Tags and Describe

composer.json

@@ -0,0 +1,20 @@
+{
+	"name": "frozen-doe.net/glip",
+	"description": "Fork of Git Library In PHP",
+	"license": "GPL-2.0+",
+	"authors": [
+		{
+			"name": "Patrik Fimml"
+		}, {
+			"name": "Josef Kufner",
+			"email": "jk@frozen-doe.net"
+		}
+	],
+	"require": {
+		"php": ">=5.1"
+	},
+	"autoload": {
+		"classmap": [ "lib/" ]
+	}
+}
+

doc/mainpage.doxygen

@@ -63,15 +63,65 @@ $master_name = $repo->getTip('master');
 $master = $repo->getObject($master_name);
 @endcode
 
-@todo It should be possible to look up any ref, not only branches.
-
 In a common git repository, this will give you a GitCommit instance in
 $master, referring to the last commit made to the @em master branch.
 
+You can also lookup tag or any ref:
+
+@code
+$tag_name = $repo->getTip('v1.0');
+$tag = $repo->getObject($tag_name);
+@endcode
+
+@code
+$origin_master_name = $repo->getTip('refs/remotes/origin/master');
+$origin_master = $repo->getObject($tag_name);
+@endcode
+
+When you get bored with branches and tags, try Git::getHead():
+
+@code
+$head_name = $repo->getHead();
+$last_commit = $repo->getObject($head_name);
+
+echo $repo->getHead(false);	// false means 'Do not resolve ref, give me human readable name instead.'
+@endcode
+
 GitObject%s hold all related data in public attributes. For example,
 GitCommit::$summary contains the commit summary of a particular commit.
 Utility functions are provided to make it easier to perform common functions.
 
+@subsection tags_refs Working with tags and refs
+
+Tags and refs can be listed using Git::getTags() and Git::getRefs():
+
+@code
+echo "<ul>\n";
+foreach ($repo->getTags() as $tag => $hash) {
+	echo "<li>", htmlspecialchars($tag), " &rarr; <code>", sha1_hex($hash), "</code></li>\n";
+}
+echo "</ul>\n";
+@endcode
+
+Usage of Git::getRefs is same, but it returns 'refs/tags/v1.0' instead of 'v1.0'.
+
+@subsection describe Git Describe
+
+There is partial reimplementation of handy 'git describe' command in Git::describe():
+
+@code
+$master_name = $repo->getTip('master');
+$master = $repo->getObject($master_name);	// This is optional, Git::describe() can do this for you.
+
+$describe = $repo->describe($master);		// You can use $master_name here also.
+echo htmlspecialchars($describe);
+@endcode
+
+@note Current implementation is way more stupid than original, but it should be
+enough for usual use.
+
+@attention Hash digits included in result string may not uniquely describe commit. There is no check for ambiguous abbrevations.
+
 @section writing Writing to a git repository
 
 To change things in a repository, you currently have to directly make changes

lib/git.class.php

@@ -1,6 +1,7 @@
 <?php
 /*
  * Copyright (C) 2008, 2009 Patrik Fimml
+ * Copyright (C) 2011 Josef Kufner  <jk@frozen-doe.net>
  *
  * This file is part of glip.
  *
@@ -18,13 +19,6 @@
  * along with glip.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-require_once('binary.class.php');
-require_once('git_object.class.php');
-require_once('git_blob.class.php');
-require_once('git_commit.class.php');
-require_once('git_commit_stamp.class.php');
-require_once('git_tree.class.php');
-
 /**
  * @relates Git
  * @brief Convert a SHA-1 hash from hexadecimal to binary representation.
@@ -90,7 +84,27 @@ static public function getTypeName($type)
     public function __construct($dir)
     {
         $this->dir = realpath($dir);
-        if ($this->dir === FALSE || !@is_dir($this->dir))
+        if ($this->dir === FALSE)
+            throw new Exception(sprintf('repository not found: %s', $dir));
+
+        if (is_file($this->dir)) {
+            $repo = file_get_contents($this->dir);
+            if (preg_match('/^gitdir: (.*)/', $repo, $m)) {
+                if ($m[1][0] == '.') {
+                    if (basename($this->dir) == '.git') {
+                        $this->dir = rtrim(dirname($this->dir), '/').'/'.$m[1];
+                    } else {
+                        $this->dir = rtrim($this->dir, '/').'/'.$m[1];
+                    }
+                } else {
+                    $this->dir = $m[1];
+                }
+            } else {
+                throw new Exception(sprintf('unknown repository format: %s', $this->dir));
+            }
+        }
+
+        if (!@is_dir($this->dir))
             throw new Exception(sprintf('not a directory: %s', $dir));
 
 	$this->packs = array();
@@ -403,36 +417,215 @@ public function getObject($name)
     }
 
     /**
-     * @brief Look up a branch.
+     * @brief Look up a branch or tag.
      *
-     * @param $branch (string) The branch to look up, defaulting to @em master.
+     * @param $branch (string) The branch or tag to look up, defaulting to @em master.
      * @returns (string) The tip of the branch (binary sha1).
      */
     public function getTip($branch='master')
     {
-	$subpath = sprintf('refs/heads/%s', $branch);
-	$path = sprintf('%s/%s', $this->dir, $subpath);
-	if (file_exists($path))
-	    return sha1_bin(file_get_contents($path));
-	$path = sprintf('%s/packed-refs', $this->dir);
-	if (file_exists($path))
-	{
-	    $head = NULL;
-	    $f = fopen($path, 'rb');
-	    flock($f, LOCK_SH);
-	    while ($head === NULL && ($line = fgets($f)) !== FALSE)
-	    {
-		if ($line{0} == '#')
-		    continue;
-		$parts = explode(' ', trim($line));
-		if (count($parts) == 2 && $parts[1] == $subpath)
-		    $head = sha1_bin($parts[0]);
-	    }
-	    fclose($f);
-	    if ($head !== NULL)
-		return $head;
-	}
-	throw new Exception(sprintf('no such branch: %s', $branch));
+        if (strchr($branch, '/') !== FALSE)
+        {
+            $subpath = array($branch);
+        }
+        else
+        {
+            $subpath = array(
+                    sprintf('refs/heads/%s', $branch),
+                    sprintf('refs/tags/%s', $branch)
+            );
+        }
+        foreach ($subpath as $sp)
+        {
+            $path = sprintf('%s/%s', $this->dir, $sp);
+            if (file_exists($path))
+                return sha1_bin(file_get_contents($path));
+        }
+        $path = sprintf('%s/packed-refs', $this->dir);
+        if (file_exists($path))
+        {
+            $head = NULL;
+            $f = fopen($path, 'rb');
+            flock($f, LOCK_SH);
+            while ($head === NULL && ($line = fgets($f)) !== FALSE)
+            {
+                if ($line{0} == '#')
+                    continue;
+                $parts = explode(' ', trim($line));
+                if (count($parts) == 2 && in_array($parts[1], $subpath))
+                    $head = sha1_bin($parts[0]);
+            }
+            fclose($f);
+            if ($head !== NULL)
+                return $head;
+        }
+        throw new Exception(sprintf('no such branch: %s', $branch));
+    }
+
+
+    /**
+     * @brief Get current head
+     *
+     * @param $resolve (bool) It true, returned value is binary sha1, otherwise readable string is returned.
+     * @returns (string) Current head as readable string or binary sha1 (depends on $resolve arg.). On error, FALSE is returned.
+     */
+    public function getHead($resolve = true)
+    {
+        $content = file_get_contents($this->dir.'/HEAD');
+
+        if ($content === FALSE)
+        {
+            return FALSE;
+        }
+        else if (sscanf($content, 'ref: %s', $head) == 1)
+        {
+            return $resolve ? $this->getTip($head) : $head;
+        }
+        else if (sscanf($content, '%[0-9a-fA-F]s', $hash) == 1)
+        {
+            return $resolve ? sha1_bin($hash) : $hash;
+        }
+        else
+        {
+            return FALSE;
+        }
+    }
+
+
+    /**
+     * @brief List all known refs
+     *
+     * @returns (array) List of all known refs (ref -> binary sha1).
+     */
+    public function getRefs()
+    {
+        $refs = array();
+
+        // refs in files
+        foreach (array('refs/heads', 'refs/tags') as $subpath)
+        {
+            $path = sprintf('%s/%s', $this->dir, $subpath);
+            foreach(scandir($path) as $f)
+            {
+                $file = $path.'/'.$f;
+                if ($f[0] != '.' && is_file($file)) {
+                    $refs[$subpath.'/'.$f] = sha1_bin(file_get_contents($file));
+                }
+            }
+        }
+
+        // packed refs
+        $path = sprintf('%s/packed-refs', $this->dir);
+        if (file_exists($path))
+        {
+            $head = NULL;
+            $f = fopen($path, 'rb');
+            flock($f, LOCK_SH);
+            while ($head === NULL && ($line = fgets($f)) !== FALSE)
+            {
+                if ($line{0} == '#')
+                    continue;
+                $parts = explode(' ', trim($line));
+                if (count($parts) == 2)
+                    $refs[$parts[1]] = sha1_bin($parts[0]);
+            }
+            fclose($f);
+            if ($head !== NULL)
+                return $head;
+        }
+
+        return $refs;
+    }
+
+
+    /**
+     * @brief List all tags
+     *
+     * @returns (array) List of all tags (tag name -> binary sha1).
+     */
+    public function getTags()
+    {
+        $tags = array();
+        foreach($this->getRefs() as $ref => $hash)
+        {
+            if (strncmp($ref, 'refs/tags/', 10) == 0)
+            {
+                $tags[substr($ref, 10)] = $hash;
+            }
+        }
+        return $tags;
+    }
+
+    /**
+     * @brief Implementation of 'git describe' (partial)
+     *
+     * @param $commit (GitCommit) Commit to describe or binary sha1 of commit.
+     * @param $abbrev (int) Hash digits count. Hash may not be uniqe, no checks done.
+     * @returns (string) 'git describe' string
+     */
+    public function describe($commit, $abbrev = 7)
+    {
+        if (is_string($commit))
+        {
+            $commit = $this->getObject($commit);
+        }
+
+        if ($commit->getType() == Git::OBJ_TAG)
+        {
+            return $commit->tag;
+        }
+
+        // Load tags and get their objects
+        $tags = array();
+        foreach($this->getTags() as $tag_name => $hash)
+        {
+            $t = $this->getObject($hash);
+            if ($t->getType() == Git::OBJ_TAG)
+            {
+                foreach($t->getObjects() as $obj)
+                {
+                    $tags[$obj] = $t->tag;
+                }
+            }
+        }
+
+        $queue = array(array($commit, 0));
+        $tag_name = false;
+        $tag_depth = false;
+
+        // DFS (simplified for DAG)
+        while (!empty($queue))
+        {
+            list($tag_object, $tag_depth) = array_shift($queue);
+            $commit_name = $tag_object->getName();
+            if (array_key_exists($commit_name, $tags))
+            {
+                // Tag found
+                $tag_name = $tags[$commit_name];
+                break;
+            }
+
+            // enqueue ancestors
+            foreach($tag_object->parents as $parent)
+            {
+                $parent_object = $this->getObject($parent);
+                array_push($queue, array($parent_object, $tag_depth + 1));
+            }
+        }
+
+        // Format result
+        if ($tag_name === false)
+        {
+            return substr(sha1_hex($commit->getName()), 0, $abbrev);
+        }
+        if ($tag_depth == 0)
+        {
+            return $tag_name;
+        }
+        else
+        {
+            return sprintf('%s-%d-g%s', $tag_name, $tag_depth, substr(sha1_hex($commit->getName()), 0, $abbrev));
+        }
     }
 }
 

lib/git_blob.class.php

@@ -18,8 +18,6 @@
  * along with glip.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-require_once('git_object.class.php');
-
 class GitBlob extends GitObject
 {
     /**

lib/git_commit.class.php

@@ -18,9 +18,6 @@
  * along with glip.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-require_once('git_object.class.php');
-require_once('git_commit_stamp.class.php');
-
 class GitCommit extends GitObject
 {
     /**