text: # 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 six.moves.cPickle as pickle
  import json
  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, wsgi, Timeout, tpool
  from eventlet.greenthread import spawn
  
  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, parse_mime_headers, \
      iter_multipart_mime_documents, extract_swift_bytes, safe_json_loads, \
      config_auto_int_value
  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, \
      ChunkReadError, DiskFileXattrNotSupported
  from swift.obj import ssync_receiver
  from swift.common.http import is_success
  from swift.common.base_storage_server import BaseStorageServer
  from swift.common.header_key_dict import HeaderKeyDict
  from swift.common.request_helpers import get_name_and_placement, \
      is_user_meta, is_sys_or_user_meta, is_object_transient_sysmeta, \
      resolve_etag_is_at_header, is_sys_meta
  from swift.common.swob import HTTPAccepted, HTTPBadRequest, HTTPCreated, \
      HTTPInternalServerError, HTTPNoContent, HTTPNotFound, \
      HTTPPreconditionFailed, HTTPRequestTimeout, HTTPUnprocessableEntity, \
      HTTPClientDisconnect, HTTPMethodNotAllowed, Request, Response, \
      HTTPInsufficientStorage, HTTPForbidden, HTTPException, HTTPConflict, \
      HTTPServerError
  from swift.obj.diskfile import RESERVED_DATAFILE_META, DiskFileRouter
  
  
  def iter_mime_headers_and_bodies(wsgi_input, mime_boundary, read_chunk_size):
      mime_documents_iter = iter_multipart_mime_documents(
          wsgi_input, mime_boundary, read_chunk_size)
  
      for file_like in mime_documents_iter:
          hdrs = parse_mime_headers(file_like)
          yield (hdrs, file_like)
  
  
  def drain(file_like, read_size, timeout):
      """
      Read and discard any bytes from file_like.
  
      :param file_like: file-like object to read from
      :param read_size: how big a chunk to read at a time
      :param timeout: how long to wait for a read (use None for no timeout)
  
      :raises ChunkReadTimeout: if no chunk was read in time
      """
  
      while True:
          with ChunkReadTimeout(timeout):
              chunk = file_like.read(read_size)
              if not chunk:
                  break
  
  
  def _make_backend_fragments_header(fragments):
      if fragments:
          result = {}
          for ts, frag_list in fragments.items():
              result[ts.internal] = frag_list
          return json.dumps(result)
      return None
  
  
  class EventletPlungerString(str):
      """
      Eventlet won't send headers until it's accumulated at least
      eventlet.wsgi.MINIMUM_CHUNK_SIZE bytes or the app iter is exhausted. If we
      want to send the response body behind Eventlet's back, perhaps with some
      zero-copy wizardry, then we have to unclog the plumbing in eventlet.wsgi
      to force the headers out, so we use an EventletPlungerString to empty out
      all of Eventlet's buffers.
      """
      def __len__(self):
          return wsgi.MINIMUM_CHUNK_SIZE + 1
  
  
  class ObjectController(BaseStorageServer):
      """Implements the WSGI application for the Swift Object Server."""
  
      server_type = '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.
          """
          super(ObjectController, self).__init__(conf)
          self.logger = logger or get_logger(conf, log_route='object-server')
          self.node_timeout = float(conf.get('node_timeout', 3))
          self.container_update_timeout = float(
              conf.get('container_update_timeout', 1))
          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'))
  
          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 RESERVED_DATAFILE_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_router = DiskFileRouter(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)
  
          servers_per_port = int(conf.get('servers_per_port', '0') or 0)
          if servers_per_port:
              # The typical servers-per-port deployment also uses one port per
              # disk, so you really get N servers per disk. In that case,
              # having a pool of 20 threads per server per disk is far too
              # much. For example, given a 60-disk chassis and 4 servers per
              # disk, the default configuration will give us 21 threads per
              # server (the main thread plus the twenty tpool threads), for a
              # total of around 60 * 21 * 4 = 5040 threads. This is clearly
              # too high.
              #
              # Instead, we use a tpool size of 1, giving us 2 threads per
              # process. In the example above, that's 60 * 2 * 4 = 480
              # threads, which is reasonable since there are 240 processes.
              default_tpool_size = 1
          else:
              # If we're not using servers-per-port, then leave the tpool size
              # alone. The default (20) is typically good enough for one
              # object server handling requests for many disks.
              default_tpool_size = None
  
          tpool_size = config_auto_int_value(
              conf.get('eventlet_tpool_num_threads'),
              default_tpool_size)
  
          if tpool_size:
              tpool.set_num_threads(tpool_size)
  
      def get_diskfile(self, device, partition, account, container, obj,
                       policy, **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_router[policy].get_diskfile(
              device, partition, account, container, obj, policy, **kwargs)
  
      def async_update(self, op, account, container, obj, host, partition,
                       contdevice, headers_out, objdevice, policy,
                       logger_thread_locals=None):
          """
          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: partition 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: the associated BaseStoragePolicy instance
          :param logger_thread_locals: The thread local values to be set on the
                                       self.logger to retain transaction
                                       logging information.
          """
          if logger_thread_locals:
              self.logger.thread_locals = logger_thread_locals
          headers_out['user-agent'] = 'object-server %s' % os.getpid()
          full_path = '/%s/%s/%s' % (account, container, obj)
          if all([host, partition, contdevice]):
              try:
                  with ConnectionTimeout(self.conn_timeout):
                      ip, port = host.rsplit(':', 1)
                      conn = http_connect(ip, port, contdevice, partition, op,
                                          full_path, headers_out)
                  with Timeout(self.node_timeout):
                      response = conn.getresponse()
                      response.read()
                      if is_success(response.status):
                          return
                      else:
                          self.logger.error(_(
                              'ERROR Container update failed '
                              '(saving for async update later): %(status)d '
                              'response from %(ip)s:%(port)s/%(dev)s'),
                              {'status': response.status, 'ip': ip, 'port': port,
                               'dev': contdevice})
              except (Exception, Timeout):
                  self.logger.exception(_(
                      'ERROR container update failed with '
                      '%(ip)s:%(port)s/%(dev)s (saving for async update later)'),
                      {'ip': ip, 'port': port, 'dev': contdevice})
          data = {'op': op, 'account': account, 'container': container,
                  'obj': obj, 'headers': headers_out}
          timestamp = headers_out.get('x-meta-timestamp',
                                      headers_out.get('x-timestamp'))
          self._diskfile_router[policy].pickle_async_update(
              objdevice, account, container, obj, data, timestamp, policy)
  
      def container_update(self, op, account, container, obj, request,
                           headers_out, objdevice, policy):
          """
          Update the container when objects are updated.
  
          :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 request: the original request object driving the update
          :param headers_out: dictionary of headers to send in the container
                              request(s)
          :param objdevice: device name that the object is in
          :param policy:  the BaseStoragePolicy instance
          """
          headers_in = request.headers
          conthosts = [h.strip() for h in
                       headers_in.get('X-Container-Host', '').split(',')]
          contdevices = [d.strip() for d in
                         headers_in.get('X-Container-Device', '').split(',')]
          contpartition = headers_in.get('X-Container-Partition', '')
  
          if len(conthosts) != len(contdevices):
              # This shouldn't happen unless there's a bug in the proxy,
              # but if there is, we want to know about it.
              self.logger.error(_(
                  'ERROR Container update failed: different '
                  'numbers of hosts and devices in request: '
                  '"%(hosts)s" vs "%(devices)s"') % {
                      'hosts': headers_in.get('X-Container-Host', ''),
                      'devices': headers_in.get('X-Container-Device', '')})
              return
  
          if contpartition:
              updates = zip(conthosts, contdevices)
          else:
              updates = []
  
          headers_out['x-trans-id'] = headers_in.get('x-trans-id', '-')
          headers_out['referer'] = request.as_referer()
          headers_out['X-Backend-Storage-Policy-Index'] = int(policy)
          update_greenthreads = []
          for conthost, contdevice in updates:
              gt = spawn(self.async_update, op, account, container, obj,
                         conthost, contpartition, contdevice, headers_out,
                         objdevice, policy,
                         logger_thread_locals=self.logger.thread_locals)
              update_greenthreads.append(gt)
          # Wait a little bit to see if the container updates are successful.
          # If we immediately return after firing off the greenthread above, then
          # we're more likely to confuse the end-user who does a listing right
          # after getting a successful response to the object create. The
          # `container_update_timeout` bounds the length of time we wait so that
          # one slow container server doesn't make the entire request lag.
          try:
              with Timeout(self.container_update_timeout):
                  for gt in update_greenthreads:
                      gt.wait()
          except Timeout:
              # updates didn't go through, log it and return
              self.logger.debug(
                  'Container update timeout (%.4fs) waiting for %s',
                  self.container_update_timeout, updates)
  
      def delete_at_update(self, op, delete_at, account, container, obj,
                           request, objdevice, policy):
          """
          Update the expiring objects container when objects are updated.
  
          :param op: operation performed (ex: 'PUT', or 'DELETE')
          :param delete_at: scheduled delete in UNIX seconds, int
          :param account: account name for the object
          :param container: container name for the object
          :param obj: object name
          :param request: the original request driving the update
          :param objdevice: device name that the object is in
          :param policy: the BaseStoragePolicy instance (used for tmp dir)
          """
          if config_true_value(
                  request.headers.get('x-backend-replication', 'f')):
              return
          delete_at = normalize_delete_at_timestamp(delete_at)
          updates = [(None, None)]
  
          partition = None
          hosts = contdevices = [None]
          headers_in = request.headers
          headers_out = HeaderKeyDict({
              # system accounts are always Policy-0
              'X-Backend-Storage-Policy-Index': 0,
              'x-timestamp': request.timestamp.internal,
              'x-trans-id': headers_in.get('x-trans-id', '-'),
              'referer': request.as_referer()})
          if op != 'DELETE':
              delete_at_container = headers_in.get('X-Delete-At-Container', None)
              if not delete_at_container:
                  self.logger.warning(
                      'X-Delete-At-Container header must be specified for '
                      'expiring objects background %s to work properly. Making '
                      'best guess as to the container name for now.' % op)
                  # TODO(gholt): In a future release, change the above warning to
                  # a raised exception and remove the guess code below.
                  delete_at_container = get_expirer_container(
                      delete_at, self.expiring_objects_container_divisor,
                      account, container, obj)
              partition = headers_in.get('X-Delete-At-Partition', None)
              hosts = headers_in.get('X-Delete-At-Host', '')
              contdevices = headers_in.get('X-Delete-At-Device', '')
              updates = [upd for upd in
                         zip((h.strip() for h in hosts.split(',')),
                             (c.strip() for c in contdevices.split(',')))
                         if all(upd) and partition]
              if not updates:
                  updates = [(None, None)]
              headers_out['x-size'] = '0'
              headers_out['x-content-type'] = 'text/plain'
              headers_out['x-etag'] = 'd41d8cd98f00b204e9800998ecf8427e'
          else:
              # DELETEs of old expiration data have no way of knowing what the
              # old X-Delete-At-Container was at the time of the initial setting
              # of the data, so a best guess is made here.
              # Worst case is a DELETE is issued now for something that doesn't
              # exist there and the original data is left where it is, where
              # it will be ignored when the expirer eventually tries to issue the
              # object DELETE later since the X-Delete-At value won't match up.
              delete_at_container = get_expirer_container(
                  delete_at, self.expiring_objects_container_divisor,
                  account, container, obj)
          delete_at_container = normalize_delete_at_timestamp(
              delete_at_container)
  
          for host, contdevice in updates:
              self.async_update(
                  op, self.expiring_objects_account, delete_at_container,
                  '%s-%s/%s/%s' % (delete_at, account, container, obj),
                  host, partition, contdevice, headers_out, objdevice,
                  policy)
  
      def _make_timeout_reader(self, file_like):
          def timeout_reader():
              with ChunkReadTimeout(self.client_timeout):
                  try:
                      return file_like.read(self.network_chunk_size)
                  except (IOError, ValueError):
                      raise ChunkReadError
          return timeout_reader
  
      def _read_put_commit_message(self, mime_documents_iter):
          rcvd_commit = False
          try:
              with ChunkReadTimeout(self.client_timeout):
                  commit_hdrs, commit_iter = next(mime_documents_iter)
                  if commit_hdrs.get('X-Document', None) == "put commit":
                      rcvd_commit = True
              drain(commit_iter, self.network_chunk_size, self.client_timeout)
          except ChunkReadError:
              raise HTTPClientDisconnect()
          except ChunkReadTimeout:
              raise HTTPRequestTimeout()
          except StopIteration:
              raise HTTPBadRequest(body="couldn't find PUT commit MIME doc")
          return rcvd_commit
  
      def _read_metadata_footer(self, mime_documents_iter):
          try:
              with ChunkReadTimeout(self.client_timeout):
                  footer_hdrs, footer_iter = next(mime_documents_iter)
          except ChunkReadError:
              raise HTTPClientDisconnect()
          except ChunkReadTimeout:
              raise HTTPRequestTimeout()
          except StopIteration:
              raise HTTPBadRequest(body="couldn't find footer MIME doc")
  
          timeout_reader = self._make_timeout_reader(footer_iter)
          try:
              footer_body = ''.join(iter(timeout_reader, ''))
          except ChunkReadError:
              raise HTTPClientDisconnect()
          except ChunkReadTimeout:
              raise HTTPRequestTimeout()
  
          footer_md5 = footer_hdrs.get('Content-MD5')
          if not footer_md5:
              raise HTTPBadRequest(body="no Content-MD5 in footer")
          if footer_md5 != md5(footer_body).hexdigest():
              raise HTTPUnprocessableEntity(body="footer MD5 mismatch")
  
          try:
              return HeaderKeyDict(json.loads(footer_body))
          except ValueError:
              raise HTTPBadRequest("invalid JSON for footer doc")
  
      def _check_container_override(self, update_headers, metadata,
                                    footers=None):
          """
          Applies any overrides to the container update headers.
  
          Overrides may be in the x-object-sysmeta-container-update- namespace or
          the x-backend-container-update-override- namespace. The former is
          preferred and is used by proxy middlewares. The latter is historical
          but is still used with EC policy PUT requests; for backwards
          compatibility the header names used with EC policy requests have not
          been changed to the sysmeta namespace - that way the EC PUT path of a
          newer proxy will remain compatible with an object server that pre-dates
          the introduction of the x-object-sysmeta-container-update- namespace
          and vice-versa.
  
          :param update_headers: a dict of headers used in the container update
          :param metadata: a dict that may container override items
          :param footers: another dict that may container override items, at a
                          higher priority than metadata
          """
          footers = footers or {}
          # the order of this list is significant:
          # x-object-sysmeta-container-update-override-* headers take precedence
          # over x-backend-container-update-override-* headers
          override_prefixes = ['x-backend-container-update-override-',
                               'x-object-sysmeta-container-update-override-']
          for override_prefix in override_prefixes:
              for key, val in metadata.items():
                  if key.lower().startswith(override_prefix):
                      override = key.lower().replace(override_prefix, 'x-')
                      update_headers[override] = val
              # apply x-backend-container-update-override* from footers *before*
              # x-object-sysmeta-container-update-override-* from headers
              for key, val in footers.items():
                  if key.lower().startswith(override_prefix):
                      override = key.lower().replace(override_prefix, 'x-')
                      update_headers[override] = val
  
      @public
      @timing_stats()
      def POST(self, request):
          """Handle HTTP POST requests for the Swift Object Server."""
          device, partition, account, container, obj, policy = \
              get_name_and_placement(request, 5, 5, True)
          req_timestamp = valid_timestamp(request)
          new_delete_at = int(request.headers.get('X-Delete-At') or 0)
          if new_delete_at and new_delete_at < time.time():
              return HTTPBadRequest(body='X-Delete-At in past', request=request,
                                    content_type='text/plain')
          next_part_power = request.headers.get('X-Backend-Next-Part-Power')
          try:
              disk_file = self.get_diskfile(
                  device, partition, account, container, obj,
                  policy=policy, open_expired=config_true_value(
                      request.headers.get('x-backend-replication', 'false')),
                  next_part_power=next_part_power)
          except DiskFileDeviceUnavailable:
              return HTTPInsufficientStorage(drive=device, request=request)
          try:
              orig_metadata = disk_file.read_metadata()
          except DiskFileXattrNotSupported:
              return HTTPInsufficientStorage(drive=device, request=request)
          except (DiskFileNotExist, DiskFileQuarantined):
              return HTTPNotFound(request=request)
          orig_timestamp = Timestamp(orig_metadata.get('X-Timestamp', 0))
          orig_ctype_timestamp = disk_file.content_type_timestamp
          req_ctype_time = '0'
          req_ctype = request.headers.get('Content-Type')
          if req_ctype:
              req_ctype_time = request.headers.get('Content-Type-Timestamp',
                                                   req_timestamp.internal)
          req_ctype_timestamp = Timestamp(req_ctype_time)
          if orig_timestamp >= req_timestamp \
                  and orig_ctype_timestamp >= req_ctype_timestamp:
              return HTTPConflict(
                  request=request,
                  headers={'X-Backend-Timestamp': orig_timestamp.internal})
  
          if req_timestamp > orig_timestamp:
              metadata = {'X-Timestamp': req_timestamp.internal}
              metadata.update(val for val in request.headers.items()
                              if (is_user_meta('object', val[0]) or
                                  is_object_transient_sysmeta(val[0])))
              headers_to_copy = (
                  request.headers.get(
                      'X-Backend-Replication-Headers', '').split() +
                  list(self.allowed_headers))
              for header_key in headers_to_copy:
                  if header_key in request.headers:
                      header_caps = header_key.title()
                      metadata[header_caps] = request.headers[header_key]
              orig_delete_at = int(orig_metadata.get('X-Delete-At') or 0)
              if orig_delete_at != new_delete_at:
                  if new_delete_at:
                      self.delete_at_update(
                          'PUT', new_delete_at, account, container, obj, request,
                          device, policy)
                  if orig_delete_at:
                      self.delete_at_update('DELETE', orig_delete_at, account,
                                            container, obj, request, device,
                                            policy)
          else:
              # preserve existing metadata, only content-type may be updated
              metadata = dict(disk_file.get_metafile_metadata())
  
          if req_ctype_timestamp > orig_ctype_timestamp:
              # we have a new content-type, add to metadata and container update
              content_type_headers = {
                  'Content-Type': request.headers['Content-Type'],
                  'Content-Type-Timestamp': req_ctype_timestamp.internal
              }
              metadata.update(content_type_headers)
          else:
              # send existing content-type with container update
              content_type_headers = {
                  'Content-Type': disk_file.content_type,
                  'Content-Type-Timestamp': orig_ctype_timestamp.internal
              }
              if orig_ctype_timestamp != disk_file.data_timestamp:
                  # only add to metadata if it's not the datafile content-type
                  metadata.update(content_type_headers)
  
          try:
              disk_file.write_metadata(metadata)
          except (DiskFileXattrNotSupported, DiskFileNoSpace):
              return HTTPInsufficientStorage(drive=device, request=request)
  
          if (content_type_headers['Content-Type-Timestamp']
                  != disk_file.data_timestamp):
              # Current content-type is not from the datafile, but the datafile
              # content-type may have a swift_bytes param that was appended by
              # SLO and we must continue to send that with the container update.
              # Do this (rather than use a separate header) for backwards
              # compatibility because there may be 'legacy' container updates in
              # async pending that have content-types with swift_bytes params, so
              # we have to be able to handle those in container server anyway.
              _, swift_bytes = extract_swift_bytes(
                  disk_file.get_datafile_metadata()['Content-Type'])
              if swift_bytes:
                  content_type_headers['Content-Type'] += (';swift_bytes=%s'
                                                           % swift_bytes)
  
          update_headers = HeaderKeyDict({
              'x-size': orig_metadata['Content-Length'],
              'x-content-type': content_type_headers['Content-Type'],
              'x-timestamp': disk_file.data_timestamp.internal,
              'x-content-type-timestamp':
              content_type_headers['Content-Type-Timestamp'],
              'x-meta-timestamp': metadata['X-Timestamp'],
              'x-etag': orig_metadata['ETag']})
  
          # Special cases for backwards compatibility.
          # For EC policy, send X-Object-Sysmeta-Ec-Etag which is same as the
          # X-Backend-Container-Update-Override-Etag value sent with the original
          # PUT. Similarly send X-Object-Sysmeta-Ec-Content-Length which is the
          # same as the X-Backend-Container-Update-Override-Size value. We have
          # to send Etag and size with a POST container update because the
          # original PUT container update may have failed or be in async_pending.
          if 'X-Object-Sysmeta-Ec-Etag' in orig_metadata:
              update_headers['X-Etag'] = orig_metadata[
                  'X-Object-Sysmeta-Ec-Etag']
          if 'X-Object-Sysmeta-Ec-Content-Length' in orig_metadata:
              update_headers['X-Size'] = orig_metadata[
                  'X-Object-Sysmeta-Ec-Content-Length']
  
          self._check_container_override(update_headers, orig_metadata)
  
          # object POST updates are PUT to the container server
          self.container_update(
              'PUT', account, container, obj, request, update_headers,
              device, policy)
  
          # Add sysmeta to response
          resp_headers = {}
          for key, value in orig_metadata.items():
              if is_sys_meta('object', key):
                  resp_headers[key] = value
  
          return HTTPAccepted(request=request, headers=resp_headers)
  
      @public
      @timing_stats()
      def PUT(self, request):
          """Handle HTTP PUT requests for the Swift Object Server."""
          device, partition, account, container, obj, policy = \
              get_name_and_placement(request, 5, 5, True)
          req_timestamp = valid_timestamp(request)
          error_response = check_object_creation(request, obj)
          if error_response:
              return error_response
          new_delete_at = int(request.headers.get('X-Delete-At') or 0)
          try:
              fsize = request.message_length()
          except ValueError as e:
              return HTTPBadRequest(body=str(e), request=request,
                                    content_type='text/plain')
  
          # In case of multipart-MIME put, the proxy sends a chunked request,
          # but may let us know the real content length so we can verify that
          # we have enough disk space to hold the object.
          if fsize is None:
              fsize = request.headers.get('X-Backend-Obj-Content-Length')
              if fsize is not None:
                  try:
                      fsize = int(fsize)
                  except ValueError as e:
                      return HTTPBadRequest(body=str(e), request=request,
                                            content_type='text/plain')
          # SSYNC will include Frag-Index header for subrequests to primary
          # nodes; handoff nodes should 409 subrequests to over-write an
          # existing data fragment until they offloaded the existing fragment
          frag_index = request.headers.get('X-Backend-Ssync-Frag-Index')
          next_part_power = request.headers.get('X-Backend-Next-Part-Power')
          try:
              disk_file = self.get_diskfile(
                  device, partition, account, container, obj,
                  policy=policy, frag_index=frag_index,
                  next_part_power=next_part_power)
          except DiskFileDeviceUnavailable:
              return HTTPInsufficientStorage(drive=device, request=request)
          try:
              orig_metadata = disk_file.read_metadata()
              orig_timestamp = disk_file.data_timestamp
          except DiskFileXattrNotSupported:
              return HTTPInsufficientStorage(drive=device, request=request)
          except DiskFileDeleted as e:
              orig_metadata = {}
              orig_timestamp = e.timestamp
          except (DiskFileNotExist, DiskFileQuarantined):
              orig_metadata = {}
              orig_timestamp = Timestamp(0)
  
          # Checks for If-None-Match
          if request.if_none_match is not None and orig_metadata:
              if '*' in request.if_none_match:
                  # File exists already so return 412
                  return HTTPPreconditionFailed(request=request)
              if orig_metadata.get('ETag') in request.if_none_match:
                  # The current ETag matches, so return 412
                  return HTTPPreconditionFailed(request=request)
  
          if orig_timestamp >= req_timestamp:
              return HTTPConflict(
                  request=request,
                  headers={'X-Backend-Timestamp': orig_timestamp.internal})
          orig_delete_at = int(orig_metadata.get('X-Delete-At') or 0)
          upload_expiration = time.time() + self.max_upload_time
          etag = md5()
          elapsed_time = 0
          try:
              with disk_file.create(size=fsize) as writer:
                  upload_size = 0
  
                  # If the proxy wants to send us object metadata after the
                  # object body, it sets some headers. We have to tell the
                  # proxy, in the 100 Continue response, that we're able to
                  # parse a multipart MIME document and extract the object and
                  # metadata from it. If we don't, then the proxy won't
                  # actually send the footer metadata.
                  have_metadata_footer = False
                  use_multiphase_commit = False
                  mime_documents_iter = iter([])
                  obj_input = request.environ['wsgi.input']
  
                  hundred_continue_headers = []
                  if config_true_value(
                          request.headers.get(
                              'X-Backend-Obj-Multiphase-Commit')):
                      use_multiphase_commit = True
                      hundred_continue_headers.append(
                          ('X-Obj-Multiphase-Commit', 'yes'))
  
                  if config_true_value(
                          request.headers.get('X-Backend-Obj-Metadata-Footer')):
                      have_metadata_footer = True
                      hundred_continue_headers.append(
                          ('X-Obj-Metadata-Footer', 'yes'))
  
                  if have_metadata_footer or use_multiphase_commit:
                      obj_input.set_hundred_continue_response_headers(
                          hundred_continue_headers)
                      mime_boundary = request.headers.get(
                          'X-Backend-Obj-Multipart-Mime-Boundary')
                      if not mime_boundary:
                          return HTTPBadRequest("no MIME boundary")
  
                      try:
                          with ChunkReadTimeout(self.client_timeout):
                              mime_documents_iter = iter_mime_headers_and_bodies(
                                  request.environ['wsgi.input'],
                                  mime_boundary, self.network_chunk_size)
                              _junk_hdrs, obj_input = next(mime_documents_iter)
                      except ChunkReadError:
                          return HTTPClientDisconnect(request=request)
                      except ChunkReadTimeout:
                          return HTTPRequestTimeout(request=request)
  
                  timeout_reader = self._make_timeout_reader(obj_input)
                  try:
                      for chunk in iter(timeout_reader, ''):
                          start_time = time.time()
                          if start_time > upload_expiration:
                              self.logger.increment('PUT.timeouts')
                              return HTTPRequestTimeout(request=request)
                          etag.update(chunk)
                          upload_size = writer.write(chunk)
                          elapsed_time += time.time() - start_time
                  except ChunkReadError:
                      return HTTPClientDisconnect(request=request)
                  except ChunkReadTimeout:
                      return HTTPRequestTimeout(request=request)
                  if upload_size:
                      self.logger.transfer_rate(
                          'PUT.' + device + '.timing', elapsed_time,
                          upload_size)
                  if fsize is not None and fsize != upload_size:
                      return HTTPClientDisconnect(request=request)
  
                  footer_meta = {}
                  if have_metadata_footer:
                      footer_meta = self._read_metadata_footer(
                          mime_documents_iter)
  
                  request_etag = (footer_meta.get('etag') or
                                  request.headers.get('etag', '')).lower()
                  etag = etag.hexdigest()
                  if request_etag and request_etag != etag:
                      return HTTPUnprocessableEntity(request=request)
                  metadata = {
                      'X-Timestamp': request.timestamp.internal,
                      'Content-Type': request.headers['content-type'],
                      'ETag': etag,
                      'Content-Length': str(upload_size),
                  }
                  metadata.update(val for val in request.headers.items()
                                  if (is_sys_or_user_meta('object', val[0]) or
                                      is_object_transient_sysmeta(val[0])))
                  metadata.update(val for val in footer_meta.items()
                                  if (is_sys_or_user_meta('object', val[0]) or
                                      is_object_transient_sysmeta(val[0])))
                  headers_to_copy = (
                      request.headers.get(
                          'X-Backend-Replication-Headers', '').split() +
                      list(self.allowed_headers))
                  for header_key in headers_to_copy:
                      if header_key in request.headers:
                          header_caps = header_key.title()
                          metadata[header_caps] = request.headers[header_key]
                  writer.put(metadata)
  
                  # if the PUT requires a two-phase commit (a data and a commit
                  # phase) send the proxy server another 100-continue response
                  # to indicate that we are finished writing object data
                  if use_multiphase_commit:
                      request.environ['wsgi.input'].\
                          send_hundred_continue_response()
                      if not self._read_put_commit_message(mime_documents_iter):
                          return HTTPServerError(request=request)
  
                  # got 2nd phase confirmation (when required), call commit to
                  # indicate a successful PUT
                  writer.commit(request.timestamp)
  
                  # Drain any remaining MIME docs from the socket. There
                  # shouldn't be any, but we must read the whole request body.
                  try:
                      while True:
                          with ChunkReadTimeout(self.client_timeout):
                              _junk_hdrs, _junk_body = next(mime_documents_iter)
                          drain(_junk_body, self.network_chunk_size,
                                self.client_timeout)
                  except ChunkReadError:
                      raise HTTPClientDisconnect()
                  except ChunkReadTimeout:
                      raise HTTPRequestTimeout()
                  except StopIteration:
                      pass
  
          except (DiskFileXattrNotSupported, DiskFileNoSpace):
              return HTTPInsufficientStorage(drive=device, request=request)
          if orig_delete_at != new_delete_at:
              if new_delete_at:
                  self.delete_at_update(
                      'PUT', new_delete_at, account, container, obj, request,
                      device, policy)
              if orig_delete_at:
                  self.delete_at_update(
                      'DELETE', orig_delete_at, account, container, obj,
                      request, device, policy)
          update_headers = HeaderKeyDict({
              'x-size': metadata['Content-Length'],
              'x-content-type': metadata['Content-Type'],
              'x-timestamp': metadata['X-Timestamp'],
              'x-etag': metadata['ETag']})
          # apply any container update header overrides sent with request
          self._check_container_override(update_headers, request.headers,
                                         footer_meta)
          self.container_update(
              'PUT', account, container, obj, request,
              update_headers,
              device, policy)
          return HTTPCreated(request=request, etag=etag)
  
      @public
      @timing_stats()
      def GET(self, request):
          """Handle HTTP GET requests for the Swift Object Server."""
          device, partition, account, container, obj, policy = \
              get_name_and_placement(request, 5, 5, True)
          frag_prefs = safe_json_loads(
              request.headers.get('X-Backend-Fragment-Preferences'))
          try:
              disk_file = self.get_diskfile(
                  device, partition, account, container, obj,
                  policy=policy, frag_prefs=frag_prefs,
                  open_expired=config_true_value(
                      request.headers.get('x-backend-replication', 'false')))
          except DiskFileDeviceUnavailable:
              return HTTPInsufficientStorage(drive=device, request=request)
          try:
              with disk_file.open():
                  metadata = disk_file.get_metadata()
                  obj_size = int(metadata['Content-Length'])
                  file_x_ts = Timestamp(metadata['X-Timestamp'])
                  keep_cache = (self.keep_cache_private or
                                ('X-Auth-Token' not in request.headers and
                                 'X-Storage-Token' not in request.headers))
                  conditional_etag = resolve_etag_is_at_header(request, metadata)
                  response = Response(
                      app_iter=disk_file.reader(keep_cache=keep_cache),
                      request=request, conditional_response=True,
                      conditional_etag=conditional_etag)
                  response.headers['Content-Type'] = metadata.get(
                      'Content-Type', 'application/octet-stream')
                  for key, value in metadata.items():
                      if (is_sys_or_user_meta('object', key) or
                              is_object_transient_sysmeta(key) or
                              key.lower() in self.allowed_headers):
                          response.headers[key] = value
                  response.etag = metadata['ETag']
                  response.last_modified = math.ceil(float(file_x_ts))
                  response.content_length = obj_size
                  try:
                      response.content_encoding = metadata[
                          'Content-Encoding']
                  except KeyError:
                      pass
                  response.headers['X-Timestamp'] = file_x_ts.normal
                  response.headers['X-Backend-Timestamp'] = file_x_ts.internal
                  response.headers['X-Backend-Data-Timestamp'] = \
                      disk_file.data_timestamp.internal
                  if disk_file.durable_timestamp:
                      response.headers['X-Backend-Durable-Timestamp'] = \
                          disk_file.durable_timestamp.internal
                  response.headers['X-Backend-Fragments'] = \
                      _make_backend_fragments_header(disk_file.fragments)
                  resp = request.get_response(response)
          except DiskFileXattrNotSupported:
              return HTTPInsufficientStorage(drive=device, request=request)
          except (DiskFileNotExist, DiskFileQuarantined) as e:
              headers = {}
              if hasattr(e, 'timestamp'):
                  headers['X-Backend-Timestamp'] = e.timestamp.internal
              resp = HTTPNotFound(request=request, headers=headers,
                                  conditional_response=True)
          return resp
  
      @public
      @timing_stats(sample_rate=0.8)
      def HEAD(self, request):
          """Handle HTTP HEAD requests for the Swift Object Server."""
          device, partition, account, container, obj, policy = \
              get_name_and_placement(request, 5, 5, True)
          frag_prefs = safe_json_loads(
              request.headers.get('X-Backend-Fragment-Preferences'))
          try:
              disk_file = self.get_diskfile(
                  device, partition, account, container, obj,
                  policy=policy, frag_prefs=frag_prefs,
                  open_expired=config_true_value(
                      request.headers.get('x-backend-replication', 'false')))
          except DiskFileDeviceUnavailable:
              return HTTPInsufficientStorage(drive=device, request=request)
          try:
              metadata = disk_file.read_metadata()
          except DiskFileXattrNotSupported:
              return HTTPInsufficientStorage(drive=device, request=request)
          except (DiskFileNotExist, DiskFileQuarantined) as e:
              headers = {}
              if hasattr(e, 'timestamp'):
                  headers['X-Backend-Timestamp'] = e.timestamp.internal
              return HTTPNotFound(request=request, headers=headers,
                                  conditional_response=True)
          conditional_etag = resolve_etag_is_at_header(request, metadata)
          response = Response(request=request, conditional_response=True,
                              conditional_etag=conditional_etag)
          response.headers['Content-Type'] = metadata.get(
              'Content-Type', 'application/octet-stream')
          for key, value in metadata.items():
              if (is_sys_or_user_meta('object', key) or
                      is_object_transient_sysmeta(key) or
                      key.lower() in self.allowed_headers):
                  response.headers[key] = value
          response.etag = metadata['ETag']
          ts = Timestamp(metadata['X-Timestamp'])
          response.last_modified = math.ceil(float(ts))
          # Needed for container sync feature
          response.headers['X-Timestamp'] = ts.normal
          response.headers['X-Backend-Timestamp'] = ts.internal
          response.headers['X-Backend-Data-Timestamp'] = \
              disk_file.data_timestamp.internal
          if disk_file.durable_timestamp:
              response.headers['X-Backend-Durable-Timestamp'] = \
                  disk_file.durable_timestamp.internal
          response.headers['X-Backend-Fragments'] = \
              _make_backend_fragments_header(disk_file.fragments)
          response.content_length = int(metadata['Content-Length'])
          try:
              response.content_encoding = metadata['Content-Encoding']
          except KeyError:
              pass
          return response
  
      @public
      @timing_stats()
      def DELETE(self, request):
          """Handle HTTP DELETE requests for the Swift Object Server."""
          device, partition, account, container, obj, policy = \
              get_name_and_placement(request, 5, 5, True)
          req_timestamp = valid_timestamp(request)
          next_part_power = request.headers.get('X-Backend-Next-Part-Power')
          try:
              disk_file = self.get_diskfile(
                  device, partition, account, container, obj,
                  policy=policy, next_part_power=next_part_power)
          except DiskFileDeviceUnavailable:
              return HTTPInsufficientStorage(drive=device, request=request)
          try:
              orig_metadata = disk_file.read_metadata()
          except DiskFileXattrNotSupported:
              return HTTPInsufficientStorage(drive=device, request=request)
          except DiskFileExpired as e:
              orig_timestamp = e.timestamp
              orig_metadata = e.metadata
              response_class = HTTPNotFound
          except DiskFileDeleted as e:
              orig_timestamp = e.timestamp
              orig_metadata = {}
              response_class = HTTPNotFound
          except (DiskFileNotExist, DiskFileQuarantined):
              orig_timestamp = 0
              orig_metadata = {}
              response_class = HTTPNotFound
          else:
              orig_timestamp = disk_file.data_timestamp
              if orig_timestamp < req_timestamp:
                  response_class = HTTPNoContent
              else:
                  response_class = HTTPConflict
          response_timestamp = max(orig_timestamp, req_timestamp)
          orig_delete_at = int(orig_metadata.get('X-Delete-At') or 0)
          try:
              req_if_delete_at_val = request.headers['x-if-delete-at']
              req_if_delete_at = int(req_if_delete_at_val)
          except KeyError:
              pass
          except ValueError:
              return HTTPBadRequest(
                  request=request,
                  body='Bad X-If-Delete-At header value')
          else:
              # request includes x-if-delete-at; we must not place a tombstone
              # if we can not verify the x-if-delete-at time
              if not orig_timestamp:
                  # no object found at all
                  return HTTPNotFound()
              if orig_delete_at != req_if_delete_at:
                  return HTTPPreconditionFailed(
                      request=request,
                      body='X-If-Delete-At and X-Delete-At do not match')
              else:
                  # differentiate success from no object at all
                  response_class = HTTPNoContent
          if orig_delete_at:
              self.delete_at_update('DELETE', orig_delete_at, account,
                                    container, obj, request, device,
                                    policy)
          if orig_timestamp < req_timestamp:
              try:
                  disk_file.delete(req_timestamp)
              except DiskFileNoSpace:
                  return HTTPInsufficientStorage(drive=device, request=request)
              self.container_update(
                  'DELETE', account, container, obj, request,
                  HeaderKeyDict({'x-timestamp': req_timestamp.internal}),
                  device, policy)
          return response_class(
              request=request,
              headers={'X-Backend-Timestamp': response_timestamp.internal})
  
      @public
      @replication
      @timing_stats(sample_rate=0.1)
      def REPLICATE(self, request):
          """
          Handle REPLICATE requests for the Swift Object Server.  This is used
          by the object replicator to get hashes for directories.
  
          Note that the name REPLICATE is preserved for historical reasons as
          this verb really just returns the hashes information for the specified
          parameters and is used, for example, by both replication and EC.
          """
          device, partition, suffix_parts, policy = \
              get_name_and_placement(request, 2, 3, True)
          suffixes = suffix_parts.split('-') if suffix_parts else []
          try:
              hashes = self._diskfile_router[policy].get_hashes(
                  device, partition, suffixes, policy)
          except DiskFileDeviceUnavailable:
              resp = HTTPInsufficientStorage(drive=device, request=request)
          else:
              resp = Response(body=pickle.dumps(hashes))
          return resp
  
      @public
      @replication
      @timing_stats(sample_rate=0.1)
      def SSYNC(self, request):
          return Response(app_iter=ssync_receiver.Receiver(self, request)())
  
      def __call__(self, env, start_response):
          """WSGI Application entry point for the Swift Object Server."""
          start_time = time.time()
          req = Request(env)
          self.logger.txn_id = req.headers.get('x-trans-id', None)
  
          if not check_utf8(req.path_info):
              res = HTTPPreconditionFailed(body='Invalid UTF8 or contains NULL')
          else:
              try:
                  # disallow methods which have not been marked 'public'
                  if req.method not in self.allowed_methods:
                      res = HTTPMethodNotAllowed()
                  else:
                      res = getattr(self, req.method)(req)
              except DiskFileCollision:
                  res = HTTPForbidden(request=req)
              except HTTPException as error_response:
                  res = error_response
              except (Exception, Timeout):
                  self.logger.exception(_(
                      'ERROR __call__ error with %(method)s'
                      ' %(path)s '), {'method': req.method, 'path': req.path})
                  res = HTTPInternalServerError(body=traceback.format_exc())
          trans_time = time.time() - start_time
          res.fix_conditional_response()
          if self.log_requests:
              log_line = get_log_line(req, res, trans_time, '')
              if req.method in ('REPLICATE', 'SSYNC') or \
                      'X-Backend-Replication' in req.headers:
                  self.logger.debug(log_line)
              else:
                  self.logger.info(log_line)
          if req.method in ('PUT', 'DELETE'):
              slow = self.slow - trans_time
              if slow > 0:
                  sleep(slow)
  
          # To be able to zero-copy send the object, we need a few things.
          # First, we have to be responding successfully to a GET, or else we're
          # not sending the object. Second, we have to be able to extract the
          # socket file descriptor from the WSGI input object. Third, the
          # diskfile has to support zero-copy send.
          #
          # There's a good chance that this could work for 206 responses too,
          # but the common case is sending the whole object, so we'll start
          # there.
          if req.method == 'GET' and res.status_int == 200 and \
             isinstance(env['wsgi.input'], wsgi.Input):
              app_iter = getattr(res, 'app_iter', None)
              checker = getattr(app_iter, 'can_zero_copy_send', None)
              if checker and checker():
                  # For any kind of zero-copy thing like sendfile or splice, we
                  # need the file descriptor. Eventlet doesn't provide a clean
                  # way of getting that, so we resort to this.
                  wsock = env['wsgi.input'].get_socket()
                  wsockfd = wsock.fileno()
  
                  # Don't call zero_copy_send() until after we force the HTTP
                  # headers out of Eventlet and into the socket.
                  def zero_copy_iter():
                      # If possible, set TCP_CORK so that headers don't
                      # immediately go on the wire, but instead, wait for some
                      # response body to make the TCP frames as large as
                      # possible (and hence as few packets as possible).
                      #
                      # On non-Linux systems, we might consider TCP_NODELAY, but
                      # since the only known zero-copy-capable diskfile uses
                      # Linux-specific syscalls, we'll defer that work until
                      # someone needs it.
                      if hasattr(socket, 'TCP_CORK'):
                          wsock.setsockopt(socket.IPPROTO_TCP,
                                           socket.TCP_CORK, 1)
                      yield EventletPlungerString()
                      try:
                          app_iter.zero_copy_send(wsockfd)
                      except Exception:
                          self.logger.exception("zero_copy_send() blew up")
                          raise
                      yield ''
  
                  # Get headers ready to go out
                  res(env, start_response)
                  return zero_copy_iter()
              else:
                  return res(env, start_response)
          else:
              return res(env, start_response)
  
  
  def global_conf_callback(preloaded_app_conf, global_conf):
      """
      Callback for swift.common.wsgi.run_wsgi during the global_conf
      creation so that we can add our replication_semaphore, used to
      limit the number of concurrent SSYNC_REQUESTS across all
      workers.
  
      :param preloaded_app_conf: The preloaded conf for the WSGI app.
                                 This conf instance will go away, so
                                 just read from it, don't write.
      :param global_conf: The global conf that will eventually be
                          passed to the app_factory function later.
                          This conf is created before the worker
                          subprocesses are forked, so can be useful to
                          set up semaphores, shared memory, etc.
      """
      replication_concurrency = int(
          preloaded_app_conf.get('replication_concurrency') or 4)
      if replication_concurrency:
          # Have to put the value in a list so it can get past paste
          global_conf['replication_semaphore'] = [
              multiprocessing.BoundedSemaphore(replication_concurrency)]
  
  
  def app_factory(global_conf, **local_conf):
      """paste.deploy app factory for creating WSGI object server apps"""
      conf = global_conf.copy()
      conf.update(local_conf)
      return ObjectController(conf)
  