misc/libphysfs/lzma/CS/7zip/Compress/LZ/LzBinTree.cs
changeset 12213 bb5522e88ab2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libphysfs/lzma/CS/7zip/Compress/LZ/LzBinTree.cs	Mon Apr 10 12:06:43 2017 -0400
@@ -0,0 +1,367 @@
+// LzBinTree.cs
+
+using System;
+
+namespace SevenZip.Compression.LZ
+{
+	public class BinTree : InWindow, IMatchFinder
+	{
+		UInt32 _cyclicBufferPos;
+		UInt32 _cyclicBufferSize = 0;
+		UInt32 _matchMaxLen;
+
+		UInt32[] _son;
+		UInt32[] _hash;
+
+		UInt32 _cutValue = 0xFF;
+		UInt32 _hashMask;
+		UInt32 _hashSizeSum = 0;
+
+		bool HASH_ARRAY = true;
+
+		const UInt32 kHash2Size = 1 << 10;
+		const UInt32 kHash3Size = 1 << 16;
+		const UInt32 kBT2HashSize = 1 << 16;
+		const UInt32 kStartMaxLen = 1;
+		const UInt32 kHash3Offset = kHash2Size;
+		const UInt32 kEmptyHashValue = 0;
+		const UInt32 kMaxValForNormalize = ((UInt32)1 << 31) - 1;
+	
+		UInt32 kNumHashDirectBytes = 0;
+		UInt32 kMinMatchCheck = 4;
+		UInt32 kFixHashSize = kHash2Size + kHash3Size;
+		
+		public void SetType(int numHashBytes)
+		{
+			HASH_ARRAY = (numHashBytes > 2);
+			if (HASH_ARRAY)
+			{
+				kNumHashDirectBytes = 0;
+				kMinMatchCheck = 4;
+				kFixHashSize = kHash2Size + kHash3Size;
+			}
+			else
+			{
+				kNumHashDirectBytes = 2;
+				kMinMatchCheck = 2 + 1;
+				kFixHashSize = 0;
+			}
+		}
+
+		public new void SetStream(System.IO.Stream stream) { base.SetStream(stream); }
+		public new void ReleaseStream() { base.ReleaseStream(); }
+		
+		public new void Init()
+		{
+			base.Init();
+			for (UInt32 i = 0; i < _hashSizeSum; i++)
+				_hash[i] = kEmptyHashValue;
+			_cyclicBufferPos = 0;
+			ReduceOffsets(-1);
+		}
+
+		public new void MovePos()
+		{
+			if (++_cyclicBufferPos >= _cyclicBufferSize)
+				_cyclicBufferPos = 0;
+			base.MovePos();
+			if (_pos == kMaxValForNormalize)
+				Normalize();
+		}
+
+		public new Byte GetIndexByte(Int32 index) { return base.GetIndexByte(index); }
+
+		public new UInt32 GetMatchLen(Int32 index, UInt32 distance, UInt32 limit)
+		{ return base.GetMatchLen(index, distance, limit); }
+
+		public new UInt32 GetNumAvailableBytes() { return base.GetNumAvailableBytes(); }
+
+		public void Create(UInt32 historySize, UInt32 keepAddBufferBefore,
+				UInt32 matchMaxLen, UInt32 keepAddBufferAfter)
+		{
+			if (historySize > kMaxValForNormalize - 256)
+				throw new Exception();
+			_cutValue = 16 + (matchMaxLen >> 1);
+				
+			UInt32 windowReservSize = (historySize + keepAddBufferBefore +
+					matchMaxLen + keepAddBufferAfter) / 2 + 256;
+
+			base.Create(historySize + keepAddBufferBefore, matchMaxLen + keepAddBufferAfter, windowReservSize);
+
+			_matchMaxLen = matchMaxLen;
+
+			UInt32 cyclicBufferSize = historySize + 1;
+			if (_cyclicBufferSize != cyclicBufferSize)
+				_son = new UInt32[(_cyclicBufferSize = cyclicBufferSize) * 2];
+
+			UInt32 hs = kBT2HashSize;
+
+			if (HASH_ARRAY)
+			{
+				hs = historySize - 1;
+				hs |= (hs >> 1);
+				hs |= (hs >> 2);
+				hs |= (hs >> 4);
+				hs |= (hs >> 8);
+				hs >>= 1;
+				hs |= 0xFFFF;
+				if (hs > (1 << 24))
+					hs >>= 1;
+				_hashMask = hs;
+				hs++;
+				hs += kFixHashSize;
+			}
+			if (hs != _hashSizeSum)
+				_hash = new UInt32[_hashSizeSum = hs];
+		}
+
+		public UInt32 GetMatches(UInt32[] distances)
+		{
+			UInt32 lenLimit;
+			if (_pos + _matchMaxLen <= _streamPos)
+				lenLimit = _matchMaxLen;
+			else
+			{
+				lenLimit = _streamPos - _pos;
+				if (lenLimit < kMinMatchCheck)
+				{
+					MovePos();
+					return 0;
+				}
+			}
+
+			UInt32 offset = 0;
+			UInt32 matchMinPos = (_pos > _cyclicBufferSize) ? (_pos - _cyclicBufferSize) : 0;
+			UInt32 cur = _bufferOffset + _pos;
+			UInt32 maxLen = kStartMaxLen; // to avoid items for len < hashSize;
+			UInt32 hashValue, hash2Value = 0, hash3Value = 0;
+
+			if (HASH_ARRAY)
+			{
+				UInt32 temp = CRC.Table[_bufferBase[cur]] ^ _bufferBase[cur + 1];
+				hash2Value = temp & (kHash2Size - 1);
+				temp ^= ((UInt32)(_bufferBase[cur + 2]) << 8);
+				hash3Value = temp & (kHash3Size - 1);
+				hashValue = (temp ^ (CRC.Table[_bufferBase[cur + 3]] << 5)) & _hashMask;
+			}
+			else
+				hashValue = _bufferBase[cur] ^ ((UInt32)(_bufferBase[cur + 1]) << 8);
+
+			UInt32 curMatch = _hash[kFixHashSize + hashValue];
+			if (HASH_ARRAY)
+			{
+				UInt32 curMatch2 = _hash[hash2Value];
+				UInt32 curMatch3 = _hash[kHash3Offset + hash3Value];
+				_hash[hash2Value] = _pos;
+				_hash[kHash3Offset + hash3Value] = _pos;
+				if (curMatch2 > matchMinPos)
+					if (_bufferBase[_bufferOffset + curMatch2] == _bufferBase[cur])
+					{
+						distances[offset++] = maxLen = 2;
+						distances[offset++] = _pos - curMatch2 - 1;
+					}
+				if (curMatch3 > matchMinPos)
+					if (_bufferBase[_bufferOffset + curMatch3] == _bufferBase[cur])
+					{
+						if (curMatch3 == curMatch2)
+							offset -= 2;
+						distances[offset++] = maxLen = 3;
+						distances[offset++] = _pos - curMatch3 - 1;
+						curMatch2 = curMatch3;
+					}
+				if (offset != 0 && curMatch2 == curMatch)
+				{
+					offset -= 2;
+					maxLen = kStartMaxLen;
+				}
+			}
+
+			_hash[kFixHashSize + hashValue] = _pos;
+
+			UInt32 ptr0 = (_cyclicBufferPos << 1) + 1;
+			UInt32 ptr1 = (_cyclicBufferPos << 1);
+
+			UInt32 len0, len1;
+			len0 = len1 = kNumHashDirectBytes;
+			
+			if (kNumHashDirectBytes != 0)
+			{
+				if (curMatch > matchMinPos)
+				{
+					if (_bufferBase[_bufferOffset + curMatch + kNumHashDirectBytes] !=
+							_bufferBase[cur + kNumHashDirectBytes])
+					{
+						distances[offset++] = maxLen = kNumHashDirectBytes;
+						distances[offset++] = _pos - curMatch - 1;
+					}
+				}
+			}
+			
+			UInt32 count = _cutValue;
+			
+			while(true)
+			{
+				if(curMatch <= matchMinPos || count-- == 0)
+				{
+					_son[ptr0] = _son[ptr1] = kEmptyHashValue;
+					break;
+				}
+				UInt32 delta = _pos - curMatch;
+				UInt32 cyclicPos = ((delta <= _cyclicBufferPos) ?
+							(_cyclicBufferPos - delta) :
+							(_cyclicBufferPos - delta + _cyclicBufferSize)) << 1;
+
+				UInt32 pby1 = _bufferOffset + curMatch;
+				UInt32 len = Math.Min(len0, len1);
+				if (_bufferBase[pby1 + len] == _bufferBase[cur + len])
+				{
+					while(++len != lenLimit)
+						if (_bufferBase[pby1 + len] != _bufferBase[cur + len])
+							break;
+					if (maxLen < len)
+					{
+						distances[offset++] = maxLen = len;
+						distances[offset++] = delta - 1;
+						if (len == lenLimit)
+						{
+							_son[ptr1] = _son[cyclicPos];
+							_son[ptr0] = _son[cyclicPos + 1];
+							break;
+						}
+					}
+				}
+				if (_bufferBase[pby1 + len] < _bufferBase[cur + len])
+				{
+					_son[ptr1] = curMatch;
+					ptr1 = cyclicPos + 1;
+					curMatch = _son[ptr1];
+					len1 = len;
+				}
+				else
+				{
+					_son[ptr0] = curMatch;
+					ptr0 = cyclicPos;
+					curMatch = _son[ptr0];
+					len0 = len;
+				}
+			}
+			MovePos();
+			return offset;
+		}
+
+		public void Skip(UInt32 num)
+		{
+			do
+			{
+				UInt32 lenLimit;
+				if (_pos + _matchMaxLen <= _streamPos)
+					lenLimit = _matchMaxLen;
+				else
+				{
+					lenLimit = _streamPos - _pos;
+					if (lenLimit < kMinMatchCheck)
+					{
+						MovePos();
+						continue;
+					}
+				}
+
+				UInt32 matchMinPos = (_pos > _cyclicBufferSize) ? (_pos - _cyclicBufferSize) : 0;
+				UInt32 cur = _bufferOffset + _pos;
+
+				UInt32 hashValue;
+
+				if (HASH_ARRAY)
+				{
+					UInt32 temp = CRC.Table[_bufferBase[cur]] ^ _bufferBase[cur + 1];
+					UInt32 hash2Value = temp & (kHash2Size - 1);
+					_hash[hash2Value] = _pos;
+					temp ^= ((UInt32)(_bufferBase[cur + 2]) << 8);
+					UInt32 hash3Value = temp & (kHash3Size - 1);
+					_hash[kHash3Offset + hash3Value] = _pos;
+					hashValue = (temp ^ (CRC.Table[_bufferBase[cur + 3]] << 5)) & _hashMask;
+				}
+				else
+					hashValue = _bufferBase[cur] ^ ((UInt32)(_bufferBase[cur + 1]) << 8);
+
+				UInt32 curMatch = _hash[kFixHashSize + hashValue];
+				_hash[kFixHashSize + hashValue] = _pos;
+
+				UInt32 ptr0 = (_cyclicBufferPos << 1) + 1;
+				UInt32 ptr1 = (_cyclicBufferPos << 1);
+
+				UInt32 len0, len1;
+				len0 = len1 = kNumHashDirectBytes;
+
+				UInt32 count = _cutValue;
+				while (true)
+				{
+					if (curMatch <= matchMinPos || count-- == 0)
+					{
+						_son[ptr0] = _son[ptr1] = kEmptyHashValue;
+						break;
+					}
+
+					UInt32 delta = _pos - curMatch;
+					UInt32 cyclicPos = ((delta <= _cyclicBufferPos) ?
+								(_cyclicBufferPos - delta) :
+								(_cyclicBufferPos - delta + _cyclicBufferSize)) << 1;
+
+					UInt32 pby1 = _bufferOffset + curMatch;
+					UInt32 len = Math.Min(len0, len1);
+					if (_bufferBase[pby1 + len] == _bufferBase[cur + len])
+					{
+						while (++len != lenLimit)
+							if (_bufferBase[pby1 + len] != _bufferBase[cur + len])
+								break;
+						if (len == lenLimit)
+						{
+							_son[ptr1] = _son[cyclicPos];
+							_son[ptr0] = _son[cyclicPos + 1];
+							break;
+						}
+					}
+					if (_bufferBase[pby1 + len] < _bufferBase[cur + len])
+					{
+						_son[ptr1] = curMatch;
+						ptr1 = cyclicPos + 1;
+						curMatch = _son[ptr1];
+						len1 = len;
+					}
+					else
+					{
+						_son[ptr0] = curMatch;
+						ptr0 = cyclicPos;
+						curMatch = _son[ptr0];
+						len0 = len;
+					}
+				}
+				MovePos();
+			}
+			while (--num != 0);
+		}
+
+		void NormalizeLinks(UInt32[] items, UInt32 numItems, UInt32 subValue)
+		{
+			for (UInt32 i = 0; i < numItems; i++)
+			{
+				UInt32 value = items[i];
+				if (value <= subValue)
+					value = kEmptyHashValue;
+				else
+					value -= subValue;
+				items[i] = value;
+			}
+		}
+
+		void Normalize()
+		{
+			UInt32 subValue = _pos - _cyclicBufferSize;
+			NormalizeLinks(_son, _cyclicBufferSize * 2, subValue);
+			NormalizeLinks(_hash, _hashSizeSum, subValue);
+			ReduceOffsets((Int32)subValue);
+		}
+
+		public void SetCutValue(UInt32 cutValue) { _cutValue = cutValue; }
+	}
+}