From ca9abf66f5e7c70e2774086d276eb9688a8b9c09 Mon Sep 17 00:00:00 2001
From: Ben Roberts <ben@sihnon.net>
Date: Sat, 14 Aug 2010 18:22:53 +0100
Subject: [PATCH] Added ForegroundTask class

New class to run a command in the foreground, and process the stdout and
stderr output streams.
---
 lib/HandBrakeCluster/ForegroundTask.class.php | 111 ++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 lib/HandBrakeCluster/ForegroundTask.class.php

diff --git a/lib/HandBrakeCluster/ForegroundTask.class.php b/lib/HandBrakeCluster/ForegroundTask.class.php
new file mode 100644
index 0000000..51890a7
--- /dev/null
+++ b/lib/HandBrakeCluster/ForegroundTask.class.php
@@ -0,0 +1,111 @@
+<?php
+
+class HandBrakeCluster_ForegroundTask {
+    
+    const PIPE_STDIN  = 0;
+    const PIPE_STDOUT = 1;
+    const PIPE_STDERR = 2;
+    
+    private function __construct() {
+    
+    }
+    
+    /**
+     * 
+     * Code largely taken from user submitted comment on http://php.sihnon.net/manual/en/function.proc-open.php
+     * @param unknown_type $command
+     * @param unknown_type $cwd
+     * @param unknown_type $env
+     * @param unknown_type $stdin
+     * @param unknown_type $callback_stdout
+     * @param unknown_type $callback_stderr
+     */
+    public static function execute($command, $cwd = null, $env = null, $stdin = null, $callback_stdout = null, $callback_stderr = null, $identifier = null) {
+        $txOff = 0;
+        $txLen = strlen($stdin);
+        $stdout = '';
+        $stdoutDone = FALSE;
+        $stderr = '';
+        $stderrDone = FALSE;
+        
+        $descriptors = array(
+            self::PIPE_STDIN  => array('pipe', 'r'),
+            self::PIPE_STDOUT => array('pipe', 'w'),
+            self::PIPE_STDERR => array('pipe', 'w'),
+        );
+        
+        $pipes = array();
+        $process = proc_open($handbrake_cmd, $descriptors, $pipes);
+        
+        stream_set_blocking($pipes[0], 0); // Make stdin/stdout/stderr non-blocking
+        stream_set_blocking($pipes[1], 0);
+        stream_set_blocking($pipes[2], 0);
+        
+        if ($txLen == 0) {
+            fclose($pipes[0]);
+        }
+        
+        while (true) {
+            $rx = array(); // The program's stdout/stderr
+            if (!$stdoutDone) {
+                $rx[] = $pipes[1];
+            }
+            if (!$stderrDone) {
+                $rx[] = $pipes[2];
+            }
+            
+            $tx = array(); // The program's stdin
+            if ($txOff < $txLen) {
+                $tx[] = $pipes[0];
+            }
+            
+            stream_select($rx, $tx, $ex = null, null, null); // Block til r/w possible
+            if (!empty($tx)) {
+                $txRet = fwrite($pipes[0], substr($stdin, $txOff, 8192));
+                if ($txRet !== false) {
+                    $txOff += $txRet;
+                }
+                if ($txOff >= $txLen) {
+                    fclose($pipes[0]);
+                }
+            }
+            
+            foreach ($rx as $r) {
+                if ($r == $pipes[1]) {
+                    $chunk = fread($pipes[1], 8192);
+                    if (feof($pipes[1])) { 
+                        fclose($pipes[1]); $stdoutDone = true;
+                    }
+                    
+                    if ($callback_stderr) {
+                        call_user_func($callback_stdout, $identifier, $chunk);
+                    } else {
+                        $stdout .= $chunk;
+                    }
+                    
+                } else if ($r == $pipes[2]) {
+                    $chunk = fread($pipes[2], 8192);
+                    if (feof($pipes[2])) {
+                        fclose($pipes[2]); $stderrDone = true;
+                    }
+                    
+                    if ($callback_stderr) {
+                        call_user_func($callback_stderr, $identifier, $chunk);
+                    } else {
+                        $stderr .= $chunk;
+                    }
+                }
+            }
+            
+            if (!is_resource($process))
+                break;
+                
+            if ($txOff >= $txLen && $stdoutDone && $stderrDone)
+                break;
+        }
+        
+        return array(proc_close($process), $stdout, $stderr);
+    }
+    
+}
+