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#include <qfile.h>
00018
#include "chmfile.h"
00019
#include "decompress.h"
00020
00021 uint
Chm::getEncInt(
QFile& f, uint &value)
const
00022
{
00023
int c;
00024 uint result = 0;
00025 ulong count = 0;
00026
00027
do
00028 {
00029 c = f.getch();
00030 result <<= 7;
00031 result |= (c & 0x7F);
00032 count++;
00033 }
while (c & 0x80);
00034
00035 value = result;
00036
return count;
00037 }
00038
00039 uint
Chm::getName(
QFile& f,
QString& name)
const
00040
{
00041
int len = f.getch();
00042
char *buf =
new char[
len];
00043 f.readBlock(buf,
len);
00044 name = QString::fromUtf8(buf,
len);
00045
if (name.startsWith(
"/"))
00046 name = name.lower();
00047
delete buf;
00048
return len + 1;
00049 }
00050
00051 uint
Chm::getIntel32(
QFile& f)
const
00052
{
00053 uint value = f.getch() | f.getch() << 8 | f.getch() << 16 | f.getch() << 24;
00054
return value;
00055 }
00056
00057 uint
Chm::getIntel64(
QFile& f)
const
00058
{
00059 uint value =
getIntel32(f);
00060 f.at(f.at() + 4);
00061
return value;
00062 }
00063
00064 bool Chm::getChunk(
QFile& f, uint chunkSize,
ChmDirectoryMap& directoryMap)
const
00065
{
00066
char tag[4];
00067
if (f.readBlock(tag, 4) != 4)
return false;
00068
00069
if (!qstrncmp(tag,
"PMGL", 4))
00070 {
00071 uint quickref_length =
getIntel32(f);
00072 f.at(f.at() + 12);
00073
00074 uint pos = 20;
00075
while (pos < chunkSize - quickref_length)
00076 {
00077 uint section, offset,
length;
00078
QString name;
00079 pos +=
getName(f, name);
00080 pos +=
getEncInt(f, section);
00081 pos += getEncInt(f, offset);
00082 pos += getEncInt(f,
length);
00083 directoryMap[name] =
ChmDirTableEntry(section, offset,
length);
00084
if (name.endsWith(
".hhc"))
00085 directoryMap[
"/@contents"] = ChmDirTableEntry(section, offset,
length);
00086 }
00087
00088
return (f.at(f.at() + quickref_length));
00089 }
00090
else if (!qstrncmp(tag,
"PMGI", 4))
00091 {
00092
00093
return f.at(f.at() + chunkSize - 4);
00094 }
00095
else
00096 {
00097
return false;
00098 }
00099 }
00100
00101 bool Chm::read(
const QString& fileSpec,
ChmDirectoryMap& dirMap,
QByteArray& contents)
const
00102
{
00103
QFile f(fileSpec);
00104
if (!f.open(IO_ReadOnly))
return false;
00105
00106
00107
char tag[4];
00108
if (f.readBlock(tag, 4) != 4 || qstrncmp(tag,
"ITSF", 4))
return false;
00109 uint chm_version =
getIntel32(f);
00110
if (!f.at(f.at() + 0x30))
return false;
00111
00112
00113 uint section_0_offset =
getIntel64(f);
00114 uint section_0_length = getIntel64(f);
00115 uint section_1_offset = getIntel64(f);
00116 uint section_1_length = getIntel64(f);
00117
00118 uint contentStart = 0;
00119
if (chm_version >= 3) contentStart = getIntel32(f);
00120
00121
00122
if (!f.at(section_1_offset))
return false;
00123
if (f.readBlock(tag, 4) != 4 || qstrncmp(tag,
"ITSP", 4))
return false;
00124
if (!f.at(f.at() + 12))
return false;
00125 uint directory_chunk_size = getIntel32(f);
00126
if (!f.at(f.at() + 24))
return false;
00127 uint num_directory_chunks = getIntel32(f);
00128
if (!f.at(f.at() + 36))
return false;
00129
00130
00131
for (uint i = 0; i < num_directory_chunks; i++)
00132
if (!
getChunk(f, directory_chunk_size, dirMap))
return false;
00133
00134
00135
if (chm_version < 3) contentStart = f.at();
00136
00137
00138
if (!f.at(contentStart))
return false;
00139 uint resetTableOffset =
00140 dirMap[
"::DataSpace/Storage/MSCompressed/Transform/{7FC28940-9D31-11D0-9B27-00A0C91E9C7C}/InstanceData/ResetTable"].offset;
00141
if (!f.at(f.at() + resetTableOffset + 4))
return false;
00142 uint numResetTableEntries = getIntel32(f);
00143
if (!f.at(f.at() + 8))
return false;
00144 uint uncompressedLength = getIntel64(f);
00145 uint compressedLength = getIntel64(f);
00146 uint blockSize = getIntel64(f);
00147 uint *resetTable =
new uint[numResetTableEntries + 1];
00148
00149
for (uint i = 0; i < numResetTableEntries; i++)
00150 resetTable[i] = getIntel64(f);
00151
00152 resetTable[numResetTableEntries] = compressedLength;
00153
00154
00155
if (!f.at(contentStart))
return false;
00156 uint contentsOffset = dirMap[
"::DataSpace/Storage/MSCompressed/Content"].offset;
00157
if (!f.at(f.at() + contentsOffset))
return false;
00158
char *compressedContents =
new char[compressedLength];
00159
if ((uint)f.readBlock(compressedContents, compressedLength) != compressedLength)
return false;
00160
00161 f.close();
00162
00163
00164
char *uncompressedContents =
new char[uncompressedLength];
00165
00166
00167 uint window = 1;
00168 uint tmp = blockSize;
00169
while (tmp >>= 1) window++;
00170
00171
00172 uint outlen = uncompressedLength;
00173
int res = 1;
00174
00175
for (uint i = 0; i < numResetTableEntries; i++)
00176 {
00177
if (!(i & 1))
LZXinit(window);
00178
00179 uint inlen = resetTable[i+1] - resetTable[i];
00180 res =
LZXdecompress((uchar*)&compressedContents[resetTable[i]],
00181 inlen,
00182 (uchar*)uncompressedContents + i * blockSize,
00183 (outlen < blockSize) ? outlen : blockSize);
00184
if (res)
break;
00185 outlen -= blockSize;
00186 }
00187
00188
delete [] resetTable;
00189
delete [] compressedContents;
00190
00191
if (res == 0)
00192 contents.duplicate(uncompressedContents, uncompressedLength);
00193
00194
delete [] uncompressedContents;
00195
00196
return (res == 0);
00197 }