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-rw-r--r--parts/documentation/protocols/chm/chmfile.cpp197
1 files changed, 197 insertions, 0 deletions
diff --git a/parts/documentation/protocols/chm/chmfile.cpp b/parts/documentation/protocols/chm/chmfile.cpp
new file mode 100644
index 00000000..f69d354a
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+++ b/parts/documentation/protocols/chm/chmfile.cpp
@@ -0,0 +1,197 @@
+/* This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public
+ License as published by the Free Software Foundation; either
+ version 2 of the License, or (at your option) any later version.
+
+ This library 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public License
+ along with this library; see the file COPYING.LIB. If not, write to
+ the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+*/
+
+#include <qfile.h>
+#include "chmfile.h"
+#include "decompress.h"
+
+uint Chm::getEncInt(QFile& f, uint &value) const
+{
+ int c;
+ uint result = 0;
+ ulong count = 0;
+
+ do
+ {
+ c = f.getch();
+ result <<= 7;
+ result |= (c & 0x7F);
+ count++;
+ } while (c & 0x80);
+
+ value = result;
+ return count;
+}
+
+uint Chm::getName(QFile& f, QString& name) const
+{
+ int len = f.getch();
+ char *buf = new char[len];
+ f.readBlock(buf, len);
+ name = QString::fromUtf8(buf, len);
+ if (name.startsWith("/"))
+ name = name.lower();
+ delete [] buf;
+ return len + 1;
+}
+
+uint Chm::getIntel32(QFile& f) const
+{
+ uint value = f.getch() | f.getch() << 8 | f.getch() << 16 | f.getch() << 24;
+ return value;
+}
+
+uint Chm::getIntel64(QFile& f) const
+{
+ uint value = getIntel32(f);
+ f.at(f.at() + 4);
+ return value;
+}
+
+bool Chm::getChunk(QFile& f, uint chunkSize, ChmDirectoryMap& directoryMap) const
+{
+ char tag[4];
+ if (f.readBlock(tag, 4) != 4) return false;
+
+ if (!qstrncmp(tag, "PMGL", 4))
+ {
+ uint quickref_length = getIntel32(f);
+ f.at(f.at() + 12);
+
+ uint pos = 20;
+ while (pos < chunkSize - quickref_length)
+ {
+ uint section, offset, length;
+ QString name;
+ pos += getName(f, name);
+ pos += getEncInt(f, section);
+ pos += getEncInt(f, offset);
+ pos += getEncInt(f, length);
+ directoryMap[name] = ChmDirTableEntry(section, offset, length);
+ if (name.endsWith(".hhc"))
+ directoryMap["/@contents"] = ChmDirTableEntry(section, offset, length);
+ }
+
+ return (f.at(f.at() + quickref_length));
+ }
+ else if (!qstrncmp(tag, "PMGI", 4))
+ {
+ // evaluation of the index chunk is not yet implemented => skip it
+ return f.at(f.at() + chunkSize - 4);
+ }
+ else
+ {
+ return false;
+ }
+}
+
+bool Chm::read(const QString& fileSpec, ChmDirectoryMap& dirMap, QByteArray& contents) const
+{
+ QFile f(fileSpec);
+ if (!f.open(IO_ReadOnly)) return false;
+
+ // read CHM file header
+ char tag[4];
+ if (f.readBlock(tag, 4) != 4 || qstrncmp(tag, "ITSF", 4)) return false;
+ uint chm_version = getIntel32(f);
+ if (!f.at(f.at() + 0x30)) return false;
+
+ // read header section table
+ uint section_0_offset = getIntel64(f);
+ uint section_0_length = getIntel64(f);
+ uint section_1_offset = getIntel64(f);
+ uint section_1_length = getIntel64(f);
+
+ uint contentStart = 0;
+ if (chm_version >= 3) contentStart = getIntel32(f);
+
+ // read directory header
+ if (!f.at(section_1_offset)) return false;
+ if (f.readBlock(tag, 4) != 4 || qstrncmp(tag, "ITSP", 4)) return false;
+ if (!f.at(f.at() + 12)) return false;
+ uint directory_chunk_size = getIntel32(f);
+ if (!f.at(f.at() + 24)) return false;
+ uint num_directory_chunks = getIntel32(f);
+ if (!f.at(f.at() + 36)) return false;
+
+ // read directory table
+ for (uint i = 0; i < num_directory_chunks; i++)
+ if (!getChunk(f, directory_chunk_size, dirMap)) return false;
+
+ // current position is start of content area
+ if (chm_version < 3) contentStart = f.at();
+
+ // read reset table
+ if (!f.at(contentStart)) return false;
+ uint resetTableOffset =
+ dirMap["::DataSpace/Storage/MSCompressed/Transform/{7FC28940-9D31-11D0-9B27-00A0C91E9C7C}/InstanceData/ResetTable"].offset;
+ if (!f.at(f.at() + resetTableOffset + 4)) return false;
+ uint numResetTableEntries = getIntel32(f);
+ if (!f.at(f.at() + 8)) return false;
+ uint uncompressedLength = getIntel64(f);
+ uint compressedLength = getIntel64(f);
+ uint blockSize = getIntel64(f);
+ uint *resetTable = new uint[numResetTableEntries + 1];
+
+ for (uint i = 0; i < numResetTableEntries; i++)
+ resetTable[i] = getIntel64(f);
+
+ resetTable[numResetTableEntries] = compressedLength;
+
+ // read compressed contents
+ if (!f.at(contentStart)) return false;
+ uint contentsOffset = dirMap["::DataSpace/Storage/MSCompressed/Content"].offset;
+ if (!f.at(f.at() + contentsOffset)) return false;
+ char *compressedContents = new char[compressedLength];
+ if ((uint)f.readBlock(compressedContents, compressedLength) != compressedLength) return false;
+
+ f.close();
+
+ // allocate buffer for uncompressed contents
+ char *uncompressedContents = new char[uncompressedLength];
+
+ // get window size
+ uint window = 1;
+ uint tmp = blockSize;
+ while (tmp >>= 1) window++;
+
+ // decompress
+ uint outlen = uncompressedLength;
+ int res = 1;
+
+ for (uint i = 0; i < numResetTableEntries; i++)
+ {
+ if (!(i & 1)) LZXinit(window);
+
+ uint inlen = resetTable[i+1] - resetTable[i];
+ res = LZXdecompress((uchar*)&compressedContents[resetTable[i]],
+ inlen,
+ (uchar*)uncompressedContents + i * blockSize,
+ (outlen < blockSize) ? outlen : blockSize);
+ if (res) break;
+ outlen -= blockSize;
+ }
+
+ delete [] resetTable;
+ delete [] compressedContents;
+
+ if (res == 0)
+ contents.duplicate(uncompressedContents, uncompressedLength);
+
+ delete [] uncompressedContents;
+
+ return (res == 0);
+}