Rework the way IDF's SCM interface provides downloadable snapshots.

Instead of returning a command which gets executed and which should
pass through / stream its output data to the client, we're just
returning an instance of Pluf_HTTP_Response. This is needed, because
some SCMs, most noticable monotone, have no locally executable command
to provide a snapshot archive (and probably never will for our kind
of setup).

We therefor added a little BSD-licensed class "ZipArchive" which allows
the creation of pkzip-compatible archives on the fly by letting it eat
the file contents directly feed from the (remote) stdio instance.
Download performance is ok and lies between 15K/s and 110K/s, but at
least we do no longer block the browser while we pre-generate the zip
file server-side.

Thanks to Patrick Georgi for all his work!

src/IDF/Scm.php

@@ -393,13 +393,13 @@ class IDF_Scm
     }
 
     /**
-     * Generate the command to create a zip archive at a given commit.
+     * Generate a zip archive at a given commit, wrapped in a HTTP response, suitable for pushing to client.
      *
      * @param string Commit
      * @param string Prefix ('repository/')
-     * @return string Command
+     * @return Pluf_HTTP_Response The HTTP Response containing the zip archive
      */
-    public function getArchiveCommand($commit, $prefix='repository/')
+    public function getArchiveStream($commit, $prefix='repository/')
     {
         throw new Pluf_Exception_NotImplemented();
     }

src/IDF/Scm/Git.php

@@ -547,13 +547,14 @@ class IDF_Scm_Git extends IDF_Scm
         return $res;
     }
 
-    public function getArchiveCommand($commit, $prefix='repository/')
+    public function getArchiveStream($commit, $prefix='repository/')
     {
-        return sprintf(Pluf::f('idf_exec_cmd_prefix', '').
+        $cmd = sprintf(Pluf::f('idf_exec_cmd_prefix', '').
                        'GIT_DIR=%s '.Pluf::f('git_path', 'git').' archive --format=zip --prefix=%s %s',
                        escapeshellarg($this->repo),
                        escapeshellarg($prefix),
                        escapeshellarg($commit));
+        return new Pluf_HTTP_Response_CommandPassThru($cmd, 'application/x-zip');
     }
 
     /*
@@ -806,4 +807,4 @@ class IDF_Scm_Git extends IDF_Scm
         }
         return false;
     }
-}
+}

src/IDF/Scm/Mercurial.php

@@ -449,17 +449,18 @@ class IDF_Scm_Mercurial extends IDF_Scm
     }
 
     /**
-     * Generate the command to create a zip archive at a given commit.
+     * Generate a zip archive at a given commit.
      *
      * @param string Commit
      * @param string Prefix ('git-repo-dump')
-     * @return string Command
+     * @return Pluf_HTTP_Response The HTTP response containing the zip archive
      */
-    public function getArchiveCommand($commit, $prefix='')
+    protected function getArchiveStream($commit, $prefix='')
     {
-        return sprintf(Pluf::f('idf_exec_cmd_prefix', '').
+        $cmd = sprintf(Pluf::f('idf_exec_cmd_prefix', '').
                        Pluf::f('hg_path', 'hg').' archive --type=zip -R %s -r %s -',
                        escapeshellarg($this->repo),
                        escapeshellarg($commit));
+        return new Pluf_HTTP_Response_CommandPassThru($cmd, 'application/x-zip');
     }
 }

src/IDF/Scm/Monotone.php

@@ -21,8 +21,8 @@
 #
 # ***** END LICENSE BLOCK ***** */
 
-require_once(dirname(__FILE__) . "/Monotone/Stdio.php");
-require_once(dirname(__FILE__) . "/Monotone/BasicIO.php");
+//require_once(dirname(__FILE__) . "/Monotone/Stdio.php");
+//require_once(dirname(__FILE__) . "/Monotone/BasicIO.php");
 
 /**
  * Monotone scm class
@@ -135,6 +135,20 @@ class IDF_Scm_Monotone extends IDF_Scm
         return $branch;
     }
 
+    /**
+     * @see IDF_Scm::getArchiveStream
+     */
+    public function getArchiveStream($commit, $prefix='repository/')
+    {
+        $revs = $this->_resolveSelector($commit);
+        // sanity: this should actually not happen, because the 
+        // revision is validated before already
+        if (count($revs) == 0) {
+            return new Pluf_HTTP_Response_NotFound();
+        }
+        return new IDF_Scm_Monotone_ZipRender($this->stdio, $revs[0]); 
+    }
+
     /**
      * expands a selector or a partial revision id to zero, one or
      * multiple 40 byte revision ids

src/IDF/Scm/Monotone/ZipRender.php

@@ -0,0 +1,78 @@
+<?php
+/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+# ***** BEGIN LICENSE BLOCK *****
+# This file is part of InDefero, an open source project management application.
+# Copyright (C) 2010 Céondo Ltd and contributors.
+#
+# Plume Framework is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 2.1 of the License, or
+# (at your option) any later version.
+#
+# Plume Framework is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+# ***** END LICENSE BLOCK ***** */
+
+require_once(IDF_PATH.'/../contrib/zipstream-php-0.2.2/zipstream.php');
+
+/**
+ * Special response object to output 
+ *
+ * The Content-Length will not be set as it is not possible to predict it.
+ *
+ * Note: The ZipArchive version 0.2.2 has been patched in-tree with this
+ *       patch http://pastebin.ca/1977584 to avoid a couple of PHP notices
+ *
+ */
+class IDF_Scm_Monotone_ZipRender extends Pluf_HTTP_Response
+{
+    /**
+     * The revision argument must be a safe string!
+     *
+     * @param Object stdio context
+     * @param string revision
+     * @param string Mimetype (null)
+     */
+
+    private $stdio = null;
+    private $revision = null;
+
+    function __construct($stdio, $revision)
+    {
+        parent::__construct($revision, 'application/x-zip');
+        $this->stdio = $stdio;
+        $this->revision = $revision;
+    }
+
+    /**
+     * Render a response object.
+     */
+    function render($output_body=true)
+    {
+        $this->outputHeaders();
+
+        if ($output_body) {
+            $manifest = $this->stdio->exec(array('get_manifest_of', $this->revision));
+            $stanzas = IDF_Scm_Monotone_BasicIO::parse($manifest);
+
+            $zip = new ZipStream();
+
+            foreach ($stanzas as $stanza) {
+                if ($stanza[0]['key'] != 'file')
+                    continue;
+                $content = $this->stdio->exec(array('get_file', $stanza[1]['hash']));
+                $zip->add_file($stanza[0]['values'][0], $content);
+            }
+
+            $zip->finish();
+        }
+    }
+}

src/IDF/Views/Source.php

@@ -434,8 +434,7 @@ class IDF_Views_Source
         $commit = trim($match[2]);
         $scm = IDF_Scm::get($request->project);
         $base = $request->project->shortname.'-'.$commit;
-        $cmd = $scm->getArchiveCommand($commit, $base.'/');
-        $rep = new Pluf_HTTP_Response_CommandPassThru($cmd, 'application/x-zip');
+        $rep = $scm->getArchiveStream($commit, $base.'/');
         $rep->headers['Content-Transfer-Encoding'] = 'binary';
         $rep->headers['Content-Disposition'] = 'attachment; filename="'.$base.'.zip"';
         return $rep;

src/IDF/templates/idf/source/mtn/tree.html

@@ -48,7 +48,7 @@
 </table>
 {aurl 'url', 'IDF_Views_Source::download', array($project.shortname, $commit)}
 <p class="right soft">
-{* <a href="{$url}"><img style="vertical-align: text-bottom;" src="{media '/idf/img/package-grey.png'}" alt="{trans 'Archive'}" align="bottom" /></a> <a href="{$url}">{trans 'Download this version'}</a> {trans 'or'} *}
+<a href="{$url}"><img style="vertical-align: text-bottom;" src="{media '/idf/img/package-grey.png'}" alt="{trans 'Archive'}" align="bottom" /></a> <a href="{$url}">{trans 'Download this version'}</a> {trans 'or'}
 <kbd>mtn clone {$project.getSourceAccessUrl($user, $commit)}</kbd> <a href="{url 'IDF_Views_Source::help', array($project.shortname)}"><img style="vertical-align: text-bottom;" src="{media '/idf/img/help.png'}" alt="{trans 'Help'}" /></a>
 </p>