Vehicle-Anti-Theft-Face-Rec.../venv/Lib/site-packages/gcloud/bigtable/column_family.py

339 lines
11 KiB
Python

# Copyright 2015 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""User friendly container for Google Cloud Bigtable Column Family."""
import datetime
from google.protobuf import duration_pb2
from gcloud._helpers import _total_seconds
from gcloud.bigtable._generated_v2 import (
table_pb2 as table_v2_pb2)
from gcloud.bigtable._generated_v2 import (
bigtable_table_admin_pb2 as table_admin_v2_pb2)
def _timedelta_to_duration_pb(timedelta_val):
"""Convert a Python timedelta object to a duration protobuf.
.. note::
The Python timedelta has a granularity of microseconds while
the protobuf duration type has a duration of nanoseconds.
:type timedelta_val: :class:`datetime.timedelta`
:param timedelta_val: A timedelta object.
:rtype: :class:`google.protobuf.duration_pb2.Duration`
:returns: A duration object equivalent to the time delta.
"""
seconds_decimal = _total_seconds(timedelta_val)
# Truncate the parts other than the integer.
seconds = int(seconds_decimal)
if seconds_decimal < 0:
signed_micros = timedelta_val.microseconds - 10**6
else:
signed_micros = timedelta_val.microseconds
# Convert nanoseconds to microseconds.
nanos = 1000 * signed_micros
return duration_pb2.Duration(seconds=seconds, nanos=nanos)
def _duration_pb_to_timedelta(duration_pb):
"""Convert a duration protobuf to a Python timedelta object.
.. note::
The Python timedelta has a granularity of microseconds while
the protobuf duration type has a duration of nanoseconds.
:type duration_pb: :class:`google.protobuf.duration_pb2.Duration`
:param duration_pb: A protobuf duration object.
:rtype: :class:`datetime.timedelta`
:returns: The converted timedelta object.
"""
return datetime.timedelta(
seconds=duration_pb.seconds,
microseconds=(duration_pb.nanos / 1000.0),
)
class GarbageCollectionRule(object):
"""Garbage collection rule for column families within a table.
Cells in the column family (within a table) fitting the rule will be
deleted during garbage collection.
.. note::
This class is a do-nothing base class for all GC rules.
.. note::
A string ``gc_expression`` can also be used with API requests, but
that value would be superceded by a ``gc_rule``. As a result, we
don't support that feature and instead support via native classes.
"""
def __ne__(self, other):
return not self.__eq__(other)
class MaxVersionsGCRule(GarbageCollectionRule):
"""Garbage collection limiting the number of versions of a cell.
:type max_num_versions: int
:param max_num_versions: The maximum number of versions
"""
def __init__(self, max_num_versions):
self.max_num_versions = max_num_versions
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return other.max_num_versions == self.max_num_versions
def to_pb(self):
"""Converts the garbage collection rule to a protobuf.
:rtype: :class:`.table_v2_pb2.GcRule`
:returns: The converted current object.
"""
return table_v2_pb2.GcRule(max_num_versions=self.max_num_versions)
class MaxAgeGCRule(GarbageCollectionRule):
"""Garbage collection limiting the age of a cell.
:type max_age: :class:`datetime.timedelta`
:param max_age: The maximum age allowed for a cell in the table.
"""
def __init__(self, max_age):
self.max_age = max_age
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return other.max_age == self.max_age
def to_pb(self):
"""Converts the garbage collection rule to a protobuf.
:rtype: :class:`.table_v2_pb2.GcRule`
:returns: The converted current object.
"""
max_age = _timedelta_to_duration_pb(self.max_age)
return table_v2_pb2.GcRule(max_age=max_age)
class GCRuleUnion(GarbageCollectionRule):
"""Union of garbage collection rules.
:type rules: list
:param rules: List of :class:`GarbageCollectionRule`.
"""
def __init__(self, rules):
self.rules = rules
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return other.rules == self.rules
def to_pb(self):
"""Converts the union into a single GC rule as a protobuf.
:rtype: :class:`.table_v2_pb2.GcRule`
:returns: The converted current object.
"""
union = table_v2_pb2.GcRule.Union(
rules=[rule.to_pb() for rule in self.rules])
return table_v2_pb2.GcRule(union=union)
class GCRuleIntersection(GarbageCollectionRule):
"""Intersection of garbage collection rules.
:type rules: list
:param rules: List of :class:`GarbageCollectionRule`.
"""
def __init__(self, rules):
self.rules = rules
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return other.rules == self.rules
def to_pb(self):
"""Converts the intersection into a single GC rule as a protobuf.
:rtype: :class:`.table_v2_pb2.GcRule`
:returns: The converted current object.
"""
intersection = table_v2_pb2.GcRule.Intersection(
rules=[rule.to_pb() for rule in self.rules])
return table_v2_pb2.GcRule(intersection=intersection)
class ColumnFamily(object):
"""Representation of a Google Cloud Bigtable Column Family.
We can use a :class:`ColumnFamily` to:
* :meth:`create` itself
* :meth:`update` itself
* :meth:`delete` itself
:type column_family_id: str
:param column_family_id: The ID of the column family. Must be of the
form ``[_a-zA-Z0-9][-_.a-zA-Z0-9]*``.
:type table: :class:`Table <gcloud.bigtable.table.Table>`
:param table: The table that owns the column family.
:type gc_rule: :class:`GarbageCollectionRule`
:param gc_rule: (Optional) The garbage collection settings for this
column family.
"""
def __init__(self, column_family_id, table, gc_rule=None):
self.column_family_id = column_family_id
self._table = table
self.gc_rule = gc_rule
@property
def name(self):
"""Column family name used in requests.
.. note::
This property will not change if ``column_family_id`` does not, but
the return value is not cached.
The table name is of the form
``"projects/../zones/../clusters/../tables/../columnFamilies/.."``
:rtype: str
:returns: The column family name.
"""
return self._table.name + '/columnFamilies/' + self.column_family_id
def __eq__(self, other):
if not isinstance(other, self.__class__):
return False
return (other.column_family_id == self.column_family_id and
other._table == self._table and
other.gc_rule == self.gc_rule)
def __ne__(self, other):
return not self.__eq__(other)
def create(self):
"""Create this column family."""
if self.gc_rule is None:
column_family = table_v2_pb2.ColumnFamily()
else:
column_family = table_v2_pb2.ColumnFamily(
gc_rule=self.gc_rule.to_pb())
request_pb = table_admin_v2_pb2.ModifyColumnFamiliesRequest(
name=self._table.name)
request_pb.modifications.add(
id=self.column_family_id,
create=column_family,
)
client = self._table._instance._client
# We expect a `.table_v2_pb2.ColumnFamily`. We ignore it since the only
# data it contains are the GC rule and the column family ID already
# stored on this instance.
client._table_stub.ModifyColumnFamilies(request_pb,
client.timeout_seconds)
def update(self):
"""Update this column family.
.. note::
Only the GC rule can be updated. By changing the column family ID,
you will simply be referring to a different column family.
"""
if self.gc_rule is None:
column_family = table_v2_pb2.ColumnFamily()
else:
column_family = table_v2_pb2.ColumnFamily(
gc_rule=self.gc_rule.to_pb())
request_pb = table_admin_v2_pb2.ModifyColumnFamiliesRequest(
name=self._table.name)
request_pb.modifications.add(
id=self.column_family_id,
update=column_family)
client = self._table._instance._client
# We expect a `.table_v2_pb2.ColumnFamily`. We ignore it since the only
# data it contains are the GC rule and the column family ID already
# stored on this instance.
client._table_stub.ModifyColumnFamilies(request_pb,
client.timeout_seconds)
def delete(self):
"""Delete this column family."""
request_pb = table_admin_v2_pb2.ModifyColumnFamiliesRequest(
name=self._table.name)
request_pb.modifications.add(
id=self.column_family_id,
drop=True)
client = self._table._instance._client
# We expect a `google.protobuf.empty_pb2.Empty`
client._table_stub.ModifyColumnFamilies(request_pb,
client.timeout_seconds)
def _gc_rule_from_pb(gc_rule_pb):
"""Convert a protobuf GC rule to a native object.
:type gc_rule_pb: :class:`.table_v2_pb2.GcRule`
:param gc_rule_pb: The GC rule to convert.
:rtype: :class:`GarbageCollectionRule` or :data:`NoneType <types.NoneType>`
:returns: An instance of one of the native rules defined
in :module:`column_family` or :data:`None` if no values were
set on the protobuf passed in.
:raises: :class:`ValueError <exceptions.ValueError>` if the rule name
is unexpected.
"""
rule_name = gc_rule_pb.WhichOneof('rule')
if rule_name is None:
return None
if rule_name == 'max_num_versions':
return MaxVersionsGCRule(gc_rule_pb.max_num_versions)
elif rule_name == 'max_age':
max_age = _duration_pb_to_timedelta(gc_rule_pb.max_age)
return MaxAgeGCRule(max_age)
elif rule_name == 'union':
return GCRuleUnion([_gc_rule_from_pb(rule)
for rule in gc_rule_pb.union.rules])
elif rule_name == 'intersection':
rules = [_gc_rule_from_pb(rule)
for rule in gc_rule_pb.intersection.rules]
return GCRuleIntersection(rules)
else:
raise ValueError('Unexpected rule name', rule_name)