Channeled output support for maintenance scripts.

Channeled output (for the lack of better name) allows outputting stuff into same line, channel, so that each channel change starts a new line.

diff --git a/maintenance/Maintenance.php b/maintenance/Maintenance.php
index 534e368..202963f 100644 (file)
--- a/maintenance/Maintenance.php
+++ b/maintenance/Maintenance.php
@@ -98,6 +98,7 @@ abstract class Maintenance {
         */
        public function __construct() {
                $this->addDefaultParams();
+               register_shutdown_function( array( $this, 'outputChanneled' ), false );
        }
 
        /**
@@ -214,14 +215,14 @@ abstract class Maintenance {
         * Throw some output to the user. Scripts can call this with no fears,
         * as we handle all --quiet stuff here
         * @param $out String The text to show to the user
+        * @param $channel Mixed Unique identifier for the channel. See function outputChanneled.
         */
-       protected function output( $out ) {
+       protected function output( $out, $channel = null ) {
                if( $this->mQuiet ) {
                        return;
                }
-               $f = fopen( 'php://stdout', 'w' );
-               fwrite( $f, $out );
-               fclose( $f );
+               $out = preg_replace( '/\n\z/', '', $out );
+               $this->outputChanneled( $out, $channel );
        }
 
        /**
@@ -231,6 +232,7 @@ abstract class Maintenance {
         * @param $die boolean If true, go ahead and die out.
         */
        protected function error( $err, $die = false ) {
+               $this->outputChanneled( false );
                if ( php_sapi_name() == 'cli' ) {
                        fwrite( STDERR, $err . "\n" );
                } else {
@@ -241,6 +243,45 @@ abstract class Maintenance {
                if( $die ) die();
        }
 
+       private $atLineStart = true;
+       private $lastChannel = null;
+       
+       /**
+        * Message outputter with channeled message support. Messages on the
+        * same channel are concatenated, but any intervening messages in another
+        * channel start a new line.
+        * @param $msg String The message without trailing newline
+        * @param $channel Channel identifier or null for no channel. Channel comparison uses ===.
+        */
+       public function outputChanneled( $msg, $channel = null ) {
+               $handle = fopen( 'php://stdout', 'w' ); 
+
+               if ( $msg === false ) {
+                       // For cleanup
+                       if ( !$this->atLineStart ) fwrite( $handle, "\n" );
+                       fclose( $handle );
+                       return;
+               }
+
+               // End the current line if necessary
+               if ( !$this->atLineStart && $channel !== $this->lastChannel ) {
+                       fwrite( $handle, "\n" );
+               }
+
+               fwrite( $handle, $msg );
+
+               $this->atLineStart = false;
+               if ( $channel === null ) {
+                       // For unchanneled messages, output trailing newline immediately
+                       fwrite( $handle, "\n" );
+                       $this->atLineStart = true;
+               }
+               $this->lastChannel = $channel;
+
+               // Cleanup handle
+               fclose( $handle );
+       }
+
        /**
         * Does the script need different DB access? By default, we give Maintenance
         * scripts normal rights to the DB. Sometimes, a script needs admin rights