public static void RenormDictT(StreamT *dict, byte *src)
{
if ((dict->CurrentOffset <= 0x80000000) && (dict->CurrentOffset <= (ulong)src))
{
return;
}
uint delta = dict->CurrentOffset - 64 * KB;
byte *dictEnd = dict->Dictionary + dict->DictSize;
for (int i = 0; i < HashSizeU32; i++)
{
if (dict->HashTable[i] < delta)
{
dict->HashTable[i] = 0;
}
else
{
dict->HashTable[i] -= delta;
}
}
dict->CurrentOffset = 64 * KB;
if (dict->DictSize > 64 * KB)
{
dict->DictSize = 64 * KB;
}
dict->Dictionary = dictEnd - dict->DictSize;
}
public static int CompressDestSizeExtState(StreamT *state, byte *src, byte *dst, int *srcSizePtr, int targetDstSize)
{
ResetStream(state);
return(targetDstSize >= CompressBound(*srcSizePtr)
? CompressFastExtState(
state,
src,
dst,
*srcSizePtr,
targetDstSize,
1)
: CompressDestSizeGeneric(
state,
src,
dst,
srcSizePtr,
targetDstSize,
TableType(*srcSizePtr)));
}
public static int SaveDict(StreamT *dict, byte *safeBuffer, int dictSize)
{
byte *previousDictEnd = dict->Dictionary + dict->DictSize;
if ((uint)dictSize > 64 * KB)
{
dictSize = 64 * KB;
}
if ((uint)dictSize > dict->DictSize)
{
dictSize = (int)dict->DictSize;
}
LZ4MemoryHelper.Move(safeBuffer, previousDictEnd - dictSize, dictSize);
dict->Dictionary = safeBuffer;
dict->DictSize = (uint)dictSize;
return(dictSize);
}
//--------------------------------------------------------------------
public static int LoadDict(StreamT *lz4dict, byte *dictionary, int dictSize)
{
StreamT *dict = lz4dict;
byte * p = dictionary;
byte * dictEnd = p + dictSize;
if (dict->InitCheck != 0 || dict->CurrentOffset > 1 * GB)
{
ResetStream(lz4dict);
}
if (dictSize < HashUnit)
{
dict->Dictionary = null;
dict->DictSize = 0;
return(0);
}
if (dictEnd - p > 64 * KB)
{
p = dictEnd - 64 * KB;
}
dict->CurrentOffset += 64 * KB;
byte *srcBase = p - dict->CurrentOffset;
dict->Dictionary = p;
dict->DictSize = (uint)(dictEnd - p);
dict->CurrentOffset += dict->DictSize;
while (p <= dictEnd - HashUnit)
{
PutPosition(p, dict->HashTable, TableTypeT.ByU32, srcBase);
p += 3;
}
return((int)dict->DictSize);
}
public static int CompressFastExtState(StreamT *state, byte *source, byte *dest, int inputSize, int maxOutputSize, int acceleration)
{
ResetStream(state);
if (acceleration < 1)
{
acceleration = AccelerationDefault;
}
LimitedOutputDirective limited = maxOutputSize >= CompressBound(inputSize)
? LimitedOutputDirective.NoLimit
: LimitedOutputDirective.LimitedOutput;
return(CompressGeneric(
state,
source,
dest,
inputSize,
limited == LimitedOutputDirective.NoLimit ? 0 : maxOutputSize,
limited,
TableType(inputSize),
DictDirective.NoDict,
DictIssueDirective.NoDictIssue,
(uint)acceleration));
}
public static int CompressFastContinue(StreamT *streamPtr, byte *source, byte *dest, int inputSize, int maxOutputSize, int acceleration)
{
byte *dictEnd = streamPtr->Dictionary + streamPtr->DictSize;
byte *smallest = source;
if (streamPtr->InitCheck != 0)
{
return(0); // Uninitialized structure detected
}
if (streamPtr->DictSize > 0 && smallest > dictEnd)
{
smallest = dictEnd;
}
RenormDictT(streamPtr, smallest);
if (acceleration < 1)
{
acceleration = AccelerationDefault;
}
// Check overlapping input/dictionary space
{
byte *sourceEnd = source + inputSize;
if (sourceEnd > streamPtr->Dictionary && sourceEnd < dictEnd)
{
streamPtr->DictSize = (uint)(dictEnd - sourceEnd);
if (streamPtr->DictSize > 64 * KB)
{
streamPtr->DictSize = 64 * KB;
}
if (streamPtr->DictSize < 4)
{
streamPtr->DictSize = 0;
}
streamPtr->Dictionary = dictEnd - streamPtr->DictSize;
}
}
DictIssueDirective dictIssue = (streamPtr->DictSize < 64 * KB) && (streamPtr->DictSize < streamPtr->CurrentOffset)
? DictIssueDirective.DictSmall
: DictIssueDirective.NoDictIssue;
DictDirective dictMode = dictEnd == source
? DictDirective.WithPrefix64k
: DictDirective.UsingExtDict;
int result = CompressGeneric(
streamPtr,
source,
dest,
inputSize,
maxOutputSize,
LimitedOutputDirective.LimitedOutput,
TableTypeT.ByU32,
dictMode,
dictIssue,
(uint)acceleration);
if (dictMode == DictDirective.WithPrefix64k)
{
// prefix mode : source data follows dictionary
streamPtr->DictSize += (uint)inputSize;
streamPtr->CurrentOffset += (uint)inputSize;
}
else
{
// external dictionary mode
streamPtr->Dictionary = source;
streamPtr->DictSize = (uint)inputSize;
streamPtr->CurrentOffset += (uint)inputSize;
}
return(result);
}
private static int CompressDestSizeGeneric(StreamT *ctx, byte *src, byte *dst, int *srcSizePtr, int targetDstSize, TableTypeT tableType)
{
byte *ip = src;
byte *srcBase = src;
byte *lowLimit = src;
byte *anchor = ip;
byte *iend = ip + *srcSizePtr;
byte *mflimit = iend - MFLimit;
byte *matchlimit = iend - LastLiterals;
byte *op = dst;
byte *oend = op + targetDstSize;
byte *oMaxLit = op + targetDstSize - 2 - 8 - 1;
byte *oMaxMatch = op + targetDstSize - (LastLiterals + 1);
byte *oMaxSeq = oMaxLit - 1;
if (targetDstSize < 1)
{
return(0);
}
if (*srcSizePtr > MaxInputSize)
{
return(0);
}
if ((tableType == TableTypeT.ByU16) && (*srcSizePtr >= Limit64k))
{
return(0);
}
if (*srcSizePtr < LZ4MinLength)
{
goto _last_literals; // Input too small, no compression (all literals)
}
*srcSizePtr = 0;
PutPosition(ip, ctx->HashTable, tableType, srcBase);
ip++;
uint forwardH = HashPosition(ip, tableType);
for (; ;)
{
byte *match;
byte *token;
{
byte *forwardIp = ip;
uint step = 1u;
uint searchMatchNb = 1u << SkipTrigger;
do
{
uint h = forwardH;
ip = forwardIp;
forwardIp += step;
step = searchMatchNb++ >> SkipTrigger;
if (forwardIp > mflimit)
{
goto _last_literals;
}
match = GetPositionOnHash(h, ctx->HashTable, tableType, srcBase);
forwardH = HashPosition(forwardIp, tableType);
PutPositionOnHash(ip, h, ctx->HashTable, tableType, srcBase);
}while ((tableType != TableTypeT.ByU16) && (match + MaxDistance < ip) ||
(LZ4MemoryHelper.Peek32(match) != LZ4MemoryHelper.Peek32(ip)));
}
while ((ip > anchor) && (match > lowLimit) && (ip[-1] == match[-1]))
{
ip--;
match--;
}
{
uint litLength = (uint)(ip - anchor);
token = op++;
if (op + (litLength + 240) / 255 + litLength > oMaxLit)
{
op--;
goto _last_literals;
}
if (litLength >= RunMask)
{
uint len = litLength - RunMask;
*token = (byte)(RunMask << MLBits);
for (; len >= 255; len -= 255)
{
*op++ = 255;
}
*op++ = (byte)len;
}
else
{
*token = (byte)(litLength << MLBits);
}
LZ4MemoryHelper.WildCopy(op, anchor, op + litLength);
op += litLength;
}
_next_match:
LZ4MemoryHelper.Poke16(op, (ushort)(ip - match));
op += 2;
{
int matchLength = (int)Count(ip + MinMatch, match + MinMatch, matchlimit);
if (op + (matchLength + 240) / 255 > oMaxMatch)
{
matchLength = (int)(15 - 1 + (oMaxMatch - op) * 255);
}
ip += MinMatch + matchLength;
if (matchLength >= MLMask)
{
*token += (byte)MLMask;
matchLength -= (int)MLMask;
while (matchLength >= 255)
{
matchLength -= 255;
*op++ = 255;
}
*op++ = (byte)matchLength;
}
else
{
*token += (byte)matchLength;
}
}
anchor = ip;
if (ip > mflimit)
{
break;
}
if (op > oMaxSeq)
{
break;
}
PutPosition(ip - 2, ctx->HashTable, tableType, srcBase);
match = GetPosition(ip, ctx->HashTable, tableType, srcBase);
PutPosition(ip, ctx->HashTable, tableType, srcBase);
if ((match + MaxDistance >= ip) && (LZ4MemoryHelper.Peek32(match) == LZ4MemoryHelper.Peek32(ip)))
{
token = op++;
*token = 0;
goto _next_match;
}
forwardH = HashPosition(++ip, tableType);
}
_last_literals:
{
int lastRunSize = (int)(iend - anchor);
if (op + 1 + (lastRunSize + 240) / 255 + lastRunSize > oend)
{
lastRunSize = (int)(oend - op) - 1;
lastRunSize -= (lastRunSize + 240) / 255;
}
ip = anchor + lastRunSize;
if (lastRunSize >= RunMask)
{
long accumulator = lastRunSize - RunMask;
*op++ = (byte)(RunMask << MLBits);
for (; accumulator >= 255; accumulator -= 255)
{
*op++ = 255;
}
*op++ = (byte)accumulator;
}
else
{
*op++ = (byte)(lastRunSize << MLBits);
}
LZ4MemoryHelper.Copy(op, anchor, lastRunSize);
op += lastRunSize;
}
*srcSizePtr = (int)(ip - src);
return((int)(op - dst));
}
public static void ResetStream(StreamT *state)
{
LZ4MemoryHelper.Zero((byte *)state, sizeof(StreamT));
}
public static int CompressGeneric(StreamT *cctx, byte *source, byte *dest, int inputSize, int maxOutputSize,
LimitedOutputDirective outputLimited, TableTypeT tableType,
DictDirective dict, DictIssueDirective dictIssue, uint acceleration)
{
byte *ip = source;
byte *ibase;
byte *lowLimit;
byte *lowRefLimit = ip - cctx->DictSize;
byte *dictionary = cctx->Dictionary;
byte *dictEnd = dictionary + cctx->DictSize;
long dictDelta = dictEnd - source;
byte *anchor = source;
byte *iend = ip + inputSize;
byte *mflimit = iend - MFLimit;
byte *matchlimit = iend - LastLiterals;
byte *op = dest;
byte *olimit = op + maxOutputSize;
if (inputSize > MaxInputSize)
{
return(0);
}
switch (dict)
{
case DictDirective.WithPrefix64k:
ibase = source - cctx->CurrentOffset;
lowLimit = source - cctx->DictSize;
break;
case DictDirective.UsingExtDict:
ibase = source - cctx->CurrentOffset;
lowLimit = source;
break;
default:
ibase = source;
lowLimit = source;
break;
}
if ((tableType == TableTypeT.ByU16) && (inputSize >= Limit64k))
{
return(0);
}
if (inputSize < LZ4MinLength)
{
goto _last_literals;
}
PutPosition(ip, cctx->HashTable, tableType, ibase);
ip++;
uint forwardH = HashPosition(ip, tableType);
for (; ;)
{
long refDelta = 0L;
byte *match;
byte *token;
{
byte *forwardIp = ip;
uint step = 1u;
uint searchMatchNb = acceleration << SkipTrigger;
do
{
uint h = forwardH;
ip = forwardIp;
forwardIp += step;
step = searchMatchNb++ >> SkipTrigger;
if (forwardIp > mflimit)
{
goto _last_literals;
}
match = GetPositionOnHash(h, cctx->HashTable, tableType, ibase);
if (dict == DictDirective.UsingExtDict)
{
if (match < source)
{
refDelta = dictDelta;
lowLimit = dictionary;
}
else
{
refDelta = 0;
lowLimit = source;
}
}
forwardH = HashPosition(forwardIp, tableType);
PutPositionOnHash(ip, h, cctx->HashTable, tableType, ibase);
}while ((dictIssue == DictIssueDirective.DictSmall) && (match < lowRefLimit) ||
(tableType != TableTypeT.ByU16) && (match + MaxDistance < ip) ||
(LZ4MemoryHelper.Peek32(match + refDelta) != LZ4MemoryHelper.Peek32(ip)));
}
while ((ip > anchor) && (match + refDelta > lowLimit) && (ip[-1] == match[refDelta - 1]))
{
ip--;
match--;
}
{
uint litLength = (uint)(ip - anchor);
token = op++;
if ((outputLimited == LimitedOutputDirective.LimitedOutput) &&
(op + litLength + (2 + 1 + LastLiterals) + litLength / 255 > olimit))
{
return(0);
}
if (litLength >= RunMask)
{
int len = (int)(litLength - RunMask);
*token = (byte)(RunMask << MLBits);
for (; len >= 255; len -= 255)
{
*op++ = 255;
}
*op++ = (byte)len;
}
else
{
*token = (byte)(litLength << MLBits);
}
LZ4MemoryHelper.WildCopy(op, anchor, op + litLength);
op += litLength;
}
_next_match:
LZ4MemoryHelper.Poke16(op, (ushort)(ip - match));
op += 2;
{
uint matchCode;
if ((dict == DictDirective.UsingExtDict) && (lowLimit == dictionary))
{
match += refDelta;
byte *limit = ip + (dictEnd - match);
if (limit > matchlimit)
{
limit = matchlimit;
}
matchCode = Count(ip + MinMatch, match + MinMatch, limit);
ip += MinMatch + matchCode;
if (ip == limit)
{
uint more = Count(ip, source, matchlimit);
matchCode += more;
ip += more;
}
}
else
{
matchCode = Count(ip + MinMatch, match + MinMatch, matchlimit);
ip += MinMatch + matchCode;
}
if ((outputLimited == LimitedOutputDirective.LimitedOutput) &&
(op + (1 + LastLiterals) + (matchCode >> 8) > olimit))
{
return(0);
}
if (matchCode >= MLMask)
{
*token += (byte)MLMask;
matchCode -= MLMask;
LZ4MemoryHelper.Poke32(op, 0xFFFFFFFF);
while (matchCode >= 4 * 255)
{
op += 4;
LZ4MemoryHelper.Poke32(op, 0xFFFFFFFF);
matchCode -= 4 * 255;
}
op += matchCode / 255;
*op++ = (byte)(matchCode % 255);
}
else
{
*token += (byte)matchCode;
}
}
anchor = ip;
if (ip > mflimit)
{
break;
}
PutPosition(ip - 2, cctx->HashTable, tableType, ibase);
match = GetPosition(ip, cctx->HashTable, tableType, ibase);
if (dict == DictDirective.UsingExtDict)
{
if (match < source)
{
refDelta = dictDelta;
lowLimit = dictionary;
}
else
{
refDelta = 0;
lowLimit = source;
}
}
PutPosition(ip, cctx->HashTable, tableType, ibase);
if ((dictIssue != DictIssueDirective.DictSmall || match >= lowRefLimit) &&
(match + MaxDistance >= ip) &&
(LZ4MemoryHelper.Peek32(match + refDelta) == LZ4MemoryHelper.Peek32(ip)))
{
token = op++;
*token = 0;
goto _next_match;
}
forwardH = HashPosition(++ip, tableType);
}
_last_literals:
{
int lastRun = (int)(iend - anchor);
if ((outputLimited == LimitedOutputDirective.LimitedOutput) &&
(op - dest + lastRun + 1 + (lastRun + 255 - RunMask) / 255 > (uint)maxOutputSize))
{
return(0);
}
if (lastRun >= RunMask)
{
int accumulator = (int)(lastRun - RunMask);
*op++ = (byte)(RunMask << MLBits);
for (; accumulator >= 255; accumulator -= 255)
{
*op++ = 255;
}
*op++ = (byte)accumulator;
}
else
{
*op++ = (byte)(lastRun << MLBits);
}
LZ4MemoryHelper.Copy(op, anchor, lastRun);
op += lastRun;
}
return((int)(op - dest));
}