diff options
Diffstat (limited to 'src/olpc/datastore/datastore.py')
| -rw-r--r-- | src/olpc/datastore/datastore.py | 145 |
1 files changed, 121 insertions, 24 deletions
diff --git a/src/olpc/datastore/datastore.py b/src/olpc/datastore/datastore.py index 4ca13b6..0a37f49 100644 --- a/src/olpc/datastore/datastore.py +++ b/src/olpc/datastore/datastore.py @@ -17,13 +17,10 @@ import dbus.service import dbus.mainloop.glib from olpc.datastore import utils +from olpc.datastore import lru +from olpc.datastore.sxattr import Xattr +from olpc.datastore.config import * -# the name used by the logger -DS_LOG_CHANNEL = 'org.laptop.sugar.DataStore' - -DS_SERVICE = "org.laptop.sugar.DataStore" -DS_DBUS_INTERFACE = "org.laptop.sugar.DataStore" -DS_OBJECT_PATH = "/org/laptop/sugar/DataStore" logger = logging.getLogger(DS_LOG_CHANNEL) @@ -36,6 +33,9 @@ class DataStore(dbus.service.Object): self.backends = [] self.mountpoints = {} self.root = None + + # maps uids to the mountpoint of the tip revision + self._mpcache = lru.LRU(20) # global handle to the main look dbus.mainloop.glib.DBusGMainLoop(set_as_default=True) @@ -172,7 +172,7 @@ class DataStore(dbus.service.Object): def _resolveMountpoint(self, mountpoint=None): if isinstance(mountpoint, dict): mountpoint = mountpoint.pop('mountpoint', None) - + if mountpoint is not None: # this should be the id of a mount point mp = self.mountpoints[mountpoint] @@ -181,6 +181,61 @@ class DataStore(dbus.service.Object): mp = self.root return mp + + def _mountpointFor(self, uid): + # XXX: this is flawed in that we really need to resolve merge + # cases where objects exist in branches over two or more + # stores + # (and this have the same rev for different heads) + + # first, is it in the LRU cache? + if uid in self._mpcache: + return self._mpcache[uid] + + # attempt to resolve (and cache the mount point) + # this is the start of some merge code + on = [] + for mp in self.mountpoints.itervalues(): + try: + if "versions" in mp.capabilities: + c = mp.get(uid, allow_many=True) + if c: on.append((mp, c)) + else: + c = mp.get(uid) + if c: on.append((mp, c)) + except KeyError: + pass + + if on: + # find the single most recent revision + def versionCmp(x, y): + mpa, ca = x # mp, content + mpb, cb = y + # first by revision + r = cmp(int(ca.get_property('vid')), + int(cb.get_property('vid'))) + if r != 0: return r + # if they have the same revision we've detected a + # branch + # we should resolve the common parent in a merge case, + # etc. + # XXX: here we defer to time + return cmp(ca.get_property('mtime', 0), cb.get_property('mtime', 0)) + + + if len(on) > 1: + on.sort(versionCmp) + # the first mount point should be the most recent + # revision + mp = on[0][0] + else: + # No store has this uid. Doesn't mean it doesn't exist, + # just that its not mounted + mp = None + + self._mpcache[uid] = mp + return mp + # PUBLIC API @dbus.service.method(DS_DBUS_INTERFACE, in_signature='a{sv}s', @@ -192,11 +247,27 @@ class DataStore(dbus.service.Object): This method returns the uid and version id tuple. """ - mp = self._resolveMountpoint(props) + mp = None + # dbus cleaning + props = utils._convert(props) + + if filelike is not None: + filelike = str(filelike) + if filelike: + # attempt to scan the xattr namespace for information that can + # allow us to process this request more quickly + x = Xattr(filelike, XATTR_NAMESPACE) + known = x.asDict() + if "mountpoint" not in props and "mountpoint" in known: + mp = self._resolveMountpoint(known['mountpoint']) + + if not mp: + mp = self._resolveMountpoint(props) + if "versions" not in mp.capabilities: - uid = props.get('uid') vid = "1" # we don't care about vid on # non-versioning stores + uid = props.get('uid') if uid: # this is an update operation # and uid refers to the single object @@ -208,8 +279,9 @@ class DataStore(dbus.service.Object): else: # use the unified checkin on the backingstore uid, vid = mp.checkin(props, filelike) - - return uid, vid + + self._mpcache[uid] = mp + return uid, str(vid) @dbus.service.method(DS_DBUS_INTERFACE, @@ -223,7 +295,18 @@ class DataStore(dbus.service.Object): histories of the same object. """ ## XXX: review this when repo merge code is in place - mp = self._resolveMountpoint(mountpoint) + + # dbus cleanup + uid = str(uid) + vid = vid and str(vid) or None + mountpoint = mountpoint and str(mountpoint) or None + target = target and str(target) or None + dir = dir and str(dir) or None + + mp = self._mountpointFor(uid) + if not mp: + raise KeyError("Object with %s uid not found in datastore" % uid) + if "versions" not in mp.capabilities: content = mp.get(uid) props = content.properties @@ -310,7 +393,7 @@ class DataStore(dbus.service.Object): for hit in res: existing = d.get(hit.id) if not existing or \ - existing.get_property('mtime') < hit.get_property('mtime'): + existing.get_property('vid') < hit.get_property('vid'): # XXX: age/version check d[hit.id] = hit @@ -434,11 +517,11 @@ class DataStore(dbus.service.Object): return (d, len(results)) - def get(self, uid, mountpoint=None): + def get(self, uid, rev=None, mountpoint=None): mp = self._resolveMountpoint(mountpoint) c = None try: - c = mp.get(uid) + c = mp.get(uid, rev) if c: return c except KeyError: pass @@ -446,27 +529,36 @@ class DataStore(dbus.service.Object): if not c: for mp in self.mountpoints.itervalues(): try: - c = mp.get(uid) + if "versions" in mp.capabilities: + c = mp.get(uid, rev) + else: + c = mp.get(uid) + if c: break except KeyError: continue return c @dbus.service.method(DS_DBUS_INTERFACE, - in_signature='s', + in_signature='sss', out_signature='s') - def get_filename(self, uid): - content = self.get(uid) + def get_filename(self, uid, vid=None, mountpoint=None): + vid = vid and str(vid) or None + mountpoint = mountpoint and str(mountpoint) or None + content = self.get(uid, vid, mountpoint) if content: try: return content.filename except AttributeError: pass return '' @dbus.service.method(DS_DBUS_INTERFACE, - in_signature='s', + in_signature='sss', out_signature='a{sv}') - def get_properties(self, uid): - content = self.get(uid) + def get_properties(self, uid, vid=None, mountpoint=None): + vid = vid and str(vid) or None + mountpoint = mountpoint and str(mountpoint) or None + + content = self.get(uid, vid, mountpoint) props = content.properties props['mountpoint'] = content.backingstore.id return props @@ -510,7 +602,7 @@ class DataStore(dbus.service.Object): in_signature='ss', out_signature='') def delete(self, uid, mountpoint=None): - content = self.get(uid, mountpoint) + content = self.get(uid, mountpoint=mountpoint) if content: content.backingstore.delete(uid) self.Deleted(uid) @@ -520,8 +612,13 @@ class DataStore(dbus.service.Object): @dbus.service.signal(DS_DBUS_INTERFACE, signature="s") def Deleted(self, uid): pass + + @dbus.service.method(DS_DBUS_INTERFACE, + in_signature='', + out_signature='') def stop(self): - """shutdown the service""" + """shutdown the service. this is intended only for automated + testing or system shutdown.""" self.Stopped() self._connection.get_connection()._unregister_object_path(DS_OBJECT_PATH) for mp in self.mountpoints.values(): mp.stop() |