peardb.php

PhpWiki是sourceforge的一个开源项目

            $order = "hits DESC";
            $where = " AND hits > 0";
        }
        $orderby = '';
        if ($sortby != '-hits') {
            if ($order = $this->sortby($sortby, 'db'))
                $orderby = " ORDER BY " . $order;
        } else {
            $orderby = " ORDER BY $order";
        }
        //$limitclause = $limit ? " LIMIT $limit" : '';
        $sql = "SELECT "
            . $this->page_tbl_fields
            . " FROM $nonempty_tbl, $page_tbl"
            . " WHERE $nonempty_tbl.id=$page_tbl.id" 
            . $where
            . $orderby;
         if ($limit) {
             list($from, $count) = $this->limit($limit);
             $result = $dbh->limitQuery($sql, $from, $count);
         } else {
             $result = $dbh->query($sql);
         }

        return new WikiDB_backend_PearDB_iter($this, $result);
    }

    /**
     * Find recent changes.
     */
    function most_recent($params) {
        $limit = 0;
        $since = 0;
        $include_minor_revisions = false;
        $exclude_major_revisions = false;
        $include_all_revisions = false;
        extract($params);

        $dbh = &$this->_dbh;
        extract($this->_table_names);

        $pick = array();
        if ($since)
            $pick[] = "mtime >= $since";
			
        
        if ($include_all_revisions) {
            // Include all revisions of each page.
            $table = "$page_tbl, $version_tbl";
            $join_clause = "$page_tbl.id=$version_tbl.id";

            if ($exclude_major_revisions) {
		// Include only minor revisions
                $pick[] = "minor_edit <> 0";
            }
            elseif (!$include_minor_revisions) {
		// Include only major revisions
                $pick[] = "minor_edit = 0";
            }
        }
        else {
            $table = "$page_tbl, $recent_tbl";
            $join_clause = "$page_tbl.id=$recent_tbl.id";
            $table .= ", $version_tbl";
            $join_clause .= " AND $version_tbl.id=$page_tbl.id";
            
            if ($exclude_major_revisions) {
                // Include only most recent minor revision
                $pick[] = 'version=latestminor';
            }
            elseif (!$include_minor_revisions) {
                // Include only most recent major revision
                $pick[] = 'version=latestmajor';
            }
            else {
                // Include only the latest revision (whether major or minor).
                $pick[] ='version=latestversion';
            }
        }
        $order = "DESC";
        if($limit < 0){
            $order = "ASC";
            $limit = -$limit;
        }
        // $limitclause = $limit ? " LIMIT $limit" : '';
        $where_clause = $join_clause;
        if ($pick)
            $where_clause .= " AND " . join(" AND ", $pick);

        // FIXME: use SQL_BUFFER_RESULT for mysql?
        $sql = "SELECT " 
               . $this->page_tbl_fields . ", " . $this->version_tbl_fields
               . " FROM $table"
               . " WHERE $where_clause"
               . " ORDER BY mtime $order";
        if ($limit) {
             list($from, $count) = $this->limit($limit);
             $result = $dbh->limitQuery($sql, $from, $count);
        } else {
            $result = $dbh->query($sql);
        }
        return new WikiDB_backend_PearDB_iter($this, $result);
    }

    /**
     * Find referenced empty pages.
     */
    function wanted_pages($exclude_from='', $exclude='', $sortby=false, $limit=false) {
        $dbh = &$this->_dbh;
        extract($this->_table_names);
        if ($orderby = $this->sortby($sortby, 'db', array('pagename','wantedfrom')))
            $orderby = 'ORDER BY ' . $orderby;

        if ($exclude_from) // array of pagenames
            $exclude_from = " AND linked.pagename NOT IN ".$this->_sql_set($exclude_from);
        if ($exclude) // array of pagenames
            $exclude = " AND $page_tbl.pagename NOT IN ".$this->_sql_set($exclude);

        $sql = "SELECT $page_tbl.pagename,linked.pagename as wantedfrom"
            . " FROM $link_tbl,$page_tbl as linked "
            . " LEFT JOIN $page_tbl ON($link_tbl.linkto=$page_tbl.id)"
            . " LEFT JOIN $nonempty_tbl ON($link_tbl.linkto=$nonempty_tbl.id)" 
            . " WHERE ISNULL($nonempty_tbl.id) AND linked.id=$link_tbl.linkfrom"
            . $exclude_from
            . $exclude
            . $orderby;
        if ($limit) {
            list($from, $count) = $this->limit($limit);
            $result = $dbh->limitQuery($sql, $from, $count * 3);
        } else {
            $result = $dbh->query($sql);
        }
        return new WikiDB_backend_PearDB_generic_iter($this, $result);
    }

    function _sql_set(&$pagenames) {
        $s = '(';
        foreach ($pagenames as $p) {
            $s .= ("'".$this->_dbh->escapeSimple($p)."',");
        }
        return substr($s,0,-1).")";
    }

    /**
     * Rename page in the database.
     */
    function rename_page($pagename, $to) {
        $dbh = &$this->_dbh;
        extract($this->_table_names);
        
        $this->lock();
        if (($id = $this->_get_pageid($pagename, false)) ) {
            if ($new = $this->_get_pageid($to, false)) {
                // Cludge Alert!
                // This page does not exist (already verified before), but exists in the page table.
                // So we delete this page.
                $dbh->query("DELETE FROM $page_tbl WHERE id=$new");
                $dbh->query("DELETE FROM $version_tbl WHERE id=$new");
                $dbh->query("DELETE FROM $recent_tbl WHERE id=$new");
                $dbh->query("DELETE FROM $nonempty_tbl WHERE id=$new");
                // We have to fix all referring tables to the old id
                $dbh->query("UPDATE $link_tbl SET linkfrom=$id WHERE linkfrom=$new");
                $dbh->query("UPDATE $link_tbl SET linkto=$id WHERE linkto=$new");
            }
            $dbh->query(sprintf("UPDATE $page_tbl SET pagename='%s' WHERE id=$id",
                                $dbh->escapeSimple($to)));
        }
        $this->unlock();
        return $id;
    }

    function _update_recent_table($pageid = false) {
        $dbh = &$this->_dbh;
        extract($this->_table_names);
        extract($this->_expressions);

        $pageid = (int)$pageid;

        $this->lock();
        $dbh->query("DELETE FROM $recent_tbl"
                    . ( $pageid ? " WHERE id=$pageid" : ""));
        $dbh->query( "INSERT INTO $recent_tbl"
                     . " (id, latestversion, latestmajor, latestminor)"
                     . " SELECT id, $maxversion, $maxmajor, $maxminor"
                     . " FROM $version_tbl"
                     . ( $pageid ? " WHERE id=$pageid" : "")
                     . " GROUP BY id" );
        $this->unlock();
    }

    function _update_nonempty_table($pageid = false) {
        $dbh = &$this->_dbh;
        extract($this->_table_names);

        $pageid = (int)$pageid;

        extract($this->_expressions);
        $this->lock();
        $dbh->query("DELETE FROM $nonempty_tbl"
                    . ( $pageid ? " WHERE id=$pageid" : ""));
        $dbh->query("INSERT INTO $nonempty_tbl (id)"
                    . " SELECT $recent_tbl.id"
                    . " FROM $recent_tbl, $version_tbl"
                    . " WHERE $recent_tbl.id=$version_tbl.id"
                    . "       AND version=latestversion"
                    // We have some specifics here (Oracle)
                    //. "  AND content<>''"
                    . "  AND content $notempty"
                    . ( $pageid ? " AND $recent_tbl.id=$pageid" : ""));
        
        $this->unlock();
    }


    /**
     * Grab a write lock on the tables in the SQL database.
     *
     * Calls can be nested.  The tables won't be unlocked until
     * _unlock_database() is called as many times as _lock_database().
     *
     * @access protected
     */
    function lock($tables = false, $write_lock = true) {
        if ($this->_lock_count++ == 0)
            $this->_lock_tables($write_lock);
    }

    /**
     * Actually lock the required tables.
     */
    function _lock_tables($write_lock) {
        trigger_error("virtual", E_USER_ERROR);
    }
    
    /**
     * Release a write lock on the tables in the SQL database.
     *
     * @access protected
     *
     * @param $force boolean Unlock even if not every call to lock() has been matched
     * by a call to unlock().
     *
     * @see _lock_database
     */
    function unlock($tables = false, $force = false) {
        if ($this->_lock_count == 0)
            return;
        if (--$this->_lock_count <= 0 || $force) {
            $this->_unlock_tables();
            $this->_lock_count = 0;
        }
    }

    /**
     * Actually unlock the required tables.
     */
    function _unlock_tables($write_lock) {
        trigger_error("virtual", E_USER_ERROR);
    }


    /**
     * Serialize data
     */
    function _serialize($data) {
        if (empty($data))
            return '';
        assert(is_array($data));
        return serialize($data);
    }

    /**
     * Unserialize data
     */
    function _unserialize($data) {
        return empty($data) ? array() : unserialize($data);
    }
    
    /**
     * Callback for PEAR (DB) errors.
     *
     * @access protected
     *
     * @param A PEAR_error object.
     */
    function _pear_error_callback($error) {
        if ($this->_is_false_error($error))
            return;
        
        $this->_dbh->setErrorHandling(PEAR_ERROR_PRINT);	// prevent recursive loops.
        $this->close();
        trigger_error($this->_pear_error_message($error), E_USER_ERROR);
    }

    /**
     * Detect false errors messages from PEAR DB.
     *
     * The version of PEAR DB which ships with PHP 4.0.6 has a bug in that
     * it doesn't recognize "LOCK" and "UNLOCK" as SQL commands which don't
     * return any data.  (So when a "LOCK" command doesn't return any data,
     * DB reports it as an error, when in fact, it's not.)
     *
     * @access private
     * @return bool True iff error is not really an error.
     */
    function _is_false_error($error) {
        if ($error->getCode() != DB_ERROR)
            return false;

        $query = $this->_dbh->last_query;

        if (! preg_match('/^\s*"?(INSERT|UPDATE|DELETE|REPLACE|CREATE'
                         . '|DROP|ALTER|GRANT|REVOKE|LOCK|UNLOCK)\s/', $query)) {
            // Last query was not of the sort which doesn't return any data.
            //" <--kludge for brain-dead syntax coloring
            return false;
        }
        
        if (! in_array('ismanip', get_class_methods('DB'))) {
            // Pear shipped with PHP 4.0.4pl1 (and before, presumably)
            // does not have the DB::isManip method.
            return true;
        }
        
        if (DB::isManip($query)) {
            // If Pear thinks it's an isManip then it wouldn't have thrown
            // the error we're testing for....
            return false;
        }

        return true;
    }

    function _pear_error_message($error) {
        $class = get_class($this);
        $message = "$class: fatal database error\n"
             . "\t" . $error->getMessage() . "\n"
             . "\t(" . $error->getDebugInfo() . ")\n";

        // Prevent password from being exposed during a connection error
        $safe_dsn = preg_replace('| ( :// .*? ) : .* (?=@) |xs',
                                 '\\1:XXXXXXXX', $this->_dsn);
        return str_replace($this->_dsn, $safe_dsn, $message);
    }

    /**
     * Filter PHP errors notices from PEAR DB code.
     *
     * The PEAR DB code which ships with PHP 4.0.6 produces spurious
     * errors and notices.  This is an error callback (for use with
     * ErrorManager which will filter out those spurious messages.)
     * @see _is_false_error, ErrorManager
     * @access private
     */
    function _pear_notice_filter($err) {
        return ( $err->isNotice()
                 && preg_match('|DB[/\\\\]common.php$|', $err->errfile)
                 && $err->errline == 126
                 && preg_match('/Undefined offset: +0\b/', $err->errstr) );
    }