Unpacking of packed objects

public_html/libgit/base.php

@@ -29,6 +29,13 @@ function number_from_bin($bin)
         return $c[1];
 }
 
+define("OBJ_COMMIT", 1);
+define("OBJ_TREE", 2);
+define("OBJ_BLOB", 3);
+define("OBJ_TAG", 4);
+define("OBJ_OFS_DELTA", 6);
+define("OBJ_REF_DELTA", 7);
+
 class GitBranchNotFoundException extends Exception {}
 class GitTagNotFoundException extends Exception {}
 class GitInvalidOriginException extends Exception {}
@@ -36,7 +43,9 @@ class GitInvalidElementException extends Exception {}
 class GitInvalidFormatException extends Exception {}
 class GitUnsupportedVersionException extends Exception {}
 class GitPathNotFoundException extends Exception {}
+class GitObjectNotFoundException extends Exception {}
 class GitCorruptIndexException extends Exception {}
+class GitUnknownTypeException extends Exception {}
 
 require(dirname(__FILE__) . "/class.repository.php");
 require(dirname(__FILE__) . "/class.branch.php");

public_html/libgit/class.pack.php

@@ -2,15 +2,62 @@
 class GitPack
 {
 	public $repo = null;
-	public $index = array();
+	public $index = null;
+	public $pack_filename = "";
 	
 	function __construct($repo, $name)
 	{
 		$this->repo = $repo;
 		
 		$index_filename = "{$repo->path}/objects/pack/{$name}.idx";
-		$pack_filename = "{$repo->path}/objects/pack/{$name}.pack";
+		$this->pack_filename = "{$repo->path}/objects/pack/{$name}.pack";
 		
 		$this->index = new GitPackIndex(file_get_contents($index_filename));
 	}
+	
+	function UnpackObject($sha)
+	{
+		if(isset($this->index->index[$sha]))
+		{
+			$start = $this->index->index[$sha];
+			
+			$file = fopen($this->pack_filename, "rb");
+			fseek($file, $start);
+			
+			$header = ord(fread($file, 1));
+			$type = ($header >> 4) & 7;
+			$hasnext = ($header & 128) >> 7;
+			$size = $header & 0xf;
+			$offset = 4;
+			
+			while($hasnext)
+			{
+				$byte = ord(fread($file, 1));
+				$size |= ($byte & 0x7f) << $offset;
+				$hasnext = ($byte & 128) >> 7;
+				$offset += 7;
+			}
+			
+			switch($type)
+			{
+				case OBJ_COMMIT:
+				case OBJ_TREE:
+				case OBJ_BLOB:
+				case OBJ_TAG:
+					// this is a compressed object
+					$data = fread($file, $size);
+					break;
+				case OBJ_OFS_DELTA:
+				case OBJ_REF_DELTA:
+					// this is a delta
+					break;
+				default:
+					throw new GitUnknownTypeException("The object type is not supported.");
+			}
+		}
+		else
+		{
+			throw new GitObjectNotFoundException("The specified object does not exist in this pack.");
+		}
+	}
 }