# Copyright (c) 2010-2012 OpenStack Foundation
#
# 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.

""" Object Server for Swift """

import cPickle as pickle
import os
import multiprocessing
import time
import traceback
import socket
import math
from swift import gettext_ as _
from hashlib import md5

from eventlet import sleep, Timeout

from swift.common.utils import public, get_logger, \
    config_true_value, timing_stats, replication, \
    normalize_delete_at_timestamp, get_log_line, Timestamp, \
    get_expirer_container
from swift.common.bufferedhttp import http_connect
from swift.common.constraints import check_object_creation, \
    valid_timestamp, check_utf8
from swift.common.exceptions import ConnectionTimeout, DiskFileQuarantined, \
    DiskFileNotExist, DiskFileCollision, DiskFileNoSpace, DiskFileDeleted, \
    DiskFileDeviceUnavailable, DiskFileExpired, ChunkReadTimeout
from swift.obj import ssync_receiver
from swift.common.http import is_success
from swift.common.request_helpers import get_name_and_placement, \
    is_user_meta, is_sys_or_user_meta
from swift.common.swob import HTTPAccepted, HTTPBadRequest, HTTPCreated, \
    HTTPInternalServerError, HTTPNoContent, HTTPNotFound, \
    HTTPPreconditionFailed, HTTPRequestTimeout, HTTPUnprocessableEntity, \
    HTTPClientDisconnect, HTTPMethodNotAllowed, Request, Response, \
    HTTPInsufficientStorage, HTTPForbidden, HTTPException, HeaderKeyDict, \
    HTTPConflict
from swift.obj.diskfile import DATAFILE_SYSTEM_META, DiskFileManager


class ObjectController(object):
    """Implements the WSGI application for the Swift Object Server."""

    def __init__(self, conf, logger=None):
        """
        Creates a new WSGI application for the Swift Object Server. An
        example configuration is given at
        <source-dir>/etc/object-server.conf-sample or
        /etc/swift/object-server.conf-sample.
        """
        self.logger = logger or get_logger(conf, log_route='object-server')
        self.node_timeout = int(conf.get('node_timeout', 3))
        self.conn_timeout = float(conf.get('conn_timeout', 0.5))
        self.client_timeout = int(conf.get('client_timeout', 60))
        self.disk_chunk_size = int(conf.get('disk_chunk_size', 65536))
        self.network_chunk_size = int(conf.get('network_chunk_size', 65536))
        self.log_requests = config_true_value(conf.get('log_requests', 'true'))
        self.max_upload_time = int(conf.get('max_upload_time', 86400))
        self.slow = int(conf.get('slow', 0))
        self.keep_cache_private = \
            config_true_value(conf.get('keep_cache_private', 'false'))
        replication_server = conf.get('replication_server', None)
        if replication_server is not None:
            replication_server = config_true_value(replication_server)
        self.replication_server = replication_server

        default_allowed_headers = '''
            content-disposition,
            content-encoding,
            x-delete-at,
            x-object-manifest,
            x-static-large-object,
        '''
        extra_allowed_headers = [
            header.strip().lower() for header in conf.get(
                'allowed_headers', default_allowed_headers).split(',')
            if header.strip()
        ]
        self.allowed_headers = set()
        for header in extra_allowed_headers:
            if header not in DATAFILE_SYSTEM_META:
                self.allowed_headers.add(header)
        self.auto_create_account_prefix = \
            conf.get('auto_create_account_prefix') or '.'
        self.expiring_objects_account = self.auto_create_account_prefix + \
            (conf.get('expiring_objects_account_name') or 'expiring_objects')
        self.expiring_objects_container_divisor = \
            int(conf.get('expiring_objects_container_divisor') or 86400)
        # Initialization was successful, so now apply the network chunk size
        # parameter as the default read / write buffer size for the network
        # sockets.
        #
        # NOTE WELL: This is a class setting, so until we get set this on a
        # per-connection basis, this affects reading and writing on ALL
        # sockets, those between the proxy servers and external clients, and
        # those between the proxy servers and the other internal servers.
        #
        # ** Because the primary motivation for this is to optimize how data
        # is written back to the proxy server, we could use the value from the
        # disk_chunk_size parameter. However, it affects all created sockets
        # using this class so we have chosen to tie it to the
        # network_chunk_size parameter value instead.
        socket._fileobject.default_bufsize = self.network_chunk_size

        # Provide further setup specific to an object server implementation.
        self.setup(conf)

    def setup(self, conf):
        """
        Implementation specific setup. This method is called at the very end
        by the constructor to allow a specific implementation to modify
        existing attributes or add its own attributes.

        :param conf: WSGI configuration parameter
        """

        # Common on-disk hierarchy shared across account, container and object
        # servers.
        self._diskfile_mgr = DiskFileManager(conf, self.logger)
        # This is populated by global_conf_callback way below as the semaphore
        # is shared by all workers.
        if 'replication_semaphore' in conf:
            # The value was put in a list so it could get past paste
            self.replication_semaphore = conf['replication_semaphore'][0]
        else:
            self.replication_semaphore = None
        self.replication_failure_threshold = int(
            conf.get('replication_failure_threshold') or 100)
        self.replication_failure_ratio = float(
            conf.get('replication_failure_ratio') or 1.0)

    def get_diskfile(self, device, partition, account, container, obj,
                     policy_idx, **kwargs):
        """
        Utility method for instantiating a DiskFile object supporting a given
        REST API.

        An implementation of the object server that wants to use a different
        DiskFile class would simply over-ride this method to provide that
        behavior.
        """
        return self._diskfile_mgr.get_diskfile(
            device, partition, account, container, obj, policy_idx, **kwargs)

    def async_update(self, op, account, container, obj, host, partition,
                     contdevice, headers_out, objdevice, policy_index):
        """
        Sends or saves an async update.

        :param op: operation performed (ex: 'PUT', or 'DELETE')
        :param account: account name for the object
        :param container: container name for the object
        :param obj: object name
        :param host: host that the container is on
        :param partition: pa
rtition that the container is on
        :param contdevice: device name that the container is on
        :param headers_out: dictionary of headers to send in the container
                            request
        :param objdevice: device name that the object is in
        :param policy_index: the associated storage policy index
        """
        headers_out['user-agent'] = 'object-server %s' % os.getpid()
        full_path = '/%s/%s/%s' % (account, container, obj)
        if all([host, parti
tion, contdevice]):
            try:
                with ConnectionTimeout(self.conn_timeout):
                    ip, port = host.rsplit(':', 1)
                    conn = http_connect(ip, port, contdevice, partition, op,
                                        full_path, h