Add new RepoAliasResolver class to resolve repo names with aliases.

3 files changed, 163 insertions, 0 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index de1b9f85..23d9f8b6 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -46,6 +46,7 @@ import morph2
 import morphologyfactory
 import remoteartifactcache
 import remoterepocache
+import repoaliasresolver
 import savefile
 import source
 import sourcepool
diff --git a/morphlib/repoaliasresolver.py b/morphlib/repoaliasresolver.py
new file mode 100644
index 00000000..3daf34dd
--- /dev/null
+++ b/morphlib/repoaliasresolver.py
@@ -0,0 +1,83 @@
+# Copyright (C) 2012  Codethink Limited
+# 
+# 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; version 2 of the License.
+# 
+# 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.
+
+
+import logging
+import re
+
+
+class RepoAliasResolver(object):
+
+    def __init__(self, aliases):
+        self.aliases = aliases
+
+    def pull_url(self, reponame):
+        '''Expand a possibly shortened repo name to a pull url.'''
+        return self._expand_reponame(reponame, 'pullpat')
+
+    def push_url(self, reponame):
+        '''Expand a possibly shortened repo name to a push url.'''
+        return self._expand_reponame(reponame, 'pushpat')
+
+    def _expand_reponame(self, reponame, patname):
+        logging.debug('expanding: reponame=%s' % reponame)
+        logging.debug('expanding: patname=%s' % patname)
+
+        prefix, suffix = self._split_reponame(reponame)
+        logging.debug('expanding: prefix=%s' % prefix)
+        logging.debug('expanding: suffix=%s' % suffix)
+
+        # There was no prefix.
+        if prefix is None:
+            logging.debug('expanding: no prefix')
+            return reponame
+
+        pat = r'^(?P<prefix>[a-z0-9]+)=(?P<pullpat>[^#]+)#(?P<pushpat>[^#]+)$'
+        for alias in self.aliases:
+            logging.debug('expanding: alias="%s"' % alias)
+            m = re.match(pat, alias)
+            logging.debug('expanding: m=%s' % repr(m))
+            if m:
+                logging.debug('expanding: prefix group=%s' % m.group('prefix'))
+            if m and m.group('prefix') == prefix:
+                pullpat = m.group(patname)
+                logging.debug('expanding: pullpat=%s' % pullpat)
+                return self._apply_url_pattern(pullpat, suffix)
+
+        # Unknown prefix. Which means it may be a real URL instead.
+        # Let the caller deal with it.        
+        logging.debug('expanding: unknown prefix')
+        return reponame
+    
+    def _split_reponame(self, reponame):
+        '''Split reponame into prefix and suffix.
+        
+        The prefix is returned as None if there was no prefix.
+        
+        '''
+
+        pat = r'^(?P<prefix>[a-z0-9]+):(?P<rest>.*)$'
+        m = re.match(pat, reponame)
+        if m:
+            return m.group('prefix'), m.group('rest')
+        else:
+            return None, reponame
+    
+    def _apply_url_pattern(self, pattern, shortname):
+        if '%s' in pattern:
+            return shortname.join(pattern.split('%s'))
+        else:
+            return pattern + shortname
+    
diff --git a/morphlib/repoaliasresolver_tests.py b/morphlib/repoaliasresolver_tests.py
new file mode 100644
index 00000000..fc6095ca
--- /dev/null
+++ b/morphlib/repoaliasresolver_tests.py
@@ -0,0 +1,79 @@
+# Copyright (C) 2012  Codethink Limited
+# 
+# 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; version 2 of the License.
+# 
+# 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.
+
+
+import morphlib
+import unittest
+
+
+class RepoAliasResolverTests(unittest.TestCase):
+
+    def setUp(self):
+        self.aliases = [
+            'upstream='
+                'git://gitorious.org/baserock-morphs/%s#'
+                'git@gitorious.org:baserock-morphs/%s.git',
+            'baserock='
+                'git://gitorious.org/baserock/%s#'
+                'git@gitorious.org:baserock/%s.git',
+            'append='
+                'git://append/#'
+                'git@append/',
+        ]
+        self.resolver = morphlib.repoaliasresolver.RepoAliasResolver(
+                self.aliases)
+
+    def test_resolve_urls_without_alias_prefix(self):
+        self.assertEqual(self.resolver.pull_url('bar'), 'bar')
+        self.assertEqual(self.resolver.push_url('bar'), 'bar')
+
+        self.assertEqual(self.resolver.pull_url('foo'), 'foo')
+        self.assertEqual(self.resolver.push_url('foo'), 'foo')
+        
+    def test_resolve_urls_for_repos_of_one_alias(self):
+        url = self.resolver.pull_url('upstream:foo')
+        self.assertEqual(url, 'git://gitorious.org/baserock-morphs/foo')
+        url = self.resolver.push_url('upstream:foo')
+        self.assertEqual(url, 'git@gitorious.org:baserock-morphs/foo.git')
+
+        url = self.resolver.pull_url('upstream:bar')
+        self.assertEqual(url, 'git://gitorious.org/baserock-morphs/bar')
+        url = self.resolver.push_url('upstream:bar')
+        self.assertEqual(url, 'git@gitorious.org:baserock-morphs/bar.git')
+
+    def test_resolve_urls_for_repos_of_another_alias(self):
+        url = self.resolver.pull_url('baserock:foo')
+        self.assertEqual(url, 'git://gitorious.org/baserock/foo')
+        url = self.resolver.push_url('baserock:foo')
+        self.assertEqual(url, 'git@gitorious.org:baserock/foo.git')
+
+        url = self.resolver.pull_url('baserock:bar')
+        self.assertEqual(url, 'git://gitorious.org/baserock/bar')
+        url = self.resolver.push_url('baserock:bar')
+        self.assertEqual(url, 'git@gitorious.org:baserock/bar.git')
+
+    def test_resolve_urls_for_unknown_alias(self):
+        self.assertEqual(self.resolver.pull_url('unknown:foo'), 'unknown:foo')
+        self.assertEqual(self.resolver.push_url('unknown:foo'), 'unknown:foo')
+
+        self.assertEqual(self.resolver.pull_url('unknown:bar'), 'unknown:bar')
+        self.assertEqual(self.resolver.push_url('unknown:bar'), 'unknown:bar')
+
+    def test_resolve_urls_for_pattern_without_placeholder(self):
+        self.assertEqual(self.resolver.pull_url('append:foo'), 'git://append/foo')
+        self.assertEqual(self.resolver.push_url('append:foo'), 'git@append/foo')
+
+        self.assertEqual(self.resolver.pull_url('append:bar'), 'git://append/bar')
+        self.assertEqual(self.resolver.push_url('append:bar'), 'git@append/bar')