public int LZ4_loadDict(LZ4_stream_t *LZ4_dict, byte *dictionary, int dictSize)
{
const int HASH_UNIT = ALGORITHM_ARCH;
var dict = LZ4_dict;
const tableType_t tableType = tableType_t.byU32;
var p = dictionary;
var dictEnd = p + dictSize;
LZ4_initStream(LZ4_dict);
dict->currentOffset += 64 * KB;
if (dictSize < HASH_UNIT)
{
return(0);
}
if (dictEnd - p > 64 * KB)
{
p = dictEnd - 64 * KB;
}
var @base = dictEnd - dict->currentOffset;
dict->dictionary = p;
dict->dictSize = (uint)(dictEnd - p);
dict->tableType = tableType;
while (p <= dictEnd - HASH_UNIT)
{
LZ4_putPosition(p, dict->hashTable, tableType, @base);
p += 3;
}
return((int)dict->dictSize);
}
private static uint LZ4_hashPosition(void *p, tableType_t tableType)
{
if (tableType != tableType_t.byU16)
{
return(LZ4_hash5(LZ4_read_ARCH(p), tableType));
}
return(LZ4_hash4(LZ4Mem.Peek32(p), tableType));
}
private static uint LZ4_hashPosition(void *p, tableType_t tableType)
{
#if !BIT32
if (tableType != tableType_t.byU16)
{
return(LZ4_hash5(LZ4_read_ARCH(p), tableType));
}
#endif
return(LZ4_hash4(LZ4_read32(p), tableType));
}
protected static uint LZ4_hashPosition(void *p, tableType_t tableType)
{
#if !BIT32
if (tableType != tableType_t.byU16)
{
return(LZ4_hash5(Mem.PeekW(p), tableType));
}
#endif
return(LZ4_hash4(Mem.Peek4(p), tableType));
}
protected static byte *LZ4_getPositionOnHash(
uint h, void *tableBase, tableType_t tableType, byte *srcBase)
{
switch (tableType)
{
case tableType_t.byPtr: return(((byte **)tableBase)[h]);
case tableType_t.byU32: return(((uint *)tableBase)[h] + srcBase);
default: return(((ushort *)tableBase)[h] + srcBase);
}
}
protected static uint LZ4_getIndexOnHash(uint h, void *tableBase, tableType_t tableType)
{
Assert(LZ4_MEMORY_USAGE > 2);
switch (tableType)
{
case tableType_t.byU32:
Assert(h < (1U << (LZ4_MEMORY_USAGE - 2)));
return(((uint *)tableBase)[h]);
case tableType_t.byU16:
Assert(h < (1U << (LZ4_MEMORY_USAGE - 1)));
return(((ushort *)tableBase)[h]);
default:
Assert(false);
return(0);
}
}
protected static void LZ4_putPositionOnHash(
byte *p, uint h, void *tableBase, tableType_t tableType, byte *srcBase)
{
switch (tableType)
{
case tableType_t.byPtr:
((byte **)tableBase)[h] = p;
return;
case tableType_t.byU32:
((uint *)tableBase)[h] = (uint)(p - srcBase);
return;
default:
((ushort *)tableBase)[h] = (ushort)(p - srcBase);
return;
}
}
protected static void LZ4_putIndexOnHash(
uint idx, uint h, void *tableBase, tableType_t tableType)
{
switch (tableType)
{
case tableType_t.byU32:
((uint *)tableBase)[h] = idx;
return;
case tableType_t.byU16:
Assert(idx < 65536);
((ushort *)tableBase)[h] = (ushort)idx;
return;
default:
Assert(false);
return;
}
}
protected static void LZ4_clearHash(uint h, void *tableBase, tableType_t tableType)
{
switch (tableType)
{
case tableType_t.byPtr:
((byte **)tableBase)[h] = null;
return;
case tableType_t.byU32:
((uint *)tableBase)[h] = 0;
return;
case tableType_t.byU16:
((ushort *)tableBase)[h] = 0;
return;
default:
Assert(false);
return;
}
}
protected static uint LZ4_hash5(ulong sequence, tableType_t tableType)
{
var hashLog = tableType == tableType_t.byU16 ? LZ4_HASHLOG + 1 : LZ4_HASHLOG;
return((uint)(((sequence << 24) * 889523592379ul) >> (64 - hashLog)));
}
protected static uint LZ4_hash4(uint sequence, tableType_t tableType)
{
var hashLog = tableType == tableType_t.byU16 ? LZ4_HASHLOG + 1 : LZ4_HASHLOG;
return((sequence * 2654435761u) >> (MINMATCH * 8 - hashLog));
}
public static int LZ4_compress_fast_continue(
LZ4_stream_t *LZ4_stream,
byte *source, byte *dest,
int inputSize, int maxOutputSize,
int acceleration)
{
const tableType_t tableType = tableType_t.byU32;
var streamPtr = LZ4_stream;
var dictEnd = streamPtr->dictionary + streamPtr->dictSize;
if (streamPtr->dirty)
{
return(0);
}
LZ4_renormDictT(streamPtr, inputSize);
if (acceleration < 1)
{
acceleration = ACCELERATION_DEFAULT;
}
if (streamPtr->dictSize - 1 < 4 - 1 && dictEnd != source)
{
streamPtr->dictSize = 0;
streamPtr->dictionary = source;
dictEnd = source;
}
{
var 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;
}
}
if (dictEnd == source)
{
if (streamPtr->dictSize < 64 * KB && streamPtr->dictSize < streamPtr->currentOffset)
{
return(LZ4_compress_generic(
streamPtr, source, dest, inputSize, null, maxOutputSize,
limitedOutput_directive.limitedOutput, tableType,
dict_directive.withPrefix64k, dictIssue_directive.dictSmall,
acceleration));
}
else
{
return(LZ4_compress_generic(
streamPtr, source, dest, inputSize, null, maxOutputSize,
limitedOutput_directive.limitedOutput, tableType,
dict_directive.withPrefix64k, dictIssue_directive.noDictIssue,
acceleration));
}
}
{
int result;
if (streamPtr->dictCtx != null)
{
if (inputSize > 4 * KB)
{
Mem.Copy((byte *)streamPtr, (byte *)streamPtr->dictCtx, sizeof(LZ4_stream_t));
result = LZ4_compress_generic(
streamPtr, source, dest, inputSize, null, maxOutputSize, limitedOutput_directive.limitedOutput,
tableType, dict_directive.usingExtDict, dictIssue_directive.noDictIssue, acceleration);
}
else
{
result = LZ4_compress_generic(
streamPtr, source, dest, inputSize, null, maxOutputSize, limitedOutput_directive.limitedOutput,
tableType, dict_directive.usingDictCtx, dictIssue_directive.noDictIssue, acceleration);
}
}
else
{
if ((streamPtr->dictSize < 64 * KB) && (streamPtr->dictSize < streamPtr->currentOffset))
{
result = LZ4_compress_generic(
streamPtr, source, dest, inputSize, null, maxOutputSize, limitedOutput_directive.limitedOutput,
tableType, dict_directive.usingExtDict, dictIssue_directive.dictSmall, acceleration);
}
else
{
result = LZ4_compress_generic(
streamPtr, source, dest, inputSize, null, maxOutputSize, limitedOutput_directive.limitedOutput,
tableType, dict_directive.usingExtDict, dictIssue_directive.noDictIssue, acceleration);
}
}
streamPtr->dictionary = source;
streamPtr->dictSize = (uint)inputSize;
return(result);
}
}
protected static int LZ4_compress_generic(
LZ4_stream_t *cctx,
byte *source,
byte *dest,
int inputSize,
int *inputConsumed, /* only written when outputDirective == fillOutput */
int maxOutputSize,
limitedOutput_directive outputDirective,
tableType_t tableType,
dict_directive dictDirective,
dictIssue_directive dictIssue,
int acceleration)
{
int result;
byte *ip = (byte *)source;
uint startIndex = cctx->currentOffset;
byte * @base = (byte *)source - startIndex;
byte * lowLimit;
LZ4_stream_t *dictCtx = (LZ4_stream_t *)cctx->dictCtx;
byte * dictionary =
dictDirective == dict_directive.usingDictCtx ? dictCtx->dictionary
: cctx->dictionary;
uint dictSize =
dictDirective == dict_directive.usingDictCtx ? dictCtx->dictSize : cctx->dictSize;
uint dictDelta = (dictDirective == dict_directive.usingDictCtx)
? startIndex - dictCtx->currentOffset : 0;
bool maybe_extMem = (dictDirective == dict_directive.usingExtDict) ||
(dictDirective == dict_directive.usingDictCtx);
uint prefixIdxLimit = startIndex - dictSize;
byte *dictEnd = dictionary + dictSize;
byte *anchor = (byte *)source;
byte *iend = ip + inputSize;
byte *mflimitPlusOne = iend - MFLIMIT + 1;
byte *matchlimit = iend - LASTLITERALS;
/* the dictCtx currentOffset is indexed on the start of the dictionary,
* while a dictionary in the current context precedes the currentOffset */
byte *dictBase = (dictDirective == dict_directive.usingDictCtx) ?
dictionary + dictSize - dictCtx->currentOffset :
dictionary + dictSize - startIndex;
byte *op = (byte *)dest;
byte *olimit = op + maxOutputSize;
uint offset = 0;
uint forwardH;
if (outputDirective == limitedOutput_directive.fillOutput && maxOutputSize < 1)
{
return(0);
}
if ((uint)inputSize > (uint)LZ4_MAX_INPUT_SIZE)
{
return(0);
}
if ((tableType == tableType_t.byU16) && (inputSize >= LZ4_64Klimit))
{
return(0);
}
if (tableType == tableType_t.byPtr)
{
Assert(dictDirective == dict_directive.noDict);
}
Assert(acceleration >= 1);
lowLimit = (byte *)source
- (dictDirective == dict_directive.withPrefix64k ? dictSize : 0);
/* Update context state */
if (dictDirective == dict_directive.usingDictCtx)
{
/* Subsequent linked blocks can't use the dictionary. */
/* Instead, they use the block we just compressed. */
cctx->dictCtx = null;
cctx->dictSize = (uint)inputSize;
}
else
{
cctx->dictSize += (uint)inputSize;
}
cctx->currentOffset += (uint)inputSize;
cctx->tableType = tableType;
if (inputSize < LZ4_minLength)
{
goto _last_literals;
}
/* First Byte */
LZ4_putPosition(ip, cctx->hashTable, tableType, @base);
ip++;
forwardH = LZ4_hashPosition(ip, tableType);
/* Main Loop */
for (;;)
{
byte *match;
byte *token;
byte *filledIp;
/* Find a match */
if (tableType == tableType_t.byPtr)
{
byte *forwardIp = ip;
int step = 1;
int searchMatchNb = acceleration << LZ4_skipTrigger;
do
{
uint h = forwardH;
ip = forwardIp;
forwardIp += step;
step = (searchMatchNb++ >> LZ4_skipTrigger);
if ((forwardIp > mflimitPlusOne))
{
goto _last_literals;
}
Assert(ip < mflimitPlusOne);
match = LZ4_getPositionOnHash(h, cctx->hashTable, tableType, @base);
forwardH = LZ4_hashPosition(forwardIp, tableType);
LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, @base);
}while ((match + LZ4_DISTANCE_MAX < ip) || (Mem.Peek4(match) != Mem.Peek4(ip)));
}
else
{
/* byU32, byU16 */
byte *forwardIp = ip;
int step = 1;
int searchMatchNb = acceleration << LZ4_skipTrigger;
do
{
uint h = forwardH;
uint current = (uint)(forwardIp - @base);
uint matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType);
Assert(matchIndex <= current);
Assert(forwardIp - @base < (2 * GB - 1));
ip = forwardIp;
forwardIp += step;
step = (searchMatchNb++ >> LZ4_skipTrigger);
if ((forwardIp > mflimitPlusOne))
{
goto _last_literals;
}
Assert(ip < mflimitPlusOne);
if (dictDirective == dict_directive.usingDictCtx)
{
if (matchIndex < startIndex)
{
Assert(tableType == tableType_t.byU32);
matchIndex = LZ4_getIndexOnHash(
h, dictCtx->hashTable, tableType_t.byU32);
match = dictBase + matchIndex;
matchIndex += dictDelta;
lowLimit = dictionary;
}
else
{
match = @base + matchIndex;
lowLimit = (byte *)source;
}
}
else if (dictDirective == dict_directive.usingExtDict)
{
if (matchIndex < startIndex)
{
Assert(startIndex - matchIndex >= MINMATCH);
match = dictBase + matchIndex;
lowLimit = dictionary;
}
else
{
match = @base + matchIndex;
lowLimit = (byte *)source;
}
}
else
{
match = @base + matchIndex;
}
forwardH = LZ4_hashPosition(forwardIp, tableType);
LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType);
if ((dictIssue == dictIssue_directive.dictSmall) &&
(matchIndex < prefixIdxLimit))
{
continue;
}
Assert(matchIndex < current);
if (((tableType != tableType_t.byU16) ||
(LZ4_DISTANCE_MAX < LZ4_DISTANCE_ABSOLUTE_MAX)) &&
(matchIndex + LZ4_DISTANCE_MAX < current))
{
continue;
}
Assert((current - matchIndex) <= LZ4_DISTANCE_MAX);
if (Mem.Peek4(match) == Mem.Peek4(ip))
{
if (maybe_extMem)
{
offset = current - matchIndex;
}
break;
}
}while (true);
}
filledIp = ip;
while (((ip > anchor) & (match > lowLimit)) && ((ip[-1] == match[-1])))
{
ip--;
match--;
}
{
var litLength = (uint)(ip - anchor);
token = op++;
if ((outputDirective == limitedOutput_directive.limitedOutput) &&
((op + litLength + (2 + 1 + LASTLITERALS) + (litLength / 255) > olimit)))
{
return(0);
}
if ((outputDirective == limitedOutput_directive.fillOutput) &&
((op + (litLength + 240) / 255 + litLength + 2 + 1 + MFLIMIT - MINMATCH
> olimit)))
{
op--;
goto _last_literals;
}
if (litLength >= RUN_MASK)
{
int len = (int)(litLength - RUN_MASK);
*token = (byte)(RUN_MASK << ML_BITS);
for (; len >= 255; len -= 255)
{
*op++ = 255;
}
*op++ = (byte)len;
}
else
{
*token = (byte)(litLength << ML_BITS);
}
Mem.WildCopy8(op, anchor, op + litLength);
op += litLength;
}
_next_match:
/* at this stage, the following variables must be correctly set :
* - ip : at start of LZ operation
* - match : at start of previous pattern occurence; can be within current prefix, or within extDict
* - offset : if maybe_ext_memSegment==1 (constant)
* - lowLimit : must be == dictionary to mean "match is within extDict"; must be == source otherwise
* - token and *token : position to write 4-bits for match length; higher 4-bits for literal length supposed already written
*/
if ((outputDirective == limitedOutput_directive.fillOutput) &&
(op + 2 + 1 + MFLIMIT - MINMATCH > olimit))
{
/* the match was too close to the end, rewind and go to last literals */
op = token;
goto _last_literals;
}
/* Encode Offset */
if (maybe_extMem)
{
/* static test */
Assert(offset <= LZ4_DISTANCE_MAX && offset > 0);
Mem.Poke2(op, (ushort)offset);
op += 2;
}
else
{
Assert(ip - match <= LZ4_DISTANCE_MAX);
Mem.Poke2(op, (ushort)(ip - match));
op += 2;
}
/* Encode MatchLength */
{
uint matchCode;
if ((dictDirective == dict_directive.usingExtDict ||
dictDirective == dict_directive.usingDictCtx) &&
(lowLimit == dictionary) /* match within extDict */)
{
byte *limit = ip + (dictEnd - match);
Assert(dictEnd > match);
if (limit > matchlimit)
{
limit = matchlimit;
}
matchCode = LZ4_count(ip + MINMATCH, match + MINMATCH, limit);
ip += (uint)matchCode + MINMATCH;
if (ip == limit)
{
uint more = LZ4_count(limit, (byte *)source, matchlimit);
matchCode += more;
ip += more;
}
}
else
{
matchCode = LZ4_count(ip + MINMATCH, match + MINMATCH, matchlimit);
ip += (uint)matchCode + MINMATCH;
}
if ((outputDirective != 0) &&
((op + (1 + LASTLITERALS) + (matchCode + 240) / 255 > olimit)))
{
if (outputDirective == limitedOutput_directive.fillOutput)
{
/* Match description too long : reduce it */
uint newMatchCode =
15 - 1 + ((uint)(olimit - op) - 1 - LASTLITERALS) * 255;
ip -= matchCode - newMatchCode;
Assert(newMatchCode < matchCode);
matchCode = newMatchCode;
if ((ip <= filledIp))
{
/* We have already filled up to filledIp so if ip ends up less than filledIp
* we have positions in the hash table beyond the current position. This is
* a problem if we reuse the hash table. So we have to remove these positions
* from the hash table.
*/
byte *ptr;
for (ptr = ip; ptr <= filledIp; ++ptr)
{
uint h = LZ4_hashPosition(ptr, tableType);
LZ4_clearHash(h, cctx->hashTable, tableType);
}
}
}
else
{
Assert(outputDirective == limitedOutput_directive.limitedOutput);
return(0);
}
}
if (matchCode >= ML_MASK)
{
*token += (byte)ML_MASK; //!!!
matchCode -= ML_MASK;
Mem.Poke4(op, 0xFFFFFFFF);
while (matchCode >= 4 * 255)
{
op += 4;
Mem.Poke4(op, 0xFFFFFFFF);
matchCode -= 4 * 255;
}
op += matchCode / 255;
*op++ = (byte)(matchCode % 255);
}
else
{
*token += (byte)(matchCode);
}
}
/* Ensure we have enough space for the last literals. */
Assert(
!(outputDirective == limitedOutput_directive.fillOutput &&
op + 1 + LASTLITERALS > olimit));
anchor = ip;
/* Test end of chunk */
if (ip >= mflimitPlusOne)
{
break;
}
/* Fill table */
LZ4_putPosition(ip - 2, cctx->hashTable, tableType, @base);
/* Test next position */
if (tableType == tableType_t.byPtr)
{
match = LZ4_getPosition(ip, cctx->hashTable, tableType, @base);
LZ4_putPosition(ip, cctx->hashTable, tableType, @base);
if ((match + LZ4_DISTANCE_MAX >= ip) && (Mem.Peek4(match) == Mem.Peek4(ip)))
{
token = op++;
*token = 0;
goto _next_match;
}
}
else
{
/* byU32, byU16 */
uint h = LZ4_hashPosition(ip, tableType);
uint current = (uint)(ip - @base);
uint matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType);
Assert(matchIndex < current);
if (dictDirective == dict_directive.usingDictCtx)
{
if (matchIndex < startIndex)
{
matchIndex = LZ4_getIndexOnHash(
h, dictCtx->hashTable, tableType_t.byU32);
match = dictBase + matchIndex;
lowLimit = dictionary;
matchIndex += dictDelta;
}
else
{
match = @base + matchIndex;
lowLimit = (byte *)source;
}
}
else if (dictDirective == dict_directive.usingExtDict)
{
if (matchIndex < startIndex)
{
match = dictBase + matchIndex;
lowLimit = dictionary;
}
else
{
match = @base + matchIndex;
lowLimit = (byte *)source;
}
}
else
{
match = @base + matchIndex;
}
LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType);
Assert(matchIndex < current);
if (((dictIssue != dictIssue_directive.dictSmall) ||
(matchIndex >= prefixIdxLimit)) &&
(((tableType == tableType_t.byU16) &&
(LZ4_DISTANCE_MAX == LZ4_DISTANCE_ABSOLUTE_MAX)) ||
(matchIndex + LZ4_DISTANCE_MAX >= current)) &&
(Mem.Peek4(match) == Mem.Peek4(ip)))
{
token = op++;
*token = 0;
if (maybe_extMem)
{
offset = current - matchIndex;
}
goto _next_match;
}
}
forwardH = LZ4_hashPosition(++ip, tableType);
}
_last_literals:
{
var lastRun = (size_t)(iend - anchor);
if ((outputDirective != 0) &&
(op + lastRun + 1 + ((lastRun + 255 - RUN_MASK) / 255) > olimit))
{
if (outputDirective == limitedOutput_directive.fillOutput)
{
Assert(olimit >= op);
lastRun = (size_t)(olimit - op) - 1;
lastRun -= (lastRun + 240) / 255;
}
else
{
Assert(outputDirective == limitedOutput_directive.limitedOutput);
return(0);
}
}
if (lastRun >= RUN_MASK)
{
var accumulator = (size_t)(lastRun - RUN_MASK);
*op++ = (byte)(RUN_MASK << ML_BITS);
for (; accumulator >= 255; accumulator -= 255)
{
*op++ = 255;
}
*op++ = (byte)accumulator;
}
else
{
*op++ = (byte)(lastRun << ML_BITS);
}
Mem.Copy(op, anchor, (int)lastRun);
ip = anchor + lastRun;
op += lastRun;
}
if (outputDirective == limitedOutput_directive.fillOutput)
{
*inputConsumed = (int)(((byte *)ip) - source);
}
result = (int)(((byte *)op) - dest);
Assert(result > 0);
return(result);
}
private static int LZ4_compress_destSize_generic(
LZ4_stream_t *ctx,
byte *src,
byte *dst,
int *srcSizePtr,
int targetDstSize,
tableType_t tableType)
{
var ip = src;
var base_ = src;
var lowLimit = src;
var anchor = ip;
var iend = ip + *srcSizePtr;
var mflimit = iend - MFLIMIT;
var matchlimit = iend - LASTLITERALS;
var op = dst;
var oend = op + targetDstSize;
var oMaxLit = op + targetDstSize - 2 - 8 - 1;
var oMaxMatch = op + targetDstSize - (LASTLITERALS + 1);
var oMaxSeq = oMaxLit - 1;
if (targetDstSize < 1)
{
return(0);
}
if (*srcSizePtr > LZ4_MAX_INPUT_SIZE)
{
return(0);
}
if (tableType == tableType_t.byU16 && *srcSizePtr >= LZ4_64Klimit)
{
return(0);
}
if (*srcSizePtr < LZ4_minLength)
{
goto _last_literals; /* Input too small, no compression (all literals) */
}
*srcSizePtr = 0;
LZ4_putPosition(ip, ctx->hashTable, tableType, base_);
ip++;
var forwardH = LZ4_hashPosition(ip, tableType);
for (;;)
{
byte *match;
byte *token;
{
var forwardIp = ip;
var step = 1u;
var searchMatchNb = 1u << LZ4_skipTrigger;
do
{
var h = forwardH;
ip = forwardIp;
forwardIp += step;
step = searchMatchNb++ >> LZ4_skipTrigger;
if (forwardIp > mflimit)
{
goto _last_literals;
}
match = LZ4_getPositionOnHash(h, ctx->hashTable, tableType, base_);
forwardH = LZ4_hashPosition(forwardIp, tableType);
LZ4_putPositionOnHash(ip, h, ctx->hashTable, tableType, base_);
} while (
tableType != tableType_t.byU16 && match + MAX_DISTANCE < ip ||
LZ4Mem.Peek32(match) != LZ4Mem.Peek32(ip));
}
while (ip > anchor && match > lowLimit && ip[-1] == match[-1])
{
ip--;
match--;
}
{
var litLength = (uint)(ip - anchor);
token = op++;
if (op + (litLength + 240) / 255 + litLength > oMaxLit)
{
op--;
goto _last_literals;
}
if (litLength >= RUN_MASK)
{
var len = litLength - RUN_MASK;
*token = (byte)(RUN_MASK << ML_BITS);
for (; len >= 255; len -= 255)
{
*op++ = 255;
}
*op++ = (byte)len;
}
else
{
*token = (byte)(litLength << ML_BITS);
}
LZ4Mem.WildCopy(op, anchor, op + litLength);
op += litLength;
}
_next_match:
LZ4Mem.Poke16(op, (ushort)(ip - match));
op += 2;
{
var matchLength = (int)LZ4_count(ip + MINMATCH, match + MINMATCH, matchlimit);
if (op + (matchLength + 240) / 255 > oMaxMatch)
{
matchLength = (int)(15 - 1 + (oMaxMatch - op) * 255);
}
ip += MINMATCH + matchLength;
if (matchLength >= ML_MASK)
{
*token += (byte)ML_MASK;
matchLength -= (int)ML_MASK;
while (matchLength >= 255)
{
matchLength -= 255;
*op++ = 255;
}
*op++ = (byte)matchLength;
}
else
{
*token += (byte)matchLength;
}
}
anchor = ip;
if (ip > mflimit)
{
break;
}
if (op > oMaxSeq)
{
break;
}
LZ4_putPosition(ip - 2, ctx->hashTable, tableType, base_);
match = LZ4_getPosition(ip, ctx->hashTable, tableType, base_);
LZ4_putPosition(ip, ctx->hashTable, tableType, base_);
if (match + MAX_DISTANCE >= ip && LZ4Mem.Peek32(match) == LZ4Mem.Peek32(ip))
{
token = op++;
*token = 0;
goto _next_match;
}
forwardH = LZ4_hashPosition(++ip, tableType);
}
_last_literals:
{
var 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 >= RUN_MASK)
{
var accumulator = lastRunSize - RUN_MASK;
*op++ = (byte)(RUN_MASK << ML_BITS);
for (; accumulator >= 255; accumulator -= 255)
{
*op++ = 255;
}
*op++ = (byte)accumulator;
}
else
{
*op++ = (byte)(lastRunSize << ML_BITS);
}
LZ4Mem.Copy(op, anchor, lastRunSize);
op += lastRunSize;
}
*srcSizePtr = (int)(ip - src);
return((int)(op - dst));
}
private static byte *LZ4_getPosition(byte *p, void *tableBase, tableType_t tableType, byte *srcBase) => LZ4_getPositionOnHash(LZ4_hashPosition(p, tableType), tableBase, tableType, srcBase);
public static int LZ4_compress_generic(
LZ4_stream_t *cctx,
byte *source,
byte *dest,
int inputSize,
int maxOutputSize,
limitedOutput_directive outputLimited,
tableType_t tableType,
dict_directive dict,
dictIssue_directive dictIssue,
uint acceleration)
{
var ip = source;
byte *ibase;
byte *lowLimit;
var lowRefLimit = ip - cctx->dictSize;
var dictionary = cctx->dictionary;
var dictEnd = dictionary + cctx->dictSize;
var dictDelta = dictEnd - source;
var anchor = source;
var iend = ip + inputSize;
var mflimit = iend - MFLIMIT;
var matchlimit = iend - LASTLITERALS;
var op = dest;
var olimit = op + maxOutputSize;
if (inputSize > LZ4_MAX_INPUT_SIZE)
{
return(0);
}
switch (dict)
{
case dict_directive.withPrefix64k:
ibase = source - cctx->currentOffset;
lowLimit = source - cctx->dictSize;
break;
case dict_directive.usingExtDict:
ibase = source - cctx->currentOffset;
lowLimit = source;
break;
default:
ibase = source;
lowLimit = source;
break;
}
if (tableType == tableType_t.byU16 && inputSize >= LZ4_64Klimit)
{
return(0);
}
if (inputSize < LZ4_minLength)
{
goto _last_literals;
}
LZ4_putPosition(ip, cctx->hashTable, tableType, ibase);
ip++;
var forwardH = LZ4_hashPosition(ip, tableType);
for (;;)
{
var refDelta = 0L;
byte *match;
byte *token;
{
var forwardIp = ip;
var step = 1u;
var searchMatchNb = acceleration << LZ4_skipTrigger;
do
{
var h = forwardH;
ip = forwardIp;
forwardIp += step;
step = searchMatchNb++ >> LZ4_skipTrigger;
if (forwardIp > mflimit)
{
goto _last_literals;
}
match = LZ4_getPositionOnHash(h, cctx->hashTable, tableType, ibase);
if (dict == dict_directive.usingExtDict)
{
if (match < source)
{
refDelta = dictDelta;
lowLimit = dictionary;
}
else
{
refDelta = 0;
lowLimit = source;
}
}
forwardH = LZ4_hashPosition(forwardIp, tableType);
LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, ibase);
} while (
dictIssue == dictIssue_directive.dictSmall && match < lowRefLimit ||
tableType != tableType_t.byU16 && match + MAX_DISTANCE < ip ||
LZ4Mem.Peek32(match + refDelta) != LZ4Mem.Peek32(ip));
}
while (ip > anchor && match + refDelta > lowLimit && ip[-1] == match[refDelta - 1])
{
ip--;
match--;
}
{
var litLength = (uint)(ip - anchor);
token = op++;
if (outputLimited == limitedOutput_directive.limitedOutput &&
op + litLength + (2 + 1 + LASTLITERALS) + litLength / 255 > olimit)
{
return(0);
}
if (litLength >= RUN_MASK)
{
var len = (int)(litLength - RUN_MASK);
*token = (byte)(RUN_MASK << ML_BITS);
for (; len >= 255; len -= 255)
{
*op++ = 255;
}
*op++ = (byte)len;
}
else
{
*token = (byte)(litLength << ML_BITS);
}
LZ4Mem.WildCopy(op, anchor, op + litLength);
op += litLength;
}
_next_match:
LZ4Mem.Poke16(op, (ushort)(ip - match));
op += 2;
{
uint matchCode;
if (dict == dict_directive.usingExtDict && lowLimit == dictionary)
{
match += refDelta;
var limit = ip + (dictEnd - match);
if (limit > matchlimit)
{
limit = matchlimit;
}
matchCode = LZ4_count(ip + MINMATCH, match + MINMATCH, limit);
ip += MINMATCH + matchCode;
if (ip == limit)
{
var more = LZ4_count(ip, source, matchlimit);
matchCode += more;
ip += more;
}
}
else
{
matchCode = LZ4_count(ip + MINMATCH, match + MINMATCH, matchlimit);
ip += MINMATCH + matchCode;
}
if (outputLimited == limitedOutput_directive.limitedOutput &&
op + (1 + LASTLITERALS) + (matchCode >> 8) > olimit)
{
return(0);
}
if (matchCode >= ML_MASK)
{
*token += (byte)ML_MASK;
matchCode -= ML_MASK;
LZ4Mem.Poke32(op, 0xFFFFFFFF);
while (matchCode >= 4 * 255)
{
op += 4;
LZ4Mem.Poke32(op, 0xFFFFFFFF);
matchCode -= 4 * 255;
}
op += matchCode / 255;
*op++ = (byte)(matchCode % 255);
}
else
{
*token += (byte)matchCode;
}
}
anchor = ip;
if (ip > mflimit)
{
break;
}
LZ4_putPosition(ip - 2, cctx->hashTable, tableType, ibase);
match = LZ4_getPosition(ip, cctx->hashTable, tableType, ibase);
if (dict == dict_directive.usingExtDict)
{
if (match < source)
{
refDelta = dictDelta;
lowLimit = dictionary;
}
else
{
refDelta = 0;
lowLimit = source;
}
}
LZ4_putPosition(ip, cctx->hashTable, tableType, ibase);
if ((dictIssue != dictIssue_directive.dictSmall || match >= lowRefLimit) &&
match + MAX_DISTANCE >= ip &&
LZ4Mem.Peek32(match + refDelta) == LZ4Mem.Peek32(ip))
{
token = op++;
*token = 0;
goto _next_match;
}
forwardH = LZ4_hashPosition(++ip, tableType);
}
_last_literals:
{
var lastRun = (int)(iend - anchor);
if (outputLimited == limitedOutput_directive.limitedOutput &&
op - dest + lastRun + 1 + (lastRun + 255 - RUN_MASK) / 255 > (uint)maxOutputSize)
{
return(0);
}
if (lastRun >= RUN_MASK)
{
var accumulator = (int)(lastRun - RUN_MASK);
*op++ = (byte)(RUN_MASK << ML_BITS);
for (; accumulator >= 255; accumulator -= 255)
{
*op++ = 255;
}
*op++ = (byte)accumulator;
}
else
{
*op++ = (byte)(lastRun << ML_BITS);
}
LZ4Mem.Copy(op, anchor, lastRun);
op += lastRun;
}
return((int)(op - dest));
}
protected static void LZ4_putPosition(
byte *p, void *tableBase, tableType_t tableType, byte *srcBase) =>
LZ4_putPositionOnHash(p, LZ4_hashPosition(p, tableType), tableBase, tableType, srcBase);
