Your IP : 108.162.216.192
<?php
/**
* This is a port of D.J. Bernstein's CDB to PHP. It's based on the copy that
* appears in PHP 5.3. Changes are:
* * Error returns replaced with exceptions
* * Exception thrown if sizes or offsets are between 2GB and 4GB
* * Some variables renamed
*
* 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.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
/**
* Common functions for readers and writers
*/
class CdbFunctions {
/**
* Take a modulo of a signed integer as if it were an unsigned integer.
* $b must be less than 0x40000000 and greater than 0
*
* @param $a
* @param $b
*
* @return int
*/
public static function unsignedMod( $a, $b ) {
if ( $a & 0x80000000 ) {
$m = ( $a & 0x7fffffff ) % $b + 2 * ( 0x40000000 % $b );
return $m % $b;
} else {
return $a % $b;
}
}
/**
* Shift a signed integer right as if it were unsigned
* @param $a
* @param $b
* @return int
*/
public static function unsignedShiftRight( $a, $b ) {
if ( $b == 0 ) {
return $a;
}
if ( $a & 0x80000000 ) {
return ( ( $a & 0x7fffffff ) >> $b ) | ( 0x40000000 >> ( $b - 1 ) );
} else {
return $a >> $b;
}
}
/**
* The CDB hash function.
*
* @param $s string
*
* @return
*/
public static function hash( $s ) {
$h = 5381;
for ( $i = 0; $i < strlen( $s ); $i++ ) {
$h5 = ($h << 5) & 0xffffffff;
// Do a 32-bit sum
// Inlined here for speed
$sum = ($h & 0x3fffffff) + ($h5 & 0x3fffffff);
$h =
(
( $sum & 0x40000000 ? 1 : 0 )
+ ( $h & 0x80000000 ? 2 : 0 )
+ ( $h & 0x40000000 ? 1 : 0 )
+ ( $h5 & 0x80000000 ? 2 : 0 )
+ ( $h5 & 0x40000000 ? 1 : 0 )
) << 30
| ( $sum & 0x3fffffff );
$h ^= ord( $s[$i] );
$h &= 0xffffffff;
}
return $h;
}
}
/**
* CDB reader class
*/
class CdbReader_PHP extends CdbReader {
/** The filename */
var $fileName;
/** The file handle */
var $handle;
/* number of hash slots searched under this key */
var $loop;
/* initialized if loop is nonzero */
var $khash;
/* initialized if loop is nonzero */
var $kpos;
/* initialized if loop is nonzero */
var $hpos;
/* initialized if loop is nonzero */
var $hslots;
/* initialized if findNext() returns true */
var $dpos;
/* initialized if cdb_findnext() returns 1 */
var $dlen;
/**
* @param $fileName string
* @throws MWException
*/
function __construct( $fileName ) {
$this->fileName = $fileName;
$this->handle = fopen( $fileName, 'rb' );
if ( !$this->handle ) {
throw new MWException( 'Unable to open CDB file "' . $this->fileName . '".' );
}
$this->findStart();
}
function close() {
if( isset( $this->handle ) ) {
fclose( $this->handle );
}
unset( $this->handle );
}
/**
* @param $key
* @return bool|string
*/
public function get( $key ) {
// strval is required
if ( $this->find( strval( $key ) ) ) {
return $this->read( $this->dlen, $this->dpos );
} else {
return false;
}
}
/**
* @param $key
* @param $pos
* @return bool
*/
protected function match( $key, $pos ) {
$buf = $this->read( strlen( $key ), $pos );
return $buf === $key;
}
protected function findStart() {
$this->loop = 0;
}
/**
* @throws MWException
* @param $length
* @param $pos
* @return string
*/
protected function read( $length, $pos ) {
if ( fseek( $this->handle, $pos ) == -1 ) {
// This can easily happen if the internal pointers are incorrect
throw new MWException(
'Seek failed, file "' . $this->fileName . '" may be corrupted.' );
}
if ( $length == 0 ) {
return '';
}
$buf = fread( $this->handle, $length );
if ( $buf === false || strlen( $buf ) !== $length ) {
throw new MWException(
'Read from CDB file failed, file "' . $this->fileName . '" may be corrupted.' );
}
return $buf;
}
/**
* Unpack an unsigned integer and throw an exception if it needs more than 31 bits
* @param $s
* @throws MWException
* @return mixed
*/
protected function unpack31( $s ) {
$data = unpack( 'V', $s );
if ( $data[1] > 0x7fffffff ) {
throw new MWException(
'Error in CDB file "' . $this->fileName . '", integer too big.' );
}
return $data[1];
}
/**
* Unpack a 32-bit signed integer
* @param $s
* @return int
*/
protected function unpackSigned( $s ) {
$data = unpack( 'va/vb', $s );
return $data['a'] | ( $data['b'] << 16 );
}
/**
* @param $key
* @return bool
*/
protected function findNext( $key ) {
if ( !$this->loop ) {
$u = CdbFunctions::hash( $key );
$buf = $this->read( 8, ( $u << 3 ) & 2047 );
$this->hslots = $this->unpack31( substr( $buf, 4 ) );
if ( !$this->hslots ) {
return false;
}
$this->hpos = $this->unpack31( substr( $buf, 0, 4 ) );
$this->khash = $u;
$u = CdbFunctions::unsignedShiftRight( $u, 8 );
$u = CdbFunctions::unsignedMod( $u, $this->hslots );
$u <<= 3;
$this->kpos = $this->hpos + $u;
}
while ( $this->loop < $this->hslots ) {
$buf = $this->read( 8, $this->kpos );
$pos = $this->unpack31( substr( $buf, 4 ) );
if ( !$pos ) {
return false;
}
$this->loop += 1;
$this->kpos += 8;
if ( $this->kpos == $this->hpos + ( $this->hslots << 3 ) ) {
$this->kpos = $this->hpos;
}
$u = $this->unpackSigned( substr( $buf, 0, 4 ) );
if ( $u === $this->khash ) {
$buf = $this->read( 8, $pos );
$keyLen = $this->unpack31( substr( $buf, 0, 4 ) );
if ( $keyLen == strlen( $key ) && $this->match( $key, $pos + 8 ) ) {
// Found
$this->dlen = $this->unpack31( substr( $buf, 4 ) );
$this->dpos = $pos + 8 + $keyLen;
return true;
}
}
}
return false;
}
/**
* @param $key
* @return bool
*/
protected function find( $key ) {
$this->findStart();
return $this->findNext( $key );
}
}
/**
* CDB writer class
*/
class CdbWriter_PHP extends CdbWriter {
var $handle, $realFileName, $tmpFileName;
var $hplist;
var $numentries, $pos;
/**
* @param $fileName string
*/
function __construct( $fileName ) {
$this->realFileName = $fileName;
$this->tmpFileName = $fileName . '.tmp.' . mt_rand( 0, 0x7fffffff );
$this->handle = fopen( $this->tmpFileName, 'wb' );
if ( !$this->handle ) {
$this->throwException(
'Unable to open CDB file "' . $this->tmpFileName . '" for write.' );
}
$this->hplist = array();
$this->numentries = 0;
$this->pos = 2048; // leaving space for the pointer array, 256 * 8
if ( fseek( $this->handle, $this->pos ) == -1 ) {
$this->throwException( 'fseek failed in file "' . $this->tmpFileName . '".' );
}
}
function __destruct() {
if ( isset( $this->handle ) ) {
$this->close();
}
}
/**
* @param $key
* @param $value
* @return
*/
public function set( $key, $value ) {
if ( strval( $key ) === '' ) {
// DBA cross-check hack
return;
}
$this->addbegin( strlen( $key ), strlen( $value ) );
$this->write( $key );
$this->write( $value );
$this->addend( strlen( $key ), strlen( $value ), CdbFunctions::hash( $key ) );
}
/**
* @throws MWException
*/
public function close() {
$this->finish();
if( isset( $this->handle ) ) {
fclose( $this->handle );
}
if ( wfIsWindows() && file_exists( $this->realFileName ) ) {
unlink( $this->realFileName );
}
if ( !rename( $this->tmpFileName, $this->realFileName ) ) {
$this->throwException( 'Unable to move the new CDB file into place.' );
}
unset( $this->handle );
}
/**
* @throws MWException
* @param $buf
*/
protected function write( $buf ) {
$len = fwrite( $this->handle, $buf );
if ( $len !== strlen( $buf ) ) {
$this->throwException( 'Error writing to CDB file "' . $this->tmpFileName . '".' );
}
}
/**
* @throws MWException
* @param $len
*/
protected function posplus( $len ) {
$newpos = $this->pos + $len;
if ( $newpos > 0x7fffffff ) {
$this->throwException(
'A value in the CDB file "' . $this->tmpFileName . '" is too large.' );
}
$this->pos = $newpos;
}
/**
* @param $keylen
* @param $datalen
* @param $h
*/
protected function addend( $keylen, $datalen, $h ) {
$this->hplist[] = array(
'h' => $h,
'p' => $this->pos
);
$this->numentries++;
$this->posplus( 8 );
$this->posplus( $keylen );
$this->posplus( $datalen );
}
/**
* @throws MWException
* @param $keylen
* @param $datalen
*/
protected function addbegin( $keylen, $datalen ) {
if ( $keylen > 0x7fffffff ) {
$this->throwException( 'Key length too long in file "' . $this->tmpFileName . '".' );
}
if ( $datalen > 0x7fffffff ) {
$this->throwException( 'Data length too long in file "' . $this->tmpFileName . '".' );
}
$buf = pack( 'VV', $keylen, $datalen );
$this->write( $buf );
}
/**
* @throws MWException
*/
protected function finish() {
// Hack for DBA cross-check
$this->hplist = array_reverse( $this->hplist );
// Calculate the number of items that will be in each hashtable
$counts = array_fill( 0, 256, 0 );
foreach ( $this->hplist as $item ) {
++ $counts[ 255 & $item['h'] ];
}
// Fill in $starts with the *end* indexes
$starts = array();
$pos = 0;
for ( $i = 0; $i < 256; ++$i ) {
$pos += $counts[$i];
$starts[$i] = $pos;
}
// Excessively clever and indulgent code to simultaneously fill $packedTables
// with the packed hashtables, and adjust the elements of $starts
// to actually point to the starts instead of the ends.
$packedTables = array_fill( 0, $this->numentries, false );
foreach ( $this->hplist as $item ) {
$packedTables[--$starts[255 & $item['h']]] = $item;
}
$final = '';
for ( $i = 0; $i < 256; ++$i ) {
$count = $counts[$i];
// The size of the hashtable will be double the item count.
// The rest of the slots will be empty.
$len = $count + $count;
$final .= pack( 'VV', $this->pos, $len );
$hashtable = array();
for ( $u = 0; $u < $len; ++$u ) {
$hashtable[$u] = array( 'h' => 0, 'p' => 0 );
}
// Fill the hashtable, using the next empty slot if the hashed slot
// is taken.
for ( $u = 0; $u < $count; ++$u ) {
$hp = $packedTables[$starts[$i] + $u];
$where = CdbFunctions::unsignedMod(
CdbFunctions::unsignedShiftRight( $hp['h'], 8 ), $len );
while ( $hashtable[$where]['p'] )
if ( ++$where == $len )
$where = 0;
$hashtable[$where] = $hp;
}
// Write the hashtable
for ( $u = 0; $u < $len; ++$u ) {
$buf = pack( 'vvV',
$hashtable[$u]['h'] & 0xffff,
CdbFunctions::unsignedShiftRight( $hashtable[$u]['h'], 16 ),
$hashtable[$u]['p'] );
$this->write( $buf );
$this->posplus( 8 );
}
}
// Write the pointer array at the start of the file
rewind( $this->handle );
if ( ftell( $this->handle ) != 0 ) {
$this->throwException( 'Error rewinding to start of file "' . $this->tmpFileName . '".' );
}
$this->write( $final );
}
/**
* Clean up the temp file and throw an exception
*
* @param $msg string
* @throws MWException
*/
protected function throwException( $msg ) {
if ( $this->handle ) {
fclose( $this->handle );
unlink( $this->tmpFileName );
}
throw new MWException( $msg );
}
}