fbreader/src/formats/pdb/ZTXTStream.cpp

   1 /*
   2  * Copyright (C) 2004-2008 Geometer Plus <contact@geometerplus.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA.
  18  */
  19
  20 #include <ZLFile.h>
  21 #include <ZLZDecompressor.h>
  22
  23 #include "ZTXTStream.h"
  24
  25 ZTXTStream::ZTXTStream(ZLFile &file) : PdbStream(file) {
  26 }
  27
  28 ZTXTStream::~ZTXTStream() {
  29         close();
  30 }
  31
  32 bool ZTXTStream::open() {
  33         if (!PdbStream::open()) {
  34                 return false;
  35         }
  36
  37         myBase->seek(2, false);
  38         unsigned short records;
  39         PdbUtil::readUnsignedShort(*myBase, records);
  40         myMaxRecordIndex = std::min(records, (unsigned short)(myHeader.Offsets.size() - 1));
  41         myBase->seek(4, false);
  42         PdbUtil::readUnsignedShort(*myBase, myMaxRecordSize);
  43         if (myMaxRecordSize == 0) {
  44                 return false;
  45         }
  46         myBuffer = new char[myMaxRecordSize];
  47
  48         myRecordIndex = 0;
  49
  50         return true;
  51 }
  52
  53 bool ZTXTStream::fillBuffer() {
  54         while (myBufferOffset == myBufferLength) {
  55                 if (myRecordIndex + 1 > myMaxRecordIndex) {
  56                         return false;
  57                 }
  58                 ++myRecordIndex;
  59                 size_t currentOffset = myHeader.Offsets[myRecordIndex];
  60                 // Hmm, this works on examples from manybooks.net,
  61                 // but I don't what thi code means :((
  62                 if (myRecordIndex == 1) {
  63                         currentOffset += 2;
  64                 }
  65                 if (currentOffset < myBase->offset()) {
  66                         return false;
  67                 }
  68                 myBase->seek(currentOffset, true);
  69                 size_t nextOffset =
  70                         (myRecordIndex + 1 < myHeader.Offsets.size()) ?
  71                                 myHeader.Offsets[myRecordIndex + 1] : myBase->sizeOfOpened();
  72                 if (nextOffset < currentOffset) {
  73                         return false;
  74                 }
  75                 myBufferLength = ZLZDecompressor(nextOffset - currentOffset).decompress(*myBase, myBuffer, myMaxRecordSize);
  76                 myBufferOffset = 0;
  77         }
  78         return true;
  79 }