# Copyright (c) 2010-2012 OpenStack, LLC. # # 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. """ Database code for Swift """ from __future__ import with_statement from contextlib import contextmanager, closing import hashlib import logging import os from uuid import uuid4 import sys import time import cPickle as pickle import errno from swift import gettext_ as _ from tempfile import mkstemp from eventlet import sleep, Timeout import sqlite3 from swift.common.utils import json, normalize_timestamp, renamer, \ mkdirs, lock_parent_directory, fallocate from swift.common.exceptions import LockTimeout #: Whether calls will be made to preallocate disk space for database files. DB_PREALLOCATION = True #: Timeout for trying to connect to a DB BROKER_TIMEOUT = 25 #: Pickle protocol to use PICKLE_PROTOCOL = 2 #: Max number of pending entries PENDING_CAP = 131072 def utf8encode(*args): return [(s.encode('utf8') if isinstance(s, unicode) else s) for s in args] def utf8encodekeys(metadata): uni_keys = [k for k in metadata.keys() if isinstance(k, unicode)] for k in uni_keys: sv = metadata[k] del metadata[k] metadata[k.encode('utf-8')] = sv class DatabaseConnectionError(sqlite3.DatabaseError): """More friendly error messages for DB Errors.""" def __init__(self, path, msg, timeout=0): self.path = path self.timeout = timeout self.msg = msg def __str__(self): return 'DB connection error (%s, %s):\n%s' % ( self.path, self.timeout, self.msg) class DatabaseAlreadyExists(sqlite3.DatabaseError): """More friendly error messages for DB Errors.""" def __init__(self, path): self.path = path def __str__(self): return 'DB %s already exists' % self.path class GreenDBConnection(sqlite3.Connection): """SQLite DB Connection handler that plays well with eventlet.""" def __init__(self, *args, **kwargs): self.timeout = kwargs.get('timeout', BROKER_TIMEOUT) kwargs['timeout'] = 0 self.db_file = args[0] if args else'-' sqlite3.Connection.__init__(self, *args, **kwargs) def _timeout(self, call): with LockTimeout(self.timeout, self.db_file): while True: try: return call() except sqlite3.OperationalError as e: if 'locked' not in str(e): raise sleep(0.05) def execute(self, *args, **kwargs): return self._timeout(lambda: sqlite3.Connection.execute( self, *args, **kwargs)) def commit(self): return self._timeout(lambda: sqlite3.Connection.commit(self)) def dict_factory(crs, row): """ This should only be used when you need a real dict, i.e. when you're going to serialize the results. """ return dict( ((col[0], row[idx]) for idx, col in enumerate(crs.description))) def chexor(old, name, timestamp): """ Each entry in the account and container databases is XORed by the 128-bit hash on insert or delete. This serves as a rolling, order-independent hash of the contents. (check + XOR) :param old: hex representation of the current DB hash :param name: name of the object or container being inserted :param timestamp: timestamp of the new record :returns: a hex representation of the new hash value """ if name is None: raise Exception('name is None!') new = hashlib.md5(('%s-%s' % (name, timestamp)).encode('utf8')).hexdigest() return '%032x' % (int(old, 16) ^ int(new, 16)) def get_db_connection(path, timeout=30, okay_to_create=False): """ Returns a properly configured SQLite database connection. :param path: path to DB :param timeout: timeout for connection :param okay_to_create: if True, create the DB if it doesn't exist :returns: DB connection object """ try: connect_time = time.time() conn = sqlite3.connect(path, check_same_thread=False, factory=GreenDBConnection, timeout=timeout) if path != ':memory:' and not okay_to_create: # attempt to detect and fail when connect creates the db file stat = os.stat(path) if stat.st_size == 0 and stat.st_ctime >= connect_time: os.unlink(path) raise DatabaseConnectionError(path, 'DB file created by connect?') conn.row_factory = sqlite3.Row conn.text_factory = str with closing(conn.cursor()) as cur: cur.execute('PRAGMA synchronous = NORMAL') cur.execute('PRAGMA count_changes = OFF') cur.execute('PRAGMA temp_store = MEMORY') cur.execute('PRAGMA journal_mode = DELETE') conn.create_function('chexor', 3, chexor) except sqlite3.DatabaseError: import traceback raise DatabaseConnectionError(path, traceback.format_exc(), timeout=timeout) return conn class DatabaseBroker(object): """Encapsulates working with a database.""" def __init__(self, db_file, timeout=BROKER_TIMEOUT, logger=None, account=None, container=None, pending_timeout=None, stale_reads_ok=False): """Encapsulates working with a database.""" self.conn = None self.db_file = db_file self.pending_file = self.db_file + '.pending' self.pending_timeout = pending_timeout or 10 self.stale_reads_ok = stale_reads_ok self.db_dir = os.path.dirname(db_file) self.timeout = timeout self.logger = logger or logging.getLogger() self.account = account self.container = container self._db_version = -1 def initialize(self, put_timestamp=None): """ Create the DB :param put_timestamp: timestamp of initial PUT request """ if self.db_file == ':memory:': tmp_db_file = None conn = get_db_connection(self.db_file, self.timeout) else: mkdirs(self.db_dir) fd, tmp_db_file = mkstemp(suffix='.tmp', dir=self.db_dir) os.close(fd) conn = sqlite3.connect(tmp_db_file, check_same_thread=False, factory=GreenDBConnection, timeout=0) # creating dbs implicitly does a lot of transactions, so we # pick fast, unsafe options here and do a big fsync at the end. with closing(conn.cursor()) as cur: cur.execute('PRAGMA synchronous = OFF') cur.execute('PRAGMA temp_store = MEMORY') cur.execute('PRAGMA journal_mode = MEMORY') conn.create_function('chexor', 3, chexor) conn.row_factory = sqlite3.Row conn.text_factory = str conn.executescript(""" CREATE TABLE outgoing_sync ( remote_id TEXT UNIQUE, sync_point INTEGER, updated_at TEXT DEFAULT 0 ); CREATE TABLE incoming_sync ( remote_id TEXT UNIQUE, sync_point INTEGER, updated_at TEXT DEFAULT 0 ); CREATE TRIGGER outgoing_sync_insert AFTER INSERT ON outgoing_sync BEGIN UPDATE outgoing_sync SET updated_at = STRFTIME('%s', 'NOW') WHERE ROWID = new.ROWID; END; CREATE TRIGGER outgoing_sync_update AFTER UPDATE ON outgoing_sync BEGIN UPDATE outgoing_sync SET updated_at = STRFTIME('%s', 'NOW') WHERE ROWID = new.ROWID; END; CREATE TRIGGER incoming_sync_insert AFTER INSERT ON incoming_sync BEGIN UPDATE incoming_sync SET updated_at = STRFTIME('%s', 'NOW') WHERE ROWID = new.ROWID; END; CREATE TRIGGER incoming_sync_update AFTER UPDATE ON incoming_sync BEGIN UPDATE incoming_sync SET updated_at = STRFTIME('%s', 'NOW') WHERE ROWID = new.ROWID; END; """) if not put_timestamp: put_timestamp = normalize_timestamp(0) self._initialize(conn, put_timestamp) conn.commit() if tmp_db_file: conn.close() with open(tmp_db_file, 'r+b') as fp: os.fsync(fp.fileno()) with lock_parent_directory(self.db_file, self.pending_timeout): if os.path.exists(self.db_file): # It's as if there was a "condition" where different parts # of the system were "racing" each other. raise DatabaseAlreadyExists(self.db_file) renamer(tmp_db_file, self.db_file) self.conn = get_db_connection(self.db_file, self.timeout) else: self.conn = conn def delete_db(self, timestamp): """ Mark the DB as deleted :param timestamp: delete timestamp """ timestamp = normalize_timestamp(timestamp) # first, clear the metadata cleared_meta = {} for k in self.metadata.iterkeys(): cleared_meta[k] = ('', timestamp) self.update_metadata(cleared_meta) # then mark the db as deleted with self.get() as conn: self._delete_db(conn, timestamp) conn.commit() def possibly_quarantine(self, exc_type, exc_value, exc_traceback): """ Checks the exception info to see if it indicates a quarantine situation (malformed or corrupted database). If not, the original exception will be reraised. If so, the database will be quarantined and a new sqlite3.DatabaseError will be raised indicating the action taken. """ if 'database disk image is malformed' in str(exc_value): exc_hint = 'malformed' elif 'file is encrypted or is not a database' in str(exc_value): exc_hint = 'corrupted' else: raise exc_type, exc_value, exc_traceback prefix_path = os.path.dirname(self.db_dir) partition_path = os.path.dirname(prefix_path) dbs_path = os.path.dirname(partition_path) device_path = os.path.dirname(dbs_path) quar_path = os.path.join(device_path, 'quarantined', self.db_type + 's', os.path.basename(self.db_dir)) try: renamer(self.db_dir, quar_path) except OSError as e: if e.errno not in (errno.EEXIST, errno.ENOTEMPTY): raise quar_path = "%s-%s" % (quar_path, uuid4().hex) renamer(self.db_dir, quar_path) detail = _('Quarantined %s to %s due to %s database') % \ (self.db_dir, quar_path, exc_hint) self.logger.error(detail) raise sqlite3.DatabaseError(detail) @contextmanager def get(self): """Use with the "with" statement; returns a database connection.""" if not self.conn: if self.db_file != ':memory:' and os.path.exists(self.db_file): try: self.conn = get_db_connection(self.db_file, self.timeout) except (sqlite3.DatabaseError, DatabaseConnectionError): self.possibly_quarantine(*sys.exc_info()) else: raise DatabaseConnectionError(self.db_file, "DB doesn't exist") conn = self.conn self.conn = None try: yield conn conn.rollback() self.conn = conn except sqlite3.DatabaseError: try: conn.close() except Exception: pass self.possibly_quarantine(*sys.exc_info()) except (Exception, Timeout): conn.close() raise @contextmanager def lock(self): """Use with the "with" statement; locks a database.""" if not self.conn: if self.db_file != ':memory:' and os.path.exists(self.db_file): self.conn = get_db_connection(self.db_file, self.timeout) else: raise DatabaseConnectionError(self.db_file, "DB doesn't exist") conn = self.conn self.conn = None orig_isolation_level = conn.isolation_level conn.isolation_level = None conn.execute('BEGIN IMMEDIATE') try: yield True except (Exception, Timeout): pass try: conn.execute('ROLLBACK') conn.isolation_level = orig_isolation_level self.conn = conn except (Exception, Timeout): logging.exception( _('Broker error trying to rollback locked connection')) conn.close() def newid(self, remote_id): """ Re-id the database. This should be called after an rsync. :param remote_id: the ID of the remote database being rsynced in """ with self.get() as conn: row = conn.execute(''' UPDATE %s_stat SET id=? ''' % self.db_type, (str(uuid4()),)) row = conn.execute(''' SELECT ROWID FROM %s ORDER BY ROWID DESC LIMIT 1 ''' % self.db_contains_type).fetchone() sync_point = row['ROWID'] if row else -1 conn.execute(''' INSERT OR REPLACE INTO incoming_sync (sync_point, remote_id) VALUES (?, ?) ''', (sync_point, remote_id)) self._newid(conn) conn.commit() def _newid(self, conn): # Override for additional work when receiving an rsynced db. pass def merge_timestamps(self, created_at, put_timestamp, delete_timestamp): """ Used in replication to handle updating timestamps. :param created_at: create timestamp :param put_timestamp: put timestamp :param delete_timestamp: delete timestamp """ with self.get() as conn: conn.execute(''' UPDATE %s_stat SET created_at=MIN(?, created_at), put_timestamp=MAX(?, put_timestamp), delete_timestamp=MAX(?, delete_timestamp) ''' % self.db_type, (created_at, put_timestamp, delete_timestamp)) conn.commit() def get_items_since(self, start, count): """ Get a list of objects in the database between start and end. :param start: start ROWID :param count: number to get :returns: list of objects between start and end """ self._commit_puts_stale_ok() with self.get() as conn: curs = conn.execute(''' SELECT * FROM %s WHERE ROWID > ? ORDER BY ROWID ASC LIMIT ? ''' % self.db_contains_type, (start, count)) curs.row_factory = dict_factory return [r for r in curs] def get_sync(self, id, incoming=True): """ Gets the most recent sync point for a server from the sync table. :param id: remote ID to get the sync_point for :param incoming: if True, get the last incoming sync, otherwise get the last outgoing sync :returns: the sync point, or -1 if the id doesn't exist. """ with self.get() as conn: row = conn.execute( "SELECT sync_point FROM %s_sync WHERE remote_id=?" % ('incoming' if incoming else 'outgoing'), (id,)).fetchone() if not row: return -1 return row['sync_point'] def get_syncs(self, incoming=True): """ Get a serialized copy of the sync table. :param incoming: if True, get the last incoming sync, otherwise get the last outgoing sync :returns: list of {'remote_id', 'sync_point'} """ with self.get() as conn: curs = conn.execute(''' SELECT remote_id, sync_point FROM %s_sync ''' % 'incoming' if incoming else 'outgoing') result = [] for row in curs: result.append({'remote_id': row[0], 'sync_point': row[1]}) return result def get_replication_info(self): """ Get information about the DB required for replication. :returns: dict containing keys: hash, id, created_at, put_timestamp, delete_timestamp, count, max_row, and metadata """ self._commit_puts_stale_ok() query_part1 = ''' SELECT hash, id, created_at, put_timestamp, delete_timestamp, %s_count AS count, CASE WHEN SQLITE_SEQUENCE.seq IS NOT NULL THEN SQLITE_SEQUENCE.seq ELSE -1 END AS max_row, ''' % \ self.db_contains_type query_part2 = ''' FROM (%s_stat LEFT JOIN SQLITE_SEQUENCE ON SQLITE_SEQUENCE.name == '%s') LIMIT 1 ''' % (self.db_type, self.db_contains_type) with self.get() as conn: try: curs = conn.execute(query_part1 + 'metadata' + query_part2) except sqlite3.OperationalError as err: if 'no such column: metadata' not in str(err): raise curs = conn.execute(query_part1 + "'' as metadata" + query_part2) curs.row_factory = dict_factory return curs.fetchone() def _commit_puts(self, item_list=None): """ Scan for .pending files and commit the found records by feeding them to merge_items(). :param item_list: A list of items to commit in addition to .pending """ if self.db_file == ':memory:' or not os.path.exists(self.pending_file): return if item_list is None: item_list = [] with lock_parent_directory(self.pending_file, self.pending_timeout): self._preallocate() if not os.path.getsize(self.pending_file): if item_list: self.merge_items(item_list) return with open(self.pending_file, 'r+b') as fp: for entry in fp.read().split(':'): if entry: try: self._commit_puts_load(item_list, entry) except Exception: self.logger.exception( _('Invalid pending entry %(file)s: %(entry)s'), {'file': self.pending_file, 'entry': entry}) if item_list: self.merge_items(item_list) try: os.ftruncate(fp.fileno(), 0) except OSError as err: if err.errno != errno.ENOENT: raise def _commit_puts_stale_ok(self): """ Catch failures of _commit_puts() if broker is intended for reading of stats, and thus does not care for pending updates. """ try: self._commit_puts() except LockTimeout: if not self.stale_reads_ok: raise def _commit_puts_load(self, item_list, entry): """ Unmarshall the :param:entry and append it to :param:item_list. This is implemented by a particular broker to be compatible with its merge_items(). """ raise NotImplementedError def merge_syncs(self, sync_points, incoming=True): """ Merge a list of sync points with the incoming sync table. :param sync_points: list of sync points where a sync point is a dict of {'sync_point', 'remote_id'} :param incoming: if True, get the last incoming sync, otherwise get the last outgoing sync """ with self.get() as conn: for rec in sync_points: try: conn.execute(''' INSERT INTO %s_sync (sync_point, remote_id) VALUES (?, ?) ''' % ('incoming' if incoming else 'outgoing'), (rec['sync_point'], rec['remote_id'])) except sqlite3.IntegrityError: conn.execute(''' UPDATE %s_sync SET sync_point=max(?, sync_point) WHERE remote_id=? ''' % ('incoming' if incoming else 'outgoing'), (rec['sync_point'], rec['remote_id'])) conn.commit() def _preallocate(self): """ The idea is to allocate space in front of an expanding db. If it gets within 512k of a boundary, it allocates to the next boundary. Boundaries are 2m, 5m, 10m, 25m, 50m, then every 50m after. """ if not DB_PREALLOCATION or self.db_file == ':memory:': return MB = (1024 * 1024) def prealloc_points(): for pm in (1, 2, 5, 10, 25, 50): yield pm * MB while True: pm += 50 yield pm * MB stat = os.stat(self.db_file) file_size = stat.st_size allocated_size = stat.st_blocks * 512 for point in prealloc_points(): if file_size <= point - MB / 2: prealloc_size = point break if allocated_size < prealloc_size: with open(self.db_file, 'rb+') as fp: fallocate(fp.fileno(), int(prealloc_size)) @property def metadata(self): """ Returns the metadata dict for the database. The metadata dict values are tuples of (value, timestamp) where the timestamp indicates when that key was set to that value. """ with self.get() as conn: try: metadata = conn.execute('SELECT metadata FROM %s_stat' % self.db_type).fetchone()[0] except sqlite3.OperationalError as err: if 'no such column: metadata' not in str(err): raise metadata = '' if metadata: metadata = json.loads(metadata) utf8encodekeys(metadata) else: metadata = {} return metadata def update_metadata(self, metadata_updates): """ Updates the metadata dict for the database. The metadata dict values are tuples of (value, timestamp) where the timestamp indicates when that key was set to that value. Key/values will only be overwritten if the timestamp is newer. To delete a key, set its value to ('', timestamp). These empty keys will eventually be removed by :func:reclaim """ old_metadata = self.metadata if set(metadata_updates).issubset(set(old_metadata)): for key, (value, timestamp) in metadata_updates.iteritems(): if timestamp > old_metadata[key][1]: break else: return with self.get() as conn: try: md = conn.execute('SELECT metadata FROM %s_stat' % self.db_type).fetchone()[0] md = json.loads(md) if md else {} utf8encodekeys(md) except sqlite3.OperationalError as err: if 'no such column: metadata' not in str(err): raise conn.execute(""" ALTER TABLE %s_stat ADD COLUMN metadata TEXT DEFAULT '' """ % self.db_type) md = {} for key, value_timestamp in metadata_updates.iteritems(): value, timestamp = value_timestamp if key not in md or timestamp > md[key][1]: md[key] = value_timestamp conn.execute('UPDATE %s_stat SET metadata = ?' % self.db_type, (json.dumps(md),)) conn.commit() def reclaim(self, age_timestamp, sync_timestamp): """ Delete rows from the db_contains_type table that are marked deleted and whose created_at timestamp is < age_timestamp. Also deletes rows from incoming_sync and outgoing_sync where the updated_at timestamp is < sync_timestamp. In addition, this calls the DatabaseBroker's :func:_reclaim method. :param age_timestamp: max created_at timestamp of object rows to delete :param sync_timestamp: max update_at timestamp of sync rows to delete """ self._commit_puts() with self.get() as conn: conn.execute(''' DELETE FROM %s WHERE deleted = 1 AND %s < ? ''' % (self.db_contains_type, self.db_reclaim_timestamp), (age_timestamp,)) try: conn.execute(''' DELETE FROM outgoing_sync WHERE updated_at < ? ''', (sync_timestamp,)) conn.execute(''' DELETE FROM incoming_sync WHERE updated_at < ? ''', (sync_timestamp,)) except sqlite3.OperationalError as err: # Old dbs didn't have updated_at in the _sync tables. if 'no such column: updated_at' not in str(err): raise DatabaseBroker._reclaim(self, conn, age_timestamp) conn.commit() def _reclaim(self, conn, timestamp): """ Removes any empty metadata values older than the timestamp using the given database connection. This function will not call commit on the conn, but will instead return True if the database needs committing. This function was created as a worker to limit transactions and commits from other related functions. :param conn: Database connection to reclaim metadata within. :param timestamp: Empty metadata items last updated before this timestamp will be removed. :returns: True if conn.commit() should be called """ try: md = conn.execute('SELECT metadata FROM %s_stat' % self.db_type).fetchone()[0] if md: md = json.loads(md) keys_to_delete = [] for key, (value, value_timestamp) in md.iteritems(): if value == '' and value_timestamp < timestamp: keys_to_delete.append(key) if keys_to_delete: for key in keys_to_delete: del md[key] conn.execute('UPDATE %s_stat SET metadata = ?' % self.db_type, (json.dumps(md),)) return True except sqlite3.OperationalError as err: if 'no such column: metadata' not in str(err): raise return False def update_put_timestamp(self, timestamp): """ Update the put_timestamp. Only modifies it if it is greater than the current timestamp. :param timestamp: put timestamp """ with self.get() as conn: conn.execute( 'UPDATE %s_stat SET put_timestamp = ?' ' WHERE put_timestamp < ?' % self.db_type, (timestamp, timestamp)) conn.commit() class ContainerBroker(DatabaseBroker): """Encapsulates working with a container database.""" db_type = 'container' db_contains_type = 'object' db_reclaim_timestamp = 'created_at' def _initialize(self, conn, put_timestamp): """Creates a brand new database (tables, indices, triggers, etc.)""" if not self.account: raise ValueError( 'Attempting to create a new database with no account set') if not self.container: raise ValueError( 'Attempting to create a new database with no container set') self.create_object_table(conn) self.create_container_stat_table(conn, put_timestamp) def create_object_table(self, conn): """ Create the object table which is specifc to the container DB. :param conn: DB connection object """ conn.executescript(""" CREATE TABLE object ( ROWID INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, created_at TEXT, size INTEGER, content_type TEXT, etag TEXT, deleted INTEGER DEFAULT 0 ); CREATE INDEX ix_object_deleted_name ON object (deleted, name); CREATE TRIGGER object_insert AFTER INSERT ON object BEGIN UPDATE container_stat SET object_count = object_count + (1 - new.deleted), bytes_used = bytes_used + new.size, hash = chexor(hash, new.name, new.created_at); END; CREATE TRIGGER object_update BEFORE UPDATE ON object BEGIN SELECT RAISE(FAIL, 'UPDATE not allowed; DELETE and INSERT'); END; CREATE TRIGGER object_delete AFTER DELETE ON object BEGIN UPDATE container_stat SET object_count = object_count - (1 - old.deleted), bytes_used = bytes_used - old.size, hash = chexor(hash, old.name, old.created_at); END; """) def create_container_stat_table(self, conn, put_timestamp=None): """ Create the container_stat table which is specific to the container DB. :param conn: DB connection object :param put_timestamp: put timestamp """ if put_timestamp is None: put_timestamp = normalize_timestamp(0) conn.executescript(""" CREATE TABLE container_stat ( account TEXT, container TEXT, created_at TEXT, put_timestamp TEXT DEFAULT '0', delete_timestamp TEXT DEFAULT '0', object_count INTEGER, bytes_used INTEGER, reported_put_timestamp TEXT DEFAULT '0', reported_delete_timestamp TEXT DEFAULT '0', reported_object_count INTEGER DEFAULT 0, reported_bytes_used INTEGER DEFAULT 0, hash TEXT default '00000000000000000000000000000000', id TEXT, status TEXT DEFAULT '', status_changed_at TEXT DEFAULT '0', metadata TEXT DEFAULT '', x_container_sync_point1 INTEGER DEFAULT -1, x_container_sync_point2 INTEGER DEFAULT -1 ); INSERT INTO container_stat (object_count, bytes_used) VALUES (0, 0); """) conn.execute(''' UPDATE container_stat SET account = ?, container = ?, created_at = ?, id = ?, put_timestamp = ? ''', (self.account, self.container, normalize_timestamp(time.time()), str(uuid4()), put_timestamp)) def get_db_version(self, conn): if self._db_version == -1: self._db_version = 0 for row in conn.execute(''' SELECT name FROM sqlite_master WHERE name = 'ix_object_deleted_name' '''): self._db_version = 1 return self._db_version def _newid(self, conn): conn.execute(''' UPDATE container_stat SET reported_put_timestamp = 0, reported_delete_timestamp = 0, reported_object_count = 0, reported_bytes_used = 0''') def _delete_db(self, conn, timestamp): """ Mark the DB as deleted :param conn: DB connection object :param timestamp: timestamp to mark as deleted """ conn.execute(""" UPDATE container_stat SET delete_timestamp = ?, status = 'DELETED', status_changed_at = ? WHERE delete_timestamp < ? """, (timestamp, timestamp, timestamp)) def _commit_puts_load(self, item_list, entry): (name, timestamp, size, content_type, etag, deleted) = \ pickle.loads(entry.decode('base64')) item_list.append({'name': name, 'created_at': timestamp, 'size': size, 'content_type': content_type, 'etag': etag, 'deleted': deleted}) def empty(self): """ Check if the DB is empty. :returns: True if the database has no active objects, False otherwise """ self._commit_puts_stale_ok() with self.get() as conn: row = conn.execute( 'SELECT object_count from container_stat').fetchone() return (row[0] == 0) def delete_object(self, name, timestamp): """ Mark an object deleted. :param name: object name to be deleted :param timestamp: timestamp when the object was marked as deleted """ self.put_object(name, timestamp, 0, 'application/deleted', 'noetag', 1) def put_object(self, name, timestamp, size, content_type, etag, deleted=0): """ Creates an object in the DB with its metadata. :param name: object name to be created :param timestamp: timestamp of when the object was created :param size: object size :param content_type: object content-type :param etag: object etag :param deleted: if True, marks the object as deleted and sets the deteleted_at timestamp to timestamp """ record = {'name': name, 'created_at': timestamp, 'size': size, 'content_type': content_type, 'etag': etag, 'deleted': deleted} if self.db_file == ':memory:': self.merge_items([record]) return if not os.path.exists(self.db_file): raise DatabaseConnectionError(self.db_file, "DB doesn't exist") pending_size = 0 try: pending_size = os.path.getsize(self.pending_file) except OSError as err: if err.errno != errno.ENOENT: raise if pending_size > PENDING_CAP: self._commit_puts([record]) else: with lock_parent_directory(self.pending_file, self.pending_timeout): with open(self.pending_file, 'a+b') as fp: # Colons aren't used in base64 encoding; so they are our # delimiter fp.write(':') fp.write(pickle.dumps( (name, timestamp, size, content_type, etag, deleted), protocol=PICKLE_PROTOCOL).encode('base64')) fp.flush() def is_deleted(self, timestamp=None): """ Check if the DB is considered to be deleted. :returns: True if the DB is considered to be deleted, False otherwise """ if self.db_file != ':memory:' and not os.path.exists(self.db_file): return True self._commit_puts_stale_ok() with self.get() as conn: row = conn.execute(''' SELECT put_timestamp, delete_timestamp, object_count FROM container_stat''').fetchone() # leave this db as a tombstone for a consistency window if timestamp and row['delete_timestamp'] > timestamp: return False # The container is considered deleted if the delete_timestamp # value is greater than the put_timestamp, and there are no # objects in the container. return (row['object_count'] in (None, '', 0, '0')) and \ (float(row['delete_timestamp']) > float(row['put_timestamp'])) def get_info(self): """ Get global data for the container. :returns: dict with keys: account, container, created_at, put_timestamp, delete_timestamp, object_count, bytes_used, reported_put_timestamp, reported_delete_timestamp, reported_object_count, reported_bytes_used, hash, id, x_container_sync_point1, and x_container_sync_point2. """ self._commit_puts_stale_ok() with self.get() as conn: data = None trailing = 'x_container_sync_point1, x_container_sync_point2' while not data: try: data = conn.execute(''' SELECT account, container, created_at, put_timestamp, delete_timestamp, object_count, bytes_used, reported_put_timestamp, reported_delete_timestamp, reported_object_count, reported_bytes_used, hash, id, %s FROM container_stat ''' % (trailing,)).fetchone() except sqlite3.OperationalError as err: if 'no such column: x_container_sync_point' in str(err): trailing = '-1 AS x_container_sync_point1, ' \ '-1 AS x_container_sync_point2' else: raise data = dict(data) return data def set_x_container_sync_points(self, sync_point1, sync_point2): with self.get() as conn: orig_isolation_level = conn.isolation_level try: # We turn off auto-transactions to ensure the alter table # commands are part of the transaction. conn.isolation_level = None conn.execute('BEGIN') try: self._set_x_container_sync_points(conn, sync_point1, sync_point2) except sqlite3.OperationalError as err: if 'no such column: x_container_sync_point' not in \ str(err): raise conn.execute(''' ALTER TABLE container_stat ADD COLUMN x_container_sync_point1 INTEGER DEFAULT -1 ''') conn.execute(''' ALTER TABLE container_stat ADD COLUMN x_container_sync_point2 INTEGER DEFAULT -1 ''') self._set_x_container_sync_points(conn, sync_point1, sync_point2) conn.execute('COMMIT') finally: conn.isolation_level = orig_isolation_level def _set_x_container_sync_points(self, conn, sync_point1, sync_point2): if sync_point1 is not None and sync_point2 is not None: conn.execute(''' UPDATE container_stat SET x_container_sync_point1 = ?, x_container_sync_point2 = ? ''', (sync_point1, sync_point2)) elif sync_point1 is not None: conn.execute(''' UPDATE container_stat SET x_container_sync_point1 = ? ''', (sync_point1,)) elif sync_point2 is not None: conn.execute(''' UPDATE container_stat SET x_container_sync_point2 = ? ''', (sync_point2,)) def reported(self, put_timestamp, delete_timestamp, object_count, bytes_used): """ Update reported stats. :param put_timestamp: put_timestamp to update :param delete_timestamp: delete_timestamp to update :param object_count: object_count to update :param bytes_used: bytes_used to update """ with self.get() as conn: conn.execute(''' UPDATE container_stat SET reported_put_timestamp = ?, reported_delete_timestamp = ?, reported_object_count = ?, reported_bytes_used = ? ''', (put_timestamp, delete_timestamp, object_count, bytes_used)) conn.commit() def list_objects_iter(self, limit, marker, end_marker, prefix, delimiter, path=None): """ Get a list of objects sorted by name starting at marker onward, up to limit entries. Entries will begin with the prefix and will not have the delimiter after the prefix. :param limit: maximum number of entries to get :param marker: marker query :param end_marker: end marker query :param prefix: prefix query :param delimiter: delimiter for query :param path: if defined, will set the prefix and delimter based on the path :returns: list of tuples of (name, created_at, size, content_type, etag) """ delim_force_gte = False (marker, end_marker, prefix, delimiter, path) = utf8encode( marker, end_marker, prefix, delimiter, path) self._commit_puts_stale_ok() if path is not None: prefix = path if path: prefix = path = path.rstrip('/') + '/' delimiter = '/' elif delimiter and not prefix: prefix = '' orig_marker = marker with self.get() as conn: results = [] while len(results) < limit: query = '''SELECT name, created_at, size, content_type, etag FROM object WHERE''' query_args = [] if end_marker: query += ' name < ? AND' query_args.append(end_marker) if delim_force_gte: query += ' name >= ? AND' query_args.append(marker) # Always set back to False delim_force_gte = False elif marker and marker >= prefix: query += ' name > ? AND' query_args.append(marker) elif prefix: query += ' name >= ? AND' query_args.append(prefix) if self.get_db_version(conn) < 1: query += ' +deleted = 0' else: query += ' deleted = 0' query += ' ORDER BY name LIMIT ?' query_args.append(limit - len(results)) curs = conn.execute(query, query_args) curs.row_factory = None if prefix is None: # A delimiter without a specified prefix is ignored return [r for r in curs] if not delimiter: if not prefix: # It is possible to have a delimiter but no prefix # specified. As above, the prefix will be set to the # empty string, so avoid performing the extra work to # check against an empty prefix. return [r for r in curs] else: return [r for r in curs if r[0].startswith(prefix)] # We have a delimiter and a prefix (possibly empty string) to # handle rowcount = 0 for row in curs: rowcount += 1 marker = name = row[0] if len(results) >= limit or not name.startswith(prefix): curs.close() return results end = name.find(delimiter, len(prefix)) if path is not None: if name == path: continue if end >= 0 and len(name) > end + len(delimiter): marker = name[:end] + chr(ord(delimiter) + 1) curs.close() break elif end > 0: marker = name[:end] + chr(ord(delimiter) + 1) # we want result to be inclusinve of delim+1 delim_force_gte = True dir_name = name[:end + 1] if dir_name != orig_marker: results.append([dir_name, '0', 0, None, '']) curs.close() break results.append(row) if not rowcount: break return results def merge_items(self, item_list, source=None): """ Merge items into the object table. :param item_list: list of dictionaries of {'name', 'created_at', 'size', 'content_type', 'etag', 'deleted'} :param source: if defined, update incoming_sync with the source """ with self.get() as conn: max_rowid = -1 for rec in item_list: query = ''' DELETE FROM object WHERE name = ? AND (created_at < ?) ''' if self.get_db_version(conn) >= 1: query += ' AND deleted IN (0, 1)' conn.execute(query, (rec['name'], rec['created_at'])) query = 'SELECT 1 FROM object WHERE name = ?' if self.get_db_version(conn) >= 1: query += ' AND deleted IN (0, 1)' if not conn.execute(query, (rec['name'],)).fetchall(): conn.execute(''' INSERT INTO object (name, created_at, size, content_type, etag, deleted) VALUES (?, ?, ?, ?, ?, ?) ''', ([rec['name'], rec['created_at'], rec['size'], rec['content_type'], rec['etag'], rec['deleted']])) if source: max_rowid = max(max_rowid, rec['ROWID']) if source: try: conn.execute(''' INSERT INTO incoming_sync (sync_point, remote_id) VALUES (?, ?) ''', (max_rowid, source)) except sqlite3.IntegrityError: conn.execute(''' UPDATE incoming_sync SET sync_point=max(?, sync_point) WHERE remote_id=? ''', (max_rowid, source)) conn.commit() class AccountBroker(DatabaseBroker): """Encapsulates working with a account database.""" db_type = 'account' db_contains_type = 'container' db_reclaim_timestamp = 'delete_timestamp' def _initialize(self, conn, put_timestamp): """ Create a brand new database (tables, indices, triggers, etc.) :param conn: DB connection object :param put_timestamp: put timestamp """ if not self.account: raise ValueError( 'Attempting to create a new database with no account set') self.create_container_table(conn) self.create_account_stat_table(conn, put_timestamp) def create_container_table(self, conn): """ Create container table which is specific to the account DB. :param conn: DB connection object """ conn.executescript(""" CREATE TABLE container ( ROWID INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, put_timestamp TEXT, delete_timestamp TEXT, object_count INTEGER, bytes_used INTEGER, deleted INTEGER DEFAULT 0 ); CREATE INDEX ix_container_deleted_name ON container (deleted, name); CREATE TRIGGER container_insert AFTER INSERT ON container BEGIN UPDATE account_stat SET container_count = container_count + (1 - new.deleted), object_count = object_count + new.object_count, bytes_used = bytes_used + new.bytes_used, hash = chexor(hash, new.name, new.put_timestamp || '-' || new.delete_timestamp || '-' || new.object_count || '-' || new.bytes_used); END; CREATE TRIGGER container_update BEFORE UPDATE ON container BEGIN SELECT RAISE(FAIL, 'UPDATE not allowed; DELETE and INSERT'); END; CREATE TRIGGER container_delete AFTER DELETE ON container BEGIN UPDATE account_stat SET container_count = container_count - (1 - old.deleted), object_count = object_count - old.object_count, bytes_used = bytes_used - old.bytes_used, hash = chexor(hash, old.name, old.put_timestamp || '-' || old.delete_timestamp || '-' || old.object_count || '-' || old.bytes_used); END; """) def create_account_stat_table(self, conn, put_timestamp): """ Create account_stat table which is specific to the account DB. :param conn: DB connection object :param put_timestamp: put timestamp """ conn.executescript(""" CREATE TABLE account_stat ( account TEXT, created_at TEXT, put_timestamp TEXT DEFAULT '0', delete_timestamp TEXT DEFAULT '0', container_count INTEGER, object_count INTEGER DEFAULT 0, bytes_used INTEGER DEFAULT 0, hash TEXT default '00000000000000000000000000000000', id TEXT, status TEXT DEFAULT '', status_changed_at TEXT DEFAULT '0', metadata TEXT DEFAULT '' ); INSERT INTO account_stat (container_count) VALUES (0); """) conn.execute(''' UPDATE account_stat SET account = ?, created_at = ?, id = ?, put_timestamp = ? ''', (self.account, normalize_timestamp(time.time()), str(uuid4()), put_timestamp)) def get_db_version(self, conn): if self._db_version == -1: self._db_version = 0 for row in conn.execute(''' SELECT name FROM sqlite_master WHERE name = 'ix_container_deleted_name' '''): self._db_version = 1 return self._db_version def _delete_db(self, conn, timestamp, force=False): """ Mark the DB as deleted. :param conn: DB connection object :param timestamp: timestamp to mark as deleted """ conn.execute(""" UPDATE account_stat SET delete_timestamp = ?, status = 'DELETED', status_changed_at = ? WHERE delete_timestamp < ? """, (timestamp, timestamp, timestamp)) def _commit_puts_load(self, item_list, entry): (name, put_timestamp, delete_timestamp, object_count, bytes_used, deleted) = \ pickle.loads(entry.decode('base64')) item_list.append( {'name': name, 'put_timestamp': put_timestamp, 'delete_timestamp': delete_timestamp, 'object_count': object_count, 'bytes_used': bytes_used, 'deleted': deleted}) def empty(self): """ Check if the account DB is empty. :returns: True if the database has no active containers. """ self._commit_puts_stale_ok() with self.get() as conn: row = conn.execute( 'SELECT container_count from account_stat').fetchone() return (row[0] == 0) def put_container(self, name, put_timestamp, delete_timestamp, object_count, bytes_used): """ Create a container with the given attributes. :param name: name of the container to create :param put_timestamp: put_timestamp of the container to create :param delete_timestamp: delete_timestamp of the container to create :param object_count: number of objects in the container :param bytes_used: number of bytes used by the container """ if delete_timestamp > put_timestamp and \ object_count in (None, '', 0, '0'): deleted = 1 else: deleted = 0 record = {'name': name, 'put_timestamp': put_timestamp, 'delete_timestamp': delete_timestamp, 'object_count': object_count, 'bytes_used': bytes_used, 'deleted': deleted} if self.db_file == ':memory:': self.merge_items([record]) return if not os.path.exists(self.db_file): raise DatabaseConnectionError(self.db_file, "DB doesn't exist") pending_size = 0 try: pending_size = os.path.getsize(self.pending_file) except OSError as err: if err.errno != errno.ENOENT: raise if pending_size > PENDING_CAP: self._commit_puts([record]) else: with lock_parent_directory(self.pending_file, self.pending_timeout): with open(self.pending_file, 'a+b') as fp: # Colons aren't used in base64 encoding; so they are our # delimiter fp.write(':') fp.write(pickle.dumps( (name, put_timestamp, delete_timestamp, object_count, bytes_used, deleted), protocol=PICKLE_PROTOCOL).encode('base64')) fp.flush() def is_deleted(self): """ Check if the account DB is considered to be deleted. :returns: True if the account DB is considered to be deleted, False otherwise """ if self.db_file != ':memory:' and not os.path.exists(self.db_file): return True self._commit_puts_stale_ok() with self.get() as conn: row = conn.execute(''' SELECT put_timestamp, delete_timestamp, container_count, status FROM account_stat''').fetchone() return row['status'] == 'DELETED' or ( row['container_count'] in (None, '', 0, '0') and row['delete_timestamp'] > row['put_timestamp']) def is_status_deleted(self): """Only returns true if the status field is set to DELETED.""" with self.get() as conn: row = conn.execute(''' SELECT status FROM account_stat''').fetchone() return (row['status'] == "DELETED") def get_info(self): """ Get global data for the account. :returns: dict with keys: account, created_at, put_timestamp, delete_timestamp, container_count, object_count, bytes_used, hash, id """ self._commit_puts_stale_ok() with self.get() as conn: return dict(conn.execute(''' SELECT account, created_at, put_timestamp, delete_timestamp, container_count, object_count, bytes_used, hash, id FROM account_stat ''').fetchone()) def list_containers_iter(self, limit, marker, end_marker, prefix, delimiter): """ Get a list of containers sorted by name starting at marker onward, up to limit entries. Entries will begin with the prefix and will not have the delimiter after the prefix. :param limit: maximum number of entries to get :param marker: marker query :param end_marker: end marker query :param prefix: prefix query :param delimiter: delimiter for query :returns: list of tuples of (name, object_count, bytes_used, 0) """ (marker, end_marker, prefix, delimiter) = utf8encode( marker, end_marker, prefix, delimiter) self._commit_puts_stale_ok() if delimiter and not prefix: prefix = '' orig_marker = marker with self.get() as conn: results = [] while len(results) < limit: query = """ SELECT name, object_count, bytes_used, 0 FROM container WHERE deleted = 0 AND """ query_args = [] if end_marker: query += ' name < ? AND' query_args.append(end_marker) if marker and marker >= prefix: query += ' name > ? AND' query_args.append(marker) elif prefix: query += ' name >= ? AND' query_args.append(prefix) if self.get_db_version(conn) < 1: query += ' +deleted = 0' else: query += ' deleted = 0' query += ' ORDER BY name LIMIT ?' query_args.append(limit - len(results)) curs = conn.execute(query, query_args) curs.row_factory = None if prefix is None: # A delimiter without a specified prefix is ignored return [r for r in curs] if not delimiter: if not prefix: # It is possible to have a delimiter but no prefix # specified. As above, the prefix will be set to the # empty string, so avoid performing the extra work to # check against an empty prefix. return [r for r in curs] else: return [r for r in curs if r[0].startswith(prefix)] # We have a delimiter and a prefix (possibly empty string) to # handle rowcount = 0 for row in curs: rowcount += 1 marker = name = row[0] if len(results) >= limit or not name.startswith(prefix): curs.close() return results end = name.find(delimiter, len(prefix)) if end > 0: marker = name[:end] + chr(ord(delimiter) + 1) dir_name = name[:end + 1] if dir_name != orig_marker: results.append([dir_name, 0, 0, 1]) curs.close() break results.append(row) if not rowcount: break return results def merge_items(self, item_list, source=None): """ Merge items into the container table. :param item_list: list of dictionaries of {'name', 'put_timestamp', 'delete_timestamp', 'object_count', 'bytes_used', 'deleted'} :param source: if defined, update incoming_sync with the source """ with self.get() as conn: max_rowid = -1 for rec in item_list: record = [rec['name'], rec['put_timestamp'], rec['delete_timestamp'], rec['object_count'], rec['bytes_used'], rec['deleted']] query = ''' SELECT name, put_timestamp, delete_timestamp, object_count, bytes_used, deleted FROM container WHERE name = ? ''' if self.get_db_version(conn) >= 1: query += ' AND deleted IN (0, 1)' curs = conn.execute(query, (rec['name'],)) curs.row_factory = None row = curs.fetchone() if row: row = list(row) for i in xrange(5): if record[i] is None and row[i] is not None: record[i] = row[i] if row[1] > record[1]: # Keep newest put_timestamp record[1] = row[1] if row[2] > record[2]: # Keep newest delete_timestamp record[2] = row[2] # If deleted, mark as such if record[2] > record[1] and \ record[3] in (None, '', 0, '0'): record[5] = 1 else: record[5] = 0 conn.execute(''' DELETE FROM container WHERE name = ? AND deleted IN (0, 1) ''', (record[0],)) conn.execute(''' INSERT INTO container (name, put_timestamp, delete_timestamp, object_count, bytes_used, deleted) VALUES (?, ?, ?, ?, ?, ?) ''', record) if source: max_rowid = max(max_rowid, rec['ROWID']) if source: try: conn.execute(''' INSERT INTO incoming_sync (sync_point, remote_id) VALUES (?, ?) ''', (max_rowid, source)) except sqlite3.IntegrityError: conn.execute(''' UPDATE incoming_sync SET sync_point=max(?, sync_point) WHERE remote_id=? ''', (max_rowid, source)) conn.commit()