diff options
Diffstat (limited to 'openstack.py')
| -rw-r--r-- | openstack.py | 114 |
1 files changed, 105 insertions, 9 deletions
diff --git a/openstack.py b/openstack.py index 25f1a404..22a2d067 100644 --- a/openstack.py +++ b/openstack.py @@ -1,5 +1,6 @@ -from u1db.backends import CommonBackend from leap import * +from u1db import errors +from u1db.backends import CommonBackend from u1db.remote.http_target import HTTPSyncTarget from swiftclient import client @@ -96,21 +97,26 @@ class OpenStackDatabase(CommonBackend): raise NotImplementedError(self.close) def _get_replica_gen_and_trans_id(self, other_replica_uid): - raise NotImplementedError(self._get_replica_gen_and_trans_id) + self._update_u1db_data() + return self._sync_log.get_replica_gen_and_trans_id(other_replica_uid) def _set_replica_gen_and_trans_id(self, other_replica_uid, other_generation, other_transaction_id): - raise NotImplementedError(self._set_replica_gen_and_trans_id) + self._update_u1db_data() + return self._sync_log.set_replica_gen_and_trans_id(other_replica_uid, + other_generation, other_transaction_id) #------------------------------------------------------------------------- # implemented methods from CommonBackend #------------------------------------------------------------------------- def _get_generation(self): - raise NotImplementedError(self._get_generation) + self._update_u1db_data() + return self._transaction_log.get_generation() def _get_generation_info(self): - raise NotImplementedError(self._get_generation_info) + self._update_u1db_data() + return self._transaction_log.get_generation_info() def _get_doc(self, doc_id, check_for_conflicts=False): """Get just the document content, without fancy handling.""" @@ -119,15 +125,16 @@ class OpenStackDatabase(CommonBackend): def _has_conflicts(self, doc_id): raise NotImplementedError(self._has_conflicts) - def _get_transaction_log(self): - raise NotImplementedError(self._get_transaction_log) - def _put_and_update_indexes(self, doc_id, old_doc, new_rev, content): raise NotImplementedError(self._put_and_update_indexes) def _get_trans_id_for_gen(self, generation): - raise NotImplementedError(self._get_trans_id_for_gen) + self._update_u1db_data() + trans_id = self._transaction_log.get_trans_id_for_gen(generation) + if trans_id is None: + raise errors.InvalidGeneration + return trans_id #------------------------------------------------------------------------- # OpenStack specific methods @@ -143,6 +150,11 @@ class OpenStackDatabase(CommonBackend): self._url, self._auth_token = self._connection.get_auth() return self._url, self.auth_token + def _update_u1db_data(self): + data = self.get_doc('u1db_data').content + self._transaction_log = data['transaction_log'] + self._sync_log = data['sync_log'] + class OpenStackSyncTarget(HTTPSyncTarget): @@ -152,3 +164,87 @@ class OpenStackSyncTarget(HTTPSyncTarget): def record_sync_info(self, source_replica_uid, source_replica_generation, source_replica_transaction_id): raise NotImplementedError(self.record_sync_info) + + +class SimpleLog(object): + def __init__(self, log=None): + self._log = [] + if log: + self._log = log + + def append(self, msg): + self._log.append(msg) + + def reduce(self, func, initializer=None): + return reduce(func, self._log, initializer) + + def map(self, func): + return map(func, self._log) + + +class TransactionLog(SimpleLog): + """ + A list of (generation, doc_id, transaction_id) tuples. + """ + + def get_generation(self): + """ + Return the current generation. + """ + gens = self.map(lambda x: x[0]) + if not gens: + return 0 + return max(gens) + + def get_generation_info(self): + """ + Return the current generation and transaction id. + """ + if not self._log: + return(0, '') + info = self.map(lambda x: (x[0], x[2])) + return reduce(lambda x, y: x if (x[0] > y[0]) else y, info) + + def get_trans_id_for_gen(self, gen): + """ + Get the transaction id corresponding to a particular generation. + """ + log = self.reduce(lambda x, y: y if y[0] == gen else x) + if log is None: + return None + return log[2] + +class SyncLog(SimpleLog): + """ + A list of (replica_id, generation, transaction_id) tuples. + """ + + def find_by_replica_uid(self, replica_uid): + if not self._log: + return () + return self.reduce(lambda x, y: y if y[0] == replica_uid else x) + + def get_replica_gen_and_trans_id(self, other_replica_uid): + """ + Return the last known generation and transaction id for the other db + replica. + """ + info = self.find_by_replica_uid(other_replica_uid) + if not info: + return (0, '') + return (info[1], info[2]) + + def set_replica_gen_and_trans_id(self, other_replica_uid, + other_generation, other_transaction_id): + """ + Set the last-known generation and transaction id for the other + database replica. + """ + old_log = self._log + self._log = [] + for log in old_log: + if log[0] != other_replica_uid: + self.append(log) + self.append((other_replica_uid, other_generation, + other_transaction_id)) + |