Merge pull request #297 from lz4/devv1.7.5

v1.7.5

1 files changed, 363 insertions, 0 deletions

diff --git a/lib/lz4opt.h b/lib/lz4opt.h
new file mode 100644
index 0000000..d1913fe
--- /dev/null
+++ b/lib/lz4opt.h
@@ -0,0 +1,363 @@
+/*
+    lz4opt.h - Optimal Mode of LZ4
+    Copyright (C) 2015-2016, Przemyslaw Skibinski <inikep@gmail.com>
+    Note : this file is intended to be included within lz4hc.c
+
+    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are
+    met:
+
+    * Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+    copyright notice, this list of conditions and the following disclaimer
+    in the documentation and/or other materials provided with the
+    distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+    You can contact the author at :
+       - LZ4 source repository : https://github.com/lz4/lz4
+       - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
+*/
+
+#define LZ4_OPT_NUM   (1<<12)
+
+
+typedef struct
+{
+    int off;
+    int len;
+} LZ4HC_match_t;
+
+typedef struct
+{
+    int price;
+    int off;
+    int mlen;
+    int litlen;
+} LZ4HC_optimal_t;
+
+
+/* price in bits */
+FORCE_INLINE size_t LZ4HC_literalsPrice(size_t litlen)
+{
+    size_t price = 8*litlen;
+    if (litlen >= (size_t)RUN_MASK) price+=8*(1+(litlen-RUN_MASK)/255);
+    return price;
+}
+
+
+/* requires mlen >= MINMATCH */
+FORCE_INLINE size_t LZ4HC_sequencePrice(size_t litlen, size_t mlen)
+{
+    size_t price = 16 + 8; /* 16-bit offset + token */
+
+    price += LZ4HC_literalsPrice(litlen);
+
+    mlen -= MINMATCH;
+    if (mlen >= (size_t)ML_MASK) price+=8*(1+(mlen-ML_MASK)/255);
+
+    return price;
+}
+
+
+/*-*************************************
+*  Binary Tree search
+***************************************/
+FORCE_INLINE int LZ4HC_BinTree_InsertAndGetAllMatches (
+    LZ4HC_CCtx_internal* ctx,
+    const BYTE* const ip,
+    const BYTE* const iHighLimit,
+    size_t best_mlen,
+    LZ4HC_match_t* matches,
+    int* matchNum)
+{
+    U16* const chainTable = ctx->chainTable;
+    U32* const HashTable = ctx->hashTable;
+    const BYTE* const base = ctx->base;
+    const U32 dictLimit = ctx->dictLimit;
+    const U32 current = (U32)(ip - base);
+    const U32 lowLimit = (ctx->lowLimit + MAX_DISTANCE > current) ? ctx->lowLimit : current - (MAX_DISTANCE - 1);
+    const BYTE* const dictBase = ctx->dictBase;
+    const BYTE* match;
+    int nbAttempts = ctx->searchNum;
+    int mnum = 0;
+    U16 *ptr0, *ptr1, delta0, delta1;
+    U32 matchIndex;
+    size_t matchLength = 0;
+    U32* HashPos;
+
+    if (ip + MINMATCH > iHighLimit) return 1;
+
+    /* HC4 match finder */
+    HashPos = &HashTable[LZ4HC_hashPtr(ip)];
+    matchIndex = *HashPos;
+    *HashPos = current;
+
+    ptr0 = &DELTANEXTMAXD(current*2+1);
+    ptr1 = &DELTANEXTMAXD(current*2);
+    delta0 = delta1 = (U16)(current - matchIndex);
+
+    while ((matchIndex < current) && (matchIndex>=lowLimit) && (nbAttempts)) {
+        nbAttempts--;
+        if (matchIndex >= dictLimit) {
+            match = base + matchIndex;
+            matchLength = LZ4_count(ip, match, iHighLimit);
+        } else {
+            const BYTE* vLimit = ip + (dictLimit - matchIndex);
+            match = dictBase + matchIndex;
+            if (vLimit > iHighLimit) vLimit = iHighLimit;
+            matchLength = LZ4_count(ip, match, vLimit);
+            if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
+                matchLength += LZ4_count(ip+matchLength, base+dictLimit, iHighLimit);
+        }
+
+        if (matchLength > best_mlen) {
+            best_mlen = matchLength;
+            if (matches) {
+                if (matchIndex >= dictLimit)
+                    matches[mnum].off = (int)(ip - match);
+                else
+                    matches[mnum].off = (int)(ip - (base + matchIndex)); /* virtual matchpos */
+                matches[mnum].len = (int)matchLength;
+                mnum++;
+            }
+            if (best_mlen > LZ4_OPT_NUM) break;
+        }
+
+        if (ip+matchLength >= iHighLimit)   /* equal : no way to know if inf or sup */
+            break;   /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */
+
+        if (*(ip+matchLength) < *(match+matchLength)) {
+            *ptr0 = delta0;
+            ptr0 = &DELTANEXTMAXD(matchIndex*2);
+            if (*ptr0 == (U16)-1) break;
+            delta0 = *ptr0;
+            delta1 += delta0;
+            matchIndex -= delta0;
+        } else {
+            *ptr1 = delta1;
+            ptr1 = &DELTANEXTMAXD(matchIndex*2+1);
+            if (*ptr1 == (U16)-1) break;
+            delta1 = *ptr1;
+            delta0 += delta1;
+            matchIndex -= delta1;
+        }
+    }
+
+    *ptr0 = (U16)-1;
+    *ptr1 = (U16)-1;
+    if (matchNum) *matchNum = mnum;
+  /*  if (best_mlen > 8) return best_mlen-8; */
+    if (!matchNum) return 1;
+    return 1;
+}
+
+
+FORCE_INLINE void LZ4HC_updateBinTree(LZ4HC_CCtx_internal* ctx, const BYTE* const ip, const BYTE* const iHighLimit)
+{
+    const BYTE* const base = ctx->base;
+    const U32 target = (U32)(ip - base);
+    U32 idx = ctx->nextToUpdate;
+    while(idx < target)
+        idx += LZ4HC_BinTree_InsertAndGetAllMatches(ctx, base+idx, iHighLimit, 8, NULL, NULL);
+}
+
+
+/** Tree updater, providing best match */
+FORCE_INLINE int LZ4HC_BinTree_GetAllMatches (
+                        LZ4HC_CCtx_internal* ctx,
+                        const BYTE* const ip, const BYTE* const iHighLimit,
+                        size_t best_mlen, LZ4HC_match_t* matches, const int fullUpdate)
+{
+    int mnum = 0;
+    if (ip < ctx->base + ctx->nextToUpdate) return 0;   /* skipped area */
+    if (fullUpdate) LZ4HC_updateBinTree(ctx, ip, iHighLimit);
+    best_mlen = LZ4HC_BinTree_InsertAndGetAllMatches(ctx, ip, iHighLimit, best_mlen, matches, &mnum);
+    ctx->nextToUpdate = (U32)(ip - ctx->base + best_mlen);
+    return mnum;
+}
+
+
+#define SET_PRICE(pos, mlen, offset, litlen, price)    \
+{                                                      \
+    while (last_pos < pos)  { opt[last_pos+1].price = 1<<30; last_pos++; } \
+    opt[pos].mlen = (int)mlen;                         \
+    opt[pos].off = (int)offset;                        \
+    opt[pos].litlen = (int)litlen;                     \
+    opt[pos].price = (int)price;                       \
+}
+
+
+static int LZ4HC_compress_optimal (
+    LZ4HC_CCtx_internal* ctx,
+    const char* const source,
+    char* dest,
+    int inputSize,
+    int maxOutputSize,
+    limitedOutput_directive limit,
+    const size_t sufficient_len,
+    const int fullUpdate
+    )
+{
+    LZ4HC_optimal_t opt[LZ4_OPT_NUM + 1];
+    LZ4HC_match_t matches[LZ4_OPT_NUM + 1];
+    const BYTE *inr = NULL;
+    size_t res, cur, cur2;
+    size_t i, llen, litlen, mlen, best_mlen, price, offset, best_off, match_num, last_pos;
+
+    const BYTE* ip = (const BYTE*) source;
+    const BYTE* anchor = ip;
+    const BYTE* const iend = ip + inputSize;
+    const BYTE* const mflimit = iend - MFLIMIT;
+    const BYTE* const matchlimit = (iend - LASTLITERALS);
+    BYTE* op = (BYTE*) dest;
+    BYTE* const oend = op + maxOutputSize;
+
+    /* init */
+    ctx->end += inputSize;
+    ip++;
+
+    /* Main Loop */
+    while (ip < mflimit) {
+        memset(opt, 0, sizeof(LZ4HC_optimal_t));
+        last_pos = 0;
+        llen = ip - anchor;
+        match_num = LZ4HC_BinTree_GetAllMatches(ctx, ip, matchlimit, MINMATCH-1, matches, fullUpdate);
+        if (!match_num) { ip++; continue; }
+
+        if ((size_t)matches[match_num-1].len > sufficient_len) {
+            best_mlen = matches[match_num-1].len;
+            best_off = matches[match_num-1].off;
+            cur = 0;
+            last_pos = 1;
+            goto encode;
+        }
+
+        /* set prices using matches at position = 0 */
+        for (i = 0; i < match_num; i++) {
+           mlen = (i>0) ? (size_t)matches[i-1].len+1 : MINMATCH;
+           best_mlen = (matches[i].len < LZ4_OPT_NUM) ? matches[i].len : LZ4_OPT_NUM;
+           while (mlen <= best_mlen) {
+                litlen = 0;
+                price = LZ4HC_sequencePrice(llen + litlen, mlen) - LZ4HC_literalsPrice(llen);
+                SET_PRICE(mlen, mlen, matches[i].off, litlen, price);
+                mlen++;
+           }
+        }
+
+        if (last_pos < MINMATCH) { ip++; continue; }
+
+        /* check further positions */
+        opt[0].mlen = opt[1].mlen = 1;
+        for (cur = 1; cur <= last_pos; cur++) {
+            inr = ip + cur;
+
+            if (opt[cur-1].mlen == 1) {
+                litlen = opt[cur-1].litlen + 1;
+                if (cur != litlen) {
+                    price = opt[cur - litlen].price + LZ4HC_literalsPrice(litlen);
+                } else {
+                    price = LZ4HC_literalsPrice(llen + litlen) - LZ4HC_literalsPrice(llen);
+                }
+            } else {
+                litlen = 1;
+                price = opt[cur - 1].price + LZ4HC_literalsPrice(litlen);
+            }
+
+            mlen = 1;
+            best_mlen = 0;
+            if (cur > last_pos || price < (size_t)opt[cur].price)
+                SET_PRICE(cur, mlen, best_mlen, litlen, price);
+
+            if (cur == last_pos || inr >= mflimit) break;
+
+            match_num = LZ4HC_BinTree_GetAllMatches(ctx, inr, matchlimit, MINMATCH-1, matches, fullUpdate);
+            if (match_num > 0 && (size_t)matches[match_num-1].len > sufficient_len) {
+                best_mlen = matches[match_num-1].len;
+                best_off = matches[match_num-1].off;
+                last_pos = cur + 1;
+                goto encode;
+            }
+
+            /* set prices using matches at position = cur */
+            for (i = 0; i < match_num; i++) {
+                mlen = (i>0) ? (size_t)matches[i-1].len+1 : MINMATCH;
+                cur2 = cur;
+                best_mlen = (cur2 + matches[i].len < LZ4_OPT_NUM) ? (size_t)matches[i].len : LZ4_OPT_NUM - cur2;
+
+                while (mlen <= best_mlen) {
+                    if (opt[cur2].mlen == 1) {
+                        litlen = opt[cur2].litlen;
+
+                        if (cur2 != litlen)
+                            price = opt[cur2 - litlen].price + LZ4HC_sequencePrice(litlen, mlen);
+                        else
+                            price = LZ4HC_sequencePrice(llen + litlen, mlen) - LZ4HC_literalsPrice(llen);
+                    } else {
+                        litlen = 0;
+                        price = opt[cur2].price + LZ4HC_sequencePrice(litlen, mlen);
+                    }
+
+                    if (cur2 + mlen > last_pos || price < (size_t)opt[cur2 + mlen].price) { // || (((int)price == opt[cur2 + mlen].price) && (opt[cur2 + mlen-1].mlen == 1))) {
+                        SET_PRICE(cur2 + mlen, mlen, matches[i].off, litlen, price);
+                    }
+                    mlen++;
+                }
+            }
+        } /* for (cur = 1; cur <= last_pos; cur++) */
+
+        best_mlen = opt[last_pos].mlen;
+        best_off = opt[last_pos].off;
+        cur = last_pos - best_mlen;
+
+encode: /* cur, last_pos, best_mlen, best_off have to be set */
+        opt[0].mlen = 1;
+        while (1) {
+            mlen = opt[cur].mlen;
+            offset = opt[cur].off;
+            opt[cur].mlen = (int)best_mlen;
+            opt[cur].off = (int)best_off;
+            best_mlen = mlen;
+            best_off = offset;
+            if (mlen > cur) break;
+            cur -= mlen;
+        }
+
+        cur = 0;
+        while (cur < last_pos) {
+            mlen = opt[cur].mlen;
+            if (mlen == 1) { ip++; cur++; continue; }
+            offset = opt[cur].off;
+            cur += mlen;
+
+            res = LZ4HC_encodeSequence(&ip, &op, &anchor, (int)mlen, ip - offset, limit, oend);
+            if (res) return 0;
+        }
+    }
+
+    /* Encode Last Literals */
+    {   int lastRun = (int)(iend - anchor);
+        if ((limit) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize)) return 0;  /* Check output limit */
+        if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
+        else *op++ = (BYTE)(lastRun<<ML_BITS);
+        memcpy(op, anchor, iend - anchor);
+        op += iend-anchor;
+    }
+
+    /* End */
+    return (int) ((char*)op-dest);
+}