huffypacker.cpp

有关huffman的程序对大家学习数据结构有好处但不是所有人都用得上

// HuffyPacker.cpp: implementation of the HuffyPacker class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "HuffmanTest.h"
#include "HuffyPacker.h"

#include "HuffmanCoder.h"
#include "HuffyDict.h"

#include <sys/types.h>
#include <sys/stat.h>

#include <string>

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

HuffyPacker::HuffyPacker()
{
	InFN=OutFN=NULL;

	MyLog=NULL;
	MyListener=NULL;
}

HuffyPacker::~HuffyPacker()
{
	delete[] InFN;
	delete[] OutFN;
}

void HuffyPacker::SetUIHelpers(ProgressListener *NewListener, WinLog *NewLogTarget)
{
	MyListener=NewListener;
	MyLog=NewLogTarget;
}

void HuffyPacker::SetFileNames(const char *InFileName, const char *OutFileName)
{
	delete[] InFN;
	unsigned short FNLen=strlen(InFileName);
	InFN=new char[FNLen+1];
	strcpy(InFN,InFileName);
	InFN[FNLen]='\0';

	delete[] OutFN;
	FNLen=strlen(OutFileName);
	OutFN=new char[FNLen+1];
	strcpy(OutFN,OutFileName);
	OutFN[FNLen]='\0';
}

unsigned int HuffyPacker::ThreadEncoder(void *Self)
{
	return ((HuffyPacker *)Self)->Encode();
}

unsigned int HuffyPacker::ThreadDecoder(void *Self)
{
	return ((HuffyPacker *)Self)->Decode();
}

unsigned int HuffyPacker::Encode()
{
	if ((!MyListener) || (!MyLog))
		return 2;

	char TmpBuff[64];
	sprintf(TmpBuff,"Huffy packer v%d.%2d started.",HUFFYMAJORVER,HUFFYMINORVER);
	MyLog->LogText(TmpBuff);

	FILE *InFile=Loggedfopen(InFN,true);
	if (!InFile)
		return 1;
	unsigned int InFileLength=GetFileLength(InFN);

	MyLog->LogText("Creating adaptive dictionary...");
	MyListener->SetMax(InFileLength);
	MyListener->SetProgressMsg("Counting: %d%%");

	HuffyDict CurrDict;
	CurrDict.SetUIHelper(MyListener);
	CurrDict.CreateAdaptedDict(InFile);

	fclose(InFile);

	unsigned char MaxLen,MinLen;
	MyLog->LogText("Dictionary stats:");
	sprintf(TmpBuff,"  Symbol count: %d",CurrDict.GetStats(MaxLen,MinLen));
	MyLog->LogText(TmpBuff);
	sprintf(TmpBuff,"  Min / Max code length: %d / %d",MinLen,MaxLen);
	MyLog->LogText(TmpBuff);

	InFile=Loggedfopen(InFN,true);
	FILE *OutFile=Loggedfopen(OutFN,false);
	if ((!InFile) || (!OutFile))
		return 1;

	MyLog->LogText("Writing packed file...");
	//First, write the header...
	WritePackedHeader(OutFile,InFileLength);
	//...then the dictionary...
	MyLog->LogText("  Writing dictionary...");
	CurrDict.Serialize(OutFile);

	//...and finally, the encoded file itself.
	MyLog->LogText("  Encoding source file...");
	MyListener->SetProgressMsg("Encoding: %d%%");
	MyListener->Reset();

	HuffmanCoder MyCoder;
	MyCoder.SetProgressHelper(MyListener);
	MyCoder.SetEncDict(&CurrDict);
	MyCoder.Encode(InFile,OutFile);

	fclose(InFile);
	fclose(OutFile);
	
	MyListener->Reset();
	MyLog->LogText("Packing finished.");
	sprintf(TmpBuff,"Compression ratio was %.2f",GetFileLength(OutFN)/(float)InFileLength);
	MyLog->LogText(TmpBuff);

	return 0;
}

unsigned int HuffyPacker::Decode()
{
	if ((!MyListener) || (!MyLog))
		return 2;

	char TmpBuff[64];
	sprintf(TmpBuff,"Huffy packer v%d.%2d started.",HUFFYMAJORVER,HUFFYMINORVER);
	MyLog->LogText(TmpBuff);

	FILE *InFile=Loggedfopen(InFN,true);
	if (!InFile)
		return 1;
	unsigned int InFileLength=GetFileLength(InFN);

	unsigned int OrigSize;
	unsigned char HeaderRet=ReadPackedHeader(InFile,OrigSize);
	if (HeaderRet==1)
	{
		MyLog->LogText("Input file is not Huffy-compressed.");
		return 2;
	}
	else if (HeaderRet==2)
	{
		MyLog->LogText("Input file was compressed by another Huffy version.");
		return 2;
	}

	MyLog->LogText("Reading dictonary...");
	
	HuffyDict CurrDict;
	CurrDict.SetUIHelper(MyListener);
	CurrDict.Deserialize(InFile);

	MyLog->LogText("Generating node transition table...");
	unsigned int StateCount;
	CurrDict.GetNTTable(StateCount);

	sprintf(TmpBuff,"  State count: %d",StateCount);
	MyLog->LogText(TmpBuff);

	FILE *OutFile=Loggedfopen(OutFN,false);
	if (!OutFile)
		return 1;

	MyLog->LogText("Decoding source file...");
	MyListener->SetProgressMsg("Decoding: %d%%");
	MyListener->SetMax(OrigSize);

	HuffmanCoder MyCoder;
	MyCoder.SetProgressHelper(MyListener);
	MyCoder.SetDecDict(&CurrDict);
	MyCoder.Decode(InFile,OutFile,OrigSize);

	
	fclose(InFile);
	fclose(OutFile);
	MyListener->Reset();
	MyLog->LogText("Unpacking finished.");

	return 0;
}

void HuffyPacker::WritePackedHeader(FILE *TargetFile, unsigned int OrigSize)
{
	fwrite("Huffy",5,1,TargetFile);

	unsigned char MajVer=HUFFYMAJORVER, MinVer=HUFFYMINORVER;
	fwrite(&MajVer,1,1,TargetFile);
	fwrite(&MinVer,1,1,TargetFile);

	fwrite(&OrigSize,4,1,TargetFile);
}

unsigned char HuffyPacker::ReadPackedHeader(FILE *SourceFile, unsigned int &RetOrigSize)
{
	char HeaderTmp[5];
	fread(HeaderTmp,5,1,SourceFile);

	//Header mismatch.
	if (memcmp("Huffy",HeaderTmp,5))
		return 1;

	unsigned char MajVer,MinVer;
	fread(&MajVer,1,1,SourceFile);
	fread(&MinVer,1,1,SourceFile);

	//Archive version mismatch.
	if ((MajVer!=HUFFYMAJORVER) || (MinVer!=HUFFYMINORVER))
		return 2;

	fread(&RetOrigSize,4,1,SourceFile);
	return 0;
}

unsigned int HuffyPacker::GetFileLength(const char *FileName)
{
	//Ugly and not portable.
	struct _stat TmpOut;
	_stat(FileName,&TmpOut);
	return TmpOut.st_size;
}

FILE *HuffyPacker::Loggedfopen(const char *FileName, bool Read)
{
	FILE *RetFile;
	if (Read)
		RetFile=fopen(FileName,"rb");
	else
		RetFile=fopen(FileName,"wb");

	if (RetFile)
	{
		std::string TmpMsg="Opened file \"";
		TmpMsg+=FileName;
		TmpMsg+="\" for ";
		if (Read)
			TmpMsg+="reading.";
		else
			TmpMsg+="writing.";

		MyLog->LogText(TmpMsg.data());
	}
	else
	{
		std::string TmpMsg="FAILED to open file \"";
		TmpMsg+=FileName;
		TmpMsg+="\" for ";
		if (Read)
			TmpMsg+="reading!";
		else
			TmpMsg+="writing!";

		MyLog->LogText(TmpMsg.data());
	}

	return RetFile;
}