Changeset 16320

Timestamp:

11/12/2010 10:15:18 AM (13 years ago)

Author:

nacin

Message:

Memory usage and execution improvements in wpdb. Store and work with resources directly, rather than full copies of results. Plugins which incorrectly used wpdb->last_result (a private property) will need to shift to wpdb->get_results() with no \$query. Magic getter is introduced for back compat when using PHP5. props joelhardi, fixes #12257.

File:

• trunk/wp-includes/wp-db.php (modified) (10 diffs)

trunk/wp-includes/wp-db.php

@@ -126 +126 @@
 
     /**
-     * Results of the last query made
-     *
-     * @since 1.0.0
-     * @access private
-     * @var array|null
-     */
-    var $last_result;
+     * MySQL result resource of the last query made
+     *
+     * @since 3.1.0
+     * @access private
+     * @var resource|null
+     */
+    var $_mysql_last_result;
 
     /**
@@ -1016 +1016 @@
      */
     function flush() {
-        $this->last_result = array();
+        @mysql_free_result( $this->_mysql_last_result );
         $this->col_info    = null;
         $this->last_query  = null;
@@ -1086 +1086 @@
             $this->timer_start();
 
-        $this->result = @mysql_query( $query, $this->dbh );
+        $this->_mysql_last_result = @mysql_query( $query, $this->dbh );
         $this->num_queries++;
 
@@ -1108 +1108 @@
         } else {
             $i = 0;
-            while ( $i < @mysql_num_fields( $this->result ) ) {
-                $this->col_info[$i] = @mysql_fetch_field( $this->result );
+            while ( $i < @mysql_num_fields( $this->_mysql_last_result ) ) {
+                $this->col_info[$i] = @mysql_fetch_field( $this->_mysql_last_result );
                 $i++;
             }
-            $num_rows = 0;
-            while ( $row = @mysql_fetch_object( $this->result ) ) {
-                $this->last_result[$num_rows] = $row;
-                $num_rows++;
-            }
-
-            @mysql_free_result( $this->result );
 
             // Log number of rows the query returned
             // and return number of rows selected
-            $this->num_rows = $num_rows;
-            $return_val     = $num_rows;
+            $this->num_rows = @mysql_num_rows( $this->_mysql_last_result );
+            $return_val     = $this->num_rows;
         }
 
@@ -1282 +1275 @@
             $this->query( $query );
 
-        // Extract var out of cached results based x,y vals
-        if ( !empty( $this->last_result[$y] ) ) {
-            $values = array_values( get_object_vars( $this->last_result[$y] ) );
+        // Extract var from result resource based x,y vals
+        if ( $this->num_rows > $y ) {
+            @mysql_data_seek( $this->_mysql_last_result, $y );
+            $values = @mysql_fetch_row( $this->_mysql_last_result );
         }
 
@@ -1311 +1305 @@
             return null;
 
-        if ( !isset( $this->last_result[$y] ) )
+        if ( $this->num_rows <= $y )
             return null;
 
+        @mysql_data_seek( $this->_mysql_last_result, $y );
+
         if ( $output == OBJECT ) {
-            return $this->last_result[$y] ? $this->last_result[$y] : null;
+            return @mysql_fetch_object( $this->_mysql_last_result );
         } elseif ( $output == ARRAY_A ) {
-            return $this->last_result[$y] ? get_object_vars( $this->last_result[$y] ) : null;
+            return @mysql_fetch_assoc( $this->_mysql_last_result );
         } elseif ( $output == ARRAY_N ) {
-            return $this->last_result[$y] ? array_values( get_object_vars( $this->last_result[$y] ) ) : null;
+            return @mysql_fetch_row( $this->_mysql_last_result );
         } else {
             $this->print_error(/*WP_I18N_DB_GETROW_ERROR*/" \$db->get_row(string query, output type, int offset) -- Output type must be one of: OBJECT, ARRAY_A, ARRAY_N"/*/WP_I18N_DB_GETROW_ERROR*/);
@@ -1344 +1340 @@
         $new_array = array();
         // Extract the column values
-        for ( $i = 0, $j = count( $this->last_result ); $i < $j; $i++ ) {
-            $new_array[$i] = $this->get_var( null, $x, $i );
+        @mysql_data_seek( $this->_mysql_last_result, 0 );
+        for ( $i = 0, $j = $this->num_rows; $i < $j; $i++ ) {
+            $values = @mysql_fetch_row( $this->_mysql_last_result );
+            if ( isset( $values[$x] ) && $values[$x] !== '' )
+                $new_array[$i] = $values[$x];
+            else
+                $new_array[$i] = null;          
         }
         return $new_array;
@@ -1372 +1373 @@
 
         $new_array = array();
+        @mysql_data_seek( $this->_mysql_last_result, 0 );
         if ( $output == OBJECT ) {
             // Return an integer-keyed array of row objects
-            return $this->last_result;
+            for ( $i = 0, $j = $this->num_rows; $i < $j; $i++ ) {
+                $new_array[] = @mysql_fetch_object( $this->_mysql_last_result );
+            }
+            return $new_array;
         } elseif ( $output == OBJECT_K ) {
             // Return an array of row objects with keys from column 1
             // (Duplicates are discarded)
-            foreach ( $this->last_result as $row ) {
+            while ( $row = @mysql_fetch_object( $this->_mysql_last_result ) ) {
                 $key = array_shift( $var_by_ref = get_object_vars( $row ) );
                 if ( ! isset( $new_array[ $key ] ) )
@@ -1384 +1389 @@
             }
             return $new_array;
-        } elseif ( $output == ARRAY_A || $output == ARRAY_N ) {
-            // Return an integer-keyed array of...
-            if ( $this->last_result ) {
-                foreach( (array) $this->last_result as $row ) {
-                    if ( $output == ARRAY_N ) {
-                        // ...integer-keyed row arrays
-                        $new_array[] = array_values( get_object_vars( $row ) );
-                    } else {
-                        // ...column name-keyed row arrays
-                        $new_array[] = get_object_vars( $row );
-                    }
-                }
+        } elseif ( $output == ARRAY_A ) {
+            // Return an integer-keyed array of column name-keyed row arrays
+            for ( $i = 0, $j = $this->num_rows; $i < $j; $i++ ) {
+                $new_array[] = @mysql_fetch_assoc( $this->_mysql_last_result );
+            }
+            return $new_array;
+        } elseif ( $output == ARRAY_N ) {
+            // Return an integer-keyed array of integer-keyed row arrays
+            for ( $i = 0, $j = $this->num_rows; $i < $j; $i++ ) {
+                $new_array[] = @mysql_fetch_row( $this->_mysql_last_result );
             }
             return $new_array;
@@ -1560 +1563 @@
         return preg_replace( '/[^0-9.].*/', '', mysql_get_server_info( $this->dbh ) );
     }
+
+    /**
+     * Magic getter used for the deprecated last_result property.
+     *
+     * @since 3.1.0
+     * @access private
+     */
+    function __get( $name ) {
+        if ( 'last_result' == $name ) {
+            _deprecated_argument( 'wpdb', '3.1', __( 'The last_result property is deprecated. Use $wpdb->get_result().' ) );
+            return $this->get_results();
+        }
+        return null;
+    }
 }