Implement torrent data parsing and extraction via bencode

This allows uploading of the actual torrent file itself into the webapp
and then pulling the relevant pieces of information out of it.

Signed-off-by: Dan McGee <dan@archlinux.org>

4 files changed, 58 insertions, 5 deletions

diff --git a/releng/models.py b/releng/models.py
index 8bc54de..c7d2696 100644
--- a/releng/models.py
+++ b/releng/models.py
@@ -1,4 +1,9 @@
+from base64 import b64decode
+from bencode import bdecode, bencode
+from datetime import datetime
+import hashlib
 import markdown
+from pytz import utc
 
 from django.core.urlresolvers import reverse
 from django.db import models
@@ -150,6 +155,34 @@ class Release(models.Model):
         return mark_safe(markdown.markdown(
             self.info, safe_mode=True, enable_attributes=False))
 
+    def torrent(self):
+        try:
+            data = b64decode(self.torrent_data)
+        except TypeError:
+            return None
+        data = bdecode(data)
+        # transform the data into a template-friendly dict
+        info = data.get('info', {})
+        metadata = {
+            'comment': data.get('comment', None),
+            'created_by': data.get('created by', None),
+            'creation_date': None,
+            'announce': data.get('announce', None),
+            'file_name': info.get('name', None),
+            'file_length': info.get('length', None),
+            'piece_count': len(info.get('pieces', '')) / 20,
+            'piece_length': info.get('piece length', None),
+            'url_list': data.get('url-list', []),
+            'info_hash': None,
+        }
+        if 'creation date' in data:
+            created= datetime.utcfromtimestamp(data['creation date'])
+            metadata['creation_date'] = created.replace(tzinfo=utc)
+        if info:
+            metadata['info_hash'] = hashlib.sha1(bencode(info)).hexdigest()
+
+        return metadata
+
 
 for model in (Iso, Test, Release):
     pre_save.connect(set_created_field, sender=model,
diff --git a/requirements.txt b/requirements.txt
index 1d5b068..ae58ee5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 Django==1.4.3
 Markdown==2.2.1
 South==0.7.6
+bencode==1.0
 django-countries==1.5
 pgpdump==1.4
-pytz>=2012h
+pytz>=2012j
diff --git a/requirements_prod.txt b/requirements_prod.txt
index f84f46d..ee1b17a 100644
--- a/requirements_prod.txt
+++ b/requirements_prod.txt
@@ -1,9 +1,10 @@
 Django==1.4.3
 Markdown==2.2.1
 South==0.7.6
+bencode==1.0
 django-countries==1.5
 pgpdump==1.4
 psycopg2==2.4.6
 pyinotify==0.9.4
 python-memcached==1.48
-pytz>=2012h
+pytz>=2012j
diff --git a/templates/releng/release_detail.html b/templates/releng/release_detail.html
index fec9ce2..f4de9e5 100644
--- a/templates/releng/release_detail.html
+++ b/templates/releng/release_detail.html
@@ -9,9 +9,10 @@
         <li><strong>Release Date:</strong> {{ release.release_date|date }}</li>
         {% if release.kernel_version %}<li><strong>Kernel Version:</strong> {{ release.kernel_version }}</li>{% endif %}
         <li><strong>Available:</strong> {{ release.available|yesno }}</li>
-        {% if release.available %}<li><a href="https://www.archlinux.org/{{ release.iso_url }}.torrent"
-                title="Download torrent for {{ release.version }}">Torrent</a></li>{% endif %}
-        {% if release.available %}<li><a href="{{ release.magnet_uri }}">Magnet</a></li>{% endif %}
+        {% if release.available %}<li><strong>Download:</strong> <a href="https://www.archlinux.org/{{ release.iso_url }}.torrent"
+                title="Download torrent for {{ release.version }}">Torrent</a>,
+            <a href="{{ release.magnet_uri }}">Magnet</a></li>{% endif %}
+        {% if release.torrent_infohash %}<li><strong>Torrent Info Hash:</strong> {{ release.torrent_infohash }}</li>{% endif %}
         <li><strong>Download Size:</strong> {% if release.file_size %}{{ release.file_size|filesizeformat }}{% else %}Unknown{% endif %}</li>
     </ul>
 
@@ -20,5 +21,22 @@
 
     <div class="article-content">{{ release.info_html }}</div>
     {% endif %}
+
+    {% if release.torrent_data %}{% with release.torrent as torrent %}
+    <h3>Torrent Information</h3>
+
+    <ul>
+        <li><strong>Comment:</strong> {{ torrent.comment }}</li>
+        <li><strong>Creation Date:</strong> {{ torrent.creation_date|date:"DATETIME_FORMAT" }} UTC</li>
+        <li><strong>Created By:</strong> {{ torrent.created_by }}</li>
+        <li><strong>Announce URL:</strong> {{ torrent.announce }}</li>
+        <li><strong>File Name:</strong> {{ torrent.file_name }}</li>
+        <li><strong>File Length:</strong> {{ torrent.file_length|filesizeformat }}</li>
+        <li><strong>Piece Count:</strong> {{ torrent.piece_count }} pieces</li>
+        <li><strong>Piece Length:</strong> {{ torrent.piece_length|filesizeformat }}</li>
+        <li><strong>Computed Info Hash:</strong> {{ torrent.info_hash }}</li>
+        <li><strong>URL List Length:</strong> {{ torrent.url_list|length }} URLs</li>
+    </ul>
+    {% endwith %}{% endif %}
 </div>
 {% endblock %}