones](http://lcamtuf.coredump.cx/afl). Therefore, it's now safe to test Zstandard even within production environments.
+Its memory requirement can also be configured to fit into low-memory hardware configurations, or servers handling multiple connections/contexts in parallel.
 
-"Stable Format" is projected sometimes early 2016.
+Zstd has not yet reached "stable format" status. It doesn't guarantee yet that its current compressed format will remain stable and supported in future versions. During this period, it can still change to adapt new optimizations still being investigated. "Stable Format" is projected sometimes early 2016. 
+
+That being said, the library is now fairly robust, able to withstand hazards situations, including invalid inputs. The library reliability has been tested using [Fuzz Testing](https://en.wikipedia.org/wiki/Fuzz_testing), with both [internal tools](programs/fuzzer.c) and [external ones](http://lcamtuf.coredump.cx/afl). Therefore, it seems now safe to test Zstandard even within production environments.
 
 ### Branch Policy
 The "dev" branch is the one where all contributions will be merged before reaching "master". If you plan to propose a patch, please commit into the "dev" branch or its own feature branch. Direct commit to "master" are not permitted.

lib/huff0.c

@@ -362,7 +362,7 @@ size_t HUF_buildCTable (HUF_CElt* tree, const U32* count, U32 maxSymbolValue, U3
             U16 min = 0;
             for (n=maxNbBits; n>0; n--)
             {
-                valPerRank[n] = min;      // get starting value within each rank
+                valPerRank[n] = min;      /* get starting value within each rank */
                 min += nbPerRank[n];
                 min >>= 1;
             }
@@ -1027,18 +1027,23 @@ size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
         U32 nextRankVal = 0;
         U32 w, consumed;
         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
+        U32* rankVal0 = rankVal[0];
         for (w=1; w<=maxW; w++)
         {
             U32 current = nextRankVal;
             nextRankVal += rankStats[w] << (w+rescale);
-            rankVal[0][w] = current;
+            rankVal0[w] = current;
+        }
+        for (consumed = minBits; consumed <= memLog - minBits; consumed++)
+        {
+            U32* rankValPtr = rankVal[consumed];
+            for (w = 1; w <= maxW; w++)
+            {
+                rankValPtr[w] = rankVal0[w] >> consumed;
+            }
         }
-        for (consumed=minBits; consumed <= memLog-minBits; consumed++)
-            for (w=1; w<=maxW; w++)
-                rankVal[consumed][w] = rankVal[0][w] >> consumed;
     }
 
-
     HUF_fillDTableX4(dt, memLog,
                    sortedSymbol, sizeOfSort,
                    rankStart0, rankVal, maxW,
@@ -1394,18 +1399,23 @@ size_t HUF_readDTableX6 (U32* DTable, const void* src, size_t srcSize)
         U32 nextRankVal = 0;
         U32 w, consumed;
         const int rescale = (memLog-tableLog) - 1;   /* tableLog <= memLog */
+        U32* rankVal0 = rankVal[0];
         for (w=1; w<=maxW; w++)
         {
             U32 current = nextRankVal;
             nextRankVal += rankStats[w] << (w+rescale);
-            rankVal[0][w] = current;
+            rankVal0[w] = current;
+        }
+        for (consumed = minBits; consumed <= memLog - minBits; consumed++)
+        {
+            U32* rankValPtr = rankVal[consumed];
+            for (w = 1; w <= maxW; w++)
+            {
+                rankValPtr[w] = rankVal0[w] >> consumed;
+            }
         }
-        for (consumed=minBits; consumed <= memLog-minBits; consumed++)
-            for (w=1; w<=maxW; w++)
-                rankVal[consumed][w] = rankVal[0][w] >> consumed;
     }
 
-
     /* fill tables */
     {
         HUF_DDescX6* DDescription = (HUF_DDescX6*)(DTable+1);

lib/zstd.c

@@ -120,8 +120,6 @@
 #define GB *(1U<<30)
 
 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
-#define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
-#define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
 #define IS_RAW BIT0
 #define IS_RLE BIT1
 
@@ -570,7 +568,7 @@ static size_t ZSTD_compressBlock(ZSTD_CCtx* ctx, void* dst, size_t maxDstSize, c
     ZSTD_resetSeqStore(seqStorePtr);
 
     /* Main Search Loop */
-    while (ip <= ilimit)
+    while (ip < ilimit)  /* < instead of <=, because unconditionnal ZSTD_addPtr(ip+1) */
     {
         const BYTE* match = ZSTD_updateMatch(HashTable, ip, base);
 
@@ -591,7 +589,8 @@ static size_t ZSTD_compressBlock(ZSTD_CCtx* ctx, void* dst, size_t maxDstSize, c
             ZSTD_addPtr(HashTable, ip+1, base);
             ip += matchLength + MINMATCH;
             anchor = ip;
-            if (ip <= ilimit) ZSTD_addPtr(HashTable, ip-2, base);
+            if (ip < ilimit) /* same test as loop, for speed */
+                ZSTD_addPtr(HashTable, ip-2, base);
         }
     }
 
@@ -920,6 +919,7 @@ size_t ZSTD_decodeLiteralsBlock(void* ctx,
             {
                 if (litSize > srcSize-3) return ERROR(corruption_detected);
                 memcpy(dctx->litBuffer, istart, litSize);
+                dctx->litPtr = dctx->litBuffer;
                 dctx->litBufSize = BLOCKSIZE+8;
                 dctx->litSize = litSize;
                 return litSize+3;

lib/zstd.h

@@ -48,7 +48,7 @@ extern "C" {
 ***************************************/
 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
 #define ZSTD_VERSION_MINOR    3    /* for new (non-breaking) interface capabilities */
-#define ZSTD_VERSION_RELEASE  0    /* for tweaks, bug-fixes, or development */
+#define ZSTD_VERSION_RELEASE  3    /* for tweaks, bug-fixes, or development */
 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
 unsigned ZSTD_versionNumber (void);
 

lib/zstd_internal.h

@@ -49,6 +49,8 @@ extern "C" {
 ****************************************/
 static size_t ZSTD_read_ARCH(const void* p) { size_t r; memcpy(&r, p, sizeof(r)); return r; }
 
+#define MIN(a,b) ((a)<(b) ? (a) : (b))
+
 static unsigned ZSTD_highbit(U32 val)
 {
 #   if defined(_MSC_VER)   /* Visual */
@@ -152,7 +154,7 @@ MEM_STATIC size_t ZSTD_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pI
         return (size_t)(pIn - pStart);
     }
 
-    if (MEM_32bits()) if ((pIn<(pInLimit-3)) && (MEM_read32(pMatch) == MEM_read32(pIn))) { pIn+=4; pMatch+=4; }
+    if (MEM_64bits()) if ((pIn<(pInLimit-3)) && (MEM_read32(pMatch) == MEM_read32(pIn))) { pIn+=4; pMatch+=4; }
     if ((pIn<(pInLimit-1)) && (MEM_read16(pMatch) == MEM_read16(pIn))) { pIn+=2; pMatch+=2; }
     if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++;
     return (size_t)(pIn - pStart);
@@ -169,7 +171,9 @@ static void ZSTD_wildcopy(void* dst, const void* src, size_t length)
     const BYTE* ip = (const BYTE*)src;
     BYTE* op = (BYTE*)dst;
     BYTE* const oend = op + length;
-    do COPY8(op, ip) while (op < oend);
+    do
+        COPY8(op, ip)
+    while (op < oend);
 }
 
 
@@ -210,6 +214,10 @@ void ZSTD_resetSeqStore(seqStore_t* ssPtr);
 #define MaxLL  ((1<<LLbits) - 1)
 #define MaxOff   31
 
+#define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
+#define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
+
+
 /** ZSTD_storeSeq
     Store a sequence (literal length, literals, offset code and match length) into seqStore_t
     @offsetCode : distance to match, or 0 == repCode

lib/zstdhc.c

@@ -107,20 +107,42 @@ size_t ZSTD_HC_freeCCtx(ZSTD_HC_CCtx* cctx)
     return 0;
 }
 
+
+/** ZSTD_HC_validateParams
+    correct params value to remain within authorized range
+    optimize for srcSize if srcSize > 0 */
+void ZSTD_HC_validateParams(ZSTD_HC_parameters* params, size_t srcSize)
+{
+    const U32 chainplus = (params->strategy == ZSTD_HC_btlazy2);
+
+    /* validate params */
+    if (params->windowLog   > ZSTD_HC_WINDOWLOG_MAX) params->windowLog = ZSTD_HC_WINDOWLOG_MAX;
+    if (params->windowLog   < ZSTD_HC_WINDOWLOG_MIN) params->windowLog = ZSTD_HC_WINDOWLOG_MIN;
+
+    /* correct params, to use less memory */
+    if (srcSize > 0)
+    {
+        U32 srcLog = ZSTD_highbit((U32)srcSize-1) + 1;
+        if (params->windowLog > srcLog) params->windowLog = srcLog;
+    }
+
+    if (params->chainLog    > params->windowLog + chainplus) params->chainLog = params->windowLog+chainplus;   /* <= ZSTD_HC_CHAINLOG_MAX */
+    if (params->chainLog    < ZSTD_HC_CHAINLOG_MIN) params->chainLog = ZSTD_HC_CHAINLOG_MIN;
+    if (params->hashLog     > ZSTD_HC_HASHLOG_MAX) params->hashLog = ZSTD_HC_HASHLOG_MAX;
+    if (params->hashLog     < ZSTD_HC_HASHLOG_MIN) params->hashLog = ZSTD_HC_HASHLOG_MIN;
+    if (params->searchLog   > ZSTD_HC_SEARCHLOG_MAX) params->searchLog = ZSTD_HC_SEARCHLOG_MAX;
+    if (params->searchLog   < ZSTD_HC_SEARCHLOG_MIN) params->searchLog = ZSTD_HC_SEARCHLOG_MIN;
+    if (params->searchLength> ZSTD_HC_SEARCHLENGTH_MAX) params->searchLength = ZSTD_HC_SEARCHLENGTH_MAX;
+    if (params->searchLength< ZSTD_HC_SEARCHLENGTH_MIN) params->searchLength = ZSTD_HC_SEARCHLENGTH_MIN;
+    if ((U32)params->strategy>(U32)ZSTD_HC_btlazy2) params->strategy = ZSTD_HC_btlazy2;
+    if ((int)params->strategy<(int)ZSTD_HC_greedy) params->strategy = ZSTD_HC_greedy;
+}
+
+
 static size_t ZSTD_HC_resetCCtx_advanced (ZSTD_HC_CCtx* zc,
                                           ZSTD_HC_parameters params)
 {
-    /* validate params */
-    if (params.windowLog   > ZSTD_HC_WINDOWLOG_MAX) params.windowLog = ZSTD_HC_WINDOWLOG_MAX;
-    if (params.windowLog   < ZSTD_HC_WINDOWLOG_MIN) params.windowLog = ZSTD_HC_WINDOWLOG_MIN;
-    if (params.chainLog    > params.windowLog) params.chainLog = params.windowLog;   /* <= ZSTD_HC_CHAINLOG_MAX */
-    if (params.chainLog    < ZSTD_HC_CHAINLOG_MIN) params.chainLog = ZSTD_HC_CHAINLOG_MIN;
-    if (params.hashLog     > ZSTD_HC_HASHLOG_MAX) params.hashLog = ZSTD_HC_HASHLOG_MAX;
-    if (params.hashLog     < ZSTD_HC_HASHLOG_MIN) params.hashLog = ZSTD_HC_HASHLOG_MIN;
-    if (params.searchLog   > ZSTD_HC_SEARCHLOG_MAX) params.searchLog = ZSTD_HC_SEARCHLOG_MAX;
-    if (params.searchLog   < ZSTD_HC_SEARCHLOG_MIN) params.searchLog = ZSTD_HC_SEARCHLOG_MIN;
-    if (params.searchLength> ZSTD_HC_SEARCHLENGTH_MAX) params.searchLength = ZSTD_HC_SEARCHLENGTH_MAX;
-    if (params.searchLength< ZSTD_HC_SEARCHLENGTH_MIN) params.searchLength = ZSTD_HC_SEARCHLENGTH_MIN;
+    ZSTD_HC_validateParams(&params, 0);
 
     /* reserve table memory */
     {
@@ -173,25 +195,323 @@ static const U64 prime6bytes = 227718039650203ULL;
 static size_t ZSTD_HC_hash6(U64 u, U32 h) { return (size_t)((u * prime6bytes) << (64-48) >> (64-h)) ; }
 static size_t ZSTD_HC_hash6Ptr(const void* p, U32 h) { return ZSTD_HC_hash6(MEM_read64(p), h); }
 
-static size_t ZSTD_HC_hashPtr(const void* p, U32 h, U32 mls)
+static size_t ZSTD_HC_hashPtr(const void* p, U32 hBits, U32 mls)
 {
     switch(mls)
     {
     default:
-    case 4: return ZSTD_HC_hash4Ptr(p,h);
-    case 5: return ZSTD_HC_hash5Ptr(p,h);
-    case 6: return ZSTD_HC_hash6Ptr(p,h);
+    case 4: return ZSTD_HC_hash4Ptr(p, hBits);
+    case 5: return ZSTD_HC_hash5Ptr(p, hBits);
+    case 6: return ZSTD_HC_hash6Ptr(p, hBits);
     }
 }
 
-#define NEXT_IN_CHAIN(d)           chainTable[(d) & chainMask]   /* flexible, CHAINSIZE dependent */
+#define NEXT_IN_CHAIN(d, mask)   chainTable[(d) & mask]
 
 
 /* *************************************
-*  HC Compression
+*  Binary Tree search
 ***************************************/
+/** ZSTD_HC_insertBt1 : add one ptr to tree
+    @ip : assumed <= iend-8 */
+static void ZSTD_HC_insertBt1(ZSTD_HC_CCtx* zc, const BYTE* const ip, const U32 mls, const BYTE* const iend, U32 nbCompares)
+{
+    U32* const hashTable = zc->hashTable;
+    const U32 hashLog = zc->params.hashLog;
+    const size_t h  = ZSTD_HC_hashPtr(ip, hashLog, mls);
+    U32* const bt   = zc->chainTable;
+    const U32 btLog = zc->params.chainLog - 1;
+    const U32 btMask= (1 << btLog) - 1;
+    U32 matchIndex  = hashTable[h];
+    size_t commonLengthSmaller=0, commonLengthLarger=0;
+    const BYTE* const base = zc->base;
+    const U32 current = (U32)(ip-base);
+    const U32 btLow = btMask >= current ? 0 : current - btMask;
+    U32* smallerPtr = bt + 2*(current&btMask);
+    U32* largerPtr  = bt + 2*(current&btMask) + 1;
+    U32 dummy32;   /* to be nullified at the end */
+    const U32 windowSize = 1 << zc->params.windowLog;
+    const U32 windowLow = windowSize >= current ? 0 : current - windowSize;
+
+    hashTable[h] = (U32)(ip-base);   /* Update Hash Table */
+
+    while (nbCompares-- && (matchIndex > windowLow))
+    {
+        U32* nextPtr = bt + 2*(matchIndex & btMask);
+        const BYTE* match = base + matchIndex;
+        size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
+
+        matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
+
+        if (ip+matchLength == iend)   /* equal : no way to know if inf or sup */
+            break;   /* just drop , to guarantee consistency (miss a bit of compression; if someone knows better, please tell) */
+
+        if (match[matchLength] < ip[matchLength])
+        {
+            /* match is smaller than current */
+            *smallerPtr = matchIndex;             /* update smaller idx */
+            commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
+            if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
+            smallerPtr = nextPtr+1;               /* new "smaller" => larger of match */
+            matchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
+        }
+        else
+        {
+            /* match is larger than current */
+            *largerPtr = matchIndex;
+            commonLengthLarger = matchLength;
+            if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
+            largerPtr = nextPtr;
+            matchIndex = nextPtr[0];
+        }
+    }
+
+    *smallerPtr = *largerPtr = 0;
+}
+
+
+FORCE_INLINE /* inlining is important to hardwire a hot branch (template emulation) */
+size_t ZSTD_HC_insertBtAndFindBestMatch (
+                        ZSTD_HC_CCtx* zc,
+                        const BYTE* const ip, const BYTE* const iend,
+                        size_t* offsetPtr,
+                        U32 nbCompares, const U32 mls)
+{
+    U32* const hashTable = zc->hashTable;
+    const U32 hashLog = zc->params.hashLog;
+    const size_t h  = ZSTD_HC_hashPtr(ip, hashLog, mls);
+    U32* const bt   = zc->chainTable;
+    const U32 btLog = zc->params.chainLog - 1;
+    const U32 btMask= (1 << btLog) - 1;
+    U32 matchIndex  = hashTable[h];
+    size_t commonLengthSmaller=0, commonLengthLarger=0;
+    const BYTE* const base = zc->base;
+    const U32 current = (U32)(ip-base);
+    const U32 btLow = btMask >= current ? 0 : current - btMask;
+    const U32 windowSize = 1 << zc->params.windowLog;
+    const U32 windowLow = windowSize >= current ? 0 : current - windowSize;
+    U32* smallerPtr = bt + 2*(current&btMask);
+    U32* largerPtr  = bt + 2*(current&btMask) + 1;
+    size_t bestLength = 0;
+    U32 dummy32;   /* to be nullified at the end */
+
+    hashTable[h] = (U32)(ip-base);   /* Update Hash Table */
+
+    while (nbCompares-- && (matchIndex > windowLow))
+    {
+        U32* nextPtr = bt + 2*(matchIndex & btMask);
+        const BYTE* match = base + matchIndex;
+        size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
+
+        matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
+
+        if (matchLength > bestLength)
+        {
+            if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit(current-matchIndex+1) - ZSTD_highbit((U32)offsetPtr[0]+1)) )
+                bestLength = matchLength, *offsetPtr = current - matchIndex;
+            if (ip+matchLength == iend)   /* equal : no way to know if inf or sup */
+                break;   /* drop, next to null, to guarantee consistency (is there a way to do better ?) */
+        }
+
+        if (match[matchLength] < ip[matchLength])
+        {
+            /* match is smaller than current */
+            *smallerPtr = matchIndex;             /* update smaller idx */
+            commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
+            if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
+            smallerPtr = nextPtr+1;               /* new "smaller" => larger of match */
+            matchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
+        }
+        else
+        {
+            /* match is larger than current */
+            *largerPtr = matchIndex;
+            commonLengthLarger = matchLength;
+            if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
+            largerPtr = nextPtr;
+            matchIndex = nextPtr[0];
+        }
+    }
+
+    *smallerPtr = *largerPtr = 0;
+
+    zc->nextToUpdate = current+1;   /* current has been inserted */
+    if (bestLength < MINMATCH) return 0;
+    return bestLength;
+}
+
+
+static void ZSTD_HC_updateTree(ZSTD_HC_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
+{
+    const BYTE* const base = zc->base;
+    const U32 target = (U32)(ip - base);
+    U32 idx = zc->nextToUpdate;
+    //size_t dummy;
+
+    for( ; idx < target ; idx++)
+        ZSTD_HC_insertBt1(zc, base+idx, mls, iend, nbCompares);
+        //ZSTD_HC_insertBtAndFindBestMatch(zc, base+idx, iend, &dummy, nbCompares, mls);
+
+    zc->nextToUpdate = target;
+}
+
+
+/** Tree updater, providing best match */
+FORCE_INLINE /* inlining is important to hardwire a hot branch (template emulation) */
+size_t ZSTD_HC_BtFindBestMatch (
+                        ZSTD_HC_CCtx* zc,
+                        const BYTE* const ip, const BYTE* const iLimit,
+                        size_t* offsetPtr,
+                        const U32 maxNbAttempts, const U32 mls)
+{
+    ZSTD_HC_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
+    return ZSTD_HC_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls);
+}
+
+
+FORCE_INLINE size_t ZSTD_HC_BtFindBestMatch_selectMLS (
+                        ZSTD_HC_CCtx* zc,   /* Index table will be updated */
+                        const BYTE* ip, const BYTE* const iLimit,
+                        size_t* offsetPtr,
+                        const U32 maxNbAttempts, const U32 matchLengthSearch)
+{
+    switch(matchLengthSearch)
+    {
+    default :
+    case 4 : return ZSTD_HC_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
+    case 5 : return ZSTD_HC_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
+    case 6 : return ZSTD_HC_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
+    }
+}
+
+
+size_t ZSTD_HC_compressBlock_btLazy2(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+{
+    seqStore_t* seqStorePtr = &(ctx->seqStore);
+    const BYTE* const istart = (const BYTE*)src;
+    const BYTE* ip = istart;
+    const BYTE* anchor = istart;
+    const BYTE* const iend = istart + srcSize;
+    const BYTE* const ilimit = iend - 8;
+
+    size_t offset_2=REPCODE_STARTVALUE, offset_1=REPCODE_STARTVALUE;
+    const U32 maxSearches = 1 << ctx->params.searchLog;
+    const U32 mls = ctx->params.searchLength;
+
+    /* init */
+    ZSTD_resetSeqStore(seqStorePtr);
+    if (((ip-ctx->base) - ctx->dictLimit) < REPCODE_STARTVALUE) ip += REPCODE_STARTVALUE;
+
+    /* Match Loop */
+    while (ip <= ilimit)
+    {
+        size_t matchLength;
+        size_t offset=999999;
+        const BYTE* start;
+
+        /* try to find a first match */
+        if (MEM_read32(ip) == MEM_read32(ip - offset_2))
+        {
+            /* repcode : we take it*/
+            size_t offtmp = offset_2;
+            size_t litLength = ip - anchor;
+            matchLength = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_2, iend);
+            offset_2 = offset_1;
+            offset_1 = offtmp;
+            ZSTD_storeSeq(seqStorePtr, litLength, anchor, 0, matchLength);
+            ip += matchLength+MINMATCH;
+            anchor = ip;
+            continue;
+        }
+
+        offset_2 = offset_1;
+        matchLength = ZSTD_HC_BtFindBestMatch_selectMLS(ctx, ip, iend, &offset, maxSearches, mls);
+        if (!matchLength) { ip++; continue; }
+
+        /* let's try to find a better solution */
+        start = ip;
+
+        while (ip<ilimit)
+        {
+            ip ++;
+            if (MEM_read32(ip) == MEM_read32(ip - offset_1))
+            {
+                size_t ml2 = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_1, iend) + MINMATCH;
+                int gain2 = (int)(ml2 * 3);
+                int gain1 = (int)(matchLength*3 - ZSTD_highbit((U32)offset+1) + 1);
+                if (gain2 > gain1)
+                    matchLength = ml2, offset = 0, start = ip;
+            }
+            {
+                size_t offset2=999999;
+                size_t ml2 = ZSTD_HC_BtFindBestMatch_selectMLS(ctx, ip, iend, &offset2, maxSearches, mls);
+                int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1));   /* raw approx */
+                int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 4);
+                if (gain2 > gain1)
+                {
+                    matchLength = ml2, offset = offset2, start = ip;
+                    continue;   /* search a better one */
+                }
+            }
+
+            /* let's find an even better one */
+            if (ip<ilimit)
+            {
+                ip ++;
+                if (MEM_read32(ip) == MEM_read32(ip - offset_1))
+                {
+                    size_t ml2 = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_1, iend) + MINMATCH;
+                    int gain2 = (int)(ml2 * 4);
+                    int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 1);
+                    if (gain2 > gain1)
+                        matchLength = ml2, offset = 0, start = ip;
+                }
+                {
+                    size_t offset2=999999;
+                    size_t ml2 = ZSTD_HC_BtFindBestMatch_selectMLS(ctx, ip, iend, &offset2, maxSearches, mls);
+                    int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1));   /* raw approx */
+                    int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 7);
+                    if (gain2 > gain1)
+                    {
+                        matchLength = ml2, offset = offset2, start = ip;
+                        continue;
+                    }
+                }
+            }
+            break;  /* nothing found : store previous solution */
+        }
+
+        /* store sequence */
+        {
+            size_t litLength = start - anchor;
+            if (offset) offset_1 = offset;
+            ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
+            ip = start + matchLength;
+            anchor = ip;
+        }
+
+    }
+
+    /* Last Literals */
+    {
+        size_t lastLLSize = iend - anchor;
+        memcpy(seqStorePtr->lit, anchor, lastLLSize);
+        seqStorePtr->lit += lastLLSize;
+    }
+
+    /* Final compression stage */
+    return ZSTD_compressSequences((BYTE*)dst, maxDstSize,
+                                  seqStorePtr, srcSize);
+}
+
+
+
+/* ***********************
+*  Hash Chain
+*************************/
+
 /* Update chains up to ip (excluded) */
-static void ZSTD_HC_insert (ZSTD_HC_CCtx* zc, const BYTE* ip, U32 mls)
+static U32 ZSTD_HC_insertAndFindFirstIndex  (ZSTD_HC_CCtx* zc, const BYTE* ip, U32 mls)
 {
     U32* const hashTable  = zc->hashTable;
     const U32 hashLog = zc->params.hashLog;
@@ -204,24 +524,23 @@ static void ZSTD_HC_insert (ZSTD_HC_CCtx* zc, const BYTE* ip, U32 mls)
     while(idx < target)
     {
         size_t h = ZSTD_HC_hashPtr(base+idx, hashLog, mls);
-        NEXT_IN_CHAIN(idx) = hashTable[h];
+        NEXT_IN_CHAIN(idx, chainMask) = hashTable[h];
         hashTable[h] = idx;
         idx++;
     }
 
     zc->nextToUpdate = target;
+    return hashTable[ZSTD_HC_hashPtr(ip, hashLog, mls)];
 }
 
 
 FORCE_INLINE /* inlining is important to hardwire a hot branch (template emulation) */
 size_t ZSTD_HC_insertAndFindBestMatch (
                         ZSTD_HC_CCtx* zc,   /* Index table will be updated */
-                        const BYTE* ip, const BYTE* const iLimit,
-                        const BYTE** matchpos,
+                        const BYTE* const ip, const BYTE* const iLimit,
+                        size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 matchLengthSearch)
 {
-    U32* const hashTable = zc->hashTable;
-    const U32 hashLog = zc->params.hashLog;
     U32* const chainTable = zc->chainTable;
     const U32 chainSize = (1 << zc->params.chainLog);
     const U32 chainMask = chainSize-1;
@@ -236,20 +555,24 @@ size_t ZSTD_HC_insertAndFindBestMatch (
     size_t ml=0;
 
     /* HC4 match finder */
-    ZSTD_HC_insert(zc, ip, matchLengthSearch);
-    matchIndex = hashTable[ZSTD_HC_hashPtr(ip, hashLog, matchLengthSearch)];
+    matchIndex = ZSTD_HC_insertAndFindFirstIndex (zc, ip, matchLengthSearch);
 
-    while ((matchIndex>=lowLimit) && (nbAttempts))
+    while ((matchIndex>lowLimit) && (nbAttempts))
     {
         nbAttempts--;
         if (matchIndex >= dictLimit)
         {
             match = base + matchIndex;
-            if (*(match+ml) == *(ip+ml)
-                && (MEM_read32(match) == MEM_read32(ip)))
+            if ( (match[ml] == ip[ml])
+              && (MEM_read32(match) == MEM_read32(ip)) )   /* ensures minimum match of 4 */
             {
                 const size_t mlt = ZSTD_count(ip+MINMATCH, match+MINMATCH, iLimit) + MINMATCH;
-                if (mlt > ml) { ml = mlt; *matchpos = match; if (ip+ml >= iLimit) break; }
+                if (mlt > ml)
+                //if (((int)(4*mlt) - (int)ZSTD_highbit((U32)(ip-match)+1)) > ((int)(4*ml) - (int)ZSTD_highbit((U32)((*offsetPtr)+1))))
+                {
+                    ml = mlt; *offsetPtr = ip-match;
+                    if (ip+ml >= iLimit) break;
+                }
             }
         }
         else
@@ -263,35 +586,254 @@ size_t ZSTD_HC_insertAndFindBestMatch (
                 mlt = ZSTD_count(ip+MINMATCH, match+MINMATCH, vLimit) + MINMATCH;
                 if ((ip+mlt == vLimit) && (vLimit < iLimit))
                     mlt += ZSTD_count(ip+mlt, base+dictLimit, iLimit);
-                if (mlt > ml) { ml = mlt; *matchpos = base + matchIndex; }   /* virtual matchpos */
+                if (mlt > ml) { ml = mlt; *offsetPtr = (ip-base) - matchIndex; }
             }
         }
 
         if (base + matchIndex <= ip - chainSize) break;
-        matchIndex = NEXT_IN_CHAIN(matchIndex);
+        matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
     }
 
     return ml;
 }
 
 
-static size_t ZSTD_HC_insertAndFindBestMatch_selectMLS (
+FORCE_INLINE size_t ZSTD_HC_insertAndFindBestMatch_selectMLS (
                         ZSTD_HC_CCtx* zc,   /* Index table will be updated */
                         const BYTE* ip, const BYTE* const iLimit,
-                        const BYTE** matchpos,
+                        size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 matchLengthSearch)
 {
     switch(matchLengthSearch)
     {
     default :
-    case 4 : return ZSTD_HC_insertAndFindBestMatch(zc, ip, iLimit, matchpos, maxNbAttempts, 4);
-    case 5 : return ZSTD_HC_insertAndFindBestMatch(zc, ip, iLimit, matchpos, maxNbAttempts, 5);
-    case 6 : return ZSTD_HC_insertAndFindBestMatch(zc, ip, iLimit, matchpos, maxNbAttempts, 6);
+    case 4 : return ZSTD_HC_insertAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
+    case 5 : return ZSTD_HC_insertAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
+    case 6 : return ZSTD_HC_insertAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
     }
 }
 
 
-static size_t ZSTD_HC_compressBlock(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+size_t ZSTD_HC_compressBlock_lazydeep(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+{
+    seqStore_t* seqStorePtr = &(ctx->seqStore);
+    const BYTE* const istart = (const BYTE*)src;
+    const BYTE* ip = istart;
+    const BYTE* anchor = istart;
+    const BYTE* const iend = istart + srcSize;
+    const BYTE* const ilimit = iend - 8;
+
+    size_t offset_2=REPCODE_STARTVALUE, offset_1=REPCODE_STARTVALUE;
+    const U32 maxSearches = 1 << ctx->params.searchLog;
+    const U32 mls = ctx->params.searchLength;
+
+    /* init */
+    ZSTD_resetSeqStore(seqStorePtr);
+    if (((ip-ctx->base) - ctx->dictLimit) < REPCODE_STARTVALUE) ip += REPCODE_STARTVALUE;
+
+    /* Match Loop */
+    while (ip <= ilimit)
+    {
+        size_t matchLength;
+        size_t offset=999999;
+        const BYTE* start;
+
+        /* try to find a first match */
+        if (MEM_read32(ip) == MEM_read32(ip - offset_2))
+        {
+            /* repcode : we take it*/
+            size_t offtmp = offset_2;
+            size_t litLength = ip - anchor;
+            matchLength = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_2, iend);
+            offset_2 = offset_1;
+            offset_1 = offtmp;
+            ZSTD_storeSeq(seqStorePtr, litLength, anchor, 0, matchLength);
+            ip += matchLength+MINMATCH;
+            anchor = ip;
+            continue;
+        }
+
+        offset_2 = offset_1;
+        matchLength = ZSTD_HC_insertAndFindBestMatch_selectMLS(ctx, ip, iend, &offset, maxSearches, mls);
+        if (!matchLength) { ip++; continue; }
+
+        /* let's try to find a better solution */
+        start = ip;
+
+        while (ip<ilimit)
+        {
+            ip ++;
+            if (MEM_read32(ip) == MEM_read32(ip - offset_1))
+            {
+                size_t ml2 = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_1, iend) + MINMATCH;
+                int gain2 = (int)(ml2 * 3);
+                int gain1 = (int)(matchLength*3 - ZSTD_highbit((U32)offset+1) + 1);
+                if (gain2 > gain1)
+                    matchLength = ml2, offset = 0, start = ip;
+            }
+            {
+                size_t offset2=999999;
+                size_t ml2 = ZSTD_HC_insertAndFindBestMatch_selectMLS(ctx, ip, iend, &offset2, maxSearches, mls);
+                int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1));   /* raw approx */
+                int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 4);
+                if (gain2 > gain1)
+                {
+                    matchLength = ml2, offset = offset2, start = ip;
+                    continue;   /* search a better one */
+                }
+            }
+
+            /* let's find an even better one */
+            if (ip<ilimit)
+            {
+                ip ++;
+                if (MEM_read32(ip) == MEM_read32(ip - offset_1))
+                {
+                    size_t ml2 = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_1, iend) + MINMATCH;
+                    int gain2 = (int)(ml2 * 4);
+                    int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 1);
+                    if (gain2 > gain1)
+                        matchLength = ml2, offset = 0, start = ip;
+                }
+                {
+                    size_t offset2=999999;
+                    size_t ml2 = ZSTD_HC_insertAndFindBestMatch_selectMLS(ctx, ip, iend, &offset2, maxSearches, mls);
+                    int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1));   /* raw approx */
+                    int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 7);
+                    if (gain2 > gain1)
+                    {
+                        matchLength = ml2, offset = offset2, start = ip;
+                        continue;
+                    }
+                }
+            }
+            break;  /* nothing found : store previous solution */
+        }
+
+        /* store sequence */
+        {
+            size_t litLength = start - anchor;
+            if (offset) offset_1 = offset;
+            ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
+            ip = start + matchLength;
+            anchor = ip;
+        }
+
+    }
+
+    /* Last Literals */
+    {
+        size_t lastLLSize = iend - anchor;
+        memcpy(seqStorePtr->lit, anchor, lastLLSize);
+        seqStorePtr->lit += lastLLSize;
+    }
+
+    /* Final compression stage */
+    return ZSTD_compressSequences((BYTE*)dst, maxDstSize,
+                                  seqStorePtr, srcSize);
+}
+
+
+size_t ZSTD_HC_compressBlock_lazy(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+{
+    seqStore_t* seqStorePtr = &(ctx->seqStore);
+    const BYTE* const istart = (const BYTE*)src;
+    const BYTE* ip = istart;
+    const BYTE* anchor = istart;
+    const BYTE* const iend = istart + srcSize;
+    const BYTE* const ilimit = iend - 8;
+
+    size_t offset_2=REPCODE_STARTVALUE, offset_1=REPCODE_STARTVALUE;
+    const U32 maxSearches = 1 << ctx->params.searchLog;
+    const U32 mls = ctx->params.searchLength;
+
+    /* init */
+    ZSTD_resetSeqStore(seqStorePtr);
+    if (((ip-ctx->base) - ctx->dictLimit) < REPCODE_STARTVALUE) ip += REPCODE_STARTVALUE;
+
+    /* Match Loop */
+    while (ip <= ilimit)
+    {
+        size_t matchLength;
+        size_t offset=0;
+        const BYTE* start;
+
+        /* try to find a first match */
+        if (MEM_read32(ip) == MEM_read32(ip - offset_2))
+        {
+            /* repcode : we take it*/
+            size_t offtmp = offset_2;
+            size_t litLength = ip - anchor;
+            matchLength = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_2, iend);
+            offset_2 = offset_1;
+            offset_1 = offtmp;
+            ZSTD_storeSeq(seqStorePtr, litLength, anchor, 0, matchLength);
+            ip += matchLength+MINMATCH;
+            anchor = ip;
+            continue;
+        }
+
+        offset_2 = offset_1;
+        matchLength = ZSTD_HC_insertAndFindBestMatch_selectMLS(ctx, ip, iend, &offset, maxSearches, mls);
+        if (!matchLength) { ip++; continue; }
+
+        /* let's try to find a better solution */
+        start = ip;
+
+        while (ip<ilimit)
+        {
+            ip ++;
+            if (MEM_read32(ip) == MEM_read32(ip - offset_1))
+            {
+                size_t ml2 = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_1, iend) + MINMATCH;
+                int gain2 = (int)(ml2 * 3);
+                int gain1 = (int)(matchLength*3 - ZSTD_highbit((U32)offset+1) + 1);
+                if (gain2 > gain1)
+                {
+                    matchLength = ml2, offset = 0, start = ip;
+
+                }
+            }
+            {
+                size_t offset2=999999;
+                size_t ml2 = ZSTD_HC_insertAndFindBestMatch_selectMLS(ctx, ip, iend, &offset2, maxSearches, mls);
+                int gain2 = (int)(ml2*3 - ZSTD_highbit((U32)offset2+1));   /* raw approx */
+                int gain1 = (int)(matchLength*3 - ZSTD_highbit((U32)offset+1) + 3);
+                if (gain2 > gain1)
+                {
+                    matchLength = ml2, offset = offset2, start = ip;
+                    continue;   /* search a better one */
+                }
+            }
+
+            break;  /* nothing found : store previous one */
+        }
+
+        /* store sequence */
+        {
+            size_t litLength = start - anchor;
+            if (offset) offset_1 = offset;
+            ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
+            ip = start + matchLength;
+            anchor = ip;
+        }
+
+    }
+
+    /* Last Literals */
+    {
+        size_t lastLLSize = iend - anchor;
+        memcpy(seqStorePtr->lit, anchor, lastLLSize);
+        seqStorePtr->lit += lastLLSize;
+    }
+
+    /* Final compression stage */
+    return ZSTD_compressSequences((BYTE*)dst, maxDstSize,
+                                  seqStorePtr, srcSize);
+}
+
+
+size_t ZSTD_HC_compressBlock_greedy(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     seqStore_t* seqStorePtr = &(ctx->seqStore);
     const BYTE* const istart = (const BYTE*)src;
@@ -299,7 +841,6 @@ static size_t ZSTD_HC_compressBlock(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstS
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
-    const BYTE* match = istart;
 
     size_t offset_2=REPCODE_STARTVALUE, offset_1=REPCODE_STARTVALUE;
     const U32 maxSearches = 1 << ctx->params.searchLog;
@@ -342,12 +883,13 @@ static size_t ZSTD_HC_compressBlock(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstS
 
         /* search */
         {
-            size_t matchLength = ZSTD_HC_insertAndFindBestMatch_selectMLS(ctx, ip, iend, &match, maxSearches, mls);
+            size_t offset=999999;
+            size_t matchLength = ZSTD_HC_insertAndFindBestMatch_selectMLS(ctx, ip, iend, &offset, maxSearches, mls);
             if (!matchLength) { ip++; continue; }
             /* store sequence */
             {
                 size_t litLength = ip-anchor;
-                offset_1 = ip-match;
+                offset_1 = offset;
                 ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset_1, matchLength-MINMATCH);
                 ip += matchLength;
                 anchor = ip;
@@ -364,23 +906,58 @@ static size_t ZSTD_HC_compressBlock(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstS
 
     /* Final compression stage */
     return ZSTD_compressSequences((BYTE*)dst, maxDstSize,
+
                                   seqStorePtr, srcSize);
 }
 
+
+typedef size_t (*ZSTD_HC_blockCompressor) (ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize);
+
+
+static ZSTD_HC_blockCompressor ZSTD_HC_selectBlockCompressor(ZSTD_HC_strategy strat)
+{
+    switch(strat)
+    {
+    default :
+    case ZSTD_HC_greedy:
+        return ZSTD_HC_compressBlock_greedy;
+    case ZSTD_HC_lazy:
+        return ZSTD_HC_compressBlock_lazy;
+    case ZSTD_HC_lazydeep:
+        return ZSTD_HC_compressBlock_lazydeep;
+    case ZSTD_HC_btlazy2:
+        return ZSTD_HC_compressBlock_btLazy2;
+    }
+}
+
+
+size_t ZSTD_HC_compressBlock(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+{
+    ZSTD_HC_blockCompressor blockCompressor = ZSTD_HC_selectBlockCompressor(ctx->params.strategy);
+    return blockCompressor(ctx, dst, maxDstSize, src, srcSize);
+}
+
+
 static size_t ZSTD_HC_compress_generic (ZSTD_HC_CCtx* ctxPtr,
                                         void* dst, size_t maxDstSize,
                                   const void* src, size_t srcSize)
 {
-    static const size_t blockSize = 128 KB;
+    size_t blockSize = BLOCKSIZE;
     size_t remaining = srcSize;
     const BYTE* ip = (const BYTE*)src;
     BYTE* const ostart = (BYTE*)dst;
     BYTE* op = ostart;
-    BYTE* const oend = op + maxDstSize;
+    const ZSTD_HC_blockCompressor blockCompressor = ZSTD_HC_selectBlockCompressor(ctxPtr->params.strategy);
 
-    while (remaining > blockSize)
+    while (remaining)
     {
-        size_t cSize = ZSTD_HC_compressBlock(ctxPtr, op+3, oend-op, ip, blockSize);
+        size_t cSize;
+
+        if (maxDstSize < 3 + MIN_CBLOCK_SIZE) return ERROR(dstSize_tooSmall);   /* not enough space to store compressed block */
+
+        if (remaining < blockSize) blockSize = remaining;
+        cSize = blockCompressor(ctxPtr, op+3, maxDstSize-3, ip, blockSize);
+        if (ZSTD_isError(cSize)) return cSize;
 
         if (cSize == 0)
         {
@@ -396,30 +973,9 @@ static size_t ZSTD_HC_compress_generic (ZSTD_HC_CCtx* ctxPtr,
         }
 
         remaining -= blockSize;
+        maxDstSize -= cSize;
         ip += blockSize;
         op += cSize;
-        if (ZSTD_isError(cSize)) return cSize;
-    }
-
-    /* last block */
-    {
-        size_t cSize = ZSTD_HC_compressBlock(ctxPtr, op+3, oend-op, ip, remaining);
-
-        if (cSize == 0)
-        {
-            cSize = ZSTD_noCompressBlock(op, maxDstSize, ip, remaining);   /* block is not compressible */
-        }
-        else
-        {
-            op[0] = (BYTE)(cSize>>16);
-            op[1] = (BYTE)(cSize>>8);
-            op[2] = (BYTE)cSize;
-            op[0] += (BYTE)(bt_compressed << 6); /* is a compressed block */
-            cSize += 3;
-        }
-
-        op += cSize;
-        if (ZSTD_isError(cSize)) return cSize;
     }
 
     return op-ostart;
@@ -504,7 +1060,7 @@ size_t ZSTD_HC_compress_advanced (ZSTD_HC_CCtx* ctx,
 
     /* body (compression) */
     ctx->base = (const BYTE*)src;
-    op += ZSTD_HC_compress_generic (ctx, op,  maxDstSize, src, srcSize);
+    oSize = ZSTD_HC_compress_generic (ctx, op,  maxDstSize, src, srcSize);
     if(ZSTD_isError(oSize)) return oSize;
     op += oSize;
     maxDstSize -= oSize;

lib/zstdhc_static.h

@@ -45,6 +45,7 @@ extern "C" {
 /* *************************************
 *  Types
 ***************************************/
+typedef enum { ZSTD_HC_greedy, ZSTD_HC_lazy, ZSTD_HC_lazydeep, ZSTD_HC_btlazy2 } ZSTD_HC_strategy;
 typedef struct
 {
     U32 windowLog;     /* largest match distance : impact decompression buffer size */
@@ -52,12 +53,13 @@ typedef struct
     U32 hashLog;       /* dispatch table : larger == more memory, faster*/
     U32 searchLog;     /* nb of searches : larger == more compression, slower*/
     U32 searchLength;  /* size of matches : larger == faster decompression */
+    ZSTD_HC_strategy strategy;   /* greedy, lazy, lazydeep */
 } ZSTD_HC_parameters;
 
 /* parameters boundaries */
 #define ZSTD_HC_WINDOWLOG_MAX 26
 #define ZSTD_HC_WINDOWLOG_MIN 18
-#define ZSTD_HC_CHAINLOG_MAX ZSTD_HC_WINDOWLOG_MAX
+#define ZSTD_HC_CHAINLOG_MAX (ZSTD_HC_WINDOWLOG_MAX+1)
 #define ZSTD_HC_CHAINLOG_MIN 4
 #define ZSTD_HC_HASHLOG_MAX 28
 #define ZSTD_HC_HASHLOG_MIN 4
@@ -71,12 +73,17 @@ typedef struct
 *  Advanced function
 ***************************************/
 /** ZSTD_HC_compress_advanced
-*   Same as ZSTD_HC_compressCCtx(), but can fine-tune each compression parameter */
+*   Same as ZSTD_HC_compressCCtx(), with fine-tune control of each compression parameter */
 size_t ZSTD_HC_compress_advanced (ZSTD_HC_CCtx* ctx,
                                  void* dst, size_t maxDstSize,
                            const void* src, size_t srcSize,
                                  ZSTD_HC_parameters params);
 
+/** ZSTD_HC_validateParams
+    correct params value to remain within authorized range
+    optimize for srcSize if srcSize > 0 */
+void ZSTD_HC_validateParams(ZSTD_HC_parameters* params, size_t srcSize);
+
 
 /* *************************************
 *  Streaming functions
@@ -89,38 +96,36 @@ size_t ZSTD_HC_compressEnd(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstSize);
 /* *************************************
 *  Pre-defined compression levels
 ***************************************/
-#define ZSTD_HC_MAX_CLEVEL 26
+#define ZSTD_HC_MAX_CLEVEL 22
 static const ZSTD_HC_parameters ZSTD_HC_defaultParameters[ZSTD_HC_MAX_CLEVEL+1] = {
-    /* W,  C,  H,  S */
-    { 18, 12, 14,  1,  4 },   /* level  0 - never used */
-    { 18, 12, 14,  1,  4 },   /* level  1 - in fact redirected towards zstd fast */
-    { 18, 12, 15,  2,  4 },   /* level  2 */
-    { 19, 14, 16,  3,  4 },   /* level  3 */
-    { 20, 15, 17,  4,  5 },   /* level  4 */
-    { 20, 17, 19,  4,  5 },   /* level  5 */
-    { 20, 19, 19,  4,  5 },   /* level  6 */
-    { 20, 19, 19,  5,  5 },   /* level  7 */
-    { 20, 20, 20,  5,  5 },   /* level  8 */
-    { 20, 20, 20,  6,  5 },   /* level  9 */
-    { 21, 21, 20,  5,  5 },   /* level 10 */
-    { 22, 21, 22,  6,  5 },   /* level 11 */
-    { 23, 21, 22,  6,  5 },   /* level 12 */
-    { 23, 21, 22,  7,  5 },   /* level 13 */
-    { 22, 22, 23,  7,  5 },   /* level 14 */
-    { 22, 22, 23,  7,  5 },   /* level 15 */
-    { 22, 22, 23,  8,  5 },   /* level 16 */
-    { 22, 22, 23,  8,  5 },   /* level 17 */
-    { 22, 22, 23,  9,  5 },   /* level 18 */
-    { 22, 22, 23,  9,  5 },   /* level 19 */
-    { 23, 23, 23,  9,  5 },   /* level 20 */
-    { 23, 23, 23,  9,  5 },   /* level 21 */
-    { 23, 23, 23, 10,  5 },   /* level 22 */
-    { 23, 23, 23, 10,  5 },   /* level 23 */
-    { 23, 23, 23, 11,  5 },   /* level 24 */
-    { 23, 23, 23, 12,  5 },   /* level 25 */
-    { 23, 23, 23, 13,  5 },   /* level 26 */   /* ZSTD_HC_MAX_CLEVEL */
+    /* W,  C,  H,  S,  L, strat */
+    { 18, 12, 14,  1,  4, ZSTD_HC_greedy   },  /* level  0 - never used */
+    { 18, 12, 14,  1,  4, ZSTD_HC_greedy   },  /* level  1 - in fact redirected towards zstd fast */
+    { 18, 12, 15,  2,  4, ZSTD_HC_greedy   },  /* level  2 */
+    { 19, 14, 18,  2,  5, ZSTD_HC_greedy   },  /* level  3 */
+    { 20, 17, 19,  3,  5, ZSTD_HC_greedy   },  /* level  4 */
+    { 20, 18, 19,  2,  5, ZSTD_HC_lazy     },  /* level  5 */
+    { 21, 18, 20,  3,  5, ZSTD_HC_lazy     },  /* level  6 */
+    { 21, 20, 20,  3,  5, ZSTD_HC_lazy     },  /* level  7 */
+    { 21, 19, 20,  4,  5, ZSTD_HC_lazy     },  /* level  8 */
+    { 21, 19, 20,  5,  5, ZSTD_HC_lazy     },  /* level  9 */
+    { 21, 20, 20,  5,  5, ZSTD_HC_lazy     },  /* level 10 */
+    { 21, 20, 20,  5,  5, ZSTD_HC_lazydeep },  /* level 11 */
+    { 22, 20, 22,  5,  5, ZSTD_HC_lazydeep },  /* level 12 */
+    { 22, 20, 22,  6,  5, ZSTD_HC_lazydeep },  /* level 13 */
+    { 22, 21, 22,  6,  5, ZSTD_HC_lazydeep },  /* level 14 */
+    { 22, 21, 22,  6,  5, ZSTD_HC_lazydeep },  /* level 15 */
+    { 22, 21, 22,  5,  5, ZSTD_HC_btlazy2  },  /* level 16 */
+    { 22, 22, 23,  5,  5, ZSTD_HC_btlazy2  },  /* level 17 */
+    { 23, 23, 23,  5,  5, ZSTD_HC_btlazy2  },  /* level 18 */
+    { 25, 25, 22,  5,  5, ZSTD_HC_btlazy2  },  /* level 19 */
+    { 25, 25, 23,  8,  5, ZSTD_HC_btlazy2  },  /* level 20 */
+    { 25, 26, 23,  9,  5, ZSTD_HC_btlazy2  },  /* level 21 */
+    { 25, 26, 23,  9,  5, ZSTD_HC_btlazy2  },  /* level 22 */
 };
 
+
+
 #if defined (__cplusplus)
 }
 #endif

programs/Makefile

@@ -30,7 +30,7 @@
 # fullbench32: Same as fullbench, but forced to compile in 32-bits mode
 # ##########################################################################
 
-VERSION?= 0.3.0
+VERSION?= 0.3.3
 
 DESTDIR?=
 PREFIX ?= /usr/local

programs/bench.c

@@ -83,7 +83,7 @@
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
-#define MAX_MEM             (2 GB - 64 MB)
+static const size_t maxMemory = sizeof(size_t)==4  ?  (2 GB - 64 MB) : (size_t)(1ULL << ((sizeof(size_t)*8)-31));
 #define DEFAULT_CHUNKSIZE   (4 MB)
 
 static U32 g_compressibilityDefault = 50;
@@ -237,11 +237,11 @@ static size_t local_compress_fast (void* dst, size_t maxDstSize, const void* src
     return ZSTD_compress(dst, maxDstSize, src, srcSize);
 }
 
-#define MIN(a,b) (a<b ? a : b)
+#define MIN(a,b) ((a)<(b) ? (a) : (b))
 
 static int BMK_benchMem(void* srcBuffer, size_t srcSize, const char* fileName, int cLevel)
 {
-    const size_t blockSize = g_blockSize ? g_blockSize : srcSize;
+    const size_t blockSize = (g_blockSize ? g_blockSize : srcSize) + (!srcSize);   /* avoid div by 0 */
     const U32 nbBlocks = (U32) ((srcSize + (blockSize-1)) / blockSize);
     blockParam_t* const blockTable = (blockParam_t*) malloc(nbBlocks * sizeof(blockParam_t));
     const size_t maxCompressedSize = (size_t)nbBlocks * ZSTD_compressBound(blockSize);
@@ -401,7 +401,7 @@ static size_t BMK_findMaxMem(U64 requiredMem)
 
     requiredMem = (((requiredMem >> 26) + 1) << 26);
     requiredMem += 2 * step;
-    if (requiredMem > MAX_MEM) requiredMem = MAX_MEM;
+    if (requiredMem > maxMemory) requiredMem = maxMemory;
 
     while (!testmem)
     {

programs/fuzzer.c

@@ -328,14 +328,15 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
         sampleStart = FUZ_rand(&lseed) % (srcBufferSize - sampleSize);
         crcOrig = XXH64(srcBuffer + sampleStart, sampleSize, 0);
 
-        /* HC compression test */
-        cLevel = (FUZ_rand(&lseed) & 3) + 2;
-        cSize = ZSTD_HC_compressCCtx(hcctx, cBuffer, cBufferSize, srcBuffer + sampleStart, sampleSize, cLevel);
-        CHECK(ZSTD_isError(cSize), "ZSTD_compress failed");
-
         /* compression test */
+        /* covered by HC cLevel 1
         cSize = ZSTD_compressCCtx(ctx, cBuffer, cBufferSize, srcBuffer + sampleStart, sampleSize);
-        CHECK(ZSTD_isError(cSize), "ZSTD_compress failed");
+        CHECK(ZSTD_isError(cSize), "ZSTD_compress failed"); */
+
+        /* HC compression test */
+        cLevel = (FUZ_rand(&lseed) & 3) +1;
+        cSize = ZSTD_HC_compressCCtx(hcctx, cBuffer, cBufferSize, srcBuffer + sampleStart, sampleSize, cLevel);
+        CHECK(ZSTD_isError(cSize), "ZSTD_HC_compressCCtx failed");
 
         /* compression failure test : too small dest buffer */
         if (cSize > 3)
@@ -346,16 +347,16 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
             static const U32 endMark = 0x4DC2B1A9;
             U32 endCheck;
             memcpy(dstBuffer+tooSmallSize, &endMark, 4);
-            errorCode = ZSTD_compressCCtx(ctx, dstBuffer, tooSmallSize, srcBuffer + sampleStart, sampleSize);
-            CHECK(!ZSTD_isError(errorCode), "ZSTD_compress should have failed ! (buffer too small)");
+            errorCode = ZSTD_HC_compressCCtx(hcctx, dstBuffer, tooSmallSize, srcBuffer + sampleStart, sampleSize, cLevel);
+            CHECK(!ZSTD_isError(errorCode), "ZSTD_HC_compressCCtx should have failed ! (buffer too small : %u < %u)", (U32)tooSmallSize, (U32)cSize);
             memcpy(&endCheck, dstBuffer+tooSmallSize, 4);
-            CHECK(endCheck != endMark, "ZSTD_compress : dst buffer overflow");
+            CHECK(endCheck != endMark, "ZSTD_HC_compressCCtx : dst buffer overflow");
         }
 
         /* successfull decompression tests*/
         dSupSize = (FUZ_rand(&lseed) & 1) ? 0 : (FUZ_rand(&lseed) & 31) + 1;
         dSize = ZSTD_decompress(dstBuffer, sampleSize + dSupSize, cBuffer, cSize);
-        CHECK(dSize != sampleSize, "ZSTD_decompress failed (%s)", ZSTD_getErrorName(dSize));
+        CHECK(dSize != sampleSize, "ZSTD_decompress failed (%s) (srcSize : %u ; cSize : %u)", ZSTD_getErrorName(dSize), (U32)sampleSize, (U32)cSize);
         crcDest = XXH64(dstBuffer, sampleSize, 0);
         CHECK(crcOrig != crcDest, "dstBuffer corrupted (pos %u / %u)", (U32)findDiff(srcBuffer+sampleStart, dstBuffer, sampleSize), (U32)sampleSize);
 

programs/paramgrill.c

@@ -122,7 +122,8 @@ static U32 g_rand = 1;
 static U32 g_singleRun = 0;
 static U32 g_target = 0;
 static U32 g_noSeed = 0;
-static ZSTD_HC_parameters g_params = { 0, 0, 0, 0, 0 };
+static const ZSTD_HC_parameters* g_seedParams = ZSTD_HC_defaultParameters;
+static ZSTD_HC_parameters g_params = { 0, 0, 0, 0, 0, ZSTD_HC_greedy };
 
 void BMK_SetNbIterations(int nbLoops)
 {
@@ -283,9 +284,12 @@ static size_t BMK_benchParam(BMK_result_t* resultPtr,
     U32 Hlog = params.hashLog;
     U32 Slog = params.searchLog;
     U32 Slength = params.searchLength;
+    ZSTD_HC_strategy strat = params.strategy;
+    char name[30] = { 0 };
     U64 crcOrig;
 
     /* Memory allocation & restrictions */
+    snprintf(name, 30, "W%02uC%02uH%02uS%02uL%1ust%1u", Wlog, Clog, Hlog, Slog, Slength, strat);
     if (!compressedBuffer || !resultBuffer || !blockTable)
     {
         DISPLAY("\nError: not enough memory!\n");
@@ -344,7 +348,7 @@ static size_t BMK_benchParam(BMK_result_t* resultPtr,
             if (totalTime > g_maxParamTime) break;
 
             /* Compression */
-            DISPLAY("%1u-W%02uC%02uH%02uS%02uL%02u : %9u ->\r", loopNb, Wlog, Clog, Hlog, Slog, Slength, (U32)srcSize);
+            DISPLAY("\r%1u-%s : %9u ->", loopNb, name, (U32)srcSize);
             memset(compressedBuffer, 0xE5, maxCompressedSize);
 
             nbLoops = 0;
@@ -367,8 +371,9 @@ static size_t BMK_benchParam(BMK_result_t* resultPtr,
                 cSize += blockTable[blockNb].cSize;
             if ((double)milliTime < fastestC*nbLoops) fastestC = (double)milliTime / nbLoops;
             ratio = (double)srcSize / (double)cSize;
-            DISPLAY("%1u-W%02uC%02uH%02uS%02uL%02u : %9u ->", loopNb, Wlog, Clog, Hlog, Slog, Slength, (U32)srcSize);
-            DISPLAY(" %9u (%4.3f),%7.1f MB/s\r", (U32)cSize, ratio, (double)srcSize / fastestC / 1000.);
+            DISPLAY("\r");
+            DISPLAY("%1u-%s : %9u ->", loopNb, name, (U32)srcSize);
+            DISPLAY(" %9u (%4.3f),%7.1f MB/s", (U32)cSize, ratio, (double)srcSize / fastestC / 1000.);
             resultPtr->cSize = cSize;
             resultPtr->cSpeed = (U32)((double)srcSize / fastestC);
 
@@ -389,9 +394,10 @@ static size_t BMK_benchParam(BMK_result_t* resultPtr,
             milliTime = BMK_GetMilliSpan(milliTime);
 
             if ((double)milliTime < fastestD*nbLoops) fastestD = (double)milliTime / nbLoops;
-            DISPLAY("%1u-W%02uC%02uH%02uS%02uL%02u : %9u -> ", loopNb, Wlog, Clog, Hlog, Slog, Slength, (U32)srcSize);
+            DISPLAY("\r");
+            DISPLAY("%1u-%s : %9u -> ", loopNb, name, (U32)srcSize);
             DISPLAY("%9u (%4.3f),%7.1f MB/s, ", (U32)cSize, ratio, (double)srcSize / fastestC / 1000.);
-            DISPLAY("%7.1f MB/s\r", (double)srcSize / fastestD / 1000.);
+            DISPLAY("%7.1f MB/s", (double)srcSize / fastestD / 1000.);
             resultPtr->dSpeed = (U32)((double)srcSize / fastestD);
 
             /* CRC Checking */
@@ -416,18 +422,23 @@ static size_t BMK_benchParam(BMK_result_t* resultPtr,
     }
 
     /* End cleaning */
+    DISPLAY("\r");
     free(compressedBuffer);
     free(resultBuffer);
     return 0;
 }
 
 
+const char* g_stratName[] = { "ZSTD_HC_greedy  ", "ZSTD_HC_lazy    ", "ZSTD_HC_lazydeep", "ZSTD_HC_btlazy2 " };
+
 static void BMK_printWinner(FILE* f, U32 cLevel, BMK_result_t result, ZSTD_HC_parameters params, size_t srcSize)
 {
     DISPLAY("\r%79s\r", "");
-    fprintf(f,"    {%3u,%3u,%3u,%3u,%3u },   ", params.windowLog, params.chainLog, params.hashLog, params.searchLog, params.searchLength);
+    fprintf(f,"    {%3u,%3u,%3u,%3u,%3u, %s },  ",
+            params.windowLog, params.chainLog, params.hashLog, params.searchLog, params.searchLength,
+            g_stratName[params.strategy]);
     fprintf(f,
-            "/* level %2u */     /* R:%5.3f at %5.1f MB/s - %5.1f MB/s */ \n",
+            "/* level %2u */   /* R:%5.3f at %5.1f MB/s - %5.1f MB/s */\n",
             cLevel, (double)srcSize / result.cSize, (double)result.cSpeed / 1000., (double)result.dSpeed / 1000.);
 }
 
@@ -446,7 +457,7 @@ static void BMK_printWinners2(FILE* f, const winnerInfo_t* winners, size_t srcSi
     fprintf(f, "\n /* Selected configurations : */ \n");
     fprintf(f, "#define ZSTD_HC_MAX_CLEVEL %2u \n", ZSTD_HC_MAX_CLEVEL);
     fprintf(f, "static const ZSTD_HC_parameters ZSTD_HC_defaultParameters[ZSTD_HC_MAX_CLEVEL+1] = {\n");
-    fprintf(f, "    /* W,  C,  H,  S,  L */ \n");
+    fprintf(f, "    /* W,  C,  H,  S,  L, strat */ \n");
 
     for (cLevel=0; cLevel <= ZSTD_HC_MAX_CLEVEL; cLevel++)
         BMK_printWinner(f, cLevel, winners[cLevel].result, winners[cLevel].params, srcSize);
@@ -486,7 +497,7 @@ static int BMK_seed(winnerInfo_t* winners, const ZSTD_HC_parameters params,
             continue;
         }
 
-        if ((double)testResult.cSize <= ((double)winners[cLevel].result.cSize * (1. + (0.01 / cLevel))) )
+        if ((double)testResult.cSize <= ((double)winners[cLevel].result.cSize * (1. + (0.02 / cLevel))) )
         {
             /* Validate solution is "good enough" */
             double W_ratio = (double)srcSize / testResult.cSize;
@@ -567,13 +578,17 @@ static int BMK_seed(winnerInfo_t* winners, const ZSTD_HC_parameters params,
 static BYTE g_alreadyTested[ZSTD_HC_WINDOWLOG_MAX+1-ZSTD_HC_WINDOWLOG_MIN]
                            [ZSTD_HC_CHAINLOG_MAX+1-ZSTD_HC_CHAINLOG_MIN]
                            [ZSTD_HC_HASHLOG_MAX+1-ZSTD_HC_HASHLOG_MIN]
-                           [ZSTD_HC_SEARCHLOG_MAX+1-ZSTD_HC_SEARCHLOG_MIN] = {};   /* init to zero */
+                           [ZSTD_HC_SEARCHLOG_MAX+1-ZSTD_HC_SEARCHLOG_MIN]
+                           [ZSTD_HC_SEARCHLENGTH_MAX+1-ZSTD_HC_SEARCHLENGTH_MIN]
+                           [4 /* strategy */ ] = {};   /* init to zero */
 
 #define NB_TESTS_PLAYED(p) \
     g_alreadyTested[p.windowLog-ZSTD_HC_WINDOWLOG_MIN] \
                    [p.chainLog-ZSTD_HC_CHAINLOG_MIN]   \
                    [p.hashLog-ZSTD_HC_HASHLOG_MIN]     \
-                   [p.searchLog-ZSTD_HC_SEARCHLOG_MIN]
+                   [p.searchLog-ZSTD_HC_SEARCHLOG_MIN] \
+                   [p.searchLength-ZSTD_HC_SEARCHLENGTH_MIN] \
+                   [(U32)p.strategy]
 
 
 static void playAround(FILE* f, winnerInfo_t* winners,
@@ -581,7 +596,6 @@ static void playAround(FILE* f, winnerInfo_t* winners,
                        const void* srcBuffer, size_t srcSize,
                        ZSTD_HC_CCtx* ctx)
 {
-    const U32 srcLog = BMK_highbit((U32)( (g_blockSize ? g_blockSize : srcSize) -1))+1;
     int nbVariations = 0;
     const int startTime = BMK_GetMilliStart();
 
@@ -593,7 +607,7 @@ static void playAround(FILE* f, winnerInfo_t* winners,
 
         for (; nbChanges; nbChanges--)
         {
-            const U32 changeID = FUZ_rand(&g_rand) % 9;
+            const U32 changeID = FUZ_rand(&g_rand) % 12;
             switch(changeID)
             {
             case 0:
@@ -616,24 +630,23 @@ static void playAround(FILE* f, winnerInfo_t* winners,
                 p.searchLength++; break;
             case 9:
                 p.searchLength--; break;
+            case 10:
+                p.strategy = (ZSTD_HC_strategy)(((U32)p.strategy)+1); break;
+            case 11:
+                p.strategy = (ZSTD_HC_strategy)(((U32)p.strategy)-1); break;
             }
         }
 
         /* validate new conf */
-        if (p.windowLog > srcLog) continue;
-        if (p.windowLog > ZSTD_HC_WINDOWLOG_MAX) continue;
-        if (p.windowLog < MAX(ZSTD_HC_WINDOWLOG_MIN, p.chainLog)) continue;
-        if (p.chainLog > p.windowLog) continue;
-        if (p.chainLog < ZSTD_HC_CHAINLOG_MIN) continue;
-        if (p.hashLog > ZSTD_HC_HASHLOG_MAX) continue;
-        if (p.hashLog < ZSTD_HC_HASHLOG_MIN) continue;
-        if (p.searchLog > p.chainLog) continue;
-        if (p.searchLog < ZSTD_HC_SEARCHLOG_MIN) continue;
-        if (p.searchLength > ZSTD_HC_SEARCHLENGTH_MAX) continue;
-        if (p.searchLength < ZSTD_HC_SEARCHLENGTH_MIN) continue;
+        {
+            ZSTD_HC_parameters saved = p;
+            ZSTD_HC_validateParams(&p, g_blockSize ? g_blockSize : srcSize);
+            if (memcmp(&p, &saved, sizeof(p))) continue;  /* p was invalid */
+        }
 
         /* exclude faster if already played params */
-        if (FUZ_rand(&g_rand) & ((1 << NB_TESTS_PLAYED(p))-1)) continue;
+        if (FUZ_rand(&g_rand) & ((1 << NB_TESTS_PLAYED(p))-1))
+            continue;
 
         /* test */
         NB_TESTS_PLAYED(p)++;
@@ -662,6 +675,7 @@ static void BMK_selectRandomStart(
         p.searchLog  = FUZ_rand(&g_rand) % (ZSTD_HC_SEARCHLOG_MAX+1 - ZSTD_HC_SEARCHLOG_MIN) + ZSTD_HC_SEARCHLOG_MIN;
         p.windowLog  = FUZ_rand(&g_rand) % (ZSTD_HC_WINDOWLOG_MAX+1 - ZSTD_HC_WINDOWLOG_MIN) + ZSTD_HC_WINDOWLOG_MIN;
         p.searchLength=FUZ_rand(&g_rand) % (ZSTD_HC_SEARCHLENGTH_MAX+1 - ZSTD_HC_SEARCHLENGTH_MIN) + ZSTD_HC_SEARCHLENGTH_MIN;
+        p.strategy   = (ZSTD_HC_strategy) (FUZ_rand(&g_rand) % 4);
         playAround(f, winners, p, srcBuffer, srcSize, ctx);
     }
     else
@@ -669,8 +683,6 @@ static void BMK_selectRandomStart(
 }
 
 
-static const ZSTD_HC_parameters* g_seedParams = ZSTD_HC_defaultParameters;
-
 static void BMK_benchMem(void* srcBuffer, size_t srcSize)
 {
     ZSTD_HC_CCtx* ctx = ZSTD_HC_createCCtx();
@@ -684,6 +696,7 @@ static void BMK_benchMem(void* srcBuffer, size_t srcSize)
     if (g_singleRun)
     {
         BMK_result_t testResult;
+        ZSTD_HC_validateParams(&g_params, g_blockSize ? g_blockSize : srcSize);
         BMK_benchParam(&testResult, srcBuffer, srcSize, ctx, g_params);
         DISPLAY("\n");
         return;
@@ -955,12 +968,21 @@ int main(int argc, char** argv)
                             while ((*argument>= '0') && (*argument<='9'))
                                 g_params.searchLog *= 10, g_params.searchLog += *argument++ - '0';
                             continue;
-                        case 'l':
+                        case 'l':  /* search length */
                             g_params.searchLength = 0;
                             argument++;
                             while ((*argument>= '0') && (*argument<='9'))
                                 g_params.searchLength *= 10, g_params.searchLength += *argument++ - '0';
                             continue;
+                        case 't':  /* strategy */
+                            g_params.strategy = ZSTD_HC_greedy;
+                            argument++;
+                            while ((*argument>= '0') && (*argument<='9'))
+                            {
+                                g_params.strategy = (ZSTD_HC_strategy)((U32)g_params.strategy *10);
+                                g_params.strategy = (ZSTD_HC_strategy)((U32)g_params.strategy + *argument++ - '0');
+                            }
+                            continue;
                         case 'L':
                             {
                                 int cLevel = 0;

programs/zstdcli.c

@@ -70,7 +70,7 @@
 **************************************/
 #define COMPRESSOR_NAME "zstd command line interface"
 #ifndef ZSTD_VERSION
-#  define ZSTD_VERSION "v0.0.1"
+#  define ZSTD_VERSION "v0.3.3"
 #endif
 #define AUTHOR "Yann Collet"
 #define WELCOME_MESSAGE "*** %s %i-bits %s, by %s (%s) ***\n", COMPRESSOR_NAME, (int)(sizeof(void*)*8), ZSTD_VERSION, AUTHOR, __DATE__
@@ -178,7 +178,7 @@ int main(int argc, char** argv)
     const char* inFileName = NULL;
     const char* outFileName = NULL;
     char* dynNameSpace = NULL;
-    char extension[] = ZSTD_EXTENSION;
+    const char extension[] = ZSTD_EXTENSION;
 
     displayOut = stderr;
     /* Pick out basename component. Don't rely on stdlib because of conflicting behavior. */
@@ -351,16 +351,17 @@ int main(int argc, char** argv)
         }
         /* decompression to file (automatic name will work only if input filename has correct format extension) */
         {
-            size_t outl;
-            size_t inl = strlen(inFileName);
-            dynNameSpace = (char*)calloc(1,inl+1);
+            size_t filenameSize = strlen(inFileName);
+            if (strcmp(inFileName + (filenameSize-4), extension))
+            {
+                 DISPLAYLEVEL(1, "unknown suffix - cannot determine destination filename\n");
+                 return badusage(programName);
+            }
+            dynNameSpace = (char*)calloc(1,filenameSize+1);
             if (dynNameSpace==NULL) { DISPLAY("not enough memory\n"); exit(1); }
             outFileName = dynNameSpace;
             strcpy(dynNameSpace, inFileName);
-            outl = inl;
-            if (inl>4)
-                while ((outl >= inl-4) && (inFileName[outl] ==  extension[outl-inl+4])) dynNameSpace[outl--]=0;
-            if (outl != inl-5) { DISPLAYLEVEL(1, "Cannot determine an output filename\n"); return badusage(programName); }
+            dynNameSpace[filenameSize-4]=0;
             DISPLAYLEVEL(2, "Decoding file %s \n", outFileName);
         }
     }

visual/2012/fullbench/fullbench.vcxproj

@@ -78,7 +78,7 @@
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <LinkIncremental>false</LinkIncremental>
-    <IncludePath>$(SolutionDir)..\..\lib;$(VCInstallDir)include;$(VCInstallDir)atlmfc\include;$(WindowsSDK_IncludePath);</IncludePath>
+    <IncludePath>$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\lib;$(VCInstallDir)include;$(VCInstallDir)atlmfc\include;$(WindowsSDK_IncludePath);</IncludePath>
     <RunCodeAnalysis>true</RunCodeAnalysis>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">

visual/2012/fuzzer/fuzzer.vcxproj

@@ -78,7 +78,7 @@
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <LinkIncremental>false</LinkIncremental>
-    <IncludePath>$(SolutionDir)..\..\lib;$(VCInstallDir)include;$(VCInstallDir)atlmfc\include;$(WindowsSDK_IncludePath);</IncludePath>
+    <IncludePath>$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\lib;$(VCInstallDir)include;$(VCInstallDir)atlmfc\include;$(WindowsSDK_IncludePath);</IncludePath>
     <RunCodeAnalysis>true</RunCodeAnalysis>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">

visual/2012/zstd/zstd.vcxproj

@@ -109,7 +109,7 @@
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <LinkIncremental>false</LinkIncremental>
-    <IncludePath>$(SolutionDir)..\..\lib;$(VCInstallDir)include;$(VCInstallDir)atlmfc\include;$(WindowsSDK_IncludePath);</IncludePath>
+    <IncludePath>$(SolutionDir)..\..\programs\legacy;$(SolutionDir)..\..\lib\legacy;$(SolutionDir)..\..\lib;$(VCInstallDir)include;$(VCInstallDir)atlmfc\include;$(WindowsSDK_IncludePath);</IncludePath>
     <RunCodeAnalysis>true</RunCodeAnalysis>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">