<?php
/**
* ZeroBin
*
* a zero-knowledge paste bin
*
* @link http://sebsauvage.net/wiki/doku.php?id=php:zerobin
* @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
* @license http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
* @version 0.21.1
*/
/**
* zerobin_db
*
* Model for DB access, implemented as a singleton.
*/
class zerobin_db extends zerobin_abstract
{
/**
* cache for select queries
*
* @var array
*/
private static $_cache = array();
/**
* instance of database connection
*
* @access private
* @static
* @var PDO
*/
private static $_db;
/**
* table prefix
*
* @access private
* @static
* @var string
*/
private static $_prefix = '';
/**
* database type
*
* @access private
* @static
* @var string
*/
private static $_type = '';
/**
* get instance of singleton
*
* @access public
* @static
* @param array $options
* @throws Exception
* @return zerobin_db
*/
public static function getInstance($options = null)
{
// if needed initialize the singleton
if(!(self::$_instance instanceof zerobin_db)) {
self::$_instance = new self;
}
if (is_array($options))
{
// set table prefix if given
if (array_key_exists('tbl', $options)) self::$_prefix = $options['tbl'];
// initialize the db connection with new options
if (
array_key_exists('dsn', $options) &&
array_key_exists('usr', $options) &&
array_key_exists('pwd', $options) &&
array_key_exists('opt', $options)
)
{
// check if the database contains the required tables
self::$_type = strtolower(
substr($options['dsn'], 0, strpos($options['dsn'], ':'))
);
switch(self::$_type)
{
case 'ibm':
$sql = 'SELECT tabname FROM SYSCAT.TABLES ';
break;
case 'informix':
$sql = 'SELECT tabname FROM systables ';
break;
case 'mssql':
$sql = "SELECT name FROM sysobjects "
. "WHERE type = 'U' ORDER BY name";
break;
case 'mysql':
$sql = 'SHOW TABLES';
break;
case 'oci':
$sql = 'SELECT table_name FROM all_tables';
break;
case 'pgsql':
$sql = "SELECT c.relname AS table_name "
. "FROM pg_class c, pg_user u "
. "WHERE c.relowner = u.usesysid AND c.relkind = 'r' "
. "AND NOT EXISTS (SELECT 1 FROM pg_views WHERE viewname = c.relname) "
. "AND c.relname !~ '^(pg_|sql_)' "
. "UNION "
. "SELECT c.relname AS table_name "
. "FROM pg_class c "
. "WHERE c.relkind = 'r' "
. "AND NOT EXISTS (SELECT 1 FROM pg_views WHERE viewname = c.relname) "
. "AND NOT EXISTS (SELECT 1 FROM pg_user WHERE usesysid = c.relowner) "
. "AND c.relname !~ '^pg_'";
break;
case 'sqlite':
$sql = "SELECT name FROM sqlite_master WHERE type='table' "
. "UNION ALL SELECT name FROM sqlite_temp_master "
. "WHERE type='table' ORDER BY name";
break;
default:
throw new Exception(
'PDO type ' .
self::$_type .
' is currently not supported.',
5
);
}
self::$_db = new PDO(
$options['dsn'],
$options['usr'],
$options['pwd'],
$options['opt']
);
$statement = self::$_db->query($sql);
$tables = $statement->fetchAll(PDO::FETCH_COLUMN, 0);
// create paste table if needed
if (!array_key_exists(self::$_prefix . 'paste', $tables))
{
self::$_db->exec(
'CREATE TABLE ' . self::$_prefix . 'paste ( ' .
'dataid CHAR(16), ' .
'data TEXT, ' .
'postdate INT, ' .
'expiredate INT, ' .
'opendiscussion INT, ' .
'burnafterreading INT, ' .
'meta TEXT );'
);
}
// check if the meta column exists
else
{
try {
self::$_db->exec('SELECT meta FROM ' . self::$_prefix . 'paste LIMIT 1;');
} catch (PDOException $e) {
if ($e->getCode() == 'HY000')
{
self::$_db->exec('ALTER TABLE ' . self::$_prefix . 'paste ADD COLUMN meta TEXT;');
}
}
}
// create comment table if needed
if (!array_key_exists(self::$_prefix . 'comment', $tables))
{
self::$_db->exec(
'CREATE TABLE ' . self::$_prefix . 'comment ( ' .
'dataid CHAR(16), ' .
'pasteid CHAR(16), ' .
'parentid CHAR(16), ' .
'data TEXT, ' .
'nickname VARCHAR(255), ' .
'vizhash TEXT, ' .
'postdate INT );'
);
}
}
}
return parent::$_instance;
}
/**
* Create a paste.
*
* @access public
* @param string $pasteid
* @param array $paste
* @return bool
*/
public function create($pasteid, $paste)
{
if (
array_key_exists($pasteid, self::$_cache)
) {
if(false !== self::$_cache[$pasteid]) {
return false;
} else {
unset(self::$_cache[$pasteid]);
}
}
$opendiscussion = $burnafterreading = false;
$meta = $paste['meta'];
unset($meta['postdate']);
unset($meta['expire_date']);
if (array_key_exists('opendiscussion', $paste['meta']))
{
$opendiscussion = (bool) $paste['meta']['opendiscussion'];
unset($meta['opendiscussion']);
}
if (array_key_exists('burnafterreading', $paste['meta']))
{
$burnafterreading = (bool) $paste['meta']['burnafterreading'];
unset($meta['burnafterreading']);
}
return self::_exec(
'INSERT INTO ' . self::$_prefix . 'paste VALUES(?,?,?,?,?,?,?)',
array(
$pasteid,
$paste['data'],
$paste['meta']['postdate'],
$paste['meta']['expire_date'],
(int) $opendiscussion,
(int) $burnafterreading,
json_encode($meta),
)
);
}
/**
* Read a paste.
*
* @access public
* @param string $pasteid
* @return stdClass|false
*/
public function read($pasteid)
{
if (
!array_key_exists($pasteid, self::$_cache)
) {
self::$_cache[$pasteid] = false;
$paste = self::_select(
'SELECT * FROM ' . self::$_prefix . 'paste WHERE dataid = ?',
array($pasteid), true
);
if(false !== $paste) {
// create object
self::$_cache[$pasteid] = new stdClass;
self::$_cache[$pasteid]->data = $paste['data'];
self::$_cache[$pasteid]->meta = json_decode($paste['meta']);
self::$_cache[$pasteid]->meta->postdate = (int) $paste['postdate'];
self::$_cache[$pasteid]->meta->expire_date = (int) $paste['expiredate'];
if (
$paste['opendiscussion']
) self::$_cache[$pasteid]->meta->opendiscussion = true;
if (
$paste['burnafterreading']
) self::$_cache[$pasteid]->meta->burnafterreading = true;
}
}
return self::$_cache[$pasteid];
}
/**
* Delete a paste and its discussion.
*
* @access public
* @param string $pasteid
* @return void
*/
public function delete($pasteid)
{
self::_exec(
'DELETE FROM ' . self::$_prefix . 'paste WHERE dataid = ?',
array($pasteid)
);
self::_exec(
'DELETE FROM ' . self::$_prefix . 'comment WHERE pasteid = ?',
array($pasteid)
);
if (
array_key_exists($pasteid, self::$_cache)
) unset(self::$_cache[$pasteid]);
}
/**
* Test if a paste exists.
*
* @access public
* @param string $dataid
* @return void
*/
public function exists($pasteid)
{
if (
!array_key_exists($pasteid, self::$_cache)
) self::$_cache[$pasteid] = $this->read($pasteid);
return (bool) self::$_cache[$pasteid];
}
/**
* Create a comment in a paste.
*
* @access public
* @param string $pasteid
* @param string $parentid
* @param string $commentid
* @param array $comment
* @return int|false
*/
public function createComment($pasteid, $parentid, $commentid, $comment)
{
return self::_exec(
'INSERT INTO ' . self::$_prefix . 'comment VALUES(?,?,?,?,?,?,?)',
array(
$commentid,
$pasteid,
$parentid,
$comment['data'],
$comment['meta']['nickname'],
$comment['meta']['vizhash'],
$comment['meta']['postdate'],
)
);
}
/**
* Read all comments of paste.
*
* @access public
* @param string $pasteid
* @return array
*/
public function readComments($pasteid)
{
$rows = self::_select(
'SELECT * FROM ' . self::$_prefix . 'comment WHERE pasteid = ?',
array($pasteid)
);
// create object
$commentTemplate = new stdClass;
$commentTemplate->meta = new stdClass;
// create comment list
$comments = array();
if (count($rows))
{
foreach ($rows as $row)
{
$i = (int) $row['postdate'];
$comments[$i] = clone $commentTemplate;
$comments[$i]->data = $row['data'];
$comments[$i]->meta->nickname = $row['nickname'];
$comments[$i]->meta->vizhash = $row['vizhash'];
$comments[$i]->meta->postdate = $i;
$comments[$i]->meta->commentid = $row['dataid'];
$comments[$i]->meta->parentid = $row['parentid'];
}
ksort($comments);
}
return $comments;
}
/**
* Test if a comment exists.
*
* @access public
* @param string $dataid
* @param string $parentid
* @param string $commentid
* @return void
*/
public function existsComment($pasteid, $parentid, $commentid)
{
return (bool) self::_select(
'SELECT dataid FROM ' . self::$_prefix . 'comment ' .
'WHERE pasteid = ? AND parentid = ? AND dataid = ?',
array($pasteid, $parentid, $commentid), true
);
}
/**
* execute a statement
*
* @access private
* @static
* @param string $sql
* @param array $params
* @throws PDOException
* @return array
*/
private static function _exec($sql, array $params)
{
$statement = self::$_db->prepare($sql);
$result = $statement->execute($params);
$statement->closeCursor();
return $result;
}
/**
* run a select statement
*
* @access private
* @static
* @param string $sql
* @param array $params
* @param bool $firstOnly if only the first row should be returned
* @throws PDOException
* @return array
*/
private static function _select($sql, array $params, $firstOnly = false)
{
$statement = self::$_db->prepare($sql);
$statement->execute($params);
$result = $firstOnly ?
$statement->fetch(PDO::FETCH_ASSOC) :
$statement->fetchAll(PDO::FETCH_ASSOC);
$statement->closeCursor();
return $result;
}
}