fbreader/src/formats/pdb/PalmDocStream.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
  22 #include "PalmDocStream.h"
  23 #include "DocDecompressor.h"
  24
  25 PalmDocStream::PalmDocStream(ZLFile &file) : PdbStream(file) {
  26 }
  27
  28 PalmDocStream::~PalmDocStream() {
  29         close();
  30 }
  31
  32 bool PalmDocStream::open() {
  33         if (!PdbStream::open()) {
  34                 return false;
  35         }
  36
  37         unsigned short version;
  38         PdbUtil::readUnsignedShort(*myBase, version);
  39         myIsCompressed = (version == 2);
  40         myBase->seek(6, false);
  41         unsigned short records;
  42         PdbUtil::readUnsignedShort(*myBase, records);
  43         myMaxRecordIndex = std::min(records, (unsigned short)(myHeader.Offsets.size() - 1));
  44         PdbUtil::readUnsignedShort(*myBase, myMaxRecordSize);
  45         if (myMaxRecordSize == 0) {
  46                 return false;
  47         }
  48         myBuffer = new char[myMaxRecordSize];
  49
  50         myRecordIndex = 0;
  51
  52         return true;
  53 }
  54
  55 bool PalmDocStream::fillBuffer() {
  56         while (myBufferOffset == myBufferLength) {
  57                 if (myRecordIndex + 1 > myMaxRecordIndex) {
  58                         return false;
  59                 }
  60                 ++myRecordIndex;
  61                 size_t currentOffset = myHeader.Offsets[myRecordIndex];
  62                 if (currentOffset < myBase->offset()) {
  63                         return false;
  64                 }
  65                 myBase->seek(currentOffset, true);
  66                 size_t nextOffset =
  67                         (myRecordIndex + 1 < myHeader.Offsets.size()) ?
  68                                 myHeader.Offsets[myRecordIndex + 1] : myBase->sizeOfOpened();
  69                 if (nextOffset < currentOffset) {
  70                         return false;
  71                 }
  72                 if (myIsCompressed) {
  73                         myBufferLength = DocDecompressor().decompress(*myBase, myBuffer, nextOffset - currentOffset, myMaxRecordSize);
  74                 } else {
  75                         myBase->read(myBuffer, nextOffset - currentOffset);
  76                         myBufferLength = nextOffset - currentOffset;
  77                 }
  78                 myBufferOffset = 0;
  79         }
  80         return true;
  81 }