4 files changed, 108 insertions, 0 deletions
diff --git a/modules/system/system.api.php b/modules/system/system.api.php
index c1f597855..1f4d1d394 100644
--- a/modules/system/system.api.php
+++ b/modules/system/system.api.php
@@ -2399,6 +2399,34 @@ function hook_action_info_alter(&$actions) {
 }
 
 /**
+ * Declare archivers to the system.
+ *
+ * An archiver is a class that is able to package and unpackage one or more files
+ * into a single possibly compressed file.  Common examples of such files are
+ * zip files and tar.gz files.  All archiver classes must implement
+ * ArchiverInterface.
+ *
+ * When mapping a
+ *
+ * Each entry should be keyed on a unique value, and specify three
+ * additional keys:
+ *   - class: The name of the PHP class for this archiver.
+ *   - extensions: An array of file extensions that this archiver supports.
+ *   - weight: This optional key specifies the weight of this archiver.
+ *     When mapping file extensions to archivers, the first archiver by
+ *     weight found that supports the requested extension will be used.
+ */
+function system_archiver_info() {
+  return array(
+    'tar' => array(
+      'class' => 'ArchiverTar',
+      'extensions' => array('tar', 'tar.gz', 'tar.bz2'),
+    ),
+  );
+}
+
+
+/**
  * Defines additional date types.
  *
  * Next to the 'long', 'medium' and 'short' date types defined in core, any
diff --git a/modules/system/system.archiver.inc b/modules/system/system.archiver.inc
new file mode 100644
index 000000000..65bf63e3a
--- /dev/null
+++ b/modules/system/system.archiver.inc
@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * @file
+ * Archiver implementations provided by the system module.
+ */
+
+/**
+ * Archiver for .tar files.
+ */
+class ArchiverTar implements ArchiverInterface {
+
+  /**
+   * The underlying Archive_Tar instance that does the heavy lifting.
+   *
+   * @var Archive_Tar
+   */
+  protected $tar;
+
+  public function __construct($file_path) {
+    $this->tar = new Archive_Tar($file_path);
+  }
+
+  public function add($file_path) {
+    $this->tar->add($file_path);
+
+    return $this;
+  }
+
+  public function remove($path) {
+    // @todo Archive_Tar doesn't have a remove operation
+    // so we'll have to simulate it somehow, probably by
+    // creating a new archive with everything but the removed
+    // file.
+
+    return $this;
+  }
+
+  public function extract($path, Array $files = array()) {
+    if ($files) {
+      $this->tar->extractList($files, $path);
+    }
+    else {
+      $this->tar->extract($path);
+    }
+
+    return $this;
+  }
+
+  public function listContents() {
+    return $this->tar->listContent();
+  }
+
+  /**
+   * Retrieve the tar engine itself.
+   *
+   * In some cases it may be necessary to directly access the underlying
+   * Archive_Tar object for implementation-specific logic. This is for advanced
+   * use only as it is not shared by other implementations of ArchiveInterface.
+   *
+   * @return
+   *   The Archive_Tar object used by this object.
+   */
+  public function getArchive() {
+    return $this->tar;
+  }
+}
diff --git a/modules/system/system.info b/modules/system/system.info
index fa9a77d59..2f288d9d7 100644
--- a/modules/system/system.info
+++ b/modules/system/system.info
@@ -6,6 +6,7 @@ version = VERSION
 core = 7.x
 files[] = system.module
 files[] = system.admin.inc
+files[] = system.archiver.inc
 files[] = system.queue.inc
 files[] = image.gd.inc
 files[] = system.install
diff --git a/modules/system/system.module b/modules/system/system.module
index 70c789f8b..e89eb625b 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -3380,6 +3380,18 @@ function system_date_format_delete($dfid) {
 }
 
 /**
+ * Implement hook_archiver_info().
+ */
+function system_archiver_info() {
+  return array(
+    'tar' => array(
+      'class' => 'ArchiverTar',
+      'extensions' => array('tar', 'tar.gz', 'tar.bz2'),
+    ),
+  );
+}
+
+/**
  * Theme confirmation forms.
  *
  * By default this does not alter the appearance of a form at all,