e32tools/e32lib/e32image/deflate/deflate.cpp
changeset 37 863e2b34c16d
parent 36 3141a18cb091
parent 35 32228a6e07c0
child 38 620772202a07
--- a/e32tools/e32lib/e32image/deflate/deflate.cpp	Thu Nov 04 09:25:46 2010 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,325 +0,0 @@
-// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
-// All rights reserved.
-// This component and the accompanying materials are made available
-// under the terms of "Eclipse Public License v1.0"
-// which accompanies this distribution, and is available
-// at the URL "http://www.eclipse.org/legal/epl-v10.html".
-//
-// Initial Contributors:
-// Nokia Corporation - initial contribution.
-//
-// Contributors:
-//
-// Description:
-// e32tools\petran\Szip\deflate.cpp
-// 
-//
-
-#include "deflate.h"
-#include "h_utl.h"
-#include "panic.h"
-
-class HDeflateHash
-	{
-public:
-	inline static HDeflateHash* NewLC(TInt aLinks);
-//
-	inline TInt First(const TUint8* aPtr,TInt aPos);
-	inline TInt Next(TInt aPos,TInt aOffset) const;
-private:
-	inline HDeflateHash();
-	inline static TInt Hash(const TUint8* aPtr);
-private:
-	typedef TUint16 TOffset;
-private:
-	TInt iHash[256];
-	TOffset iOffset[1];	// or more
-	};
-
-class MDeflater
-	{
-public:
-	void DeflateL(const TUint8* aBase,TInt aLength);
-	inline virtual ~MDeflater() { }; 
-private:
-	const TUint8* DoDeflateL(const TUint8* aBase,const TUint8* aEnd,HDeflateHash& aHash);
-	static TInt Match(const TUint8* aPtr,const TUint8* aEnd,TInt aPos,HDeflateHash& aHas);
-	void SegmentL(TInt aLength,TInt aDistance);
-	virtual void LitLenL(TInt aCode) =0;
-	virtual void OffsetL(TInt aCode) =0;
-	virtual void ExtraL(TInt aLen,TUint aBits) =0;
-	};
-
-class TDeflateStats : public MDeflater
-	{
-public:
-	inline TDeflateStats(TEncoding& aEncoding);
-	inline virtual ~TDeflateStats() { } 
-private:
-// from MDeflater
-	void LitLenL(TInt aCode);
-	void OffsetL(TInt aCode);
-	void ExtraL(TInt aLen,TUint aBits);
-private:
-	TEncoding& iEncoding;
-	};
-
-class TDeflater : public MDeflater
-	{
-public:
-	inline TDeflater(TBitOutput& aOutput,const TEncoding& aEncoding);
-	inline virtual ~TDeflater() { }; 
-private:
-// from MDeflater
-	void LitLenL(TInt aCode);
-	void OffsetL(TInt aCode);
-	void ExtraL(TInt aLen,TUint aBits);
-private:
-	TBitOutput& iOutput;
-	const TEncoding& iEncoding;
-	};
-
-
-// Class HDeflateHash
-
-inline HDeflateHash::HDeflateHash()
-	{TInt* p=iHash+256;do *--p=-KDeflateMaxDistance-1; while (p>iHash);}
-
-inline HDeflateHash* HDeflateHash::NewLC(TInt aLinks)
-	{
-	return new(HMem::Alloc(0,_FOFF(HDeflateHash,iOffset[0]) + (sizeof(TOffset) * Min(aLinks,KDeflateMaxDistance)))) HDeflateHash;
-	}
-
-inline TInt HDeflateHash::Hash(const TUint8* aPtr)
-	{
-	TUint x=aPtr[0]|(aPtr[1]<<8)|(aPtr[2]<<16);
-	return (x*KDeflateHashMultiplier)>>KDeflateHashShift;
-	}
-
-inline TInt HDeflateHash::First(const TUint8* aPtr,TInt aPos)
-	{
-	TInt h=Hash(aPtr);
-	TInt offset=Min(aPos-iHash[h],KDeflateMaxDistance<<1);
-	iHash[h]=aPos;
-	iOffset[aPos&(KDeflateMaxDistance-1)]=TOffset(offset);
-	return offset;
-	}
-
-inline TInt HDeflateHash::Next(TInt aPos,TInt aOffset) const
-	{return aOffset+iOffset[(aPos-aOffset)&(KDeflateMaxDistance-1)];}
-
-
-// Class TDeflater
-//
-// generic deflation algorithm, can do either statistics and the encoder
-
-TInt MDeflater::Match(const TUint8* aPtr,const TUint8* aEnd,TInt aPos,HDeflateHash& aHash)
-	{
-	TInt offset=aHash.First(aPtr,aPos);
-	if (offset>KDeflateMaxDistance)
-		return 0;
-	TInt match=0;
-	aEnd=Min(aEnd,aPtr+KDeflateMaxLength);
-	TUint8 c=*aPtr;
-	do
-		{
-		const TUint8* p=aPtr-offset;
-		if (p[match>>16]==c)
-			{	// might be a better match
-			const TUint8* m=aPtr;
-			for (;;)
-				{
-				if (*p++!=*m++)
-					break;
-				if (m<aEnd)
-					continue;
-				return ((m-aPtr)<<16)|offset;
-				}
-			TInt l=m-aPtr-1;
-			if (l>match>>16)
-				{
-				match=(l<<16)|offset;
-				c=m[-1];
-				}
-			}
-		offset=aHash.Next(aPos,offset);
-		} while (offset<=KDeflateMaxDistance);
-	return match;
-	}
-
-const TUint8* MDeflater::DoDeflateL(const TUint8* aBase,const TUint8* aEnd,HDeflateHash& aHash)
-//
-// Apply the deflation algorithm to the data [aBase,aEnd)
-// Return a pointer after the last byte that was deflated (which may not be aEnd)
-//
-	{
-	const TUint8* ptr=aBase;
-	TInt prev=0;		// the previous deflation match
-	do
-		{
-		TInt match=Match(ptr,aEnd,ptr-aBase,aHash);
-// Extra deflation applies two optimisations which double the time taken
-// 1. If we have a match at p, then test for a better match at p+1 before using it
-// 2. When we have a match, add the hash links for all the data which will be skipped 
-		if (match>>16 < prev>>16)
-			{	// use the previous match--it was better
-			TInt len=prev>>16;
-			SegmentL(len,prev-(len<<16));
-			// fill in missing hash entries for better compression
-			const TUint8* e=ptr+len-2;
-			do 
-				{
-				++ptr;
-				if (ptr + 2 < aEnd)
-					aHash.First(ptr,ptr-aBase);
-				} while (ptr<e);
-			prev=0;
-			}
-		else if (match<=(KDeflateMinLength<<16))
-			LitLenL(*ptr);			// no deflation match here
-		else
-			{	// save this match and test the next position
-			if (prev)	// we had a match at ptr-1, but this is better
-				LitLenL(ptr[-1]);
-			prev=match;
-			}
-		++ptr;
-		} while (ptr+KDeflateMinLength-1<aEnd);
-	if (prev)
-		{		// emit the stored match
-		TInt len=prev>>16;
-		SegmentL(len,prev-(len<<16));
-		ptr+=len-1;
-		}
-	return ptr;
-	}
-
-void MDeflater::DeflateL(const TUint8* aBase,TInt aLength)
-//
-// The generic deflation algorithm
-//
-	{
-	const TUint8* end=aBase+aLength;
-	if (aLength>KDeflateMinLength)
-		{	// deflation kicks in if there is enough data
-		HDeflateHash* hash=HDeflateHash::NewLC(aLength);
-		if(hash==NULL)
-			Panic(EHuffmanOutOfMemory);
-
-		aBase=DoDeflateL(aBase,end,*hash);
-		delete hash;
-		}
-	while (aBase<end)					// emit remaining bytes
-		LitLenL(*aBase++);
-	LitLenL(TEncoding::EEos);	// eos marker
-	}
-
-void MDeflater::SegmentL(TInt aLength,TInt aDistance)
-//
-// Turn a (length,offset) pair into the deflation codes+extra bits before calling
-// the specific LitLen(), Offset() and Extra() functions.
-//
-	{
-	aLength-=KDeflateMinLength;
-	TInt extralen=0;
-	TUint len=aLength;
-	while (len>=8)
-		{
-		++extralen;
-		len>>=1;
-		}
-	LitLenL((extralen<<2)+len+TEncoding::ELiterals);
-	if (extralen)
-		ExtraL(extralen,aLength);
-//
-	aDistance--;
-	extralen=0;
-	TUint dist=aDistance;
-	while (dist>=8)
-		{
-		++extralen;
-		dist>>=1;
-		}
-	OffsetL((extralen<<2)+dist);
-	if (extralen)
-		ExtraL(extralen,aDistance);
-	}
-
-// Class TDeflateStats
-//
-// This class analyses the data stream to generate the frequency tables 
-// for the deflation algorithm
-
-inline TDeflateStats::TDeflateStats(TEncoding& aEncoding)
-	:iEncoding(aEncoding)
-	{}
-
-void TDeflateStats::LitLenL(TInt aCode)
-	{
-	++iEncoding.iLitLen[aCode];
-	}
-
-void TDeflateStats::OffsetL(TInt aCode)
-	{
-	++iEncoding.iDistance[aCode];
-	}
-
-void TDeflateStats::ExtraL(TInt,TUint)
-	{}
-
-// Class TDeflater
-//
-// Extends MDeflater to provide huffman encoding of the output
-
-inline TDeflater::TDeflater(TBitOutput& aOutput,const TEncoding& aEncoding)
-//
-// construct for encoding
-//
-	:iOutput(aOutput),iEncoding(aEncoding)
-	{}
-
-void TDeflater::LitLenL(TInt aCode)
-	{
-	iOutput.HuffmanL(iEncoding.iLitLen[aCode]);
-	}
-
-void TDeflater::OffsetL(TInt aCode)
-	{
-	iOutput.HuffmanL(iEncoding.iDistance[aCode]);
-	}
-
-void TDeflater::ExtraL(TInt aLen,TUint aBits)
-	{
-	iOutput.WriteL(aBits,aLen);
-	}
-
-void DoDeflateL(const TUint8* aBuf,TInt aLength,TBitOutput& aOutput,TEncoding& aEncoding)
-	{
-// analyse the data for symbol frequency 
-	TDeflateStats analyser(aEncoding);
-	analyser.DeflateL(aBuf,aLength);
-	
-// generate the required huffman encodings
-	Huffman::HuffmanL(aEncoding.iLitLen,TEncoding::ELitLens,aEncoding.iLitLen);
-	Huffman::HuffmanL(aEncoding.iDistance,TEncoding::EDistances,aEncoding.iDistance);
-
-// Store the encoding table
-	Huffman::ExternalizeL(aOutput,aEncoding.iLitLen,KDeflationCodes);
-
-// generate the tables
-	Huffman::Encoding(aEncoding.iLitLen,TEncoding::ELitLens,aEncoding.iLitLen);
-	Huffman::Encoding(aEncoding.iDistance,TEncoding::EDistances,aEncoding.iDistance);
-
-// now finally deflate the data with the generated encoding
-	TDeflater deflater(aOutput,aEncoding);
-	deflater.DeflateL(aBuf,aLength);
-	aOutput.PadL(1);
-	}
-
-void DeflateL(const TUint8* aBuf, TInt aLength, TBitOutput& aOutput)
-	{
-	TEncoding* encoding=new TEncoding;
-	HMem::FillZ(encoding,sizeof(TEncoding));
-	DoDeflateL(aBuf,aLength,aOutput,*encoding);
-	}
-