[Process] Add InputStream to seamlessly feed running processes

nicolas-grekas · nicolas-grekas · commit 88f45f50c4b3 · 2016-03-31T18:06:41.000+02:00
diff --git a/src/Symfony/Component/Process/InputStream.php b/src/Symfony/Component/Process/InputStream.php
@@ -0,0 +1,83 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process;
+
+use Symfony\Component\Process\Exception\RuntimeException;
+
+/**
+ * Provides a way to continously write to the input of a Process.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class InputStream implements \IteratorAggregate
+{
+    private $onEmpty = null;
+    private $input = array();
+    private $open = true;
+
+    public function __construct(callable $onEmpty = null)
+    {
+        $this->onEmpty($onEmpty);
+    }
+
+    public function onEmpty(callable $onEmpty = null)
+    {
+        $this->onEmpty = $onEmpty;
+    }
+
+    public function write($input)
+    {
+        if (null === $input) {
+            return;
+        }
+        if ($this->isClosed()) {
+            throw new RuntimeException(sprintf('%s is closed', get_class($this)));
+        }
+        $this->input[] = ProcessUtils::validateInput(__METHOD__, $input);
+
+        return $this;
+    }
+
+    public function close()
+    {
+        $this->open = false;
+    }
+
+    public function isClosed()
+    {
+        return !$this->open;
+    }
+
+    public function getIterator()
+    {
+        $this->open = true;
+
+        while ($this->open || $this->input) {
+            if (!$this->input) {
+                yield '';
+                continue;
+            }
+            $current = array_shift($this->input);
+
+            if ($current instanceof \Iterator) {
+                foreach ($current as $cur) {
+                    yield $cur;
+                }
+            } else {
+                yield $current;
+            }
+            if (!$this->input && $this->open && null !== $onEmpty = $this->onEmpty) {
+                $this->write($onEmpty($this));
+            }
+        }
+    }
+}
diff --git a/src/Symfony/Component/Process/Tests/ProcessTest.php b/src/Symfony/Component/Process/Tests/ProcessTest.php
@@ -14,6 +14,7 @@
 use Symfony\Component\Process\Exception\LogicException;
 use Symfony\Component\Process\Exception\ProcessTimedOutException;
 use Symfony\Component\Process\Exception\RuntimeException;
+use Symfony\Component\Process\InputStream;
 use Symfony\Component\Process\PhpExecutableFinder;
 use Symfony\Component\Process\Pipes\PipesInterface;
 use Symfony\Component\Process\Process;
@@ -1203,6 +1204,66 @@ public function testIteratorInput()
         $this->assertSame('pingpong', $process->getOutput());
     }
 
+    public function testSimpleInputStream()
+    {
+        $input = new InputStream();
+
+        $process = new Process(self::$phpBin.' -r '.escapeshellarg('echo \'ping\'; stream_copy_to_stream(STDIN, STDOUT);'));
+        $process->setInput($input);
+
+        $process->start(function ($type, $data) use ($input) {
+            if ('ping' === $data) {
+                $input->write('pang');
+            } elseif (!$input->isClosed()) {
+                $input->write('pong');
+                $input->close();
+            }
+        });
+
+        $process->wait();
+        $this->assertSame('pingpangpong', $process->getOutput());
+    }
+
+    public function testInputStreamWithCallable()
+    {
+        $i = 0;
+        $stream = fopen('php://memory', 'w+');
+        $stream = function () use ($stream, &$i) {
+            rewind($stream);
+            fwrite($stream, ++$i);
+            rewind($stream);
+
+            return $stream;
+        };
+
+        $input = new InputStream($stream);
+        $input->write($stream());
+
+        $process = new Process(self::$phpBin.' -r '.escapeshellarg('stream_copy_to_stream(STDIN, STDOUT);'));
+        $process->setInput($input);
+        $process->start(function ($type, $data) use ($input) {
+            $input->close();
+        });
+
+        $process->wait();
+        $this->assertStringStartsWith('123', $process->getOutput());
+    }
+
+    public function testInputStreamWithGenerator()
+    {
+        $input = new InputStream(function ($input) {
+            yield 'pong';
+            $input->close();
+        });
+
+        $process = new Process(self::$phpBin.' -r '.escapeshellarg('stream_copy_to_stream(STDIN, STDOUT);'));
+        $process->setInput($input);
+        $process->start();
+        $input->write('ping');
+        $process->wait();
+        $this->assertSame('pingpong', $process->getOutput());
+    }
+
     /**
      * @param string      $commandline
      * @param null|string $cwd
