Add SQLite database class
authorAran Dunkley <nad@users.mediawiki.org>
Wed, 7 May 2008 23:40:14 +0000 (23:40 +0000)
committerAran Dunkley <nad@users.mediawiki.org>
Wed, 7 May 2008 23:40:14 +0000 (23:40 +0000)
includes/DatabaseSqlite.php [new file with mode: 0644]

diff --git a/includes/DatabaseSqlite.php b/includes/DatabaseSqlite.php
new file mode 100644 (file)
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+<?php
+/**
+ * This script is the SQLite database abstraction layer, see http://www.organicdesign.co.nz/Extension_talk:MediaWikiLite.php
+ * - Licenced under LGPL (http://www.gnu.org/copyleft/lesser.html){{php}}
+ * - Author:  [http://www.organicdesign.co.nz/nad User:Nad]
+ * - Started: 2007-12-17
+ * - Last update: 2008-01-20
+ *
+ * {{php}}{{category:Extensions|DatabaseSqlite.php}}
+ */
+
+/**
+ * @addtogroup Database
+ */
+class DatabaseSqlite extends Database {
+
+       var $mAffectedRows;
+       var $mLastResult;
+       var $mDatabaseFile;
+
+       /**
+        * Constructor
+        */
+       function __construct($server = false, $user = false, $password = false, $dbName = false, $failFunction = false, $flags = 0) {
+               global $wgOut,$wgSQLiteDataDir;
+               if ("$wgSQLiteDataDir" == '') $wgSQLiteDataDir = dirname($_SERVER['DOCUMENT_ROOT']).'/data';
+               if (!is_dir($wgSQLiteDataDir)) mkdir($wgSQLiteDataDir,0700);
+               if (!isset($wgOut)) $wgOut = NULL; # Can't get a reference if it hasn't been set yet
+               $this->mOut =& $wgOut;
+               $this->mFailFunction = $failFunction;
+               $this->mFlags = $flags;
+               $this->mDatabaseFile = "$wgSQLiteDataDir/$dbName.sqlite";
+               $this->open($server, $user, $password, $dbName);
+       }
+
+       /**
+        * todo: check if these should be true like parent class
+        */
+       function implicitGroupby()   { return false; }
+       function implicitOrderby()   { return false; }
+
+       static function newFromParams($server, $user, $password, $dbName, $failFunction = false, $flags = 0) {
+               return new DatabaseSqlite($server, $user, $password, $dbName, $failFunction, $flags);
+       }
+
+       /** Open an SQLite database and return a resource handle to it
+        *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
+        */
+       function open($server,$user,$pass,$dbName) {
+               $this->mConn = false;
+               if ($dbName) {
+                       $file = $this->mDatabaseFile;
+                       if ($this->mFlags & DBO_PERSISTENT) $this->mConn = new PDO("sqlite:$file",$user,$pass,array(PDO::ATTR_PERSISTENT => true));
+                       else $this->mConn = new PDO("sqlite:$file",$user,$pass);
+                       if ($this->mConn === false) wfDebug("DB connection error: $err\n");;
+                       $this->mOpened = $this->mConn;
+                       $this->mConn->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_SILENT); # set error codes only, dont raise exceptions
+               }
+               return $this->mConn;
+       }
+
+       /**
+        * Close an SQLite database
+        */
+       function close() {
+               $this->mOpened = false;
+               if (is_object($this->mConn)) {
+                       if ($this->trxLevel()) $this->immediateCommit();
+                       $this->mConn = null;
+               }
+               return true;
+       }
+
+       /**
+        * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
+        */
+       function doQuery($sql) {
+               $res = $this->mConn->query($sql);
+               if ($res === false) $this->reportQueryError($this->lastError(),$this->lastErrno(),$sql,__FUNCTION__);
+               else {
+                       $r = $res instanceof ResultWrapper ? $res->result : $res;
+                       $this->mAffectedRows = $r->rowCount();
+                       $res = new ResultWrapper($this,$r->fetchAll());
+               }
+               return $res;
+       }
+
+       function freeResult(&$res) {
+               if ($res instanceof ResultWrapper) $res->result = NULL; else $res = NULL;
+       }
+
+       function fetchObject(&$res) {
+               if ($res instanceof ResultWrapper) $r =& $res->result; else $r =& $res;
+               $cur = current($r);
+               if (is_array($cur)) {
+                       next($r);
+                       $obj = new stdClass;
+                       foreach ($cur as $k => $v) if (!is_numeric($k)) $obj->$k = $v;
+                       return $obj;
+               }
+               return false;
+       }
+
+       function fetchRow(&$res) {
+               if ($res instanceof ResultWrapper) $r =& $res->result; else $r =& $res;
+               $cur = current($r);
+               if (is_array($cur)) {
+                       next($r);
+                       return $cur;
+               }
+               return false;
+       }
+
+       /**
+        * The PDO::Statement class implements the array interface so count() will work
+        */
+       function numRows(&$res) {
+               $r = $res instanceof ResultWrapper ? $res->result : $res;
+               return count($r);
+       }
+
+       function numFields(&$res) {
+               $r = $res instanceof ResultWrapper ? $res->result : $res;
+               return is_array($r) ? count($r[0]) : 0;
+       }
+
+       function fieldName(&$res,$n) {
+               $r = $res instanceof ResultWrapper ? $res->result : $res;
+               if (is_array($r)) {
+                       $keys = array_keys($r[0]);
+                       return $keys[$n];
+               }
+               return  false;
+       }
+
+       /**
+        * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
+        */
+       function tableName($name) {
+               $t = parent::tableName($name);
+               if (!empty($t)) $t = substr($t,1,-1);
+               return $t;
+       }
+
+       /**
+        * This must be called after nextSequenceVal
+        */
+       function insertId() {
+               return $this->mConn->lastInsertId();
+       }
+
+       function dataSeek(&$res,$row) {
+               if ($res instanceof ResultWrapper) $r =& $res->result; else $r =& $res;
+               reset($r);
+               if ($row > 0) for ($i = 0; $i < $row; $i++) next($r);
+       }
+
+       function lastError() {
+               if (!is_object($this->mConn)) return "Cannot return last error, no db connection";
+               $e = $this->mConn->errorInfo();
+               return isset($e[2]) ? $e[2] : '';
+       }
+
+       function lastErrno() {
+               if (!is_object($this->mConn)) return "Cannot return last error, no db connection";
+               return $this->mConn->errorCode();
+       }
+
+       function affectedRows() {
+               return $this->mAffectedRows;
+       }
+
+       /**
+        * Returns information about an index
+        * - if errors are explicitly ignored, returns NULL on failure
+        */
+       function indexInfo($table, $index, $fname = 'Database::indexExists') {
+               return false;
+       }
+
+       function indexUnique($table, $index, $fname = 'Database::indexUnique') {
+               return false;
+       }
+
+       /**
+        * Filter the options used in SELECT statements
+        */
+       function makeSelectOptions($options) {
+               foreach ($options as $k => $v) if (is_numeric($k) && $v == 'FOR UPDATE') $options[$k] = '';
+               return parent::makeSelectOptions($options);
+       }
+
+       /**
+        * Based on MySQL method (parent) with some prior SQLite-sepcific adjustments
+        */
+       function insert($table, $a, $fname = 'DatabaseSqlite::insert', $options = array()) {
+               if (!count($a)) return true;
+               if (!is_array($options)) $options = array($options);
+
+               # SQLite uses OR IGNORE not just IGNORE
+               foreach ($options as $k => $v) if ($v == 'IGNORE') $options[$k] = 'OR IGNORE';
+
+               # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
+               if (isset($a[0]) && is_array($a[0])) {
+                       $ret = true;
+                       foreach ($a as $k => $v) if (!parent::insert($table,$v,"$fname/multi-row",$options)) $ret = false;
+               }
+               else $ret = parent::insert($table,$a,"$fname/single-row",$options);
+
+               return $ret;
+       }
+
+       /**
+        * SQLite does not have a "USE INDEX" clause, so return an empty string
+        */
+       function useIndexClause($index) {
+               return '';
+       }
+
+       # Returns the size of a text field, or -1 for "unlimited"
+       function textFieldSize($table, $field) {
+               return -1;
+       }
+
+       /**
+        * No low priority option in SQLite
+        */
+       function lowPriorityOption() {
+               return '';
+       }
+
+       /**
+        * Returns an SQL expression for a simple conditional.
+        * - uses CASE on SQLite
+        */
+       function conditional($cond, $trueVal, $falseVal) {
+               return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
+       }
+
+       function wasDeadlock() {
+               return $this->lastErrno() == SQLITE_BUSY;
+       }
+
+       /**
+        * @return string wikitext of a link to the server software's web site
+        */
+       function getSoftwareLink() {
+               return "[http://sqlite.org/ SQLite]";
+       }
+
+       /**
+        * @return string Version information from the database
+        */
+       function getServerVersion() {
+               global $wgContLang;
+               $ver = $this->mConn->getAttribute(PDO::ATTR_SERVER_VERSION);
+               $size = $wgContLang->formatSize(filesize($this->mDatabaseFile));
+               $file = basename($this->mDatabaseFile);
+               return $ver." ($file: $size)";
+       }
+
+       /**
+        * Query whether a given column exists in the mediawiki schema
+        */
+       function fieldExists($table, $field) { return true; }
+
+       function fieldInfo($table, $field) { return SQLiteField::fromText($this, $table, $field); }
+
+       function begin() {
+               if ($this->mTrxLevel == 1) $this->commit();
+               $this->mConn->beginTransaction();
+               $this->mTrxLevel = 1;
+       }
+
+       function commit() {
+               if ($this->mTrxLevel == 0) return;
+               $this->mConn->commit();
+               $this->mTrxLevel = 0;
+       }
+
+       function rollback() {
+               if ($this->mTrxLevel == 0) return;
+               $this->mConn->rollBack();
+               $this->mTrxLevel = 0;
+       }
+
+       function limitResultForUpdate($sql, $num) {
+               return $sql;
+       }
+
+       function strencode($s) {
+               return substr($this->addQuotes($s),1,-1);
+       }
+
+       function encodeBlob($b) {
+               return $this->strencode($b);
+       }
+
+       function decodeBlob($b) {
+               return $b;
+       }
+
+       function addQuotes($s) {
+               return $this->mConn->quote($s);
+       }
+
+       function quote_ident($s) { return $s; }
+
+       /**
+        * For now, does nothing
+        */
+       function selectDB($db) { return true; }
+
+       /**
+        * not done
+        */
+       public function setTimeout($timeout) { return; }
+
+       function ping() {
+               wfDebug("Function ping() not written for SQLite yet");
+               return true;
+       }
+
+       /**
+        * How lagged is this slave?
+        */
+       public function getLag() {
+               return 0;
+       }
+
+       /**
+        * Called by the installer script (when modified according to the MediaWikiLite installation instructions)
+        * - this is the same way PostgreSQL works, MySQL reads in tables.sql and interwiki.sql using dbsource (which calls db->sourceFile)
+        */
+       public function setup_database() {
+               global $IP,$wgSQLiteDataDir,$wgDBTableOptions;
+               $wgDBTableOptions = '';
+               $mysql_tmpl  = "$IP/maintenance/tables.sql";
+               $mysql_iw    = "$IP/maintenance/interwiki.sql";
+               $sqlite_tmpl = "$wgSQLiteDataDir/tables.sql";
+
+               # Make an SQLite template file if it doesn't exist (based on the same one MySQL uses to create a new wiki db)
+               if (1 || !file_exists($sqlite_tmpl)) { # todo: make this conditional again
+                       $sql = file_get_contents($mysql_tmpl);
+                       $sql = preg_replace('/^\s*--.*?$/m','',$sql); # strip comments
+                       $sql = preg_replace('/^\s*(UNIQUE)?\s*(PRIMARY)?\s*KEY.+?$/m','',$sql);
+                       $sql = preg_replace('/^\s*(UNIQUE )?INDEX.+?$/m','',$sql); # These indexes should be created with a CREATE INDEX query
+                       $sql = preg_replace('/^\s*FULLTEXT.+?$/m','',$sql);        # Full text indexes
+                       $sql = preg_replace('/ENUM\(.+?\)/','TEXT',$sql); # Make ENUM's into TEXT's
+                       $sql = preg_replace('/ENUM\(.+?\)/','TEXT',$sql); # Make ENUM's into TEXT's
+                       $sql = preg_replace('/binary\(\d+\)/','BLOB',$sql);
+                       $sql = preg_replace('/(TYPE|MAX_ROWS|AVG_ROW_LENGTH)=\w+/','',$sql);
+                       $sql = preg_replace('/,\s*\)/s',')',$sql); # removing previous items may leave a trailing comma
+                       $sql = str_replace('binary','',$sql);
+                       $sql = str_replace('auto_increment','PRIMARY KEY AUTOINCREMENT',$sql);
+                       $sql = str_replace(' unsigned','',$sql);
+                       $sql = str_replace(' int ',' INTEGER ',$sql);
+                       $sql = str_replace('NOT NULL','',$sql);
+                       file_put_contents($sqlite_tmpl,$sql);
+               }
+
+               # Parse the SQLite template replacing inline variables such as /*$wgDBprefix*/
+               $err = $this->sourceFile($sqlite_tmpl);
+               if ($err !== true) $this->reportQueryError($err,0,$sql,__FUNCTION__);
+
+               # Use DatabasePostgres's code to populate interwiki from MySQL template
+               $f = fopen($mysql_iw,'r');
+               if ($f == false) dieout("<li>Could not find the interwiki.sql file");
+               $sql = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local) VALUES ";
+               while (!feof($f)) {
+                       $line = fgets($f,1024);
+                       $matches = array();
+                       if (!preg_match('/^\s*(\(.+?),(\d)\)/', $line, $matches)) continue;
+                       $this->query("$sql $matches[1],$matches[2])");
+               }
+       }
+
+}
+
+/**
+ * @addtogroup Database
+ */
+class SQLiteField extends MySQLField {
+
+       function __construct() {
+       }
+
+       static function fromText($db, $table, $field) {
+               $n = new SQLiteField;
+               $n->name = $field;
+               $n->tablename = $table;
+               return $n;
+       }
+
+} // end DatabaseSqlite class
+