Add RemoteArtifactCache. Move metadata basename code into Artifact.

1 files changed, 98 insertions, 0 deletions

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)