Add RemoteArtifactCache. Move metadata basename code into Artifact.

5 files changed, 262 insertions, 2 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index da08ac32..942ef741 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -40,6 +40,7 @@ import localrepocache
 import morph2
 import morphology
 import morphologyloader
+import remoteartifactcache
 import remoterepocache
 import savefile
 import source
diff --git a/morphlib/artifact.py b/morphlib/artifact.py
index 3a438747..cea2f2f3 100644
--- a/morphlib/artifact.py
+++ b/morphlib/artifact.py
@@ -53,5 +53,11 @@ class Artifact(object):
                              self.source.morphology['kind'],
                              self.name)
 
+    def metadata_basename(self, metadata_name): # pragma: no cover
+        return '%s.%s.%s.%s' % (self.cache_key,
+                                self.source.morphology['kind'],
+                                self.name,
+                                metadata_name)
+
     def __str__(self): # pragma: no cover
         return '%s|%s' % (self.source, self.name)
diff --git a/morphlib/localartifactcache.py b/morphlib/localartifactcache.py
index cf025210..83a668e4 100644
--- a/morphlib/localartifactcache.py
+++ b/morphlib/localartifactcache.py
@@ -65,10 +65,9 @@ class LocalArtifactCache(object):
         return os.path.join(self.cachedir, basename)
 
     def _artifact_metadata_filename(self, artifact, name):
-        basename = '%s.%s' % (artifact.basename(), name)
+        basename = artifact.metadata_basename(name)
         return os.path.join(self.cachedir, basename)
 
-
     def _source_metadata_filename(self, source, cachekey, name):
         basename = '%s.%s' % (cachekey, name)
         return os.path.join(self.cachedir, basename)
diff --git a/morphlib/remoteartifactcache.py b/morphlib/remoteartifactcache.py
new file mode 100644
index 00000000..6df91a4e
--- /dev/null
+++ b/morphlib/remoteartifactcache.py
@@ -0,0 +1,98 @@
+# 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 cliapp
+import httplib2
+import urllib2
+import urlparse
+
+
+class GetError(cliapp.AppException):
+
+    def __init__(self, cache, artifact):
+        cliapp.AppException.__init__(
+                self, 'Failed to get the artifact %s from the '
+                'artifact cache %s' % (artifact, cache))
+
+
+class GetArtifactMetadataError(cliapp.AppException):
+
+    def __init__(self, cache, artifact, name):
+        cliapp.AppException.__init__(
+                self, 'Failed to get metadata %s for the artifact %s '
+                'from the artifact cache %s' % (name, artifact, cache))
+
+
+class GetSourceMetadataError(cliapp.AppException):
+
+    def __init__(self, cache, source, cache_key, name):
+        cliapp.AppException.__init__(
+                self, 'Failed to get metadata %s for source %s '
+                'and cache key %s from the artifact cache %s' %
+                (name, source, cache_key, cache))
+
+
+class RemoteArtifactCache(object):
+
+    def __init__(self, server_url):
+        self.server_url = server_url
+
+    def has(self, artifact):
+        return self._has_file(artifact.basename())
+
+    def has_artifact_metadata(self, artifact, name):
+        return self._has_file(artifact.metadata_basename(name))
+
+    def has_source_metadata(self, source, cachekey, name):
+        filename = '%s.%s' % (cachekey, name)
+        return self._has_file(filename)
+
+    def get(self, artifact):
+        try:
+            return self._get_file(artifact.basename())
+        except:
+            raise GetError(self, artifact)
+
+    def get_artifact_metadata(self, artifact, name):
+        try:
+            return self._get_file(artifact.metadata_basename(name))
+        except:
+            raise GetArtifactMetadataError(self, artifact, name)
+
+    def get_source_metadata(self, source, cachekey, name):
+        filename = '%s.%s' % (cachekey, name)
+        try:
+            return self._get_file(filename)
+        except:
+            raise GetSourceMetadataError(self, source, cachekey, name)
+
+    def _has_file(self, filename): # pragma: no cover
+        url = self._request_url(filename)
+        http = httplib2.Http()
+        response = http.request(url, 'HEAD')
+        status = response[0]['status']
+        return status >= 200 and status < 400
+
+    def _get_file(self, filename): # pragma: no cover
+        url = self._request_url(filename)
+        return urllib2.urlopen(url)
+
+    def _request_url(self, filename): # pragma: no cover
+        server_url = self.server_url
+        if not server_url.endswith('/'):
+            server_url += '/'
+        return urlparse.urljoin(
+                server_url, '/1.0/artifacts/filename=%s' % filename)
diff --git a/morphlib/remoteartifactcache_tests.py b/morphlib/remoteartifactcache_tests.py
new file mode 100644
index 00000000..b7f10450
--- /dev/null
+++ b/morphlib/remoteartifactcache_tests.py
@@ -0,0 +1,156 @@
+# 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 StringIO
+import unittest
+
+import morphlib
+
+
+class RemoteArtifactCacheTests(unittest.TestCase):
+
+    def setUp(self):
+        morph = morphlib.morph2.Morphology(
+                '''
+                {
+                    "chunk": "chunk",
+                    "kind": "chunk",
+                    "artifacts": {
+                        "chunk-runtime": [
+                            "usr/bin",
+                            "usr/sbin",
+                            "usr/lib",
+                            "usr/libexec"
+                        ],
+                        "chunk-devel": [
+                            "usr/include"
+                        ],
+                        "chunk-doc": [
+                            "usr/share/doc"
+                        ]
+                    }
+                }
+                ''')
+        self.source = morphlib.source.Source(
+                'repo', 'ref', 'sha1', morph, 'chunk.morph')
+        self.runtime_artifact = morphlib.artifact.Artifact(
+                self.source, 'chunk-runtime')
+        self.runtime_artifact.cache_key = 'CHUNK-RUNTIME'
+        self.devel_artifact = morphlib.artifact.Artifact(
+                self.source, 'chunk-devel')
+        self.devel_artifact.cache_key = 'CHUNK-DEVEL'
+        self.doc_artifact = morphlib.artifact.Artifact(
+                self.source, 'chunk-doc')
+        self.doc_artifact.cache_key = 'CHUNK-DOC'
+
+        self.existing_files = set([
+            self.runtime_artifact.basename(),
+            self.devel_artifact.basename(),
+            self.runtime_artifact.metadata_basename('meta'),
+            '%s.%s' % (self.runtime_artifact.cache_key, 'meta'),
+        ])
+
+        self.server_url = 'http://foo.bar:8080'
+        self.cache = morphlib.remoteartifactcache.RemoteArtifactCache(
+                self.server_url)
+        self.cache._has_file = self._has_file
+        self.cache._get_file = self._get_file
+
+    def _has_file(self, filename):
+        return filename in self.existing_files
+
+    def _get_file(self, filename):
+        if filename in self.existing_files:
+            return StringIO.StringIO('%s' % filename)
+        else:
+            raise Exception('foo')
+
+    def test_sets_server_url(self):
+        self.assertEqual(self.cache.server_url, self.server_url)
+
+    def test_has_existing_artifact(self):
+        self.assertTrue(self.cache.has(self.runtime_artifact))
+
+    def test_has_a_different_existing_artifact(self):
+        self.assertTrue(self.cache.has(self.devel_artifact))
+
+    def test_does_not_have_a_non_existent_artifact(self):
+        self.assertFalse(self.cache.has(self.doc_artifact))
+
+    def test_has_existing_artifact_metadata(self):
+        self.assertTrue(self.cache.has_artifact_metadata(
+            self.runtime_artifact, 'meta'))
+
+    def test_does_not_have_non_existent_artifact_metadata(self):
+        self.assertFalse(self.cache.has_artifact_metadata(
+            self.runtime_artifact, 'non-existent-meta'))
+
+    def test_has_existing_source_metadata(self):
+        self.assertTrue(self.cache.has_source_metadata(
+            self.runtime_artifact.source,
+            self.runtime_artifact.cache_key,
+            'meta'))
+
+    def test_does_not_have_non_existent_source_metadata(self):
+        self.assertFalse(self.cache.has_source_metadata(
+            self.runtime_artifact.source,
+            self.runtime_artifact.cache_key,
+            'non-existent-meta'))
+
+    def test_get_existing_artifact(self):
+        handle = self.cache.get(self.runtime_artifact)
+        data = handle.read()
+        self.assertEqual(data, self.runtime_artifact.basename())
+
+    def test_get_a_different_existing_artifact(self):
+        handle = self.cache.get(self.devel_artifact)
+        data = handle.read()
+        self.assertEqual(data, self.devel_artifact.basename())
+
+    def test_fails_to_get_a_non_existent_artifact(self):
+        self.assertRaises(morphlib.remoteartifactcache.GetError,
+                          self.cache.get, self.doc_artifact)
+
+    def test_get_existing_artifact_metadata(self):
+        handle = self.cache.get_artifact_metadata(
+                self.runtime_artifact, 'meta')
+        data = handle.read()
+        self.assertEqual(
+                data, '%s.%s' % (self.runtime_artifact.basename(), 'meta'))
+
+    def test_fails_to_get_non_existent_artifact_metadata(self):
+        self.assertRaises(
+                morphlib.remoteartifactcache.GetArtifactMetadataError,
+                self.cache.get_artifact_metadata,
+                self.runtime_artifact,
+                'non-existent-meta')
+
+    def test_get_existing_source_metadata(self):
+        handle = self.cache.get_source_metadata(
+                self.runtime_artifact.source,
+                self.runtime_artifact.cache_key,
+                'meta')
+        data = handle.read()
+        self.assertEqual(
+                data, '%s.%s' % (self.runtime_artifact.cache_key, 'meta'))
+
+    def test_fails_to_get_non_existent_source_metadata(self):
+        self.assertRaises(
+                morphlib.remoteartifactcache.GetSourceMetadataError,
+                self.cache.get_source_metadata,
+                self.runtime_artifact.source, 
+                self.runtime_artifact.cache_key,
+                'non-existent-meta')