Rev 5133: Bring Maxb's code for querying launchpads api via a REST request. in http://bazaar.launchpad.net/~jameinel/bzr/2.2-is-up-to-date

[John Arbash Meinel]

At http://bazaar.launchpad.net/~jameinel/bzr/2.2-is-up-to-date

------------------------------------------------------------
revno: 5133
revision-id: john at arbash-meinel.com-20110712150543-201jymlxh34foi2a
parent: pqm at pqm.ubuntu.com-20110525182215-rdt09veh6tfzmril
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: 2.2-is-up-to-date
timestamp: Tue 2011-07-12 17:05:43 +0200
message:
  Bring Maxb's code for querying launchpads api via a REST request.
  
  This can be done without loading launchpadlib, so the next step is to refactor it
  for testing. But manual testing against launchpad itself shows it working.
-------------- next part --------------
=== added file 'bzrlib/plugins/launchpad/lp_api_lite.py'
--- a/bzrlib/plugins/launchpad/lp_api_lite.py	1970-01-01 00:00:00 +0000
+++ b/bzrlib/plugins/launchpad/lp_api_lite.py	2011-07-12 15:05:43 +0000
@@ -0,0 +1,126 @@
+# Copyright (C) 2009, 2010 Canonical Ltd
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+"""Tools for dealing with the Launchpad API without using launchpadlib.
+
+The api itself is a RESTful interface, so we can make HTTP queries directly.
+loading launchpadlib itself has a fairly high overhead (just calling
+Launchpad.login_anonymously() takes a 500ms once the WADL is cached, and 5+s to
+get the WADL.
+"""
+
+try:
+    # Use simplejson if available, much faster, and can be easily installed in
+    # older versions of python
+    import simplejson as json
+except ImportError:
+    # Is present since python 2.6
+    try:
+        import json
+    except ImportError:
+        json = None
+
+import urllib
+import urllib2
+
+from bzrlib import trace
+
+
+LP_API_ROOT = 'https://api.launchpad.net/1.0'
+DEFAULT_SERIES = 'oneiric'
+
+def get_latest_publication(archive, series, project):
+    """Get the most recent publication for a given project.
+
+    :param archive: Either 'ubuntu' or 'debian'
+    :param series: Something like 'natty', 'sid', etc. Can be set as None. Can
+        also include a pocket such as 'natty-proposed'.
+    :param project: Something like 'bzr'
+    :return: A version string indicating the most-recent version published in
+        Launchpad. Might return None if there is an error.
+    """
+    if json is None:
+        return None
+    archive_url = '%s/%s/+archive/primary?' % (LP_API_ROOT, archive)
+    status = 'Published'
+    if archive == 'debian':
+        # Launchpad only tracks debian packages as "Pending", it doesn't mark
+        # them Published
+        status = 'Pending'
+    pocket = None
+    # TODO: If series is None, we probably need to hard-code it. I don't have
+    #       proof yet, but otherwise we just get the most-recent version in any
+    #       series, rather than getting the one for eg 'oneiric'. The problem I
+    #       envision is that natty-proposed might have a newer version than
+    #       'oneiric'. Is this a useful distinction in practice?
+    if series is not None and '-' in series:
+        # The lp: URL 'lp:ubuntu/natty-proposed/...' is translated into series
+        # 'natty' pocket 'proposed'
+        try:
+            series, pocket = series.split('-')
+        except ValueError, e:
+            trace.mutter('failed to find series,pocket from %s' % (series,))
+            return None
+        # pocket must be in 'Title' case, so Proposed, not 'proposed'.
+        pocket = pocket.title()
+    params = {'ws.op': 'getPublishedSources',
+              'exact_match': 'true',
+              # If we need to use "" shouldn't we quote the project somehow?
+              'source_name': '"%s"' % (project,),
+              'status': status,
+              # We only need the latest one, the results seem to be properly
+              # most-recent-debian-version sorted
+              'ws.size': '1',
+    }
+    if series is not None:
+        params['distro_series'] = '/%s/%s' % (archive, series)
+    if pocket is not None:
+        params['pocket'] = pocket
+    query_url = archive_url + urllib.urlencode(params)
+    try:
+        req = urllib2.Request(query_url)
+        response = urllib2.urlopen(req)
+        json_txt = response.read()
+    except urllib2.HTTPError, e:
+        trace.mutter('failed to place query to %r' % (query_url,))
+        trace.log_exception_quietly()
+        return None
+    try:
+        o = json.loads(json_txt)
+    except Exception:
+        # simplejson raises simplejson.decoder.JSONDecodeError,
+        # but json raises ValueError, so we just catch a generic error and move
+        # on
+        trace.log_exception_quietly()
+        return None
+    try:
+        for e in o['entries']:
+            this_name = e['source_package_name']
+            this_ver = e['source_package_version']
+            # this_comp seems to always be 'main', are we supposed to do
+            # something with it?
+            # this_comp = e['component_name']
+            # pocket = e['pocket'].lower()
+            # series = e['distro_series_link'].split('/')[-1]
+            # if pocket != 'release':
+            #     series += '-' + pocket
+            return this_ver
+    except KeyError:
+        # Some expected attribute was missing
+        trace.log_exception_quietly()
+        return None
+    trace.mutter('No versions found for: %r', query_url)
+    return None