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-rw-r--r--fbreader/src/formats/chm/LZXDecompressor.cpp287
1 files changed, 0 insertions, 287 deletions
diff --git a/fbreader/src/formats/chm/LZXDecompressor.cpp b/fbreader/src/formats/chm/LZXDecompressor.cpp
deleted file mode 100644
index 38b4311..0000000
--- a/fbreader/src/formats/chm/LZXDecompressor.cpp
+++ /dev/null
@@ -1,287 +0,0 @@
-/*
- * Copyright (C) 2004-2012 Geometer Plus <[email protected]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- */
-
-#include <cstring>
-
-#include "LZXDecompressor.h"
-
-static unsigned int slotNumber(int windowSizeIndex) {
- if (windowSizeIndex == 20) {
- return 42;
- } else if (windowSizeIndex == 21) {
- return 50;
- } else {
- return 2 * windowSizeIndex;
- }
-}
-
-LZXDecompressor::LZXDecompressor(int windowSizeIndex) : myWindow(1 << windowSizeIndex, 0), mySlotNumber(slotNumber(windowSizeIndex)) {
- reset();
-}
-
-void LZXDecompressor::reset() {
- myCurrentBlockType = UNKNOWNN;
- myReadHeader = true;
-
- myState.WindowIterator = myWindow.begin();
- myState.R0 = 1;
- myState.R1 = 1;
- myState.R2 = 1;
-
- myMainTree.reset();
- myLengthTree.reset();
-
- myBlockBytesLeft = 0;
-
- myE8Decoder.reset(0);
-}
-
-static bool fill(std::vector<unsigned char> &data, std::vector<unsigned char>::iterator &it, int num, unsigned char value) {
- if (data.end() - it < num) {
- return false;
- }
- std::vector<unsigned char>::iterator end = it + num;
- while (it != end) {
- *it++ = value;
- }
- return true;
-}
-
-bool LZXDecompressor::readLengths(HuffmanDecoder &decoder, std::size_t from, std::size_t size) {
- HuffmanDecoder preTree;
- preTree.CodeLengths.reserve(20);
- for (int i = 0; i < 20; i++) {
- preTree.CodeLengths.push_back(myBitStream.get(4));
- }
- if (!preTree.buildTable()) {
- return false;
- }
-
- std::vector<unsigned char> &lengths = decoder.CodeLengths;
- if (lengths.size() < from + size) {
- lengths.insert(lengths.end(), from + size - lengths.size(), 0);
- }
- std::vector<unsigned char>::iterator start = lengths.begin() + from;
- std::vector<unsigned char>::iterator end = start + size;
- for (std::vector<unsigned char>::iterator it = start; it != end; ) {
- int z = preTree.getSymbol(myBitStream);
- if (z == 17) {
- if (!fill(lengths, it, myBitStream.get(4) + 4, 0)) {
- return false;
- }
- } else if (z == 18) {
- if (!fill(lengths, it, myBitStream.get(5) + 20, 0)) {
- return false;
- }
- } else if (z == 19) {
- unsigned int num = myBitStream.get(1) + 4;
- z = *it - preTree.getSymbol(myBitStream);
- if (!fill(lengths, it, num, (z < 0) ? z + 17 : z)) {
- return false;
- }
- } else {
- z = *it - z;
- *it++ = (z < 0) ? z + 17 : z;
- }
- }
-
- return true;
-}
-
-static const unsigned int basePosition[51] = {
- 0, 1, 2, 3, 4, 6, 8, 12,
- 16, 24, 32, 48, 64, 96, 128, 192,
- 256, 384, 512, 768, 1024, 1536, 2048, 3072,
- 4096, 6144, 8192, 12288, 16384, 24576, 32768, 49152,
- 65536, 98304, 131072, 196608, 262144, 393216, 524288, 655360,
- 786432, 917504, 1048576, 1179648, 1310720, 1441792, 1572864, 1703936,
- 1835008, 1966080, 2097152
-};
-
-bool LZXDecompressor::decodeBytes(DecodingState &state, std::size_t bytesToDecode) {
- if (myCurrentBlockType == UNCOMPRESSED) {
- if (!myBitStream.getBytesDirect(&*state.WindowIterator, bytesToDecode)) {
- return false;
- }
- state.WindowIterator += bytesToDecode;
- return true;
- }
-
- while (bytesToDecode > 0) {
- int symbol = myMainTree.getSymbol(myBitStream);
- if (symbol < 256) {
- *state.WindowIterator++ = symbol;
- --bytesToDecode;
- continue;
- }
-
- std::size_t length = symbol % 8;
- if (length == 7) {
- length += myLengthTree.getSymbol(myBitStream);
- }
- length += 2;
- if (length > bytesToDecode) {
- return false;
- }
-
- std::size_t offset = (symbol - 256) / 8;
- switch (offset) {
- case 0:
- offset = state.R0;
- break;
- case 1:
- offset = state.R1;
- state.R1 = state.R0;
- state.R0 = offset;
- break;
- case 2:
- offset = state.R2;
- state.R2 = state.R0;
- state.R0 = offset;
- break;
- default:
- if ((myCurrentBlockType == VERBATIM) && (offset == 3)) {
- offset = 1;
- } else {
- if (offset > 50) {
- return false;
- }
- const int positionFooterBits = std::max(0, std::min((int)offset / 2 - 1, 17));
- offset = basePosition[offset] - 2;
- if ((myCurrentBlockType == VERBATIM) || (positionFooterBits == 1) || (positionFooterBits == 2)) {
- offset += myBitStream.get(positionFooterBits);
- } else if (positionFooterBits == 3) {
- offset += myAlignedOffsetTree.getSymbol(myBitStream);
- } else if (positionFooterBits > 3) {
- offset += 8 * myBitStream.get(positionFooterBits - 3);
- offset += myAlignedOffsetTree.getSymbol(myBitStream);
- } else {
- offset = 1;
- }
- }
- state.R2 = state.R1;
- state.R1 = state.R0;
- state.R0 = offset;
- break;
- }
-
- if ((state.WindowIterator - myWindow.begin()) + myWindow.size() < offset) {
- return false;
- }
- if (myWindow.size() >= offset + (myWindow.end() - state.WindowIterator)) {
- offset += myWindow.size();
- if (myWindow.size() >= offset + (myWindow.end() - state.WindowIterator)) {
- return false;
- }
- }
- std::vector<unsigned char>::iterator srcIt = state.WindowIterator + (myWindow.size() - offset);
- for (std::size_t i = 0; i < length; ++i) {
- if (srcIt == myWindow.end()) {
- srcIt -= myWindow.size();
- }
- *state.WindowIterator++ = *srcIt++;
- }
- bytesToDecode -= length;
- }
- return true;
-}
-
-bool LZXDecompressor::decompress(const std::string &data, unsigned char *outBuffer, const std::size_t outSize) {
- myBitStream.setData(data);
-
- if (myReadHeader) {
- if (myBitStream.get(1) == 1) {
- myE8Decoder.reset(myBitStream.get(32));
- }
- myReadHeader = false;
- }
-
- DecodingState state = myState;
-
- for (std::size_t bytesToWrite = outSize; bytesToWrite > 0; ) {
- if (myBlockBytesLeft == 0) {
- if (myCurrentBlockType == UNCOMPRESSED) {
- if (myBlockSize & 1) {
- myBitStream.remove(8);
- }
- myBitStream.reset();
- }
-
- myCurrentBlockType = (BlockType)myBitStream.get(3);
- myBlockSize = myBitStream.get(24);
- myBlockBytesLeft = myBlockSize;
-
- switch (myCurrentBlockType) {
- case UNCOMPRESSED:
- myBitStream.reset();
- state.R0 = myBitStream.get4BytesDirect();
- state.R1 = myBitStream.get4BytesDirect();
- state.R2 = myBitStream.get4BytesDirect();
- break;
-
- case ALIGNED:
- myAlignedOffsetTree.CodeLengths.clear();
- for (int i = 0; i < 8; i++) {
- myAlignedOffsetTree.CodeLengths.push_back(myBitStream.get(3));
- }
- if (!myAlignedOffsetTree.buildTable()) {
- return false;
- }
- // no break; it's not a mistake
-
- case VERBATIM:
- if (!readLengths(myMainTree, 0, 256) ||
- !readLengths(myMainTree, 256, 8 * mySlotNumber) ||
- !readLengths(myLengthTree, 0, 249) ||
- !myMainTree.buildTable() ||
- !myLengthTree.buildTable()) {
- return false;
- }
- break;
-
- default:
- return false;
- }
- }
-
- while ((myBlockBytesLeft > 0) && (bytesToWrite > 0)) {
- std::size_t bytesToDecode = std::min(myBlockBytesLeft, bytesToWrite);
- if (state.WindowIterator + bytesToDecode > myWindow.end()) {
- return false;
- }
-
- if (!decodeBytes(state, bytesToDecode)) {
- return false;
- }
-
- bytesToWrite -= bytesToDecode;
- myBlockBytesLeft -= bytesToDecode;
- }
- }
-
- std::vector<unsigned char>::iterator jt =
- (state.WindowIterator != myWindow.begin()) ? state.WindowIterator : myWindow.end();
- std::memcpy(outBuffer, &*(jt - outSize), outSize);
-
- myState = state;
-
- myE8Decoder.decode(outBuffer, outSize);
-
- return true;
-}
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