fbreader/src/formats/pdb/PdbStream.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 <string.h>
  21
  22 #include <ZLFile.h>
  23
  24 #include "PdbStream.h"
  25
  26 PdbStream::PdbStream(ZLFile &file) : myBase(file.inputStream()) {
  27         myBuffer = 0;
  28 }
  29
  30 PdbStream::~PdbStream() {
  31 }
  32
  33 bool PdbStream::open() {
  34         close();
  35         if (myBase.isNull() || !myBase->open() || !myHeader.read(myBase)) {
  36                 return false;
  37         }
  38
  39         myBase->seek(myHeader.Offsets[0], true);
  40
  41         myBufferLength = 0;
  42         myBufferOffset = 0;
  43
  44         myOffset = 0;
  45
  46         return true;
  47 }
  48
  49 size_t PdbStream::read(char *buffer, size_t maxSize) {
  50         size_t realSize = 0;
  51         while (realSize < maxSize) {
  52                 if (!fillBuffer()) {
  53                         break;
  54                 }
  55                 size_t size = std::min((size_t)(maxSize - realSize), (size_t)(myBufferLength - myBufferOffset));
  56                 if (size > 0) {
  57                         if (buffer != 0) {
  58                                 memcpy(buffer + realSize, myBuffer + myBufferOffset, size);
  59                         }
  60                         realSize += size;
  61                         myBufferOffset += size;
  62                 }
  63         }
  64
  65         myOffset += realSize;
  66         return realSize;
  67 }
  68
  69 void PdbStream::close() {
  70         if (!myBase.isNull()) {
  71                 myBase->close();
  72         }
  73         if (myBuffer != 0) {
  74                 delete[] myBuffer;
  75                 myBuffer = 0;
  76         }
  77 }
  78
  79 void PdbStream::seek(int offset, bool absoluteOffset) {
  80         if (absoluteOffset) {
  81                 offset -= this->offset();
  82         }
  83         if (offset > 0) {
  84                 read(0, offset);
  85         } else if (offset < 0) {
  86                 offset += this->offset();
  87                 open();
  88                 if (offset >= 0) {
  89                         read(0, offset);
  90                 }
  91         }
  92 }
  93
  94 size_t PdbStream::offset() const {
  95         return myOffset;
  96 }
  97
  98 size_t PdbStream::sizeOfOpened() {
  99         // TODO: implement
 100         return 0;
 101 }