fbreader/src/formats/tcr/TcrStream.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 <algorithm>
  23
  24 #include <ZLFile.h>
  25 #include <ZLZDecompressor.h>
  26
  27 #include "TcrStream.h"
  28
  29 TcrStream::TcrStream(ZLFile &file) : myBase(file.inputStream()) {
  30 }
  31
  32 TcrStream::~TcrStream() {
  33         close();
  34 }
  35
  36 bool TcrStream::open() {
  37         close();
  38         if (myBase.isNull() || !myBase->open()) {
  39                 return false;
  40         }
  41
  42         char header[9];
  43         if ((myBase->read(header, 9) != 9) || (strncmp(header, "!!8-Bit!!", 9) != 0)) {
  44                 myBase->close();
  45                 return false;
  46         }
  47
  48         unsigned char entryLength;
  49         char entryBuffer[255];
  50         for (int i = 0; i < 256; ++i) {
  51                 if ((myBase->read((char*)&entryLength, 1) != 1) ||
  52                                 ((entryLength > 0) && (myBase->read(entryBuffer, entryLength) != entryLength))) {
  53                         myBase->close();
  54                         return false;
  55                 }
  56                 if (entryLength > 0) {
  57                         myDictionary[i].append(entryBuffer, entryLength);
  58                 }
  59         }
  60
  61         return true;
  62 }
  63
  64 void TcrStream::close() {
  65         if (!myBase.isNull()) {
  66                 myBase->close();
  67         }
  68         for (int i = 0; i < 256; ++i) {
  69                 myDictionary[i].erase();
  70         }
  71         myBuffer.erase();
  72 }
  73
  74 size_t TcrStream::read(char *buffer, size_t maxSize) {
  75         size_t size = 0;
  76         if (myBuffer.length() > 0) {
  77                 size += std::min(maxSize, myBuffer.length());
  78                 if (buffer != 0) {
  79                         strncpy(buffer, myBuffer.data(), size);
  80                 }
  81                 myBuffer.erase(0, size);
  82         }
  83         while (size < maxSize) {
  84                 unsigned char index;
  85                 if (myBase->read((char*)&index, 1) != 1) {
  86                         break;
  87                 }
  88                 size_t len = myDictionary[index].length();
  89                 if (len > 0) {
  90                         size_t freeSize = maxSize - size;
  91                         if (buffer != 0) {
  92                                 strncpy(buffer + size, myDictionary[index].data(), std::min(len, freeSize));
  93                         }
  94                         size += std::min(len, freeSize);
  95                         if (len > freeSize) {
  96                                 myBuffer = myDictionary[index].substr(freeSize);
  97                         }
  98                 }
  99         }
 100         myOffset += size;
 101         return size;
 102 }
 103
 104 void TcrStream::seek(int offset, bool absoluteOffset) {
 105         if (absoluteOffset) {
 106                 offset -= this->offset();
 107         }
 108         if (offset > 0) {
 109                 read(0, offset);
 110         } else if (offset < 0) {
 111                 offset += this->offset();
 112                 open();
 113                 if (offset >= 0) {
 114                         read(0, offset);
 115                 }
 116         }
 117 }
 118
 119 size_t TcrStream::offset() const {
 120         return myOffset;
 121 }
 122
 123 size_t TcrStream::sizeOfOpened() {
 124         // TODO: implement
 125         return 0;
 126 }