Added a first version of the new SCM backend.

doc/syncsvn.mdtext

@@ -4,8 +4,6 @@ The SyncSvn plugin allow the direct creation and synchronisation of
 subversion repositories with the InDefero database. This requires
 giving access to the repositories using the DAV_SVN module of Apache2.
 
-You need at least Subversion 1.4.6.
-
 ## To Contact the Author
 
     Baptiste Michaud

src/IDF/Scm.php

@@ -22,10 +22,47 @@
 # ***** END LICENSE BLOCK ***** */
 
 /**
- * Manage differents SCM systems
+ * Manage differents SCM systems.
+ *
+ * This is the base class with the different required methods to be
+ * implemented by the SCMs. Each SCM backend need to extend this
+ * class. We are not using an interface because this is not really
+ * needed.
+ *
+ * The philosophy behind the interface is not to provide a wrapper
+ * around the different SCMs but to provide methods to retrieve in the
+ * most efficient way the informations to be displayed/needed in the
+ * web interface. This means that each SCM can use the best options,
+ * including caching to retrieve the informations.
+ *
+ * Note on caching: You must not cache ephemeral information like the
+ * changelog, but you can cache the commit info (except with
+ * subversion where you can change commit info...).
+ *
+ * All the output of the methods must be serializable. This means that
+ * if you are parsing XML you need to correctly cast the results as
+ * string when needed.
  */
 class IDF_Scm
 {
+    /**
+     * String template for consistent error messages.
+     */
+    public $error_tpl = 'Error command "%s" returns code %d and output: %s';
+
+    /**
+     * Path to the repository.
+     */
+    public $repo = '';
+
+    /**
+     * Cache storage. 
+     *
+     * It must only be used to store data for the lifetime of the
+     * object. For example if you need to get the list of branches in
+     * several functions, better to try to get from the cache first.
+     */
+    protected $cache = array();
 
     /**
      * Returns an instance of the correct scm backend object.
@@ -42,6 +79,134 @@ class IDF_Scm
         return call_user_func(array($scms[$scm], 'factory'), $project);
     }
 
+    /**
+     * Check if the backend is available for display.
+     *
+     * @return bool Available
+     */
+    public function isAvailable()
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Returns the list of branches.
+     *
+     * @return array For example array('trunk', '1.0branch')
+     */
+    public function getBranches()
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Returns the list of tags.
+     *
+     * @return array For example array('v0.9', 'v1.0')
+     */
+    public function getTags()
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Returns the main branch.
+     *
+     * The main branch is the one displayed by default. For example
+     * master, trunk or tip.
+     *
+     * @return string
+     */
+    public function getMainBranch()
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Returns the list of files in a given folder.
+     *
+     * The list is an array of standard class objects with attributes
+     * for each file/directory/external element.
+     *
+     * This is the most important method of the SCM backend as this is
+     * the one conveying the speed feeling of the application. All the
+     * dirty optimization tricks are allowed there.
+     *
+     * @param string Revision or commit
+     * @param string Folder ('/')
+     * @param string Branch (null)
+     * @return array 
+     */
+    public function getTree($rev, $folder='/', $branch=null)
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Get commit details.
+     *
+     * @param string Commit or revision number
+     * @param bool Get commit diff (false)
+     * @return stdClass
+     */
+    public function getCommit($commit, $getdiff=false)
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Get latest changes.
+     *
+     * It default to the main branch. If possible you should code in a
+     * way to avoid repetitive calls to getCommit. Try to be
+     * efficient.
+     *
+     * @param string Branch (null)
+     * @param int Number of changes (25)
+     * @return array List of commits
+     */
+    public function getChangeLog($branch=null, $n=10)
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Given the string describing the author from the log find the
+     * author in the database.
+     *
+     * If the input is an array, it will return an array of results.
+     *
+     * @param mixed string/array Author
+     * @return mixed Pluf_User or null or array
+     */
+    public function findAuthor($author)
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+    /**
+     * Given a revision and a file path, retrieve the file content.
+     *
+     * The third parameter is to only request the command that is used
+     * to get the file content. This is used when downloading a file
+     * at a given revision as it can be passed to a
+     * Pluf_HTTP_Response_CommandPassThru reponse. This allows to
+     * stream a large response without buffering it in memory.
+     *
+     * The file definition can be a hash or a path depending on the
+     * SCM.
+     *
+     * @param string File definition
+     * @param string Revision ('')
+     * @param bool Returns command only (false)
+     * @return string File content
+     */
+    public function getFile($def, $rev='', $cmd_only=false)
+    {
+        throw new Pluf_Exception_NotImplemented();
+    }
+
+
     /**
      * Equivalent to exec but with caching.
      *

src/IDF/Scm/Git.php

@@ -25,16 +25,120 @@
  * Git utils.
  *
  */
-class IDF_Scm_Git
+class IDF_Scm_Git extends IDF_Scm
 {
-    public $repo = '';
     public $mediumtree_fmt = 'commit %H%nAuthor: %an <%ae>%nTree: %T%nDate: %ai%n%n%s%n%n%b';
     
+
     public function __construct($repo)
     {
         $this->repo = $repo;
     }
 
+    /* ============================================== *
+     *                                                *
+     *   Common Methods Implemented By All The SCMs   *
+     *                                                *
+     * ============================================== */ 
+
+    public function isAvailable()
+    {
+        try {
+            $this->getBranches();
+        } catch (IDF_Scm_Exception $e) {
+            return false;
+        }
+        return true;
+    }
+
+    public function getBranches()
+    {
+        if (isset($this->cache['branches'])) {
+            return $this->cache['branches'];
+        }
+        $cmd = Pluf::f('idf_exec_cmd_prefix', '')
+            .sprintf('GIT_DIR=%s '.Pluf::f('git_path', 'git').' branch', 
+                     escapeshellarg($this->repo));
+        exec($cmd, $out, $return);
+        if ($return != 0) {
+            throw new IDF_Scm_Exception(sprintf($this->error_tpl,
+                                                $cmd, $return, 
+                                                implode("\n", $out)));
+        }
+        $res = array();
+        foreach ($out as $b) {
+            $res[] = substr($b, 2);
+        }
+        $this->cache['branches'] = $res;
+        return $res;
+    }
+
+    public function getMainBranch()
+    {
+        return 'master';
+    }
+
+    /**
+     * Git "tree" is not the same as the tree we get here.
+     *
+     * With git each commit object stores a related tree object. This
+     * tree is basically providing what is in the given folder at the
+     * given commit. It looks something like that:
+     *
+     * <pre>
+     * 100644 blob bcd155e609c51b4651aab9838b270cce964670af	AUTHORS
+     * 100644 blob 87b44c5c7df3cc90c031317c1ac8efcfd8a13631	COPYING
+     * 100644 blob 2a0f899cbfe33ea755c343b06a13d7de6c22799f	INSTALL.mdtext
+     * 040000 tree 2f469c4c5318aa4ad48756874373370f6112f77b	doc
+     * 040000 tree 911e0bd2706f0069b04744d6ef41353faf06a0a7	logo
+     * </pre>
+     *
+     * You can then follow what is in the given folder (let say doc)
+     * by using the hash.
+     *
+     * This means that you will have not to confuse the git tree and
+     * the output tree in the following method.
+     *
+     * @see http://www.kernel.org/pub/software/scm/git/docs/git-ls-tree.html
+     *
+     */
+    public function getTree($commit, $folder='/', $branch=null)
+    {
+        $folder = ($folder == '/') ? '' : $folder;
+        // now we grab the info about this commit including its tree.
+        $co = $this->getCommit($commit);
+        if ($folder) {
+            // As we are limiting to a given folder, we need to find
+            // the tree corresponding to this folder.
+            $tinfo = $this->getTreeInfo($commit, $folder); 
+            if (isset($tinfo[0]) and $tinfo[0]->type == 'tree') {
+                $tree = $tinfo[0]->hash;
+            } else {
+                throw new Exception(sprintf(__('Folder %1$s not found in commit %2$s.'), $folder, $commit));
+            }
+        } else {
+            $tree = $co->tree;
+        }
+        $res = array();
+        foreach ($this->getTreeInfo($tree) as $file) {
+            // Now we grab the files in the current tree with as much
+            // information as possible.
+            if ($file->type == 'blob') {
+                $file->date = $co->date;
+                $file->log = '----'; 
+                $file->author = 'Unknown';
+            }
+            $file->fullpath = ($folder) ? $folder.'/'.$file->file : $file->file;
+            if ($file->type == 'commit') {
+                // We have a submodule
+                $file = $this->getSubmodule($file, $commit);
+            }
+            $res[] = $file;
+        }
+        // Grab the details for each blob and return the list.
+        return $this->getTreeDetails($res);
+    }
+
     /**
      * Given the string describing the author from the log find the
      * author in the database.
@@ -120,58 +224,6 @@ class IDF_Scm_Git
      */
     public function filesAtCommit($commit='HEAD', $folder='')
     {
-        // now we grab the info about this commit including its tree.
-        $co = $this->getCommit($commit);
-        if ($folder) {
-            // As we are limiting to a given folder, we need to find
-            // the tree corresponding to this folder.
-            $found = false;
-            foreach ($this->getTreeInfo($co->tree, true, $folder) as $file) {
-                if ($file->type == 'tree' and $file->file == $folder) {
-                    $found = true;
-                    $tree = $file->hash;
-                    break;
-                }
-            }
-            if (!$found) {
-                throw new Exception(sprintf(__('Folder %1$s not found in commit %2$s.'), $folder, $commit));
-            }
-        } else {
-            $tree = $co->tree;
-        }
-        $res = array();
-        // get the raw log corresponding to this commit to find the
-        // origin of each file.
-        $rawlog = array();
-        $cmd = sprintf('GIT_DIR=%s '.Pluf::f('git_path', 'git').' log --raw --abbrev=40 --pretty=oneline -5000 %s',
-                       escapeshellarg($this->repo), escapeshellarg($commit));
-        IDF_Scm::exec($cmd, $rawlog);
-        // We reverse the log to be able to use a fixed efficient
-        // regex without back tracking.
-        $rawlog = implode("\n", array_reverse($rawlog));
-        foreach ($this->getTreeInfo($tree, false) as $file) {
-            // Now we grab the files in the current tree with as much
-            // information as possible.
-            $matches = array();
-            if ($file->type == 'blob' and preg_match('/^\:\d{6} \d{6} [0-9a-f]{40} '.$file->hash.' .*^([0-9a-f]{40})/msU',
-                           $rawlog, $matches)) {
-                $fc = $this->getCommit($matches[1]);
-                $file->date = $fc->date;
-                $file->log = $fc->title;
-                $file->author = $fc->author;
-            } else if ($file->type == 'blob') {
-                $file->date = $co->date;
-                $file->log = '----'; 
-                $file->author = 'Unknown';
-            }
-            $file->fullpath = ($folder) ? $folder.'/'.$file->file : $file->file;
-            if ($file->type == 'commit') {
-                // We have a submodule
-                $file = $this->getSubmodule($file, $commit);
-            }
-            $res[] = $file;
-        }
-        return $res;
     }
 
     /**
@@ -179,21 +231,21 @@ class IDF_Scm_Git
      *
      * @param string Tree hash 
      * @param bool Do we recurse in subtrees (true)
+     * @param string Folder in which we want to get the info ('')
      * @return array Array of file information.
      */
-    public function getTreeInfo($tree, $recurse=true, $folder='')
+    public function getTreeInfo($tree, $folder='')
     {
-        if ('tree' != $this->testHash($tree)) {
+        if (!in_array($this->testHash($tree), array('tree', 'commit'))) {
             throw new Exception(sprintf(__('Not a valid tree: %s.'), $tree));
         }
-        $cmd_tmpl = 'GIT_DIR=%s '.Pluf::f('git_path', 'git').' ls-tree%s -t -l %s %s';
+        $cmd_tmpl = 'GIT_DIR=%s '.Pluf::f('git_path', 'git').' ls-tree -l %s %s';
-        $cmd = sprintf($cmd_tmpl, 
+        $cmd = Pluf::f('idf_exec_cmd_prefix', '')
-                       escapeshellarg($this->repo), 
+            .sprintf($cmd_tmpl, escapeshellarg($this->repo), 
-                       ($recurse) ? ' -r' : '',
                      escapeshellarg($tree), escapeshellarg($folder));
         $out = array();
         $res = array();
-        IDF_Scm::exec($cmd, $out);
+        exec($cmd, $out);
         foreach ($out as $line) {
             list($perm, $type, $hash, $size, $file) = preg_split('/ |\t/', $line, 5, PREG_SPLIT_NO_EMPTY);
             $res[] = (object) array('perm' => $perm, 'type' => $type, 
@@ -245,31 +297,15 @@ class IDF_Scm_Git
                                   escapeshellarg($request_file_info->hash)));
     }
 
-    /**
-     * Get the branches.
-     *
-     * @return array Branches.
-     */
-    public function getBranches()
-    {
-        $out = array();
-        IDF_Scm::exec(sprintf('GIT_DIR=%s '.Pluf::f('git_path', 'git').' branch', 
-                              escapeshellarg($this->repo)), $out);
-        $res = array();
-        foreach ($out as $b) {
-            $res[] = substr($b, 2);
-        }
-        return $res;
-    }
 
     /**
      * Get commit details.
      *
-     * @param string Commit ('HEAD').
+     * @param string Commit
-     * @param bool Get commit diff (false).
+     * @param bool Get commit diff (false)
-     * @return array Changes.
+     * @return array Changes
      */
-    public function getCommit($commit='HEAD', $getdiff=false)
+    public function getCommit($commit, $getdiff=false)
     {
         if ($getdiff) {
             $cmd = sprintf('GIT_DIR=%s '.Pluf::f('git_path', 'git').' show --date=iso --pretty=format:%s %s',
@@ -283,7 +319,7 @@ class IDF_Scm_Git
                            escapeshellarg($commit));
         }
         $out = array();
-        IDF_Scm::exec($cmd, $out);
+        exec($cmd, $out);
         $log = array();
         $change = array();
         $inchange = false;
@@ -440,6 +476,7 @@ class IDF_Scm_Git
     public function getSubmodule($file, $commit)
     {
         $file->type = 'extern';
+        $file->extern = '';
         $info = $this->getFileInfo('.gitmodules', $commit);
         if ($info == false) {
             return $file;
@@ -451,4 +488,200 @@ class IDF_Scm_Git
         return $file;
     }
 
+    /**
+     * Foreach file in the tree, find the details.
+     *
+     * @param array Tree information
+     * @return array Updated tree information
+     */
+    public function getTreeDetails($tree)
+    {
+        $n = count($tree);
+        $details = array();
+        for ($i=0;$i<$n;$i++) {
+            if ($tree[$i]->type == 'blob') {
+                $details[$tree[$i]->hash] = $i;
+            }
+        }
+        if (!count($details)) {
+            return $tree;
+        }
+        $res = $this->getCachedBlobInfo($details);
+        $toapp = array();
+        foreach ($details as $blob => $idx) {
+            if (isset($res[$blob])) {
+                $tree[$idx]->date = $res[$blob]->date;
+                $tree[$idx]->log = $res[$blob]->title;
+                $tree[$idx]->author = $res[$blob]->author;
+            } else {
+                $toapp[$blob] = $idx;
+            }
+        }
+        if (count($toapp)) {
+            $res = $this->appendBlobInfoCache($toapp);
+            foreach ($details as $blob => $idx) {
+                if (isset($res[$blob])) {
+                    $tree[$idx]->date = $res[$blob]->date;
+                    $tree[$idx]->log = $res[$blob]->title;
+                    $tree[$idx]->author = $res[$blob]->author;
+                }
+            }
+        }
+        return $tree;
+    }
+
+    /**
+     * Append build info cache.
+     *
+     * The append method tries to get only the necessary details, so
+     * instead of going through all the commits one at a time, it will
+     * try to find a smarter way with regex.
+     *
+     * @see self::buildBlobInfoCache
+     *
+     * @param array The blob for which we need the information
+     * @return array The information
+     */
+    public function appendBlobInfoCache($blobs)
+    {
+        $rawlog = array();
+        $cmd = Pluf::f('idf_exec_cmd_prefix', '')
+            .sprintf('GIT_DIR=%s '.Pluf::f('git_path', 'git').' log --raw --abbrev=40 --pretty=oneline -5000 --skip=%%s',
+                     escapeshellarg($this->repo));
+        $skip = 0;
+        $res = array();
+        exec(sprintf($cmd, $skip), $rawlog);
+        while (count($rawlog) and count($blobs)) {
+            $rawlog = implode("\n", array_reverse($rawlog));
+            foreach ($blobs as $blob => $idx) {
+                if (preg_match('/^\:\d{6} \d{6} [0-9a-f]{40} '
+                               .$blob.' .*^([0-9a-f]{40})/msU',
+                               $rawlog, $matches)) {
+                    $fc = $this->getCommit($matches[1]);
+                    $res[$blob] = (object) array('hash' => $blob,
+                                                 'date' => $fc->date,
+                                                 'title' => $fc->title,
+                                                 'author' => $fc->author);
+                    unset($blobs[$blob]);
+                }
+            }
+            $rawlog = array();
+            $skip += 5000;
+            if ($skip > 20000) {
+                // We are in the case of the import of a big old
+                // repository, we can store as unknown the commit info
+                // not to try to retrieve them each time.
+                foreach ($blobs as $blob => $idx) {
+                    $res[$blob] = (object) array('hash' => $blob,
+                                                 'date' => '0',
+                                                 'title' => '----',
+                                                 'author' => 'Unknown');
+                }
+                break;
+            }
+            exec(sprintf($cmd, $skip), $rawlog);
+        }
+        $this->cacheBlobInfo($res);
+        return $res;
+    }
+
+    /**
+     * Build the blob info cache.
+     *
+     * We build the blob info cache 500 commits at a time. 
+     */
+    public function buildBlobInfoCache()
+    {
+        $rawlog = array();
+        $cmd = Pluf::f('idf_exec_cmd_prefix', '')
+            .sprintf('GIT_DIR=%s '.Pluf::f('git_path', 'git').' log --raw --abbrev=40 --pretty=oneline -500 --skip=%%s',
+                     escapeshellarg($this->repo));
+        $skip = 0;
+        exec(sprintf($cmd, $skip), $rawlog);
+        while (count($rawlog)) {
+            $commit = '';
+            $data = array();
+            foreach ($rawlog as $line) {
+                if (substr($line, 0, 1) != ':') {
+                    $commit = $this->getCommit(substr($line, 0, 40));
+                    continue;
+                }
+                $blob = substr($line, 56, 40);
+                $data[] = (object) array('hash' => $blob,
+                                         'date' => $commit->date,
+                                         'title' => $commit->title,
+                                         'author' => $commit->author);
+            }
+            $this->cacheBlobInfo($data);
+            $rawlog = array();
+            $skip += 500;
+            exec(sprintf($cmd, $skip), $rawlog);
+        }
+    }
+
+    /**
+     * Get blob info.
+     *
+     * When we display the tree, we want to know when a given file was
+     * created, who was the author and at which date. This is a very
+     * slow operation for git as we need to go through the full
+     * history, find when then blob was introduced, then grab the
+     * corresponding commit. This is why we need a cache.
+     *
+     * @param array List as keys of blob hashs to get info for
+     * @return array Hash indexed results, when not found not set
+     */
+    public function getCachedBlobInfo($hashes)
+    {
+        $res = array();
+        $cache = Pluf::f('tmp_folder').'/IDF_Scm_Git-'.md5($this->repo).'.cache.db';
+        if (!file_exists($cache)) {
+            return $res;
+        }
+        $data = file_get_contents($cache);
+        if (false === $data) {
+            return $res;
+        }
+        $data = split(chr(30), $data);
+        foreach ($data as $rec) {
+            if (isset($hashes[substr($rec, 0, 40)])) {
+                //$tmp = split(chr(31), gzinflate(substr($rec, 40)), 3);
+                $tmp = split(chr(31), substr($rec, 40), 3);
+                $res[substr($rec, 0, 40)] = 
+                    (object) array('hash' => substr($rec, 0, 40),
+                                   'date' => $tmp[0],
+                                   'title' => $tmp[2],
+                                   'author' => $tmp[1]);
+            }
+        }
+        return $res;
+    }
+
+    /**
+     * Cache blob info.
+     * 
+     * Given a series of blob info, cache them.
+     *
+     * @param array Blob info
+     * @return bool Success
+     */
+    public function cacheBlobInfo($info)
+    {
+        // Prepare the data
+        $data = array();
+        foreach ($info as $file) {
+            //$data[] = $file->hash.gzdeflate($file->date.chr(31).$file->author.chr(31).$file->title, 9);
+            $data[] = $file->hash.$file->date.chr(31).$file->author.chr(31).$file->title;
+        }
+        $data = implode(chr(30), $data).chr(30);
+        $cache = Pluf::f('tmp_folder').'/IDF_Scm_Git-'.md5($this->repo).'.cache.db';
+        $fp = fopen($cache, 'ab'); 
+        if ($fp) {
+            flock($fp, LOCK_EX); 
+            fwrite($fp, $data, strlen($data));
+            fclose($fp); // releases the lock too
+            return true;
+        }
+        return false;
+    }
 }

src/IDF/Tests/TestGit.php

@@ -39,4 +39,13 @@ class IDF_Tests_TestGit extends UnitTestCase
         $this->assertEqual('Fixed the middleware to correctly return a 404 error if the project is', $log[0]->title);
 
     }
+
+    public function testGitCache()
+    {
+        $repo = substr(dirname(__FILE__), 0, -strlen('src/IDF/Tests')).'/.git';
+        $repo = '/home/loa/Vendors/linux-git/.git';
+        $git = new IDF_Scm_Git($repo);
+        $git->buildBlobInfoCache();
+        //$git->getCachedBlobInfo(array());
+    }
 }

src/IDF/Views/Source.php

@@ -102,32 +102,31 @@ class IDF_Views_Source
     public $treeBase_precond = array('IDF_Precondition::accessSource');
     public function treeBase($request, $match)
     {
-        $title = sprintf(__('%1$s %2$s Source Tree'), (string) $request->project,
+        $title = sprintf(__('%1$s %2$s Source Tree'),
-                         $this->getScmType($request));
+                         $request->project, $this->getScmType($request));
         $scm = IDF_Scm::get($request->project);
-        $commit = $match[2];
+        if (!$scm->isAvailable()) {
-        $branches = $scm->getBranches();
-        if (count($branches) == 0) {
-            // Redirect to the project home
             $url = Pluf_HTTP_URL_urlForView('IDF_Views_Source::help',
                                             array($request->project->shortname));
             return new Pluf_HTTP_Response_Redirect($url);
         }
-        if ('commit' != $scm->testHash($commit)) {
+        $commit = $match[2];
-            // Redirect to the first branch
+        $cobject = $scm->getCommit($commit);
+        if (!$cobject) {
             $url = Pluf_HTTP_URL_urlForView('IDF_Views_Source::treeBase',
                                             array($request->project->shortname,
-                                                  $branches[0]));
+                                                  $scm->getMainBranch()));
             return new Pluf_HTTP_Response_Redirect($url);
         }
+        $branches = $scm->getBranches();
         $cache = Pluf_Cache::factory();
         $key = sprintf('Project:%s::IDF_Views_Source::treeBase:%s::',
                        $request->project->id, $commit);
         if (null === ($res=$cache->get($key))) {
-            $res = new Pluf_Template_ContextVars($scm->filesAtCommit($commit));
+            $res = new Pluf_Template_ContextVars($scm->getTree($commit));
             $cache->set($key, $res);
         }
-        $cobject = $scm->getCommit($commit);
+
         $tree_in = in_array($commit, $branches);
         $scmConf = $request->conf->getVal('scm', 'git');
         $props = null;
@@ -151,15 +150,22 @@ class IDF_Views_Source
     public $tree_precond = array('IDF_Precondition::accessSource');
     public function tree($request, $match)
     {
-        $title = sprintf(__('%1$s %2$s Source Tree'), (string) $request->project,
+        $title = sprintf(__('%1$s %2$s Source Tree'), 
-                         $this->getScmType($request));
+                         $request->project, $this->getScmType($request));
         $scm = IDF_Scm::get($request->project);
+        if (!$scm->isAvailable()) {
+            $url = Pluf_HTTP_URL_urlForView('IDF_Views_Source::help',
+                                            array($request->project->shortname));
+
+            return new Pluf_HTTP_Response_Redirect($url);
+        }
+
         $branches = $scm->getBranches();
         $commit = $match[2];
         $request_file = $match[3];
         $fburl = Pluf_HTTP_URL_urlForView('IDF_Views_Source::treeBase',
                                           array($request->project->shortname,
-                                                $branches[0]));
+                                                $scm->getMainBranch()));
         if (substr($request_file, -1) == '/') {
             $request_file = substr($request_file, 0, -1);
             $url = Pluf_HTTP_URL_urlForView('IDF_Views_Source::tree',
@@ -167,19 +173,23 @@ class IDF_Views_Source
                                                   $request_file));
             return new Pluf_HTTP_Response_Redirect($url, 301);
         }
+
         if ('commit' != $scm->testHash($commit, $request_file)) {
             // Redirect to the first branch
             return new Pluf_HTTP_Response_Redirect($fburl);
         }
+
         $request_file_info = $scm->getFileInfo($request_file, $commit);
         if (!$request_file_info) {
             // Redirect to the first branch
             return new Pluf_HTTP_Response_Redirect($fburl);
         }
+
         if ($request_file_info->type != 'tree') {
             $info = self::getRequestedFileMimeType($request_file_info, 
                                                    $commit, $scm);
             if (!self::isText($info)) {
+
                 $rep = new Pluf_HTTP_Response($scm->getBlob($request_file_info, $commit),
                                               $info[0]);
                 $rep->headers['Content-Disposition'] = 'attachment; filename="'.$info[1].'"';
@@ -195,7 +205,9 @@ class IDF_Views_Source
                 return $this->viewFile($request, $match, $extra);
             }
         }
+
         $bc = self::makeBreadCrumb($request->project, $commit, $request_file_info->file);
+
         $page_title = $bc.' - '.$title;
         $cobject = $scm->getCommit($commit);
         $tree_in = in_array($commit, $branches);
@@ -204,11 +216,13 @@ class IDF_Views_Source
             $key = sprintf('Project:%s::IDF_Views_Source::tree:%s::%s',
                            $request->project->id, $commit, $request_file);
             if (null === ($res=$cache->get($key))) {
-                $res = new Pluf_Template_ContextVars($scm->filesAtCommit($commit, $request_file));
+                $res = new Pluf_Template_ContextVars($scm->getTree($commit, $request_file));
                 $cache->set($key, $res);
             }
+
         } catch (Exception $e) {
-            return new Pluf_HTTP_Response_Redirect($fburl);
+            throw $e;
+            //            return new Pluf_HTTP_Response_Redirect($fburl);
         }
         // try to find the previous level if it exists.
         $prev = split('/', $request_file);