DatabaseSqlite.php

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<?php
class DatabaseSqlite extends DatabaseBase {
    private static $fulltextEnabled = null;

    public $mDatabaseFile;

    protected $mAffectedRows;

    protected $mLastResult;

    protected $mConn;

    protected $lockMgr;

    function __construct( $p = null ) {
        global $wgSharedDB, $wgSQLiteDataDir;

        if ( !is_array( $p ) ) { // legacy calling pattern
            wfDeprecated( __METHOD__ . " method called without parameter array.", "1.22" );
            $args = func_get_args();
            $p = array(
                'host' => isset( $args[0] ) ? $args[0] : false,
                'user' => isset( $args[1] ) ? $args[1] : false,
                'password' => isset( $args[2] ) ? $args[2] : false,
                'dbname' => isset( $args[3] ) ? $args[3] : false,
                'flags' => isset( $args[4] ) ? $args[4] : 0,
                'tablePrefix' => isset( $args[5] ) ? $args[5] : 'get from global',
                'schema' => 'get from global',
                'foreign' => isset( $args[6] ) ? $args[6] : false
            );
        }
        $this->mDBname = $p['dbname'];
        parent::__construct( $p );
        // parent doesn't open when $user is false, but we can work with $dbName
        if ( $p['dbname'] && !$this->isOpen() ) {
            if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
                if ( $wgSharedDB ) {
                    $this->attachDatabase( $wgSharedDB );
                }
            }
        }

        $this->lockMgr = new FSLockManager( array( 'lockDirectory' => "$wgSQLiteDataDir/locks" ) );
    }

    function getType() {
        return 'sqlite';
    }

    function implicitGroupby() {
        return false;
    }

    function open( $server, $user, $pass, $dbName ) {
        global $wgSQLiteDataDir;

        $this->close();
        $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
        if ( !is_readable( $fileName ) ) {
            $this->mConn = false;
            throw new DBConnectionError( $this, "SQLite database not accessible" );
        }
        $this->openFile( $fileName );

        return $this->mConn;
    }

    function openFile( $fileName ) {
        $err = false;

        $this->mDatabaseFile = $fileName;
        try {
            if ( $this->mFlags & DBO_PERSISTENT ) {
                $this->mConn = new PDO( "sqlite:$fileName", '', '',
                    array( PDO::ATTR_PERSISTENT => true ) );
            } else {
                $this->mConn = new PDO( "sqlite:$fileName", '', '' );
            }
        } catch ( PDOException $e ) {
            $err = $e->getMessage();
        }

        if ( !$this->mConn ) {
            wfDebug( "DB connection error: $err\n" );
            throw new DBConnectionError( $this, $err );
        }

        $this->mOpened = !!$this->mConn;
        # set error codes only, don't raise exceptions
        if ( $this->mOpened ) {
            $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
            # Enforce LIKE to be case sensitive, just like MySQL
            $this->query( 'PRAGMA case_sensitive_like = 1' );

            return $this->mConn;
        }

        return false;
    }

    protected function closeConnection() {
        $this->mConn = null;

        return true;
    }

    public static function generateFileName( $dir, $dbName ) {
        return "$dir/$dbName.sqlite";
    }

    function checkForEnabledSearch() {
        if ( self::$fulltextEnabled === null ) {
            self::$fulltextEnabled = false;
            $table = $this->tableName( 'searchindex' );
            $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
            if ( $res ) {
                $row = $res->fetchRow();
                self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
            }
        }

        return self::$fulltextEnabled;
    }

    static function getFulltextSearchModule() {
        static $cachedResult = null;
        if ( $cachedResult !== null ) {
            return $cachedResult;
        }
        $cachedResult = false;
        $table = 'dummy_search_test';

        $db = new DatabaseSqliteStandalone( ':memory:' );

        if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
            $cachedResult = 'FTS3';
        }
        $db->close();

        return $cachedResult;
    }

    function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
        global $wgSQLiteDataDir;
        if ( !$file ) {
            $file = self::generateFileName( $wgSQLiteDataDir, $name );
        }
        $file = $this->addQuotes( $file );

        return $this->query( "ATTACH DATABASE $file AS $name", $fname );
    }

    function isWriteQuery( $sql ) {
        return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
    }

    protected function doQuery( $sql ) {
        $res = $this->mConn->query( $sql );
        if ( $res === false ) {
            return false;
        } 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;
    }

    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;
    }

    function tableName( $name, $format = 'quoted' ) {
        // table names starting with sqlite_ are reserved
        if ( strpos( $name, 'sqlite_' ) === 0 ) {
            return $name;
        }

        return str_replace( '"', '', parent::tableName( $name, $format ) );
    }

    function indexName( $index ) {
        return $index;
    }

    function insertId() {
        // PDO::lastInsertId yields a string :(
        return intval( $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";
        } else {
            $info = $this->mConn->errorInfo();

            return $info[1];
        }
    }

    function affectedRows() {
        return $this->mAffectedRows;
    }

    function indexInfo( $table, $index, $fname = __METHOD__ ) {
        $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
        $res = $this->query( $sql, $fname );
        if ( !$res ) {
            return null;
        }
        if ( $res->numRows() == 0 ) {
            return false;
        }
        $info = array();
        foreach ( $res as $row ) {
            $info[] = $row->name;
        }

        return $info;
    }

    function indexUnique( $table, $index, $fname = __METHOD__ ) {
        $row = $this->selectRow( 'sqlite_master', '*',
            array(
                'type' => 'index',
                'name' => $this->indexName( $index ),
            ), $fname );
        if ( !$row || !isset( $row->sql ) ) {
            return null;
        }

        // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
        $indexPos = strpos( $row->sql, 'INDEX' );
        if ( $indexPos === false ) {
            return null;
        }
        $firstPart = substr( $row->sql, 0, $indexPos );
        $options = explode( ' ', $firstPart );

        return in_array( 'UNIQUE', $options );
    }

    function makeSelectOptions( $options ) {
        foreach ( $options as $k => $v ) {
            if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
                $options[$k] = '';
            }
        }

        return parent::makeSelectOptions( $options );
    }

    protected function makeUpdateOptionsArray( $options ) {
        $options = parent::makeUpdateOptionsArray( $options );
        $options = self::fixIgnore( $options );

        return $options;
    }

    static function fixIgnore( $options ) {
        # SQLite uses OR IGNORE not just IGNORE
        foreach ( $options as $k => $v ) {
            if ( $v == 'IGNORE' ) {
                $options[$k] = 'OR IGNORE';
            }
        }

        return $options;
    }

    function makeInsertOptions( $options ) {
        $options = self::fixIgnore( $options );

        return parent::makeInsertOptions( $options );
    }

    function insert( $table, $a, $fname = __METHOD__, $options = array() ) {
        if ( !count( $a ) ) {
            return true;
        }

        # 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 $v ) {
                if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
                    $ret = false;
                }
            }
        } else {
            $ret = parent::insert( $table, $a, "$fname/single-row", $options );
        }

        return $ret;
    }

    function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
        if ( !count( $rows ) ) {
            return true;
        }

        # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
        if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
            $ret = true;
            foreach ( $rows as $v ) {
                if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
                    $ret = false;
                }
            }
        } else {
            $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
        }

        return $ret;
    }

    function textFieldSize( $table, $field ) {
        return -1;
    }

    function unionSupportsOrderAndLimit() {
        return false;
    }

    function unionQueries( $sqls, $all ) {
        $glue = $all ? ' UNION ALL ' : ' UNION ';

        return implode( $glue, $sqls );
    }

    function wasDeadlock() {
        return $this->lastErrno() == 5; // SQLITE_BUSY
    }

    function wasErrorReissuable() {
        return $this->lastErrno() == 17; // SQLITE_SCHEMA;
    }

    function wasReadOnlyError() {
        return $this->lastErrno() == 8; // SQLITE_READONLY;
    }

    public function getSoftwareLink() {
        return "[{{int:version-db-sqlite-url}} SQLite]";
    }

    function getServerVersion() {
        $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );

        return $ver;
    }

    public function getServerInfo() {
        return wfMessage( self::getFulltextSearchModule()
            ? 'sqlite-has-fts'
            : 'sqlite-no-fts', $this->getServerVersion() )->text();
    }

    function fieldInfo( $table, $field ) {
        $tableName = $this->tableName( $table );
        $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
        $res = $this->query( $sql, __METHOD__ );
        foreach ( $res as $row ) {
            if ( $row->name == $field ) {
                return new SQLiteField( $row, $tableName );
            }
        }

        return false;
    }

    protected function doBegin( $fname = '' ) {
        if ( $this->mTrxLevel == 1 ) {
            $this->commit( __METHOD__ );
        }
        try {
            $this->mConn->beginTransaction();
        } catch ( PDOException $e ) {
            throw new DBUnexpectedError( $this, 'Error in BEGIN query: ' . $e->getMessage() );
        }
        $this->mTrxLevel = 1;
    }

    protected function doCommit( $fname = '' ) {
        if ( $this->mTrxLevel == 0 ) {
            return;
        }
        try {
            $this->mConn->commit();
        } catch ( PDOException $e ) {
            throw new DBUnexpectedError( $this, 'Error in COMMIT query: ' . $e->getMessage() );
        }
        $this->mTrxLevel = 0;
    }

    protected function doRollback( $fname = '' ) {
        if ( $this->mTrxLevel == 0 ) {
            return;
        }
        $this->mConn->rollBack();
        $this->mTrxLevel = 0;
    }

    function strencode( $s ) {
        return substr( $this->addQuotes( $s ), 1, -1 );
    }

    function encodeBlob( $b ) {
        return new Blob( $b );
    }

    function decodeBlob( $b ) {
        if ( $b instanceof Blob ) {
            $b = $b->fetch();
        }

        return $b;
    }

    function addQuotes( $s ) {
        if ( $s instanceof Blob ) {
            return "x'" . bin2hex( $s->fetch() ) . "'";
        } elseif ( is_bool( $s ) ) {
            return (int)$s;
        } elseif ( strpos( $s, "\0" ) !== false ) {
            // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
            // This is a known limitation of SQLite's mprintf function which PDO should work around,
            // but doesn't. I have reported this to php.net as bug #63419:
            // https://bugs.php.net/bug.php?id=63419
            // There was already a similar report for SQLite3::escapeString, bug #62361:
            // https://bugs.php.net/bug.php?id=62361
            return "x'" . bin2hex( $s ) . "'";
        } else {
            return $this->mConn->quote( $s );
        }
    }

    function buildLike() {
        $params = func_get_args();
        if ( count( $params ) > 0 && is_array( $params[0] ) ) {
            $params = $params[0];
        }

        return parent::buildLike( $params ) . "ESCAPE '\' ";
    }

    public function getSearchEngine() {
        return "SearchSqlite";
    }

    public function deadlockLoop( /*...*/ ) {
        $args = func_get_args();
        $function = array_shift( $args );

        return call_user_func_array( $function, $args );
    }

    protected function replaceVars( $s ) {
        $s = parent::replaceVars( $s );
        if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
            // CREATE TABLE hacks to allow schema file sharing with MySQL

            // binary/varbinary column type -> blob
            $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
            // no such thing as unsigned
            $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
            // INT -> INTEGER
            $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
            // floating point types -> REAL
            $s = preg_replace(
                '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
                'REAL',
                $s
            );
            // varchar -> TEXT
            $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
            // TEXT normalization
            $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
            // BLOB normalization
            $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
            // BOOL -> INTEGER
            $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
            // DATETIME -> TEXT
            $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
            // No ENUM type
            $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
            // binary collation type -> nothing
            $s = preg_replace( '/\bbinary\b/i', '', $s );
            // auto_increment -> autoincrement
            $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
            // No explicit options
            $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
            // AUTOINCREMENT should immedidately follow PRIMARY KEY
            $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
        } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
            // No truncated indexes
            $s = preg_replace( '/\(\d+\)/', '', $s );
            // No FULLTEXT
            $s = preg_replace( '/\bfulltext\b/i', '', $s );
        } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
            // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
            $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
        }

        return $s;
    }

    public function lock( $lockName, $method, $timeout = 5 ) {
        global $wgSQLiteDataDir;

        if ( !is_dir( "$wgSQLiteDataDir/locks" ) ) { // create dir as needed
            if ( !is_writable( $wgSQLiteDataDir ) || !mkdir( "$wgSQLiteDataDir/locks" ) ) {
                throw new DBError( "Cannot create directory \"$wgSQLiteDataDir/locks\"." );
            }
        }

        return $this->lockMgr->lock( array( $lockName ), LockManager::LOCK_EX, $timeout )->isOK();
    }

    public function unlock( $lockName, $method ) {
        return $this->lockMgr->unlock( array( $lockName ), LockManager::LOCK_EX )->isOK();
    }

    function buildConcat( $stringList ) {
        return '(' . implode( ') || (', $stringList ) . ')';
    }

    public function buildGroupConcatField(
        $delim, $table, $field, $conds = '', $join_conds = array()
    ) {
        $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';

        return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
    }

    function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
        $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
            $this->addQuotes( $oldName ) . " AND type='table'", $fname );
        $obj = $this->fetchObject( $res );
        if ( !$obj ) {
            throw new MWException( "Couldn't retrieve structure for table $oldName" );
        }
        $sql = $obj->sql;
        $sql = preg_replace(
            '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
            $this->addIdentifierQuotes( $newName ),
            $sql,
            1
        );
        if ( $temporary ) {
            if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
                wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
            } else {
                $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
            }
        }

        return $this->query( $sql, $fname );
    }

    function listTables( $prefix = null, $fname = __METHOD__ ) {
        $result = $this->select(
            'sqlite_master',
            'name',
            "type='table'"
        );

        $endArray = array();

        foreach ( $result as $table ) {
            $vars = get_object_vars( $table );
            $table = array_pop( $vars );

            if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
                if ( strpos( $table, 'sqlite_' ) !== 0 ) {
                    $endArray[] = $table;
                }
            }
        }

        return $endArray;
    }
} // end DatabaseSqlite class

class DatabaseSqliteStandalone extends DatabaseSqlite {
    public function __construct( $fileName, $flags = 0 ) {
        $this->mFlags = $flags;
        $this->tablePrefix( null );
        $this->openFile( $fileName );
    }
}

class SQLiteField implements Field {
    private $info, $tableName;

    function __construct( $info, $tableName ) {
        $this->info = $info;
        $this->tableName = $tableName;
    }

    function name() {
        return $this->info->name;
    }

    function tableName() {
        return $this->tableName;
    }

    function defaultValue() {
        if ( is_string( $this->info->dflt_value ) ) {
            // Typically quoted
            if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
                return str_replace( "''", "'", $this->info->dflt_value );
            }
        }

        return $this->info->dflt_value;
    }

    function isNullable() {
        return !$this->info->notnull;
    }

    function type() {
        return $this->info->type;
    }
} // end SQLiteField