Source code for cassandra.metadata

# Copyright DataStax, Inc.
#
# 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.

from binascii import unhexlify
from bisect import bisect_right
from collections import defaultdict, Mapping
from functools import total_ordering
from hashlib import md5
from itertools import islice, cycle
import json
import logging
import re
import six
from six.moves import zip
import sys
from threading import RLock

murmur3 = None
try:
    from cassandra.murmur3 import murmur3
except ImportError as e:
    pass

from cassandra import SignatureDescriptor, ConsistencyLevel, InvalidRequest, Unauthorized
import cassandra.cqltypes as types
from cassandra.encoder import Encoder
from cassandra.marshal import varint_unpack
from cassandra.protocol import QueryMessage
from cassandra.query import dict_factory, bind_params
from cassandra.util import OrderedDict

log = logging.getLogger(__name__)

cql_keywords = set((
    'add', 'aggregate', 'all', 'allow', 'alter', 'and', 'apply', 'as', 'asc', 'ascii', 'authorize', 'batch', 'begin',
    'bigint', 'blob', 'boolean', 'by', 'called', 'clustering', 'columnfamily', 'compact', 'contains', 'count',
    'counter', 'create', 'custom', 'date', 'decimal', 'delete', 'desc', 'describe', 'distinct', 'double', 'drop',
    'entries', 'execute', 'exists', 'filtering', 'finalfunc', 'float', 'from', 'frozen', 'full', 'function',
    'functions', 'grant', 'if', 'in', 'index', 'inet', 'infinity', 'initcond', 'input', 'insert', 'int', 'into', 'is', 'json',
    'key', 'keys', 'keyspace', 'keyspaces', 'language', 'limit', 'list', 'login', 'map', 'materialized', 'modify', 'nan', 'nologin',
    'norecursive', 'nosuperuser', 'not', 'null', 'of', 'on', 'options', 'or', 'order', 'password', 'permission',
    'permissions', 'primary', 'rename', 'replace', 'returns', 'revoke', 'role', 'roles', 'schema', 'select', 'set',
    'sfunc', 'smallint', 'static', 'storage', 'stype', 'superuser', 'table', 'text', 'time', 'timestamp', 'timeuuid',
    'tinyint', 'to', 'token', 'trigger', 'truncate', 'ttl', 'tuple', 'type', 'unlogged', 'update', 'use', 'user',
    'users', 'using', 'uuid', 'values', 'varchar', 'varint', 'view', 'where', 'with', 'writetime'
))
"""
Set of keywords in CQL.

Derived from .../cassandra/src/java/org/apache/cassandra/cql3/Cql.g
"""

cql_keywords_unreserved = set((
    'aggregate', 'all', 'as', 'ascii', 'bigint', 'blob', 'boolean', 'called', 'clustering', 'compact', 'contains',
    'count', 'counter', 'custom', 'date', 'decimal', 'distinct', 'double', 'exists', 'filtering', 'finalfunc', 'float',
    'frozen', 'function', 'functions', 'inet', 'initcond', 'input', 'int', 'json', 'key', 'keys', 'keyspaces',
    'language', 'list', 'login', 'map', 'nologin', 'nosuperuser', 'options', 'password', 'permission', 'permissions',
    'returns', 'role', 'roles', 'sfunc', 'smallint', 'static', 'storage', 'stype', 'superuser', 'text', 'time',
    'timestamp', 'timeuuid', 'tinyint', 'trigger', 'ttl', 'tuple', 'type', 'user', 'users', 'uuid', 'values', 'varchar',
    'varint', 'writetime'
))
"""
Set of unreserved keywords in CQL.

Derived from .../cassandra/src/java/org/apache/cassandra/cql3/Cql.g
"""

cql_keywords_reserved = cql_keywords - cql_keywords_unreserved
"""
Set of reserved keywords in CQL.
"""

_encoder = Encoder()


[docs]class Metadata(object): """ Holds a representation of the cluster schema and topology. """ cluster_name = None """ The string name of the cluster. """ keyspaces = None """ A map from keyspace names to matching :class:`~.KeyspaceMetadata` instances. """ partitioner = None """ The string name of the partitioner for the cluster. """ token_map = None """ A :class:`~.TokenMap` instance describing the ring topology. """ def __init__(self): self.keyspaces = {} self._hosts = {} self._hosts_lock = RLock()
[docs] def export_schema_as_string(self): """ Returns a string that can be executed as a query in order to recreate the entire schema. The string is formatted to be human readable. """ return "\n\n".join(ks.export_as_string() for ks in self.keyspaces.values())
def refresh(self, connection, timeout, target_type=None, change_type=None, **kwargs): server_version = self.get_host(connection.host).release_version parser = get_schema_parser(connection, server_version, timeout) if not target_type: self._rebuild_all(parser) return tt_lower = target_type.lower() try: parse_method = getattr(parser, 'get_' + tt_lower) meta = parse_method(self.keyspaces, **kwargs) if meta: update_method = getattr(self, '_update_' + tt_lower) if tt_lower == 'keyspace' and connection.protocol_version < 3: # we didn't have 'type' target in legacy protocol versions, so we need to query those too user_types = parser.get_types_map(self.keyspaces, **kwargs) self._update_keyspace(meta, user_types) else: update_method(meta) else: drop_method = getattr(self, '_drop_' + tt_lower) drop_method(**kwargs) except AttributeError: raise ValueError("Unknown schema target_type: '%s'" % target_type) def _rebuild_all(self, parser): current_keyspaces = set() for keyspace_meta in parser.get_all_keyspaces(): current_keyspaces.add(keyspace_meta.name) old_keyspace_meta = self.keyspaces.get(keyspace_meta.name, None) self.keyspaces[keyspace_meta.name] = keyspace_meta if old_keyspace_meta: self._keyspace_updated(keyspace_meta.name) else: self._keyspace_added(keyspace_meta.name) # remove not-just-added keyspaces removed_keyspaces = [name for name in self.keyspaces.keys() if name not in current_keyspaces] self.keyspaces = dict((name, meta) for name, meta in self.keyspaces.items() if name in current_keyspaces) for ksname in removed_keyspaces: self._keyspace_removed(ksname) def _update_keyspace(self, keyspace_meta, new_user_types=None): ks_name = keyspace_meta.name old_keyspace_meta = self.keyspaces.get(ks_name, None) self.keyspaces[ks_name] = keyspace_meta if old_keyspace_meta: keyspace_meta.tables = old_keyspace_meta.tables keyspace_meta.user_types = new_user_types if new_user_types is not None else old_keyspace_meta.user_types keyspace_meta.indexes = old_keyspace_meta.indexes keyspace_meta.functions = old_keyspace_meta.functions keyspace_meta.aggregates = old_keyspace_meta.aggregates keyspace_meta.views = old_keyspace_meta.views if (keyspace_meta.replication_strategy != old_keyspace_meta.replication_strategy): self._keyspace_updated(ks_name) else: self._keyspace_added(ks_name) def _drop_keyspace(self, keyspace): if self.keyspaces.pop(keyspace, None): self._keyspace_removed(keyspace) def _update_table(self, meta): try: keyspace_meta = self.keyspaces[meta.keyspace_name] # this is unfortunate, but protocol v4 does not differentiate # between events for tables and views. <parser>.get_table will # return one or the other based on the query results. # Here we deal with that. if isinstance(meta, TableMetadata): keyspace_meta._add_table_metadata(meta) else: keyspace_meta._add_view_metadata(meta) except KeyError: # can happen if keyspace disappears while processing async event pass def _drop_table(self, keyspace, table): try: keyspace_meta = self.keyspaces[keyspace] keyspace_meta._drop_table_metadata(table) # handles either table or view except KeyError: # can happen if keyspace disappears while processing async event pass def _update_type(self, type_meta): try: self.keyspaces[type_meta.keyspace].user_types[type_meta.name] = type_meta except KeyError: # can happen if keyspace disappears while processing async event pass def _drop_type(self, keyspace, type): try: self.keyspaces[keyspace].user_types.pop(type, None) except KeyError: # can happen if keyspace disappears while processing async event pass def _update_function(self, function_meta): try: self.keyspaces[function_meta.keyspace].functions[function_meta.signature] = function_meta except KeyError: # can happen if keyspace disappears while processing async event pass def _drop_function(self, keyspace, function): try: self.keyspaces[keyspace].functions.pop(function.signature, None) except KeyError: pass def _update_aggregate(self, aggregate_meta): try: self.keyspaces[aggregate_meta.keyspace].aggregates[aggregate_meta.signature] = aggregate_meta except KeyError: pass def _drop_aggregate(self, keyspace, aggregate): try: self.keyspaces[keyspace].aggregates.pop(aggregate.signature, None) except KeyError: pass def _keyspace_added(self, ksname): if self.token_map: self.token_map.rebuild_keyspace(ksname, build_if_absent=False) def _keyspace_updated(self, ksname): if self.token_map: self.token_map.rebuild_keyspace(ksname, build_if_absent=False) def _keyspace_removed(self, ksname): if self.token_map: self.token_map.remove_keyspace(ksname) def rebuild_token_map(self, partitioner, token_map): """ Rebuild our view of the topology from fresh rows from the system topology tables. For internal use only. """ self.partitioner = partitioner if partitioner.endswith('RandomPartitioner'): token_class = MD5Token elif partitioner.endswith('Murmur3Partitioner'): token_class = Murmur3Token elif partitioner.endswith('ByteOrderedPartitioner'): token_class = BytesToken else: self.token_map = None return token_to_host_owner = {} ring = [] for host, token_strings in six.iteritems(token_map): for token_string in token_strings: token = token_class.from_string(token_string) ring.append(token) token_to_host_owner[token] = host all_tokens = sorted(ring) self.token_map = TokenMap( token_class, token_to_host_owner, all_tokens, self)
[docs] def get_replicas(self, keyspace, key): """ Returns a list of :class:`.Host` instances that are replicas for a given partition key. """ t = self.token_map if not t: return [] try: return t.get_replicas(keyspace, t.token_class.from_key(key)) except NoMurmur3: return []
def can_support_partitioner(self): if self.partitioner.endswith('Murmur3Partitioner') and murmur3 is None: return False else: return True
[docs] def add_or_return_host(self, host): """ Returns a tuple (host, new), where ``host`` is a Host instance, and ``new`` is a bool indicating whether the host was newly added. """ with self._hosts_lock: try: return self._hosts[host.address], False except KeyError: self._hosts[host.address] = host return host, True
def remove_host(self, host): with self._hosts_lock: return bool(self._hosts.pop(host.address, False)) def get_host(self, address): return self._hosts.get(address)
[docs] def all_hosts(self): """ Returns a list of all known :class:`.Host` instances in the cluster. """ with self._hosts_lock: return list(self._hosts.values())
REPLICATION_STRATEGY_CLASS_PREFIX = "org.apache.cassandra.locator." def trim_if_startswith(s, prefix): if s.startswith(prefix): return s[len(prefix):] return s _replication_strategies = {} class ReplicationStrategyTypeType(type): def __new__(metacls, name, bases, dct): dct.setdefault('name', name) cls = type.__new__(metacls, name, bases, dct) if not name.startswith('_'): _replication_strategies[name] = cls return cls @six.add_metaclass(ReplicationStrategyTypeType) class _ReplicationStrategy(object): options_map = None @classmethod def create(cls, strategy_class, options_map): if not strategy_class: return None strategy_name = trim_if_startswith(strategy_class, REPLICATION_STRATEGY_CLASS_PREFIX) rs_class = _replication_strategies.get(strategy_name, None) if rs_class is None: rs_class = _UnknownStrategyBuilder(strategy_name) _replication_strategies[strategy_name] = rs_class try: rs_instance = rs_class(options_map) except Exception as exc: log.warning("Failed creating %s with options %s: %s", strategy_name, options_map, exc) return None return rs_instance def make_token_replica_map(self, token_to_host_owner, ring): raise NotImplementedError() def export_for_schema(self): raise NotImplementedError() ReplicationStrategy = _ReplicationStrategy class _UnknownStrategyBuilder(object): def __init__(self, name): self.name = name def __call__(self, options_map): strategy_instance = _UnknownStrategy(self.name, options_map) return strategy_instance class _UnknownStrategy(ReplicationStrategy): def __init__(self, name, options_map): self.name = name self.options_map = options_map.copy() if options_map is not None else dict() self.options_map['class'] = self.name def __eq__(self, other): return (isinstance(other, _UnknownStrategy) and self.name == other.name and self.options_map == other.options_map) def export_for_schema(self): """ Returns a string version of these replication options which are suitable for use in a CREATE KEYSPACE statement. """ if self.options_map: return dict((str(key), str(value)) for key, value in self.options_map.items()) return "{'class': '%s'}" % (self.name, ) def make_token_replica_map(self, token_to_host_owner, ring): return {}
[docs]class SimpleStrategy(ReplicationStrategy): replication_factor = None """ The replication factor for this keyspace. """ def __init__(self, options_map): try: self.replication_factor = int(options_map['replication_factor']) except Exception: raise ValueError("SimpleStrategy requires an integer 'replication_factor' option") def make_token_replica_map(self, token_to_host_owner, ring): replica_map = {} for i in range(len(ring)): j, hosts = 0, list() while len(hosts) < self.replication_factor and j < len(ring): token = ring[(i + j) % len(ring)] host = token_to_host_owner[token] if host not in hosts: hosts.append(host) j += 1 replica_map[ring[i]] = hosts return replica_map
[docs] def export_for_schema(self): """ Returns a string version of these replication options which are suitable for use in a CREATE KEYSPACE statement. """ return "{'class': 'SimpleStrategy', 'replication_factor': '%d'}" \ % (self.replication_factor,)
def __eq__(self, other): if not isinstance(other, SimpleStrategy): return False return self.replication_factor == other.replication_factor
[docs]class NetworkTopologyStrategy(ReplicationStrategy): dc_replication_factors = None """ A map of datacenter names to the replication factor for that DC. """ def __init__(self, dc_replication_factors): self.dc_replication_factors = dict( (str(k), int(v)) for k, v in dc_replication_factors.items()) def make_token_replica_map(self, token_to_host_owner, ring): dc_rf_map = dict((dc, int(rf)) for dc, rf in self.dc_replication_factors.items() if rf > 0) # build a map of DCs to lists of indexes into `ring` for tokens that # belong to that DC dc_to_token_offset = defaultdict(list) dc_racks = defaultdict(set) hosts_per_dc = defaultdict(set) for i, token in enumerate(ring): host = token_to_host_owner[token] dc_to_token_offset[host.datacenter].append(i) if host.datacenter and host.rack: dc_racks[host.datacenter].add(host.rack) hosts_per_dc[host.datacenter].add(host) # A map of DCs to an index into the dc_to_token_offset value for that dc. # This is how we keep track of advancing around the ring for each DC. dc_to_current_index = defaultdict(int) replica_map = defaultdict(list) for i in range(len(ring)): replicas = replica_map[ring[i]] # go through each DC and find the replicas in that DC for dc in dc_to_token_offset.keys(): if dc not in dc_rf_map: continue # advance our per-DC index until we're up to at least the # current token in the ring token_offsets = dc_to_token_offset[dc] index = dc_to_current_index[dc] num_tokens = len(token_offsets) while index < num_tokens and token_offsets[index] < i: index += 1 dc_to_current_index[dc] = index replicas_remaining = dc_rf_map[dc] replicas_this_dc = 0 skipped_hosts = [] racks_placed = set() racks_this_dc = dc_racks[dc] hosts_this_dc = len(hosts_per_dc[dc]) for token_offset in islice(cycle(token_offsets), index, index + num_tokens): host = token_to_host_owner[ring[token_offset]] if replicas_remaining == 0 or replicas_this_dc == hosts_this_dc: break if host in replicas: continue if host.rack in racks_placed and len(racks_placed) < len(racks_this_dc): skipped_hosts.append(host) continue replicas.append(host) replicas_this_dc += 1 replicas_remaining -= 1 racks_placed.add(host.rack) if len(racks_placed) == len(racks_this_dc): for host in skipped_hosts: if replicas_remaining == 0: break replicas.append(host) replicas_remaining -= 1 del skipped_hosts[:] return replica_map
[docs] def export_for_schema(self): """ Returns a string version of these replication options which are suitable for use in a CREATE KEYSPACE statement. """ ret = "{'class': 'NetworkTopologyStrategy'" for dc, repl_factor in sorted(self.dc_replication_factors.items()): ret += ", '%s': '%d'" % (dc, repl_factor) return ret + "}"
def __eq__(self, other): if not isinstance(other, NetworkTopologyStrategy): return False return self.dc_replication_factors == other.dc_replication_factors
[docs]class LocalStrategy(ReplicationStrategy): def __init__(self, options_map): pass def make_token_replica_map(self, token_to_host_owner, ring): return {}
[docs] def export_for_schema(self): """ Returns a string version of these replication options which are suitable for use in a CREATE KEYSPACE statement. """ return "{'class': 'LocalStrategy'}"
def __eq__(self, other): return isinstance(other, LocalStrategy)
[docs]class KeyspaceMetadata(object): """ A representation of the schema for a single keyspace. """ name = None """ The string name of the keyspace. """ durable_writes = True """ A boolean indicating whether durable writes are enabled for this keyspace or not. """ replication_strategy = None """ A :class:`.ReplicationStrategy` subclass object. """ tables = None """ A map from table names to instances of :class:`~.TableMetadata`. """ indexes = None """ A dict mapping index names to :class:`.IndexMetadata` instances. """ user_types = None """ A map from user-defined type names to instances of :class:`~cassandra.metadata.UserType`. .. versionadded:: 2.1.0 """ functions = None """ A map from user-defined function signatures to instances of :class:`~cassandra.metadata.Function`. .. versionadded:: 2.6.0 """ aggregates = None """ A map from user-defined aggregate signatures to instances of :class:`~cassandra.metadata.Aggregate`. .. versionadded:: 2.6.0 """ views = None """ A dict mapping view names to :class:`.MaterializedViewMetadata` instances. """ _exc_info = None """ set if metadata parsing failed """ def __init__(self, name, durable_writes, strategy_class, strategy_options): self.name = name self.durable_writes = durable_writes self.replication_strategy = ReplicationStrategy.create(strategy_class, strategy_options) self.tables = {} self.indexes = {} self.user_types = {} self.functions = {} self.aggregates = {} self.views = {}
[docs] def export_as_string(self): """ Returns a CQL query string that can be used to recreate the entire keyspace, including user-defined types and tables. """ cql = "\n\n".join([self.as_cql_query() + ';'] + self.user_type_strings() + [f.export_as_string() for f in self.functions.values()] + [a.export_as_string() for a in self.aggregates.values()] + [t.export_as_string() for t in self.tables.values()]) if self._exc_info: import traceback ret = "/*\nWarning: Keyspace %s is incomplete because of an error processing metadata.\n" % \ (self.name) for line in traceback.format_exception(*self._exc_info): ret += line ret += "\nApproximate structure, for reference:\n(this should not be used to reproduce this schema)\n\n%s\n*/" % cql return ret return cql
[docs] def as_cql_query(self): """ Returns a CQL query string that can be used to recreate just this keyspace, not including user-defined types and tables. """ ret = "CREATE KEYSPACE %s WITH replication = %s " % ( protect_name(self.name), self.replication_strategy.export_for_schema()) return ret + (' AND durable_writes = %s' % ("true" if self.durable_writes else "false"))
def user_type_strings(self): user_type_strings = [] user_types = self.user_types.copy() keys = sorted(user_types.keys()) for k in keys: if k in user_types: self.resolve_user_types(k, user_types, user_type_strings) return user_type_strings def resolve_user_types(self, key, user_types, user_type_strings): user_type = user_types.pop(key) for type_name in user_type.field_types: for sub_type in types.cql_types_from_string(type_name): if sub_type in user_types: self.resolve_user_types(sub_type, user_types, user_type_strings) user_type_strings.append(user_type.export_as_string()) def _add_table_metadata(self, table_metadata): old_indexes = {} old_meta = self.tables.get(table_metadata.name, None) if old_meta: # views are not queried with table, so they must be transferred to new table_metadata.views = old_meta.views # indexes will be updated with what is on the new metadata old_indexes = old_meta.indexes # note the intentional order of add before remove # this makes sure the maps are never absent something that existed before this update for index_name, index_metadata in six.iteritems(table_metadata.indexes): self.indexes[index_name] = index_metadata for index_name in (n for n in old_indexes if n not in table_metadata.indexes): self.indexes.pop(index_name, None) self.tables[table_metadata.name] = table_metadata def _drop_table_metadata(self, table_name): table_meta = self.tables.pop(table_name, None) if table_meta: for index_name in table_meta.indexes: self.indexes.pop(index_name, None) for view_name in table_meta.views: self.views.pop(view_name, None) return # we can't tell table drops from views, so drop both # (name is unique among them, within a keyspace) view_meta = self.views.pop(table_name, None) if view_meta: try: self.tables[view_meta.base_table_name].views.pop(table_name, None) except KeyError: pass def _add_view_metadata(self, view_metadata): try: self.tables[view_metadata.base_table_name].views[view_metadata.name] = view_metadata self.views[view_metadata.name] = view_metadata except KeyError: pass
[docs]class UserType(object): """ A user defined type, as created by ``CREATE TYPE`` statements. User-defined types were introduced in Cassandra 2.1. .. versionadded:: 2.1.0 """ keyspace = None """ The string name of the keyspace in which this type is defined. """ name = None """ The name of this type. """ field_names = None """ An ordered list of the names for each field in this user-defined type. """ field_types = None """ An ordered list of the types for each field in this user-defined type. """ def __init__(self, keyspace, name, field_names, field_types): self.keyspace = keyspace self.name = name # non-frozen collections can return None self.field_names = field_names or [] self.field_types = field_types or []
[docs] def as_cql_query(self, formatted=False): """ Returns a CQL query that can be used to recreate this type. If `formatted` is set to :const:`True`, extra whitespace will be added to make the query more readable. """ ret = "CREATE TYPE %s.%s (%s" % ( protect_name(self.keyspace), protect_name(self.name), "\n" if formatted else "") if formatted: field_join = ",\n" padding = " " else: field_join = ", " padding = "" fields = [] for field_name, field_type in zip(self.field_names, self.field_types): fields.append("%s %s" % (protect_name(field_name), field_type)) ret += field_join.join("%s%s" % (padding, field) for field in fields) ret += "\n)" if formatted else ")" return ret
def export_as_string(self): return self.as_cql_query(formatted=True) + ';'
[docs]class Aggregate(object): """ A user defined aggregate function, as created by ``CREATE AGGREGATE`` statements. Aggregate functions were introduced in Cassandra 2.2 .. versionadded:: 2.6.0 """ keyspace = None """ The string name of the keyspace in which this aggregate is defined """ name = None """ The name of this aggregate """ argument_types = None """ An ordered list of the types for each argument to the aggregate """ final_func = None """ Name of a final function """ initial_condition = None """ Initial condition of the aggregate """ return_type = None """ Return type of the aggregate """ state_func = None """ Name of a state function """ state_type = None """ Type of the aggregate state """ def __init__(self, keyspace, name, argument_types, state_func, state_type, final_func, initial_condition, return_type): self.keyspace = keyspace self.name = name self.argument_types = argument_types self.state_func = state_func self.state_type = state_type self.final_func = final_func self.initial_condition = initial_condition self.return_type = return_type
[docs] def as_cql_query(self, formatted=False): """ Returns a CQL query that can be used to recreate this aggregate. If `formatted` is set to :const:`True`, extra whitespace will be added to make the query more readable. """ sep = '\n ' if formatted else ' ' keyspace = protect_name(self.keyspace) name = protect_name(self.name) type_list = ', '.join(self.argument_types) state_func = protect_name(self.state_func) state_type = self.state_type ret = "CREATE AGGREGATE %(keyspace)s.%(name)s(%(type_list)s)%(sep)s" \ "SFUNC %(state_func)s%(sep)s" \ "STYPE %(state_type)s" % locals() ret += ''.join((sep, 'FINALFUNC ', protect_name(self.final_func))) if self.final_func else '' ret += ''.join((sep, 'INITCOND ', self.initial_condition)) if self.initial_condition is not None else '' return ret
def export_as_string(self): return self.as_cql_query(formatted=True) + ';' @property def signature(self): return SignatureDescriptor.format_signature(self.name, self.argument_types)
[docs]class Function(object): """ A user defined function, as created by ``CREATE FUNCTION`` statements. User-defined functions were introduced in Cassandra 2.2 .. versionadded:: 2.6.0 """ keyspace = None """ The string name of the keyspace in which this function is defined """ name = None """ The name of this function """ argument_types = None """ An ordered list of the types for each argument to the function """ argument_names = None """ An ordered list of the names of each argument to the function """ return_type = None """ Return type of the function """ language = None """ Language of the function body """ body = None """ Function body string """ called_on_null_input = None """ Flag indicating whether this function should be called for rows with null values (convenience function to avoid handling nulls explicitly if the result will just be null) """ def __init__(self, keyspace, name, argument_types, argument_names, return_type, language, body, called_on_null_input): self.keyspace = keyspace self.name = name self.argument_types = argument_types # argument_types (frozen<list<>>) will always be a list # argument_name is not frozen in C* < 3.0 and may return None self.argument_names = argument_names or [] self.return_type = return_type self.language = language self.body = body self.called_on_null_input = called_on_null_input
[docs] def as_cql_query(self, formatted=False): """ Returns a CQL query that can be used to recreate this function. If `formatted` is set to :const:`True`, extra whitespace will be added to make the query more readable. """ sep = '\n ' if formatted else ' ' keyspace = protect_name(self.keyspace) name = protect_name(self.name) arg_list = ', '.join(["%s %s" % (protect_name(n), t) for n, t in zip(self.argument_names, self.argument_types)]) typ = self.return_type lang = self.language body = self.body on_null = "CALLED" if self.called_on_null_input else "RETURNS NULL" return "CREATE FUNCTION %(keyspace)s.%(name)s(%(arg_list)s)%(sep)s" \ "%(on_null)s ON NULL INPUT%(sep)s" \ "RETURNS %(typ)s%(sep)s" \ "LANGUAGE %(lang)s%(sep)s" \ "AS $$%(body)s$$" % locals()
def export_as_string(self): return self.as_cql_query(formatted=True) + ';' @property def signature(self): return SignatureDescriptor.format_signature(self.name, self.argument_types)
[docs]class TableMetadata(object): """ A representation of the schema for a single table. """ keyspace_name = None """ String name of this Table's keyspace """ name = None """ The string name of the table. """ partition_key = None """ A list of :class:`.ColumnMetadata` instances representing the columns in the partition key for this table. This will always hold at least one column. """ clustering_key = None """ A list of :class:`.ColumnMetadata` instances representing the columns in the clustering key for this table. These are all of the :attr:`.primary_key` columns that are not in the :attr:`.partition_key`. Note that a table may have no clustering keys, in which case this will be an empty list. """ @property def primary_key(self): """ A list of :class:`.ColumnMetadata` representing the components of the primary key for this table. """ return self.partition_key + self.clustering_key columns = None """ A dict mapping column names to :class:`.ColumnMetadata` instances. """ indexes = None """ A dict mapping index names to :class:`.IndexMetadata` instances. """ is_compact_storage = False options = None """ A dict mapping table option names to their specific settings for this table. """ compaction_options = { "min_compaction_threshold": "min_threshold", "max_compaction_threshold": "max_threshold", "compaction_strategy_class": "class"} triggers = None """ A dict mapping trigger names to :class:`.TriggerMetadata` instances. """ views = None """ A dict mapping view names to :class:`.MaterializedViewMetadata` instances. """ _exc_info = None """ set if metadata parsing failed """ @property def is_cql_compatible(self): """ A boolean indicating if this table can be represented as CQL in export """ comparator = getattr(self, 'comparator', None) if comparator: # no compact storage with more than one column beyond PK if there # are clustering columns incompatible = (self.is_compact_storage and len(self.columns) > len(self.primary_key) + 1 and len(self.clustering_key) >= 1) return not incompatible return True extensions = None """ Metadata describing configuration for table extensions """ def __init__(self, keyspace_name, name, partition_key=None, clustering_key=None, columns=None, triggers=None, options=None): self.keyspace_name = keyspace_name self.name = name self.partition_key = [] if partition_key is None else partition_key self.clustering_key = [] if clustering_key is None else clustering_key self.columns = OrderedDict() if columns is None else columns self.indexes = {} self.options = {} if options is None else options self.comparator = None self.triggers = OrderedDict() if triggers is None else triggers self.views = {}
[docs] def export_as_string(self): """ Returns a string of CQL queries that can be used to recreate this table along with all indexes on it. The returned string is formatted to be human readable. """ if self._exc_info: import traceback ret = "/*\nWarning: Table %s.%s is incomplete because of an error processing metadata.\n" % \ (self.keyspace_name, self.name) for line in traceback.format_exception(*self._exc_info): ret += line ret += "\nApproximate structure, for reference:\n(this should not be used to reproduce this schema)\n\n%s\n*/" % self._all_as_cql() elif not self.is_cql_compatible: # If we can't produce this table with CQL, comment inline ret = "/*\nWarning: Table %s.%s omitted because it has constructs not compatible with CQL (was created via legacy API).\n" % \ (self.keyspace_name, self.name) ret += "\nApproximate structure, for reference:\n(this should not be used to reproduce this schema)\n\n%s\n*/" % self._all_as_cql() else: ret = self._all_as_cql() return ret
def _all_as_cql(self): ret = self.as_cql_query(formatted=True) ret += ";" for index in self.indexes.values(): ret += "\n%s;" % index.as_cql_query() for trigger_meta in self.triggers.values(): ret += "\n%s;" % (trigger_meta.as_cql_query(),) for view_meta in self.views.values(): ret += "\n\n%s;" % (view_meta.as_cql_query(formatted=True),) if self.extensions: registry = _RegisteredExtensionType._extension_registry for k in six.viewkeys(registry) & self.extensions: # no viewkeys on OrderedMapSerializeKey ext = registry[k] cql = ext.after_table_cql(self, k, self.extensions[k]) if cql: ret += "\n\n%s" % (cql,) return ret
[docs] def as_cql_query(self, formatted=False): """ Returns a CQL query that can be used to recreate this table (index creations are not included). If `formatted` is set to :const:`True`, extra whitespace will be added to make the query human readable. """ ret = "CREATE TABLE %s.%s (%s" % ( protect_name(self.keyspace_name), protect_name(self.name), "\n" if formatted else "") if formatted: column_join = ",\n" padding = " " else: column_join = ", " padding = "" columns = [] for col in self.columns.values(): columns.append("%s %s%s" % (protect_name(col.name), col.cql_type, ' static' if col.is_static else '')) if len(self.partition_key) == 1 and not self.clustering_key: columns[0] += " PRIMARY KEY" ret += column_join.join("%s%s" % (padding, col) for col in columns) # primary key if len(self.partition_key) > 1 or self.clustering_key: ret += "%s%sPRIMARY KEY (" % (column_join, padding) if len(self.partition_key) > 1: ret += "(%s)" % ", ".join(protect_name(col.name) for col in self.partition_key) else: ret += protect_name(self.partition_key[0].name) if self.clustering_key: ret += ", %s" % ", ".join(protect_name(col.name) for col in self.clustering_key) ret += ")" # properties ret += "%s) WITH " % ("\n" if formatted else "") ret += self._property_string(formatted, self.clustering_key, self.options, self.is_compact_storage) return ret
@classmethod def _property_string(cls, formatted, clustering_key, options_map, is_compact_storage=False): properties = [] if is_compact_storage: properties.append("COMPACT STORAGE") if clustering_key: cluster_str = "CLUSTERING ORDER BY " inner = [] for col in clustering_key: ordering = "DESC" if col.is_reversed else "ASC" inner.append("%s %s" % (protect_name(col.name), ordering)) cluster_str += "(%s)" % ", ".join(inner) properties.append(cluster_str) properties.extend(cls._make_option_strings(options_map)) join_str = "\n AND " if formatted else " AND " return join_str.join(properties) @classmethod def _make_option_strings(cls, options_map): ret = [] options_copy = dict(options_map.items()) actual_options = json.loads(options_copy.pop('compaction_strategy_options', '{}')) value = options_copy.pop("compaction_strategy_class", None) actual_options.setdefault("class", value) compaction_option_strings = ["'%s': '%s'" % (k, v) for k, v in actual_options.items()] ret.append('compaction = {%s}' % ', '.join(compaction_option_strings)) for system_table_name in cls.compaction_options.keys(): options_copy.pop(system_table_name, None) # delete if present options_copy.pop('compaction_strategy_option', None) if not options_copy.get('compression'): params = json.loads(options_copy.pop('compression_parameters', '{}')) param_strings = ["'%s': '%s'" % (k, v) for k, v in params.items()] ret.append('compression = {%s}' % ', '.join(param_strings)) for name, value in options_copy.items(): if value is not None: if name == "comment": value = value or "" ret.append("%s = %s" % (name, protect_value(value))) return list(sorted(ret))
class TableExtensionInterface(object): """ Defines CQL/DDL for Cassandra table extensions. """ # limited API for now. Could be expanded as new extension types materialize -- "extend_option_strings", for example @classmethod def after_table_cql(cls, ext_key, ext_blob): """ Called to produce CQL/DDL to follow the table definition. Should contain requisite terminating semicolon(s). """ pass class _RegisteredExtensionType(type): _extension_registry = {} def __new__(mcs, name, bases, dct): cls = super(_RegisteredExtensionType, mcs).__new__(mcs, name, bases, dct) if name != 'RegisteredTableExtension': mcs._extension_registry[cls.name] = cls return cls @six.add_metaclass(_RegisteredExtensionType) class RegisteredTableExtension(TableExtensionInterface): """ Extending this class registers it by name (associated by key in the `system_schema.tables.extensions` map). """ name = None """ Name of the extension (key in the map) """ def protect_name(name): return maybe_escape_name(name) def protect_names(names): return [protect_name(n) for n in names] def protect_value(value): if value is None: return 'NULL' if isinstance(value, (int, float, bool)): return str(value).lower() return "'%s'" % value.replace("'", "''") valid_cql3_word_re = re.compile(r'^[a-z][0-9a-z_]*$') def is_valid_name(name): if name is None: return False if name.lower() in cql_keywords_reserved: return False return valid_cql3_word_re.match(name) is not None def maybe_escape_name(name): if is_valid_name(name): return name return escape_name(name) def escape_name(name): return '"%s"' % (name.replace('"', '""'),)
[docs]class ColumnMetadata(object): """ A representation of a single column in a table. """ table = None """ The :class:`.TableMetadata` this column belongs to. """ name = None """ The string name of this column. """ cql_type = None """ The CQL type for the column. """ is_static = False """ If this column is static (available in Cassandra 2.1+), this will be :const:`True`, otherwise :const:`False`. """ is_reversed = False """ If this column is reversed (DESC) as in clustering order """ _cass_type = None def __init__(self, table_metadata, column_name, cql_type, is_static=False, is_reversed=False): self.table = table_metadata self.name = column_name self.cql_type = cql_type self.is_static = is_static self.is_reversed = is_reversed def __str__(self): return "%s %s" % (self.name, self.cql_type)
[docs]class IndexMetadata(object): """ A representation of a secondary index on a column. """ keyspace_name = None """ A string name of the keyspace. """ table_name = None """ A string name of the table this index is on. """ name = None """ A string name for the index. """ kind = None """ A string representing the kind of index (COMPOSITE, CUSTOM,...). """ index_options = {} """ A dict of index options. """ def __init__(self, keyspace_name, table_name, index_name, kind, index_options): self.keyspace_name = keyspace_name self.table_name = table_name self.name = index_name self.kind = kind self.index_options = index_options
[docs] def as_cql_query(self): """ Returns a CQL query that can be used to recreate this index. """ options = dict(self.index_options) index_target = options.pop("target") if self.kind != "CUSTOM": return "CREATE INDEX %s ON %s.%s (%s)" % ( protect_name(self.name), protect_name(self.keyspace_name), protect_name(self.table_name), index_target) else: class_name = options.pop("class_name") ret = "CREATE CUSTOM INDEX %s ON %s.%s (%s) USING '%s'" % ( protect_name(self.name), protect_name(self.keyspace_name), protect_name(self.table_name), index_target, class_name) if options: ret += " WITH OPTIONS = %s" % Encoder().cql_encode_all_types(options) return ret
[docs] def export_as_string(self): """ Returns a CQL query string that can be used to recreate this index. """ return self.as_cql_query() + ';'
[docs]class TokenMap(object): """ Information about the layout of the ring. """ token_class = None """ A subclass of :class:`.Token`, depending on what partitioner the cluster uses. """ token_to_host_owner = None """ A map of :class:`.Token` objects to the :class:`.Host` that owns that token. """ tokens_to_hosts_by_ks = None """ A map of keyspace names to a nested map of :class:`.Token` objects to sets of :class:`.Host` objects. """ ring = None """ An ordered list of :class:`.Token` instances in the ring. """ _metadata = None def __init__(self, token_class, token_to_host_owner, all_tokens, metadata): self.token_class = token_class self.ring = all_tokens self.token_to_host_owner = token_to_host_owner self.tokens_to_hosts_by_ks = {} self._metadata = metadata self._rebuild_lock = RLock() def rebuild_keyspace(self, keyspace, build_if_absent=False): with self._rebuild_lock: try: current = self.tokens_to_hosts_by_ks.get(keyspace, None) if (build_if_absent and current is None) or (not build_if_absent and current is not None): ks_meta = self._metadata.keyspaces.get(keyspace) if ks_meta: replica_map = self.replica_map_for_keyspace(self._metadata.keyspaces[keyspace]) self.tokens_to_hosts_by_ks[keyspace] = replica_map except Exception: # should not happen normally, but we don't want to blow up queries because of unexpected meta state # bypass until new map is generated self.tokens_to_hosts_by_ks[keyspace] = {} log.exception("Failed creating a token map for keyspace '%s' with %s. PLEASE REPORT THIS: https://datastax-oss.atlassian.net/projects/PYTHON", keyspace, self.token_to_host_owner) def replica_map_for_keyspace(self, ks_metadata): strategy = ks_metadata.replication_strategy if strategy: return strategy.make_token_replica_map(self.token_to_host_owner, self.ring) else: return None def remove_keyspace(self, keyspace): self.tokens_to_hosts_by_ks.pop(keyspace, None)
[docs] def get_replicas(self, keyspace, token): """ Get a set of :class:`.Host` instances representing all of the replica nodes for a given :class:`.Token`. """ tokens_to_hosts = self.tokens_to_hosts_by_ks.get(keyspace, None) if tokens_to_hosts is None: self.rebuild_keyspace(keyspace, build_if_absent=True) tokens_to_hosts = self.tokens_to_hosts_by_ks.get(keyspace, None) if tokens_to_hosts: # token range ownership is exclusive on the LHS (the start token), so # we use bisect_right, which, in the case of a tie/exact match, # picks an insertion point to the right of the existing match point = bisect_right(self.ring, token) if point == len(self.ring): return tokens_to_hosts[self.ring[0]] else: return tokens_to_hosts[self.ring[point]] return []
[docs]@total_ordering class Token(object): """ Abstract class representing a token. """ def __init__(self, token): self.value = token @classmethod def hash_fn(cls, key): return key @classmethod def from_key(cls, key): return cls(cls.hash_fn(key)) @classmethod def from_string(cls, token_string): raise NotImplementedError() def __eq__(self, other): return self.value == other.value def __lt__(self, other): return self.value < other.value def __hash__(self): return hash(self.value) def __repr__(self): return "<%s: %s>" % (self.__class__.__name__, self.value) __str__ = __repr__
MIN_LONG = -(2 ** 63) MAX_LONG = (2 ** 63) - 1 class NoMurmur3(Exception): pass class HashToken(Token): @classmethod def from_string(cls, token_string): """ `token_string` should be the string representation from the server. """ # The hash partitioners just store the deciman value return cls(int(token_string))
[docs]class Murmur3Token(HashToken): """ A token for ``Murmur3Partitioner``. """ @classmethod def hash_fn(cls, key): if murmur3 is not None: h = int(murmur3(key)) return h if h != MIN_LONG else MAX_LONG else: raise NoMurmur3() def __init__(self, token): """ `token` is an int or string representing the token. """ self.value = int(token)
[docs]class MD5Token(HashToken): """ A token for ``RandomPartitioner``. """ @classmethod def hash_fn(cls, key): if isinstance(key, six.text_type): key = key.encode('UTF-8') return abs(varint_unpack(md5(key).digest()))
[docs]class BytesToken(Token): """ A token for ``ByteOrderedPartitioner``. """
[docs] @classmethod def from_string(cls, token_string): """ `token_string` should be the string representation from the server. """ # unhexlify works fine with unicode input in everythin but pypy3, where it Raises "TypeError: 'str' does not support the buffer interface" if isinstance(token_string, six.text_type): token_string = token_string.encode('ascii') # The BOP stores a hex string return cls(unhexlify(token_string))
class TriggerMetadata(object): """ A representation of a trigger for a table. """ table = None """ The :class:`.TableMetadata` this trigger belongs to. """ name = None """ The string name of this trigger. """ options = None """ A dict mapping trigger option names to their specific settings for this table. """ def __init__(self, table_metadata, trigger_name, options=None): self.table = table_metadata self.name = trigger_name self.options = options def as_cql_query(self): ret = "CREATE TRIGGER %s ON %s.%s USING %s" % ( protect_name(self.name), protect_name(self.table.keyspace_name), protect_name(self.table.name), protect_value(self.options['class']) ) return ret def export_as_string(self): return self.as_cql_query() + ';' class _SchemaParser(object): def __init__(self, connection, timeout): self.connection = connection self.timeout = timeout def _handle_results(self, success, result): if success: return dict_factory(*result.results) if result else [] else: raise result def _query_build_row(self, query_string, build_func): result = self._query_build_rows(query_string, build_func) return result[0] if result else None def _query_build_rows(self, query_string, build_func): query = QueryMessage(query=query_string, consistency_level=ConsistencyLevel.ONE) responses = self.connection.wait_for_responses((query), timeout=self.timeout, fail_on_error=False) (success, response) = responses[0] if success: result = dict_factory(*response.results) return [build_func(row) for row in result] elif isinstance(response, InvalidRequest): log.debug("user types table not found") return [] else: raise response class SchemaParserV22(_SchemaParser): _SELECT_KEYSPACES = "SELECT * FROM system.schema_keyspaces" _SELECT_COLUMN_FAMILIES = "SELECT * FROM system.schema_columnfamilies" _SELECT_COLUMNS = "SELECT * FROM system.schema_columns" _SELECT_TRIGGERS = "SELECT * FROM system.schema_triggers" _SELECT_TYPES = "SELECT * FROM system.schema_usertypes" _SELECT_FUNCTIONS = "SELECT * FROM system.schema_functions" _SELECT_AGGREGATES = "SELECT * FROM system.schema_aggregates" _table_name_col = 'columnfamily_name' _function_agg_arument_type_col = 'signature' recognized_table_options = ( "comment", "read_repair_chance", "dclocal_read_repair_chance", # kept to be safe, but see _build_table_options() "local_read_repair_chance", "replicate_on_write", "gc_grace_seconds", "bloom_filter_fp_chance", "caching", "compaction_strategy_class", "compaction_strategy_options", "min_compaction_threshold", "max_compaction_threshold", "compression_parameters", "min_index_interval", "max_index_interval", "index_interval", "speculative_retry", "rows_per_partition_to_cache", "memtable_flush_period_in_ms", "populate_io_cache_on_flush", "compression", "default_time_to_live") def __init__(self, connection, timeout): super(SchemaParserV22, self).__init__(connection, timeout) self.keyspaces_result = [] self.tables_result = [] self.columns_result = [] self.triggers_result = [] self.types_result = [] self.functions_result = [] self.aggregates_result = [] self.keyspace_table_rows = defaultdict(list) self.keyspace_table_col_rows = defaultdict(lambda: defaultdict(list)) self.keyspace_type_rows = defaultdict(list) self.keyspace_func_rows = defaultdict(list) self.keyspace_agg_rows = defaultdict(list) self.keyspace_table_trigger_rows = defaultdict(lambda: defaultdict(list)) def get_all_keyspaces(self): self._query_all() for row in self.keyspaces_result: keyspace_meta = self._build_keyspace_metadata(row) try: for table_row in self.keyspace_table_rows.get(keyspace_meta.name, []): table_meta = self._build_table_metadata(table_row) keyspace_meta._add_table_metadata(table_meta) for usertype_row in self.keyspace_type_rows.get(keyspace_meta.name, []): usertype = self._build_user_type(usertype_row) keyspace_meta.user_types[usertype.name] = usertype for fn_row in self.keyspace_func_rows.get(keyspace_meta.name, []): fn = self._build_function(fn_row) keyspace_meta.functions[fn.signature] = fn for agg_row in self.keyspace_agg_rows.get(keyspace_meta.name, []): agg = self._build_aggregate(agg_row) keyspace_meta.aggregates[agg.signature] = agg except Exception: log.exception("Error while parsing metadata for keyspace %s. Metadata model will be incomplete.", keyspace_meta.name) keyspace_meta._exc_info = sys.exc_info() yield keyspace_meta def get_table(self, keyspaces, keyspace, table): cl = ConsistencyLevel.ONE where_clause = bind_params(" WHERE keyspace_name = %%s AND %s = %%s" % (self._table_name_col,), (keyspace, table), _encoder) cf_query = QueryMessage(query=self._SELECT_COLUMN_FAMILIES + where_clause, consistency_level=cl) col_query = QueryMessage(query=self._SELECT_COLUMNS + where_clause, consistency_level=cl) triggers_query = QueryMessage(query=self._SELECT_TRIGGERS + where_clause, consistency_level=cl) (cf_success, cf_result), (col_success, col_result), (triggers_success, triggers_result) \ = self.connection.wait_for_responses(cf_query, col_query, triggers_query, timeout=self.timeout, fail_on_error=False) table_result = self._handle_results(cf_success, cf_result) col_result = self._handle_results(col_success, col_result) # handle the triggers table not existing in Cassandra 1.2 if not triggers_success and isinstance(triggers_result, InvalidRequest): triggers_result = [] else: triggers_result = self._handle_results(triggers_success, triggers_result) if table_result: return self._build_table_metadata(table_result[0], col_result, triggers_result) def get_type(self, keyspaces, keyspace, type): where_clause = bind_params(" WHERE keyspace_name = %s AND type_name = %s", (keyspace, type), _encoder) return self._query_build_row(self._SELECT_TYPES + where_clause, self._build_user_type) def get_types_map(self, keyspaces, keyspace): where_clause = bind_params(" WHERE keyspace_name = %s", (keyspace,), _encoder) types = self._query_build_rows(self._SELECT_TYPES + where_clause, self._build_user_type) return dict((t.name, t) for t in types) def get_function(self, keyspaces, keyspace, function): where_clause = bind_params(" WHERE keyspace_name = %%s AND function_name = %%s AND %s = %%s" % (self._function_agg_arument_type_col,), (keyspace, function.name, function.argument_types), _encoder) return self._query_build_row(self._SELECT_FUNCTIONS + where_clause, self._build_function) def get_aggregate(self, keyspaces, keyspace, aggregate): where_clause = bind_params(" WHERE keyspace_name = %%s AND aggregate_name = %%s AND %s = %%s" % (self._function_agg_arument_type_col,), (keyspace, aggregate.name, aggregate.argument_types), _encoder) return self._query_build_row(self._SELECT_AGGREGATES + where_clause, self._build_aggregate) def get_keyspace(self, keyspaces, keyspace): where_clause = bind_params(" WHERE keyspace_name = %s", (keyspace,), _encoder) return self._query_build_row(self._SELECT_KEYSPACES + where_clause, self._build_keyspace_metadata) @classmethod def _build_keyspace_metadata(cls, row): try: ksm = cls._build_keyspace_metadata_internal(row) except Exception: name = row["keyspace_name"] ksm = KeyspaceMetadata(name, False, 'UNKNOWN', {}) ksm._exc_info = sys.exc_info() # capture exc_info before log because nose (test) logging clears it in certain circumstances log.exception("Error while parsing metadata for keyspace %s row(%s)", name, row) return ksm @staticmethod def _build_keyspace_metadata_internal(row): name = row["keyspace_name"] durable_writes = row["durable_writes"] strategy_class = row["strategy_class"] strategy_options = json.loads(row["strategy_options"]) return KeyspaceMetadata(name, durable_writes, strategy_class, strategy_options) @classmethod def _build_user_type(cls, usertype_row): field_types = list(map(cls._schema_type_to_cql, usertype_row['field_types'])) return UserType(usertype_row['keyspace_name'], usertype_row['type_name'], usertype_row['field_names'], field_types) @classmethod def _build_function(cls, function_row): return_type = cls._schema_type_to_cql(function_row['return_type']) return Function(function_row['keyspace_name'], function_row['function_name'], function_row[cls._function_agg_arument_type_col], function_row['argument_names'], return_type, function_row['language'], function_row['body'], function_row['called_on_null_input']) @classmethod def _build_aggregate(cls, aggregate_row): cass_state_type = types.lookup_casstype(aggregate_row['state_type']) initial_condition = aggregate_row['initcond'] if initial_condition is not None: initial_condition = _encoder.cql_encode_all_types(cass_state_type.deserialize(initial_condition, 3)) state_type = _cql_from_cass_type(cass_state_type) return_type = cls._schema_type_to_cql(aggregate_row['return_type']) return Aggregate(aggregate_row['keyspace_name'], aggregate_row['aggregate_name'], aggregate_row['signature'], aggregate_row['state_func'], state_type, aggregate_row['final_func'], initial_condition, return_type) def _build_table_metadata(self, row, col_rows=None, trigger_rows=None): keyspace_name = row["keyspace_name"] cfname = row[self._table_name_col] col_rows = col_rows or self.keyspace_table_col_rows[keyspace_name][cfname] trigger_rows = trigger_rows or self.keyspace_table_trigger_rows[keyspace_name][cfname] if not col_rows: # CASSANDRA-8487 log.warning("Building table metadata with no column meta for %s.%s", keyspace_name, cfname) table_meta = TableMetadata(keyspace_name, cfname) try: comparator = types.lookup_casstype(row["comparator"]) table_meta.comparator = comparator is_dct_comparator = issubclass(comparator, types.DynamicCompositeType) is_composite_comparator = issubclass(comparator, types.CompositeType) column_name_types = comparator.subtypes if is_composite_comparator else (comparator,) num_column_name_components = len(column_name_types) last_col = column_name_types[-1] column_aliases = row.get("column_aliases", None) clustering_rows = [r for r in col_rows if r.get('type', None) == "clustering_key"] if len(clustering_rows) > 1: clustering_rows = sorted(clustering_rows, key=lambda row: row.get('component_index')) if column_aliases is not None: column_aliases = json.loads(column_aliases) if not column_aliases: # json load failed or column_aliases empty PYTHON-562 column_aliases = [r.get('column_name') for r in clustering_rows] if is_composite_comparator: if issubclass(last_col, types.ColumnToCollectionType): # collections is_compact = False has_value = False clustering_size = num_column_name_components - 2 elif (len(column_aliases) == num_column_name_components - 1 and issubclass(last_col, types.UTF8Type)): # aliases? is_compact = False has_value = False clustering_size = num_column_name_components - 1 else: # compact table is_compact = True has_value = column_aliases or not col_rows clustering_size = num_column_name_components # Some thrift tables define names in composite types (see PYTHON-192) if not column_aliases and hasattr(comparator, 'fieldnames'): column_aliases = filter(None, comparator.fieldnames) else: is_compact = True if column_aliases or not col_rows or is_dct_comparator: has_value = True clustering_size = num_column_name_components else: has_value = False clustering_size = 0 # partition key partition_rows = [r for r in col_rows if r.get('type', None) == "partition_key"] if len(partition_rows) > 1: partition_rows = sorted(partition_rows, key=lambda row: row.get('component_index')) key_aliases = row.get("key_aliases") if key_aliases is not None: key_aliases = json.loads(key_aliases) if key_aliases else [] else: # In 2.0+, we can use the 'type' column. In 3.0+, we have to use it. key_aliases = [r.get('column_name') for r in partition_rows] key_validator = row.get("key_validator") if key_validator is not None: key_type = types.lookup_casstype(key_validator) key_types = key_type.subtypes if issubclass(key_type, types.CompositeType) else [key_type] else: key_types = [types.lookup_casstype(r.get('validator')) for r in partition_rows] for i, col_type in enumerate(key_types): if len(key_aliases) > i: column_name = key_aliases[i] elif i == 0: column_name = "key" else: column_name = "key%d" % i col = ColumnMetadata(table_meta, column_name, col_type.cql_parameterized_type()) table_meta.columns[column_name] = col table_meta.partition_key.append(col) # clustering key for i in range(clustering_size): if len(column_aliases) > i: column_name = column_aliases[i] else: column_name = "column%d" % (i + 1) data_type = column_name_types[i] cql_type = _cql_from_cass_type(data_type) is_reversed = types.is_reversed_casstype(data_type) col = ColumnMetadata(table_meta, column_name, cql_type, is_reversed=is_reversed) table_meta.columns[column_name] = col table_meta.clustering_key.append(col) # value alias (if present) if has_value: value_alias_rows = [r for r in col_rows if r.get('type', None) == "compact_value"] if not key_aliases: # TODO are we checking the right thing here? value_alias = "value" else: value_alias = row.get("value_alias", None) if value_alias is None and value_alias_rows: # CASSANDRA-8487 # In 2.0+, we can use the 'type' column. In 3.0+, we have to use it. value_alias = value_alias_rows[0].get('column_name') default_validator = row.get("default_validator") if default_validator: validator = types.lookup_casstype(default_validator) else: if value_alias_rows: # CASSANDRA-8487 validator = types.lookup_casstype(value_alias_rows[0].get('validator')) cql_type = _cql_from_cass_type(validator) col = ColumnMetadata(table_meta, value_alias, cql_type) if value_alias: # CASSANDRA-8487 table_meta.columns[value_alias] = col # other normal columns for col_row in col_rows: column_meta = self._build_column_metadata(table_meta, col_row) if column_meta.name: table_meta.columns[column_meta.name] = column_meta index_meta = self._build_index_metadata(column_meta, col_row) if index_meta: table_meta.indexes[index_meta.name] = index_meta for trigger_row in trigger_rows: trigger_meta = self._build_trigger_metadata(table_meta, trigger_row) table_meta.triggers[trigger_meta.name] = trigger_meta table_meta.options = self._build_table_options(row) table_meta.is_compact_storage = is_compact except Exception: table_meta._exc_info = sys.exc_info() log.exception("Error while parsing metadata for table %s.%s row(%s) columns(%s)", keyspace_name, cfname, row, col_rows) return table_meta def _build_table_options(self, row): """ Setup the mostly-non-schema table options, like caching settings """ options = dict((o, row.get(o)) for o in self.recognized_table_options if o in row) # the option name when creating tables is "dclocal_read_repair_chance", # but the column name in system.schema_columnfamilies is # "local_read_repair_chance". We'll store this as dclocal_read_repair_chance, # since that's probably what users are expecting (and we need it for the # CREATE TABLE statement anyway). if "local_read_repair_chance" in options: val = options.pop("local_read_repair_chance") options["dclocal_read_repair_chance"] = val return options @classmethod def _build_column_metadata(cls, table_metadata, row): name = row["column_name"] type_string = row["validator"] data_type = types.lookup_casstype(type_string) cql_type = _cql_from_cass_type(data_type) is_static = row.get("type", None) == "static" is_reversed = types.is_reversed_casstype(data_type) column_meta = ColumnMetadata(table_metadata, name, cql_type, is_static, is_reversed) column_meta._cass_type = data_type return column_meta @staticmethod def _build_index_metadata(column_metadata, row): index_name = row.get("index_name") kind = row.get("index_type") if index_name or kind: options = row.get("index_options") options = json.loads(options) if options else {} options = options or {} # if the json parsed to None, init empty dict # generate a CQL index identity string target = protect_name(column_metadata.name) if kind != "CUSTOM": if "index_keys" in options: target = 'keys(%s)' % (target,) elif "index_values" in options: # don't use any "function" for collection values pass else: # it might be a "full" index on a frozen collection, but # we need to check the data type to verify that, because # there is no special index option for full-collection # indexes. data_type = column_metadata._cass_type collection_types = ('map', 'set', 'list') if data_type.typename == "frozen" and data_type.subtypes[0].typename in collection_types: # no index option for full-collection index target = 'full(%s)' % (target,) options['target'] = target return IndexMetadata(column_metadata.table.keyspace_name, column_metadata.table.name, index_name, kind, options) @staticmethod def _build_trigger_metadata(table_metadata, row): name = row["trigger_name"] options = row["trigger_options"] trigger_meta = TriggerMetadata(table_metadata, name, options) return trigger_meta def _query_all(self): cl = ConsistencyLevel.ONE queries = [ QueryMessage(query=self._SELECT_KEYSPACES, consistency_level=cl), QueryMessage(query=self._SELECT_COLUMN_FAMILIES, consistency_level=cl), QueryMessage(query=self._SELECT_COLUMNS, consistency_level=cl), QueryMessage(query=self._SELECT_TYPES, consistency_level=cl), QueryMessage(query=self._SELECT_FUNCTIONS, consistency_level=cl), QueryMessage(query=self._SELECT_AGGREGATES, consistency_level=cl), QueryMessage(query=self._SELECT_TRIGGERS, consistency_level=cl) ] responses = self.connection.wait_for_responses(*queries, timeout=self.timeout, fail_on_error=False) (ks_success, ks_result), (table_success, table_result), \ (col_success, col_result), (types_success, types_result), \ (functions_success, functions_result), \ (aggregates_success, aggregates_result), \ (triggers_success, triggers_result) = responses self.keyspaces_result = self._handle_results(ks_success, ks_result) self.tables_result = self._handle_results(table_success, table_result) self.columns_result = self._handle_results(col_success, col_result) # if we're connected to Cassandra < 2.0, the triggers table will not exist if triggers_success: self.triggers_result = dict_factory(*triggers_result.results) else: if isinstance(triggers_result, InvalidRequest): log.debug("triggers table not found") elif isinstance(triggers_result, Unauthorized): log.warning("this version of Cassandra does not allow access to schema_triggers metadata with authorization enabled (CASSANDRA-7967); " "The driver will operate normally, but will not reflect triggers in the local metadata model, or schema strings.") else: raise triggers_result # if we're connected to Cassandra < 2.1, the usertypes table will not exist if types_success: self.types_result = dict_factory(*types_result.results) else: if isinstance(types_result, InvalidRequest): log.debug("user types table not found") self.types_result = {} else: raise types_result # functions were introduced in Cassandra 2.2 if functions_success: self.functions_result = dict_factory(*functions_result.results) else: if isinstance(functions_result, InvalidRequest): log.debug("user functions table not found") else: raise functions_result # aggregates were introduced in Cassandra 2.2 if aggregates_success: self.aggregates_result = dict_factory(*aggregates_result.results) else: if isinstance(aggregates_result, InvalidRequest): log.debug("user aggregates table not found") else: raise aggregates_result self._aggregate_results() def _aggregate_results(self): m = self.keyspace_table_rows for row in self.tables_result: m[row["keyspace_name"]].append(row) m = self.keyspace_table_col_rows for row in self.columns_result: ksname = row["keyspace_name"] cfname = row[self._table_name_col] m[ksname][cfname].append(row) m = self.keyspace_type_rows for row in self.types_result: m[row["keyspace_name"]].append(row) m = self.keyspace_func_rows for row in self.functions_result: m[row["keyspace_name"]].append(row) m = self.keyspace_agg_rows for row in self.aggregates_result: m[row["keyspace_name"]].append(row) m = self.keyspace_table_trigger_rows for row in self.triggers_result: ksname = row["keyspace_name"] cfname = row[self._table_name_col] m[ksname][cfname].append(row) @staticmethod def _schema_type_to_cql(type_string): cass_type = types.lookup_casstype(type_string) return _cql_from_cass_type(cass_type) class SchemaParserV3(SchemaParserV22): _SELECT_KEYSPACES = "SELECT * FROM system_schema.keyspaces" _SELECT_TABLES = "SELECT * FROM system_schema.tables" _SELECT_COLUMNS = "SELECT * FROM system_schema.columns" _SELECT_INDEXES = "SELECT * FROM system_schema.indexes" _SELECT_TRIGGERS = "SELECT * FROM system_schema.triggers" _SELECT_TYPES = "SELECT * FROM system_schema.types" _SELECT_FUNCTIONS = "SELECT * FROM system_schema.functions" _SELECT_AGGREGATES = "SELECT * FROM system_schema.aggregates" _SELECT_VIEWS = "SELECT * FROM system_schema.views" _table_name_col = 'table_name' _function_agg_arument_type_col = 'argument_types' recognized_table_options = ( 'bloom_filter_fp_chance', 'caching', 'cdc', 'comment', 'compaction', 'compression', 'crc_check_chance', 'dclocal_read_repair_chance', 'default_time_to_live', 'gc_grace_seconds', 'max_index_interval', 'memtable_flush_period_in_ms', 'min_index_interval', 'read_repair_chance', 'speculative_retry') def __init__(self, connection, timeout): super(SchemaParserV3, self).__init__(connection, timeout) self.indexes_result = [] self.keyspace_table_index_rows = defaultdict(lambda: defaultdict(list)) self.keyspace_view_rows = defaultdict(list) def get_all_keyspaces(self): for keyspace_meta in super(SchemaParserV3, self).get_all_keyspaces(): for row in self.keyspace_view_rows[keyspace_meta.name]: view_meta = self._build_view_metadata(row) keyspace_meta._add_view_metadata(view_meta) yield keyspace_meta def get_table(self, keyspaces, keyspace, table): cl = ConsistencyLevel.ONE where_clause = bind_params(" WHERE keyspace_name = %%s AND %s = %%s" % (self._table_name_col), (keyspace, table), _encoder) cf_query = QueryMessage(query=self._SELECT_TABLES + where_clause, consistency_level=cl) col_query = QueryMessage(query=self._SELECT_COLUMNS + where_clause, consistency_level=cl) indexes_query = QueryMessage(query=self._SELECT_INDEXES + where_clause, consistency_level=cl) triggers_query = QueryMessage(query=self._SELECT_TRIGGERS + where_clause, consistency_level=cl) # in protocol v4 we don't know if this event is a view or a table, so we look for both where_clause = bind_params(" WHERE keyspace_name = %s AND view_name = %s", (keyspace, table), _encoder) view_query = QueryMessage(query=self._SELECT_VIEWS + where_clause, consistency_level=cl) (cf_success, cf_result), (col_success, col_result), (indexes_sucess, indexes_result), \ (triggers_success, triggers_result), (view_success, view_result) \ = self.connection.wait_for_responses(cf_query, col_query, indexes_query, triggers_query, view_query, timeout=self.timeout, fail_on_error=False) table_result = self._handle_results(cf_success, cf_result) col_result = self._handle_results(col_success, col_result) if table_result: indexes_result = self._handle_results(indexes_sucess, indexes_result) triggers_result = self._handle_results(triggers_success, triggers_result) return self._build_table_metadata(table_result[0], col_result, triggers_result, indexes_result) view_result = self._handle_results(view_success, view_result) if view_result: return self._build_view_metadata(view_result[0], col_result) @staticmethod def _build_keyspace_metadata_internal(row): name = row["keyspace_name"] durable_writes = row["durable_writes"] strategy_options = dict(row["replication"]) strategy_class = strategy_options.pop("class") return KeyspaceMetadata(name, durable_writes, strategy_class, strategy_options) @staticmethod def _build_aggregate(aggregate_row): return Aggregate(aggregate_row['keyspace_name'], aggregate_row['aggregate_name'], aggregate_row['argument_types'], aggregate_row['state_func'], aggregate_row['state_type'], aggregate_row['final_func'], aggregate_row['initcond'], aggregate_row['return_type']) def _build_table_metadata(self, row, col_rows=None, trigger_rows=None, index_rows=None): keyspace_name = row["keyspace_name"] table_name = row[self._table_name_col] col_rows = col_rows or self.keyspace_table_col_rows[keyspace_name][table_name] trigger_rows = trigger_rows or self.keyspace_table_trigger_rows[keyspace_name][table_name] index_rows = index_rows or self.keyspace_table_index_rows[keyspace_name][table_name] table_meta = TableMetadataV3(keyspace_name, table_name) try: table_meta.options = self._build_table_options(row) flags = row.get('flags', set()) if flags: compact_static = False table_meta.is_compact_storage = 'dense' in flags or 'super' in flags or 'compound' not in flags is_dense = 'dense' in flags else: compact_static = True table_meta.is_compact_storage = True is_dense = False self._build_table_columns(table_meta, col_rows, compact_static, is_dense) for trigger_row in trigger_rows: trigger_meta = self._build_trigger_metadata(table_meta, trigger_row) table_meta.triggers[trigger_meta.name] = trigger_meta for index_row in index_rows: index_meta = self._build_index_metadata(table_meta, index_row) if index_meta: table_meta.indexes[index_meta.name] = index_meta table_meta.extensions = row.get('extensions', {}) except Exception: table_meta._exc_info = sys.exc_info() log.exception("Error while parsing metadata for table %s.%s row(%s) columns(%s)", keyspace_name, table_name, row, col_rows) return table_meta def _build_table_options(self, row): """ Setup the mostly-non-schema table options, like caching settings """ return dict((o, row.get(o)) for o in self.recognized_table_options if o in row) def _build_table_columns(self, meta, col_rows, compact_static=False, is_dense=False): # partition key partition_rows = [r for r in col_rows if r.get('kind', None) == "partition_key"] if len(partition_rows) > 1: partition_rows = sorted(partition_rows, key=lambda row: row.get('position')) for r in partition_rows: # we have to add meta here (and not in the later loop) because TableMetadata.columns is an # OrderedDict, and it assumes keys are inserted first, in order, when exporting CQL column_meta = self._build_column_metadata(meta, r) meta.columns[column_meta.name] = column_meta meta.partition_key.append(meta.columns[r.get('column_name')]) # clustering key if not compact_static: clustering_rows = [r for r in col_rows if r.get('kind', None) == "clustering"] if len(clustering_rows) > 1: clustering_rows = sorted(clustering_rows, key=lambda row: row.get('position')) for r in clustering_rows: column_meta = self._build_column_metadata(meta, r) meta.columns[column_meta.name] = column_meta meta.clustering_key.append(meta.columns[r.get('column_name')]) for col_row in (r for r in col_rows if r.get('kind', None) not in ('partition_key', 'clustering_key')): column_meta = self._build_column_metadata(meta, col_row) if is_dense and column_meta.cql_type == types.cql_empty_type: continue if compact_static and not column_meta.is_static: # for compact static tables, we omit the clustering key and value, and only add the logical columns. # They are marked not static so that it generates appropriate CQL continue if compact_static: column_meta.is_static = False meta.columns[column_meta.name] = column_meta def _build_view_metadata(self, row, col_rows=None): keyspace_name = row["keyspace_name"] view_name = row["view_name"] base_table_name = row["base_table_name"] include_all_columns = row["include_all_columns"] where_clause = row["where_clause"] col_rows = col_rows or self.keyspace_table_col_rows[keyspace_name][view_name] view_meta = MaterializedViewMetadata(keyspace_name, view_name, base_table_name, include_all_columns, where_clause, self._build_table_options(row)) self._build_table_columns(view_meta, col_rows) view_meta.extensions = row.get('extensions', {}) return view_meta @staticmethod def _build_column_metadata(table_metadata, row): name = row["column_name"] cql_type = row["type"] is_static = row.get("kind", None) == "static" is_reversed = row["clustering_order"].upper() == "DESC" column_meta = ColumnMetadata(table_metadata, name, cql_type, is_static, is_reversed) return column_meta @staticmethod def _build_index_metadata(table_metadata, row): index_name = row.get("index_name") kind = row.get("kind") if index_name or kind: index_options = row.get("options") return IndexMetadata(table_metadata.keyspace_name, table_metadata.name, index_name, kind, index_options) else: return None @staticmethod def _build_trigger_metadata(table_metadata, row): name = row["trigger_name"] options = row["options"] trigger_meta = TriggerMetadata(table_metadata, name, options) return trigger_meta def _query_all(self): cl = ConsistencyLevel.ONE queries = [ QueryMessage(query=self._SELECT_KEYSPACES, consistency_level=cl), QueryMessage(query=self._SELECT_TABLES, consistency_level=cl), QueryMessage(query=self._SELECT_COLUMNS, consistency_level=cl), QueryMessage(query=self._SELECT_TYPES, consistency_level=cl), QueryMessage(query=self._SELECT_FUNCTIONS, consistency_level=cl), QueryMessage(query=self._SELECT_AGGREGATES, consistency_level=cl), QueryMessage(query=self._SELECT_TRIGGERS, consistency_level=cl), QueryMessage(query=self._SELECT_INDEXES, consistency_level=cl), QueryMessage(query=self._SELECT_VIEWS, consistency_level=cl) ] responses = self.connection.wait_for_responses(*queries, timeout=self.timeout, fail_on_error=False) (ks_success, ks_result), (table_success, table_result), \ (col_success, col_result), (types_success, types_result), \ (functions_success, functions_result), \ (aggregates_success, aggregates_result), \ (triggers_success, triggers_result), \ (indexes_success, indexes_result), \ (views_success, views_result) = responses self.keyspaces_result = self._handle_results(ks_success, ks_result) self.tables_result = self._handle_results(table_success, table_result) self.columns_result = self._handle_results(col_success, col_result) self.triggers_result = self._handle_results(triggers_success, triggers_result) self.types_result = self._handle_results(types_success, types_result) self.functions_result = self._handle_results(functions_success, functions_result) self.aggregates_result = self._handle_results(aggregates_success, aggregates_result) self.indexes_result = self._handle_results(indexes_success, indexes_result) self.views_result = self._handle_results(views_success, views_result) self._aggregate_results() def _aggregate_results(self): super(SchemaParserV3, self)._aggregate_results() m = self.keyspace_table_index_rows for row in self.indexes_result: ksname = row["keyspace_name"] cfname = row[self._table_name_col] m[ksname][cfname].append(row) m = self.keyspace_view_rows for row in self.views_result: m[row["keyspace_name"]].append(row) @staticmethod def _schema_type_to_cql(type_string): return type_string class TableMetadataV3(TableMetadata): compaction_options = {} option_maps = ['compaction', 'compression', 'caching'] @property def is_cql_compatible(self): return True @classmethod def _make_option_strings(cls, options_map): ret = [] options_copy = dict(options_map.items()) for option in cls.option_maps: value = options_copy.get(option) if isinstance(value, Mapping): del options_copy[option] params = ("'%s': '%s'" % (k, v) for k, v in value.items()) ret.append("%s = {%s}" % (option, ', '.join(params))) for name, value in options_copy.items(): if value is not None: if name == "comment": value = value or "" ret.append("%s = %s" % (name, protect_value(value))) return list(sorted(ret))
[docs]class MaterializedViewMetadata(object): """ A representation of a materialized view on a table """ keyspace_name = None """ A string name of the view.""" name = None """ A string name of the view.""" base_table_name = None """ A string name of the base table for this view.""" partition_key = None """ A list of :class:`.ColumnMetadata` instances representing the columns in the partition key for this view. This will always hold at least one column. """ clustering_key = None """ A list of :class:`.ColumnMetadata` instances representing the columns in the clustering key for this view. Note that a table may have no clustering keys, in which case this will be an empty list. """ columns = None """ A dict mapping column names to :class:`.ColumnMetadata` instances. """ include_all_columns = None """ A flag indicating whether the view was created AS SELECT * """ where_clause = None """ String WHERE clause for the view select statement. From server metadata """ options = None """ A dict mapping table option names to their specific settings for this view. """ extensions = None """ Metadata describing configuration for table extensions """ def __init__(self, keyspace_name, view_name, base_table_name, include_all_columns, where_clause, options): self.keyspace_name = keyspace_name self.name = view_name self.base_table_name = base_table_name self.partition_key = [] self.clustering_key = [] self.columns = OrderedDict() self.include_all_columns = include_all_columns self.where_clause = where_clause self.options = options or {}
[docs] def as_cql_query(self, formatted=False): """ Returns a CQL query that can be used to recreate this function. If `formatted` is set to :const:`True`, extra whitespace will be added to make the query more readable. """ sep = '\n ' if formatted else ' ' keyspace = protect_name(self.keyspace_name) name = protect_name(self.name) selected_cols = '*' if self.include_all_columns else ', '.join(protect_name(col.name) for col in self.columns.values()) base_table = protect_name(self.base_table_name) where_clause = self.where_clause part_key = ', '.join(protect_name(col.name) for col in self.partition_key) if len(self.partition_key) > 1: pk = "((%s)" % part_key else: pk = "(%s" % part_key if self.clustering_key: pk += ", %s" % ', '.join(protect_name(col.name) for col in self.clustering_key) pk += ")" properties = TableMetadataV3._property_string(formatted, self.clustering_key, self.options) ret = "CREATE MATERIALIZED VIEW %(keyspace)s.%(name)s AS%(sep)s" \ "SELECT %(selected_cols)s%(sep)s" \ "FROM %(keyspace)s.%(base_table)s%(sep)s" \ "WHERE %(where_clause)s%(sep)s" \ "PRIMARY KEY %(pk)s%(sep)s" \ "WITH %(properties)s" % locals() if self.extensions: registry = _RegisteredExtensionType._extension_registry for k in six.viewkeys(registry) & self.extensions: # no viewkeys on OrderedMapSerializeKey ext = registry[k] cql = ext.after_table_cql(self, k, self.extensions[k]) if cql: ret += "\n\n%s" % (cql,) return ret
def export_as_string(self): return self.as_cql_query(formatted=True) + ";"
def get_schema_parser(connection, server_version, timeout): server_major_version = int(server_version.split('.')[0]) if server_major_version >= 3: return SchemaParserV3(connection, timeout) else: # we could further specialize by version. Right now just refactoring the # multi-version parser we have as of C* 2.2.0rc1. return SchemaParserV22(connection, timeout) def _cql_from_cass_type(cass_type): """ A string representation of the type for this column, such as "varchar" or "map<string, int>". """ if issubclass(cass_type, types.ReversedType): return cass_type.subtypes[0].cql_parameterized_type() else: return cass_type.cql_parameterized_type()