/**
* Initializes the instance.
*
* @param string $string The raw string containing the data to be read.
*/
public function __construct($string)
{
parent::__construct($string);
$this->buffer = 0;
$this->bufferSize = 0;
}
/**
* Initializes the instance.
*
* @param CHM $chm The parent CHM file.
*
* @throws Exception Throws an Exception in case of errors.
*/
public function __construct(CHM $chm)
{
parent::__construct($chm);
$controlDataEntry = $chm->getEntryByPath('::DataSpace/Storage/MSCompressed/ControlData');
if ($controlDataEntry === null) {
throw new Exception("Missing required entry: '::DataSpace/Storage/MSCompressed/ControlData'");
}
if ($controlDataEntry->getContentSectionIndex() !== 0) {
throw new Exception("The content of the entry '{$controlDataEntry->getPath()}' should be in section 0, but it's in section {$controlDataEntry->getContentSectionIndex()}");
}
$controlDataReader = new StringReader($controlDataEntry->getContents());
$lzxc = new LZXC($controlDataReader);
$this->resetInterval = $lzxc->getResetInterval();
$this->windowSize = $lzxc->getWindowSize() * 32768;
$this->cachedBlocks = new LRUCache(1 + $lzxc->getCacheSize() << 2);
$resetTableEntry = $chm->getEntryByPath('::DataSpace/Storage/MSCompressed/Transform/{7FC28940-9D31-11D0-9B27-00A0C91E9C7C}/InstanceData/ResetTable');
if ($resetTableEntry === null) {
throw new Exception("Missing required entry: '::DataSpace/Storage/MSCompressed/Transform/{7FC28940-9D31-11D0-9B27-00A0C91E9C7C}/InstanceData/ResetTable'");
}
if ($resetTableEntry->getContentSectionIndex() !== 0) {
throw new Exception("The content of the entry '{$resetTableEntry->getPath()}' should be in section 0, but it's in section {$resetTableEntry->getContentSectionIndex()}");
}
$resetTableReader = new StringReader($resetTableEntry->getContents());
$resetTableVersion = $resetTableReader->readUInt32();
if ($resetTableVersion !== 2) {
throw new Exception("Unsupported LZX Reset Table version: {$resetTableVersion}");
}
$addressTableSize = $resetTableReader->readUInt32();
/* Size of table entry (8) */
$resetTableReader->readUInt32();
/* Header length (40) */
$resetTableReader->readUInt32();
$this->uncompressedLength = $resetTableReader->readUInt64();
$this->compressedLength = $resetTableReader->readUInt64();
$this->blockSize = $resetTableReader->readUInt64();
// We do not support block sizes bigger than 32-bit integers
$this->addressTable = array();
for ($i = 0; $i < $addressTableSize; ++$i) {
$this->addressTable[$i] = $resetTableReader->readUInt64();
}
$contentEntry = $chm->getEntryByPath('::DataSpace/Storage/MSCompressed/Content');
if ($contentEntry === null) {
throw new Exception("Missing required entry: '::DataSpace/Storage/MSCompressed/Content");
}
if ($this->compressedLength > $contentEntry->getLength()) {
throw new Exception("Compressed section size should be {$this->compressedLength}, but it's {$contentEntry->getLength()}");
}
$this->sectionOffset = $chm->getITSF()->getContentOffset() + $contentEntry->getOffset();
}
/**
* Retrieve the list of the data sections contained in this CHM.
*
* @throws Exception Throws an Exception in case of errors.
*/
protected function retrieveSectionList()
{
$nameList = $this->getEntryByPath('::DataSpace/NameList');
if ($nameList === null) {
throw new Exception("Missing required entry: '::DataSpace/NameList'");
}
if ($nameList->getContentSectionIndex() !== 0) {
throw new Exception("The content of the entry '{$nameList->getPath()}' should be in section 0, but it's in section {$nameList->getContentSection()}");
}
$nameListReader = new StringReader($nameList->getContents());
/* Length */
$nameListReader->readUInt16();
$numSections = $nameListReader->readUInt16();
if ($numSections === 0) {
throw new Exception('No content section defined.');
}
for ($i = 0; $i < $numSections; ++$i) {
$nameLength = $nameListReader->readUInt16();
$utf16name = $nameListReader->readString($nameLength * 2);
$nameListReader->readUInt16();
$name = iconv('UTF-16LE', 'UTF-8', $utf16name);
switch ($name) {
case 'Uncompressed':
break;
case 'MSCompressed':
if ($i === 0) {
throw new Exception('First data section should be Uncompressed');
} else {
$this->sections[$i] = new Section\MSCompressedSection($this);
}
break;
default:
throw new Exception("Unknown data section: {$name}");
}
}
}