aportis.cxx

一个小的非常好用的电子书阅读器源码

#include <stdio.h>
#include <string.h>
#include "Aportis.h"

Aportis::Aportis() : fin(NULL) { /*printf("constructing:%x\n",fin);*/ }

CList<Bkmk>* Aportis::getbkmklist()
{
  if (bCompressed != 4) return NULL;
  CList<Bkmk>* t = new CList<Bkmk>;
  size_t cur = ftell(fin);
  for (int i = 0; i < nRecs2; i++)
    {
      DWORD dwPos;
      fseek(fin, 0x56 + 8*i, SEEK_SET);
      fread(&dwPos, 4, 1, fin);
      dwPos = SwapLong(dwPos);
      fseek(fin,dwPos,SEEK_SET);
      unsigned char ch;
      fread(&ch,1,1,fin);
      if (ch != 241)
      {
	char name[17];
	name[16] = '\0';
	fseek(fin,dwPos,SEEK_SET);
	fread(name,1,16,fin);
	unsigned long lcn;
	fread(&lcn,sizeof(lcn),1,fin);
	lcn = SwapLong(lcn);
	t->push_back(Bkmk(name,lcn));
      }
    }
  fseek(fin, cur, SEEK_SET);
  return t;
}

int Aportis::openfile(char *src)
{

  //  printf("In openfile\n");
  int ret = 0;
  //  printf("closing fin:%x\n",fin);
  if (fin != NULL) fclose(fin);
  tDocHeader head;
  //  printf("opening fin\n");
  fin = fopen(src,"rb");

  if (fin==0)
    {
      return -1;
    }

  // just holds the first few chars of the file
  //	char buf[0x100];

  fread(&head, 1, sizeof(head), fin);
  if (head.dwType != 0x64414552 //   'dAER'
      || head.dwCreator != 0x74584554) // 'tXET')
    {
      return -2;
    }

  // point to start of index
  fseek(fin, 0x4E, SEEK_SET);
  // read the location of the first record
  DWORD dwPos;
  fread(&dwPos, 4, 1, fin);
  dwPos = SwapLong(dwPos);
  fseek(fin, dwPos+1, SEEK_SET);
  fread(&bCompressed, 1, 1, fin);
  if (bCompressed!=1 && bCompressed!=2 && bCompressed != 4) {
    ret = bCompressed;
    bCompressed = 2;
  }
	
  fseek(fin,0,SEEK_END);
  dwLen = ftell(fin);
  nRecs2 = nRecs = SwapWord(head.wNumRecs) - 1;

  switch (bCompressed)
    {
    case 4:
      {
	dwTLen = 0;
	int i;
	for (i = 0; i < nRecs; i++)
	  {
	    unsigned int bs = GetBS(i);
	    if (bs == 0) break;
	    else dwTLen += bs;
	  }
	nRecs = i;
	BlockSize = 0;
      }
      break;
    case 1:
    case 2:
    default:
      fseek(fin,0x56+8*nRecs+6,SEEK_SET);
      fread(&dwTLen, 4, 1, fin);
      dwTLen = SwapLong(dwTLen);

      fseek(fin,0x56+8*nRecs+12,SEEK_SET);
      fread(&BlockSize, 2, 1, fin);
      BlockSize = SwapWord(BlockSize);

      if (BlockSize == 0)
	{
	  BlockSize = 4096;
	  printf("WARNING: Blocksize not set in source file\n");
	}
    }


  // this is the main record buffer
  // it knows how to stretch to accomodate the decompress
  currentrec = 0;
  cbptr = 0;
  outptr = 0;
  refreshbuffer();
  return ret;
}

int Aportis::getch()
{
  if (bCompressed == 1)
    {
      if ((dwRecLen == 0) && !refreshbuffer()) return EOF;
      else
	{
	  int c = getc(fin);
	  dwRecLen--;
	  currentpos++;
	  return c;
	}
    }
  if (outptr != cbptr)
    {
      currentpos++;
      return (circbuf[outptr = (outptr + 1) % 2048]);
    }
  if ((dwRecLen == 0) && !refreshbuffer()) return EOF;
  currentpos++;
  unsigned int c;

  // take a char from the input buffer
  c = getc(fin);
  dwRecLen--;
  // separate the char into zones: 0, 1...8, 9...0x7F, 0x80...0xBF, 0xC0...0xFF

  // codes 1...8 mean copy that many chars; for accented chars & binary
  if (c == 0)
    {
      circbuf[outptr = cbptr = (cbptr+1)%2048] = c;
      return c;
    }
  else if (c >= 0x09 && c <= 0x7F)
    {
      circbuf[outptr = cbptr = (cbptr+1)%2048] = c;
      return c;
    }
  else if (c >= 0x01 && c <= 0x08)
    {
      dwRecLen -= c;
      while(c--)
	{
	  circbuf[cbptr = (cbptr+1)%2048] = getc(fin);
	}
      return circbuf[outptr = (outptr+1)%2048];
    }
  else if (c >= 0x80 && c <= 0xBF)
    {
      int m,n;
      c <<= 8;
      c += getc(fin);
      dwRecLen--;
      m = (c & 0x3FFF) >> COUNT_BITS;
      n = c & ((1<<COUNT_BITS) - 1);
      n += 3;
      while (n--)
	{
	  cbptr = (cbptr+1)%2048;
	  circbuf[cbptr] = circbuf[(cbptr+2048-m)%2048];
	}
      return circbuf[outptr = (outptr+1)%2048];
    }
  else if (c >= 0xC0 && c <= 0xFF)
    {
      circbuf[cbptr = (cbptr+1)%2048] = ' ';
      circbuf[cbptr = (cbptr+1)%2048] = c^0x80;
      return circbuf[outptr = (outptr+1)%2048];
    }
}

unsigned int Aportis::GetBS(unsigned int bn)
{
  DWORD dwPos;
  WORD fs;
  fseek(fin, 0x56 + 8*bn, SEEK_SET);
  fread(&dwPos, 4, 1, fin);
  dwPos = SwapLong(dwPos);
  fseek(fin,dwPos,SEEK_SET);
  unsigned char ch;
  fread(&ch,1,1,fin);
  if (ch == 241)
    {
      fread(&fs,sizeof(fs),1,fin);
      fs = SwapWord(fs);
    }
  else
    fs = 0;
  return fs;
}

unsigned int Aportis::locate()
{
  if (bCompressed == 4)
    {
      size_t cur = ftell(fin);
      unsigned int clen = 0;
      for (unsigned int i = 0; i < currentrec-1; i++)
	{
	  unsigned int bs = GetBS(i);
	  if (bs == 0) break;
	  clen += bs;
	}
      fseek(fin,cur,SEEK_SET);
      return clen+currentpos;
    }
  else
    return (currentrec-1)*BlockSize+currentpos;
}

void Aportis::locate(unsigned int n)
{
  unsigned int offset;
  //  currentrec = (n >> OFFBITS);
  switch (bCompressed)
    {
    case 4:
      {
	DWORD clen = 0;
	offset = n;
	unsigned int i;
	for (i = 0; i < nRecs; i++)
	  {
	    unsigned int bs = GetBS(i);
	    if (bs == 0) break;
	    clen += bs;
	    if (clen > n) break;
	    offset = n - clen;
	  }
	currentrec = i;
      }
      break;
    case 1:
    case 2:
    default:
      currentrec = n / BlockSize;
      offset = n % BlockSize;
    }

  outptr = cbptr;
  refreshbuffer();
  while (currentpos < offset && getch() != EOF);
}

bool Aportis::refreshbuffer()
{
  if (currentrec < nRecs)
    {
      // read the record offset
      fseek(fin, 0x56 + 8*currentrec, SEEK_SET);
      DWORD dwPos;
      fread(&dwPos, 4, 1, fin);
      dwPos = SwapLong(dwPos);

      // read start of next record

      fseek(fin, 0x5E + 8*currentrec, SEEK_SET);
      fread(&dwRecLen, 4, 1, fin);
      dwRecLen = SwapLong(dwRecLen);

      // for the last, use the file len
      if (currentrec==nRecs2-1) dwRecLen = dwLen;

      dwRecLen -= dwPos;

      fseek(fin,dwPos,SEEK_SET);

      if (bCompressed == 4)
	{
	  unsigned char t[3];
	  fread(t,1,3,fin);
	  if (t[0] != 241)
	    {
	      printf("You shouldn't be here!\n");
	      return false;
	    }
	  dwRecLen -= 3;
	}
      /*
	int n = fread(t.buf, 1, dwRecLen, fin);
	t.len = n;
	//		if(bCompressed)
	t.Decompress();

	t.buf[t.Len()] = '\0';
      */
      currentpos = 0;
      currentrec++;
      return true;
    }
  else {
    return false;
  }
}