class ReadOnlyLogger:
__version__ = '0.0.0'
def __init__(self, backend):
self._backend = TranslatingBackend(Log, backend)
def get(self, ref):
return self._backend.get(ref)
def latest_snapshot(self):
return self._backend.first(Q('operation', 'eq', Operation.SNAPSHOT),
O('modified_on', O.DESCENDING))
def after(self, timestamp):
return self._backend.query(Q('modified_on', 'gt', timestamp),
O('modified_on', O.ASCENDING))
def history(self, record_id):
"""Returns all logs pretaining to the specified record_id newest to oldest
>>> self.history('myid')[0] # Current state
>>> self.history('myid')[-1] # Initial value, generally a rename or create
"""
return self._backend.query(Q('record_id', 'eq', record_id),
O('modified_on', O.DESCENDING))
def list(self, order=None):
return self._backend.list(order)
def bulk_read(self, keys):
return self._backend.query(Q('ref', 'in', keys))
def __repr__(self):
return '<{}({})>'.format(self.__class__.__name__, self._backend)
class ReadOnlyLogger:
__version__ = "0.0.0"
def __init__(self, backend):
self._backend = TranslatingBackend(Log, backend)
def get(self, ref):
return self._backend.get(ref)
def latest_snapshot(self):
return self._backend.first(Q("operation", "eq", Operation.SNAPSHOT), O("modified_on", O.DESCENDING))
def after(self, timestamp):
return self._backend.query(Q("modified_on", "gt", timestamp), O("modified_on", O.ASCENDING))
def history(self, record_id):
"""Returns all logs pretaining to the specified record_id newest to oldest
>>> self.history('myid')[0] # Current state
>>> self.history('myid')[-1] # Initial value, generally a rename or create
"""
return self._backend.query(Q("record_id", "eq", record_id), O("modified_on", O.DESCENDING))
def list(self, order=None):
return self._backend.list(order)
def bulk_read(self, keys):
return self._backend.query(Q("ref", "in", keys))
def __repr__(self):
return "<{}({})>".format(self.__class__.__name__, self._backend)
class State:
def __init__(self, backend):
self._backend = TranslatingBackend(Document, backend)
def clear(self):
self._backend.unset_all()
def get(self, key):
return self._backend.get(key)
def list(self):
return self._backend.list()
def keys(self):
return self._backend.keys()
def _create(self, log, data, safe=True):
doc = Document.create(log, data)
self._backend.set(log.record_id, doc)
return doc
def _rename(self, log, data, safe=True):
if 'to' in log.operation_parameters:
self._backend.unset(log.record_id)
else:
doc = Document.create(log, data)
self._backend.set(log.record_id, doc)
return doc
def _delete(self, log, data, safe=True):
self._backend.unset(log.record_id)
def _replace(self, log, data, safe=True):
return self._create(log, data)
def _update(self, log, data, safe=True):
return self._create(log, data, safe=True)
def apply(self, log, data, safe=True):
# TODO implement safe
# Snapshot logs may be out of order, which should not matter
# Deleting a key that doesn't exist would cause an exception, safe would just swallow that failure
try:
op = {
Operation.CREATE: self._create,
Operation.DELETE: self._delete,
Operation.RENAME: self._rename,
Operation.REPLACE: self._replace,
Operation.UPDATE: self._update,
}[log.operation]
except KeyError:
raise Exception('Unknown operation {}'.format(log.operation))
return op(log, data, safe=safe)
def __repr__(self):
return '<{}({})>'.format(self.__class__.__name__, self._backend)
class State:
def __init__(self, backend):
self._backend = TranslatingBackend(Document, backend)
def clear(self):
self._backend.unset_all()
def get(self, key):
return self._backend.get(key)
def list(self):
return self._backend.list()
def keys(self):
return self._backend.keys()
def _create(self, log, data, safe=True):
doc = Document.create(log, data)
self._backend.set(log.record_id, doc)
return doc
def _rename(self, log, data, safe=True):
if "to" in log.operation_parameters:
self._backend.unset(log.record_id)
else:
doc = Document.create(log, data)
self._backend.set(log.record_id, doc)
return doc
def _delete(self, log, data, safe=True):
self._backend.unset(log.record_id)
def _replace(self, log, data, safe=True):
return self._create(log, data)
def _update(self, log, data, safe=True):
return self._create(log, data, safe=True)
def apply(self, log, data, safe=True):
# TODO implement safe
# Snapshot logs may be out of order, which should not matter
# Deleting a key that doesn't exist would cause an exception, safe would just swallow that failure
try:
op = {
Operation.CREATE: self._create,
Operation.DELETE: self._delete,
Operation.RENAME: self._rename,
Operation.REPLACE: self._replace,
Operation.UPDATE: self._update,
}[log.operation]
except KeyError:
raise Exception("Unknown operation {}".format(log.operation))
return op(log, data, safe=safe)
def __repr__(self):
return "<{}({})>".format(self.__class__.__name__, self._backend)