Merge pull request #33 from mathroc/feature/flock

Add flock support
michael-donat · Sep 13, 2014 · ccd513b · ccd513b
2 parents d5e33b4 + dfe6ec9
commit ccd513b
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diff --git a/src/VirtualFileSystem/Structure/File.php b/src/VirtualFileSystem/Structure/File.php
@@ -10,6 +10,8 @@
 
 namespace VirtualFileSystem\Structure;
 
+use SplObjectStorage;
+
 /**
  * Object representation of File.
  *
@@ -25,6 +27,27 @@ class File extends Node
 
     protected $data;
 
+    /**
+     * Resource with exclusive lock on this file
+     * @var resource|null
+     */
+    private $exclusiveLock = null;
+
+    /**
+     * Resources with a shared lock on this file
+     * @var SplObjectStorage
+     */
+    private $sharedLock;
+
+    /**
+     * @inherit
+     */
+    public function __construct($basename)
+    {
+        parent::__construct($basename);
+        $this->sharedLock = new SplObjectStorage;
+    }
+
     /**
      * Returns contents size.
      *
@@ -55,4 +78,40 @@ public function setData($data)
     {
         $this->data = $data;
     }
+
+    public function lock($resource, $operation)
+    {
+        if ($this->exclusiveLock === $resource) {
+            $this->exclusiveLock = null;
+        } else {
+            $this->sharedLock->detach($resource);
+        }
+
+        if ($operation & LOCK_NB) {
+            $operation -= LOCK_NB;
+        }
+
+        $unlock    = $operation === LOCK_UN;
+        $exclusive = $operation === LOCK_EX;
+
+        if ($unlock) {
+            return true;
+        }
+
+        if ($this->exclusiveLock !== null) {
+            return false;
+        }
+
+        if (!$exclusive) {
+            $this->sharedLock->attach($resource);
+            return true;
+        }
+
+        if ($this->sharedLock->count()) {
+            return false;
+        }
+
+        $this->exclusiveLock = $resource;
+        return true;
+    }
 }
diff --git a/src/VirtualFileSystem/Wrapper.php b/src/VirtualFileSystem/Wrapper.php
@@ -768,4 +768,9 @@ public function dir_rewinddir()
     {
         $this->currentlyOpenedDir->iterator()->rewind();
     }
+
+    public function stream_lock($operation)
+    {
+        return $this->currently_opened->lock($this, $operation);
+    }
 }
diff --git a/src/VirtualFileSystem/Wrapper/FileHandler.php b/src/VirtualFileSystem/Wrapper/FileHandler.php
@@ -189,4 +189,9 @@ public function isOpenedForReading()
     {
         return (bool) ($this->mode & self::READ_MODE);
     }
+
+    public function lock($resource, $operation)
+    {
+        return $this->file->lock($resource, $operation);
+    }
 }
diff --git a/tests/VirtualFileSystem/Wrapper/FileHandlerTest.php b/tests/VirtualFileSystem/Wrapper/FileHandlerTest.php
@@ -3,6 +3,7 @@
 namespace VirtualFileSystem\Wrapper;
 
 use VirtualFileSystem\Structure\File;
+use stdClass;
 
 class FileHandlerTest extends \PHPUnit_Framework_TestCase
 {

diff --git a/tests/VirtualFileSystem/WrapperTest.php b/tests/VirtualFileSystem/WrapperTest.php
@@ -1352,4 +1352,95 @@ public function testIsExecutableReturnsCorrectly()
 
         $this->assertTrue(is_executable($fs->path('/file')));
     }
+
+    public function testExclusiveLock()
+    {
+        $fs = new FileSystem();
+        $file = $fs->path($fs->createFile('/file')->path());
+
+        $fh1 = fopen($file, 'c');
+        $fh2 = fopen($file, 'c');
+
+        $this->assertTrue(flock($fh1, LOCK_EX|LOCK_NB));
+        $this->assertFalse(flock($fh2, LOCK_EX|LOCK_NB));
+    }
+
+    public function testSharedLock()
+    {
+        $fs = new FileSystem();
+        $file = $fs->path($fs->createFile('/file')->path());
+
+        $fh1 = fopen($file, 'c');
+        $fh2 = fopen($file, 'c');
+        $fh3 = fopen($file, 'c');
+
+        $this->assertTrue(flock($fh1, LOCK_SH|LOCK_NB));
+        $this->assertTrue(flock($fh2, LOCK_SH|LOCK_NB));
+        $this->assertFalse(flock($fh3, LOCK_EX|LOCK_NB));
+    }
+
+    public function testUnlockSharedLock()
+    {
+        $fs = new FileSystem();
+        $file = $fs->path($fs->createFile('/file')->path());
+
+        $fh1 = fopen($file, 'c');
+        $fh2 = fopen($file, 'c');
+
+        $this->assertTrue(flock($fh1, LOCK_SH|LOCK_NB));
+        $this->assertTrue(flock($fh1, LOCK_UN|LOCK_NB));
+        $this->assertTrue(flock($fh2, LOCK_EX|LOCK_NB));
+    }
+
+    public function testUnlockExclusiveLock()
+    {
+        $fs = new FileSystem();
+        $file = $fs->path($fs->createFile('/file')->path());
+
+        $fh1 = fopen($file, 'c');
+        $fh2 = fopen($file, 'c');
+
+        $this->assertTrue(flock($fh1, LOCK_EX|LOCK_NB));
+        $this->assertTrue(flock($fh1, LOCK_UN|LOCK_NB));
+        $this->assertTrue(flock($fh2, LOCK_EX|LOCK_NB));
+    }
+
+    public function testDowngradeExclusiveLock()
+    {
+        $fs = new FileSystem();
+        $file = $fs->path($fs->createFile('/file')->path());
+
+        $fh1 = fopen($file, 'c');
+        $fh2 = fopen($file, 'c');
+
+        $this->assertTrue(flock($fh1, LOCK_EX|LOCK_NB));
+        $this->assertTrue(flock($fh1, LOCK_SH|LOCK_NB));
+        $this->assertTrue(flock($fh2, LOCK_SH|LOCK_NB));
+    }
+
+    public function testUpgradeSharedLock()
+    {
+        $fs = new FileSystem();
+        $file = $fs->path($fs->createFile('/file')->path());
+
+        $fh1 = fopen($file, 'c');
+        $fh2 = fopen($file, 'c');
+
+        $this->assertTrue(flock($fh1, LOCK_SH|LOCK_NB));
+        $this->assertTrue(flock($fh1, LOCK_EX|LOCK_NB));
+        $this->assertFalse(flock($fh2, LOCK_SH|LOCK_NB));
+    }
+
+    public function testUpgradeSharedLockImpossible()
+    {
+        $fs = new FileSystem();
+        $file = $fs->path($fs->createFile('/file')->path());
+
+        $fh1 = fopen($file, 'c');
+        $fh2 = fopen($file, 'c');
+
+        $this->assertTrue(flock($fh1, LOCK_SH|LOCK_NB));
+        $this->assertTrue(flock($fh2, LOCK_SH|LOCK_NB));
+        $this->assertFalse(flock($fh1, LOCK_EX|LOCK_NB));
+    }
 }