// -------------------------------------------------------------------------------
private static unsafe byte[] PickleV0(byte *target, int targetLength, int sourceLength)
{
int diff = sourceLength - targetLength;
int llen = diff == 0 ? 0
: diff < 0x100 ? 1
: diff < 0x10000 ? 2
: 4;
byte[] result = new byte[targetLength + 1 + llen];
fixed(byte *resultPtr = result)
{
int llenFlags = llen == 4 ? 3 : llen; // 2 bits
byte flags = (byte)((llenFlags << 6) | CurrentVersion);
LZ4MemoryHelper.Poke8(resultPtr + 0, flags);
if (llen == 1)
{
LZ4MemoryHelper.Poke8(resultPtr + 1, (byte)diff);
}
else if (llen == 2)
{
LZ4MemoryHelper.Poke16(resultPtr + 1, (ushort)diff);
}
else if (llen == 4)
{
LZ4MemoryHelper.Poke32(resultPtr + 1, (uint)diff);
}
LZ4MemoryHelper.Move(resultPtr + llen + 1, target, targetLength);
}
return(result);
}
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));
}
public static int DecompressGeneric(byte *src, byte *dst, int srcSize, int outputSize,
EndConditionDirective endOnInput, EarlyEndDirective partialDecoding,
int targetOutputSize, DictDirective dict, byte *lowPrefix, byte *dictStart, int dictSize)
{
byte *ip = src;
byte *iend = ip + srcSize;
byte *op = dst;
byte *oend = op + outputSize;
byte *oexit = op + targetOutputSize;
byte *dictEnd = dictStart + dictSize;
bool safeDecode = endOnInput == EndConditionDirective.EndOnInputSize;
bool checkOffset = safeDecode && dictSize < 64 * KB;
if ((partialDecoding != EarlyEndDirective.Full) && (oexit > oend - MFLimit))
{
oexit = oend - MFLimit;
}
if ((endOnInput == EndConditionDirective.EndOnInputSize) && (outputSize == 0))
{
return(srcSize == 1 && *ip == 0 ? 0 : -1);
}
if ((endOnInput != EndConditionDirective.EndOnInputSize) && (outputSize == 0))
{
return(*ip == 0 ? 1 : -1);
}
for (; ;)
{
int length;
uint token = *ip++;
if ((ip + 14 + 2 <= iend) &&
(op + 14 + 18 <= oend) &&
(token < 15 << MLBits) &&
((token & MLMask) != 15))
{
int ll = (int)(token >> MLBits);
int off = LZ4MemoryHelper.Peek16(ip + ll);
byte *matchPtr = op + ll - off;
if (off >= 18 && matchPtr >= lowPrefix)
{
int ml = (int)((token & MLMask) + MinMatch);
LZ4MemoryHelper.Copy16(op, ip);
op += ll;
ip += ll + 2;
LZ4MemoryHelper.Copy18(op, matchPtr);
op += ml;
continue;
}
}
if ((length = (int)(token >> MLBits)) == RunMask)
{
uint s;
do
{
s = *ip++;
length += (int)s;
}while (
(endOnInput != EndConditionDirective.EndOnInputSize || ip < iend - RunMask) &&
(s == 255));
if (safeDecode && op + length < op)
{
goto _output_error;
}
if (safeDecode && ip + length < ip)
{
goto _output_error;
}
}
byte *cpy = op + length;
if ((endOnInput == EndConditionDirective.EndOnInputSize) &&
((cpy > (partialDecoding == EarlyEndDirective.Partial ? oexit : oend - MFLimit)) ||
(ip + length > iend - (2 + 1 + LastLiterals))) ||
(endOnInput != EndConditionDirective.EndOnInputSize) && (cpy > oend - WildCopyLength))
{
if (partialDecoding == EarlyEndDirective.Partial)
{
if (cpy > oend)
{
goto _output_error;
}
if ((endOnInput == EndConditionDirective.EndOnInputSize) && (ip + length > iend))
{
goto _output_error;
}
}
else
{
if ((endOnInput != EndConditionDirective.EndOnInputSize) && (cpy != oend))
{
goto _output_error;
}
if ((endOnInput == EndConditionDirective.EndOnInputSize) &&
(ip + length != iend || cpy > oend))
{
goto _output_error;
}
}
LZ4MemoryHelper.Copy(op, ip, length);
ip += length;
op += length;
break;
}
LZ4MemoryHelper.WildCopy(op, ip, cpy);
ip += length;
op = cpy;
int offset = LZ4MemoryHelper.Peek16(ip);
ip += 2;
byte *match = op - offset;
if (checkOffset && match + dictSize < lowPrefix)
{
goto _output_error;
}
LZ4MemoryHelper.Poke32(op, (uint)offset);
length = (int)(token & MLMask);
if (length == MLMask)
{
uint s;
do
{
s = *ip++;
if ((endOnInput == EndConditionDirective.EndOnInputSize) && (ip > iend - LastLiterals))
{
goto _output_error;
}
length += (int)s;
}while (s == 255);
if (safeDecode && (op + length < op))
{
goto _output_error;
}
}
length += MinMatch;
if ((dict == DictDirective.UsingExtDict) && (match < lowPrefix))
{
if (op + length > oend - LastLiterals)
{
goto _output_error;
}
if (length <= lowPrefix - match)
{
LZ4MemoryHelper.Move(op, dictEnd - (lowPrefix - match), length);
op += length;
}
else
{
int copySize = (int)(lowPrefix - match);
int restSize = length - copySize;
LZ4MemoryHelper.Copy(op, dictEnd - copySize, copySize);
op += copySize;
if (restSize > (int)(op - lowPrefix))
{
byte *endOfMatch = op + restSize;
byte *copyFrom = lowPrefix;
while (op < endOfMatch)
{
*op++ = *copyFrom++;
}
}
else
{
LZ4MemoryHelper.Copy(op, lowPrefix, restSize);
op += restSize;
}
}
continue;
}
cpy = op + length;
if (offset < 8)
{
op[0] = match[0];
op[1] = match[1];
op[2] = match[2];
op[3] = match[3];
match += _inc32table[offset];
LZ4MemoryHelper.Copy(op + 4, match, 4);
match -= _dec64table[offset];
}
else
{
LZ4MemoryHelper.Copy8(op, match);
match += 8;
}
op += 8;
if (cpy > oend - 12)
{
byte *oCopyLimit = oend - (WildCopyLength - 1);
if (cpy > oend - LastLiterals)
{
goto _output_error;
}
if (op < oCopyLimit)
{
LZ4MemoryHelper.WildCopy(op, match, oCopyLimit);
match += oCopyLimit - op;
op = oCopyLimit;
}
while (op < cpy)
{
*op++ = *match++;
}
}
else
{
LZ4MemoryHelper.Copy8(op, match);
if (length > 16)
{
LZ4MemoryHelper.WildCopy(op + 8, match + 8, cpy);
}
}
op = cpy; // correction
}
// end of decoding
if (endOnInput == EndConditionDirective.EndOnInputSize)
{
return((int)(op - dst)); // Nb of output bytes decoded
}
return((int)(ip - src)); // Nb of input bytes read
// Overflow error detected
_output_error:
return((int)-(ip - src) - 1);
}