# 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.

""" Object Server for Swift """

from __future__ import with_statement
import cPickle as pickle
import errno
import os
import time
import traceback
from collections import defaultdict
from datetime import datetime
from hashlib import md5
from tempfile import mkstemp
from urllib import unquote
from contextlib import contextmanager

from xattr import getxattr, setxattr
from eventlet import sleep, Timeout

from swift.common.utils import mkdirs, normalize_timestamp, public, \
    storage_directory, hash_path, renamer, fallocate, fsync, fdatasync, \
    split_path, drop_buffer_cache, get_logger, write_pickle, \
    config_true_value, validate_device_partition, timing_stats, \
    ThreadPool
from swift.common.bufferedhttp import http_connect
from swift.common.constraints import check_object_creation, check_mount, \
    check_float, check_utf8
from swift.common.exceptions import ConnectionTimeout, DiskFileError, \
    DiskFileNotExist, DiskFileCollision, DiskFileNoSpace
from swift.obj.base import invalidate_hash, \
    quarantine_renamer, get_hashes
from swift.common.http import is_success
from swift.common.swob import HTTPAccepted, HTTPBadRequest, HTTPCreated, \
    HTTPInternalServerError, HTTPNoContent, HTTPNotFound, HTTPNotModified, \
    HTTPPreconditionFailed, HTTPRequestTimeout, HTTPUnprocessableEntity, \
    HTTPClientDisconnect, HTTPMethodNotAllowed, Request, Response, UTC, \
    HTTPInsufficientStorage, HTTPForbidden, multi_range_iterator, \
    HeaderKeyDict


DATADIR = 'objects'
ASYNCDIR = 'async_pending'
PICKLE_PROTOCOL = 2
METADATA_KEY = 'user.swift.metadata'
MAX_OBJECT_NAME_LENGTH = 1024
# keep these lower-case
DISALLOWED_HEADERS = set('content-length content-type deleted etag'.split())


def read_metadata(fd):
    """
    Helper function to read the pickled metadata from an object file.

    :param fd: file descriptor to load the metadata from

    :returns: dictionary of metadata
    """
    metadata = ''
    key = 0
    try:
        while True:
            metadata += getxattr(fd, '%s%s' % (METADATA_KEY, (key or '')))
            key += 1
    except IOError:
        pass
    return pickle.loads(metadata)


def write_metadata(fd, metadata):
    """
    Helper function to write pickled metadata for an object file.

    :param fd: file descriptor to write the metadata
    :param metadata: metadata to write
    """
    metastr = pickle.dumps(metadata, PICKLE_PROTOCOL)
    key = 0
    while metastr:
        setxattr(fd, '%s%s' % (METADATA_KEY, key or ''), metastr[:254])
        metastr = metastr[254:]
        key += 1


class DiskWriter(object):
    """
    Encapsulation of the write context for servicing PUT REST API
    requests. Serves as the context manager object for DiskFile's writer()
    method.
    """
    def __init__(self, disk_file, fd, tmppath, threadpool):
        self.disk_file = disk_file
        self.fd = fd
        self.tmppath = tmppath
        self.upload_size = 0
        self.last_sync = 0
        self.threadpool = threadpool

    def write(self, chunk):
        """
        Write a chunk of data into the temporary file.

        :param chunk: the chunk of data to write as a string object
        """

        def _write_entire_chunk(chunk):
            while chunk:
                written = os.write(self.fd, chunk)
                self.upload_size += written
                chunk = chunk[written:]

        self.threadpool.run_in_thread(_write_entire_chunk, chunk)

        # For large files sync every 512MB (by default) written
        diff = self.upload_size - self.last_sync
        if diff >= self.disk_file.bytes_per_sync:
            self.threadpool.force_run_in_thread(fdatasync, self.fd)
            drop_buffer_cache(self.fd, self.last_sync, diff)
            self.last_sync = self.upload_size

    def put(self, metadata, extension='.data'):
        """
        Finalize writing the file on disk, and renames it from the temp file
        to the real location.  This should be called after the data has been
        written to the temp file.

        :param metadata: dictionary of metadata to be written
        :param extension: extension to be used when making the file
        """
        assert self.tmppath is not None
        timestamp = normalize_timestamp(metadata['X-Timestamp'])
        metadata['name'] = self.disk_file.name

        def finalize_put():
            # Write the metadata before calling fsync() so that both data and
            # metadata are flushed to disk.
            write_metadata(self.fd, metadata)
            # We call fsync() before calling drop_cache() to lower the amount
            # of redundant work the drop cache code will perform on the pages
            # (now that after fsync the pages will be all clean).
            fsync(self.fd)
            # From the Department of the Redundancy Department, make sure
            # we call drop_cache() after fsync() to avoid redundant work
            # (pages all clean).
            drop_buffer_cache(self.fd, 0, self.upload_size)
            invalidate_hash(os.path.dirname(self.disk_file.datadir))
            # After the rename completes, this object will be available for
            # other requests to reference.
            renamer(self.tmppath,
                    os.path.join(self.disk_file.datadir,
                                 timestamp + extension))

        self.threadpool.force_run_in_thread(finalize_put)
        self.disk_file.metadata = metadata


class DiskFile(object):
    """
    Manage object files on disk.

    :param path: path to devices on the node
    :param device: device name
    :param partition: partition on the device the object lives in
    :param account: account name for the object
    :param container: container name for the object
    :param obj: object name for the object
    :param keep_data_fp: if True, don't close the fp, otherwise close it
    :param disk_chunk_size: size of chunks on file reads
    :param bytes_per_sync: number of bytes between fdatasync calls
    :param iter_hook: called when __iter__ returns a chunk
    :param threadpool: thread pool in which to do blocking operations

    :raises DiskFileCollision: on md5 collision
    """

    def __init__(self, path, device, partition, account, container, obj,
                 logger, keep_data_fp=False, disk_chunk_size=65536,
                 bytes_per_sync=(512 * 1024 * 1024), iter_hook=None,
                 threadpool=None):
        self.disk_chunk_size = disk_chunk_size
        self.bytes_per_sync = bytes_per_sync
        self.iter_hook = iter_hook
        self.name = '/' + '/'.join((account, container, obj))
        name_hash = hash_path(account, container, obj)
        self.datadir = os.path.join(
            path, device, storage_directory(DATADIR, partition, name_hash))
        self.device_path = os.path.join(path, device)
        self.tmpdir = os.path.join(path, device, 'tmp')
        self.logger = logger
        self.metadata = {}
        self.meta_file = None
        self.data_file = None
        self.fp = None
        self.iter_etag = None
        self.started_at_0 = False
        self.read_to_eof = False
        self.quarantined_dir = None
        self.keep_cache = False
        self.suppress_file_closing = False
        self.threadpool = threadpool or ThreadPool(nthreads=0)
        if not os.path.exists(self.datadir):
            return
        files = sorted(os.listdir(self.datadir), reverse=True)
        for afile in files:
            if afile.endswith('.ts'):
                self.data_file = self.meta_file = None
                self.metadata = {'deleted': True}
                return
            if afile.endswith('.meta') and not self.meta_file:
                self.meta_file = os.path.join(self.datadir, afile)
            if afile.endswith('.data') and not self.data_file:
                self.data_file = os.path.join(self.datadir, afile)
                break
        if not self.data_file:
            return
        self.fp = open(self.data_file, 'rb')
        self.metadata = read_metadata(self.fp)
        if not keep_data_fp:
            self.close(verify_file=False)
        if self.meta_file:
            with open(self.meta_file) as mfp:
                for key in self.metadata.keys():
                    if key.lower() not in DISALLOWED_HEADERS:
                        del self.metadata[key]
                self.metadata.update(read_metadata(mfp))
        if 'name' in self.metadata:
            if self.metadata['name'] != self.name:
                self.logger.error(_('Client path %(client)s does not match '
                                    'path stored in object metadata %(meta)s'),
                                  {'client': self.name,
                                   'meta': self.metadata['name']})
                raise DiskFileCollision('Client path does not match path '
                                        'stored in object metadata')

    def __iter__(self):
        """Returns an iterator over the data file."""
        try:
            dropped_cache = 0
            read = 0
            self.started_at_0 = False
            self.read_to_eof = False
            if self.fp.tell() == 0:
                self.started_at_0 = True
                self.iter_etag = md5()
            while True:
                chunk = self.threadpool.run_in_thread(
                    self.fp.read, self.disk_chunk_size)
                if chunk:
                    if self.iter_etag:
                        self.iter_etag.update(chunk)
                    read += len(chunk)
                    if read - dropped_cache > (1024 * 1024):
                        self._drop_cache(self.fp.fileno(), dropped_cache,
                                         read - dropped_cache)
                        dropped_cache = read
                    yield chunk
                    if self.iter_hook:
                        self.iter_hook()
                else:
                    self.read_to_eof = True
                    self._drop_cache(self.fp.fileno(), dropped_cache,
                                     read - dropped_cache)
                    break
        finally:
            if not self.suppress_file_closing:
                self.close()

    def app_iter_range(self, start, stop):
        """Returns an iterator over the data file for range (start, stop)"""
        if start or start == 0:
            self.fp.seek(start)
        if stop is not None:
            length = stop - start
        else:
            length = None
        for chunk in self:
            if length is not None:
                length -= len(chunk)
                if length < 0:
                    # Chop off the extra:
                    yield chunk[:length]
                    break
            yield chunk

    def app_iter_ranges(self, ranges, content_type, boundary, size):
        """Returns an iterator over the data file for a set of ranges"""
        if not ranges:
            yield ''
        else:
            try:
                self.suppress_file_closing = True
                for chunk in multi_range_iterator(
                        ranges, content_type, boundary, size,
                        self.app_iter_range):
                    yield chunk
            finally:
                self.suppress_file_closing = False
                self.close()

    def _handle_close_quarantine(self):
        """Check if file needs to be quarantined"""
        try:
            self.get_data_file_size()
        except DiskFileError:
            self.quarantine()
            return
        except DiskFileNotExist:
            return

        if self.iter_etag and self.started_at_0 and self.read_to_eof and \
                'ETag' in self.metadata and \
                self.iter_etag.hexdigest() != self.metadata.get('ETag'):
            self.quarantine()

    def close(self, verify_file=True):
        """
        Close the file. Will handle quarantining file if necessary.

        :param verify_file: Defaults to True. If false, will not check
                            file to see if it needs quarantining.
        """
        if self.fp:
            try:
                if verify_file:
                    self._handle_close_quarantine()
            except (Exception, Timeout), e:
                self.logger.error(_(
                    'ERROR DiskFile %(data_file)s in '
                    '%(data_dir)s close failure: %(exc)s : %(stack)'),
                    {'exc': e, 'stack': ''.join(traceback.format_stack()),
                     'data_file': self.data_file, 'data_dir': self.datadir})
            finally:
                self.fp.close()
                self.fp = None

    def is_deleted(self):
        """
        Check if the file is deleted.

        :returns: True if the file doesn't exist or has been flagged as
                  deleted.
        """
        return not self.data_file or 'deleted' in self.metadata

    def is_expired(self):
        """
        Check if the file is expired.

        :returns: True if the file has an X-Delete-At in the past
        """
        return ('X-Delete-At' in self.metadata and
                int(self.metadata['X-Delete-At']) <= time.time())

    @contextmanager
    def writer(self, size=None):
        """
        Context manager to write a file. We create a temporary file first, and
        then return a DiskWriter object to encapsulate the state.

        :param size: optional initial size of file to explicitly allocate on
                     disk
        :raises DiskFileNoSpace: if a size is specified and allocation fails
        """
        if not os.path.exists(self.tmpdir):
            mkdirs(self.tmpdir)
        fd, tmppath = mkstemp(dir=self.tmpdir)
        try:
            if size is not None and size > 0:
                try:
                    fallocate(fd, size)
                except OSError:
                    raise DiskFileNoSpace()
            yield DiskWriter(self, fd, tmppath, self.threadpool)
        finally:
            try:
                os.close(fd)
            except OSError:
                pass
            try:
                os.unlink(tmppath)
            except OSError:
                pass

    def put_metadata(self, metadata, tombstone=False):
        """
        Short hand for putting metadata to .meta and .ts files.

        :param metadata: dictionary of metadata to be written
        :param tombstone: whether or not we are writing a tombstone
        """
        extension = '.ts' if tombstone else '.meta'
        with self.writer() as writer:
            writer.put(metadata, extension=extension)

    def unlinkold(self, timestamp):
        """
        Remove any older versions of the object file.  Any file that has an
        older timestamp than timestamp will be deleted.

        :param timestamp: timestamp to compare with each file
        """
        timestamp = normalize_timestamp(timestamp)

        def _unlinkold():
            for fname in os.listdir(self.datadir):
                if fname < timestamp:
                    try:
                        os.unlink(os.path.join(self.datadir, fname))
                    except OSError, err:    # pragma: no cover
                        if err.errno != errno.ENOENT:
                            raise
        self.threadpool.run_in_thread(_unlinkold)

    def _drop_cache(self, fd, offset, length):
        """Method for no-oping buffer cache drop method."""
        if not self.keep_cache:
            drop_buffer_cache(fd, offset, length)

    def quarantine(self):
        """
        In the case that a file is corrupted, move it to a quarantined
        area to allow replication to fix it.

        :returns: if quarantine is successful, path to quarantined
                  directory otherwise None
        """
        if not (self.is_deleted() or self.quarantined_dir):
            self.quarantined_dir = self.threadpool.run_in_thread(
                quarantine_renamer, self.device_path, self.data_file)
            self.logger.increment('quarantines')
            return self.quarantined_dir

    def get_data_file_size(self):
        """
        Returns the os.path.getsize for the file.  Raises an exception if this
        file does not match the Content-Length stored in the metadata. Or if
        self.data_file does not exist.

        :returns: file size as an int
        :raises DiskFileError: on file size mismatch.
        :raises DiskFileNotExist: on file not existing (including deleted)
        """
        try:
            file_size = 0
            if self.data_file:
                file_size = self.threadpool.run_in_thread(
                    os.path.getsize, self.data_file)
                if 'Content-Length' in self.metadata:
                    metadata_size = int(self.metadata['Content-Length'])
                    if file_size != metadata_size:
                        raise DiskFileError(
                            'Content-Length of %s does not match file size '
                            'of %s' % (metadata_size, file_size))
                return file_size
        except OSError, err:
            if err.errno != errno.ENOENT:
                raise
        raise DiskFileNotExist('Data File does not exist.')


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

    def __init__(self, conf):
        """
        Creates a new WSGI application for the Swift Object Server. An
        example configuration is given at
        <source-dir>/etc/object-server.conf-sample or
        /usr/local/etc/swift/object-server.conf-sample.
        """
        self.logger = get_logger(conf, log_route='object-server')
        self.devices = conf.get('devices', '/srv/node/')
        self.mount_check = config_true_value(conf.get('mount_check', 'true'))
        self.node_timeout = int(conf.get('node_timeout', 3))
        self.conn_timeout = float(conf.get('conn_timeout', 0.5))
        self.disk_chunk_size = int(conf.get('disk_chunk_size', 65536))
        self.network_chunk_size = int(conf.get('network_chunk_size', 65536))
        self.keep_cache_size = int(conf.get('keep_cache_size', 5242880))
        self.keep_cache_private = \
            config_true_value(conf.get('keep_cache_private', 'false'))
        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.bytes_per_sync = int(conf.get('mb_per_sync', 512)) * 1024 * 1024
        replication_server = conf.get('replication_server', None)
        if replication_server is None:
            allowed_methods = ['DELETE', 'PUT', 'HEAD', 'GET', 'REPLICATE',
                               'POST']
        else:
            replication_server = config_true_value(replication_server)
            if replication_server:
                allowed_methods = ['REPLICATE']
            else:
                allowed_methods = ['DELETE', 'PUT', 'HEAD', 'GET', 'POST']
        self.replication_server = replication_server
        self.allowed_methods = allowed_methods
        self.threads_per_disk = int(conf.get('threads_per_disk', '0'))
        self.threadpools = defaultdict(
            lambda: ThreadPool(nthreads=self.threads_per_disk))
        default_allowed_headers = '''
            content-disposition,
            content-encoding,
            x-delete-at,
            x-object-manifest,
            x-static-large-object,
        '''
        self.allowed_headers = set(
            i.strip().lower() for i in
            conf.get('allowed_headers', default_allowed_headers).split(',')
            if i.strip() and i.strip().lower() not in DISALLOWED_HEADERS)
        self.expiring_objects_account = \
            (conf.get('auto_create_account_prefix') or '.') + \
            'expiring_objects'
        self.expiring_objects_container_divisor = \
            int(conf.get('expiring_objects_container_divisor') or 86400)

    def _diskfile(self, device, partition, account, container, obj, **kwargs):
        """ Utility method for instantiating a DiskFile. """
        kwargs.setdefault('bytes_per_sync', self.bytes_per_sync)
        kwargs.setdefault('disk_chunk_size', self.disk_chunk_size)
        kwargs.setdefault('logger', self.logger)
        kwargs.setdefault('threadpool', self.threadpools[device])
        return DiskFile(self.devices, device, partition, account,
                        container, obj, **kwargs)

    def async_update(self, op, account, container, obj, host, partition,
                     contdevice, headers_out, objdevice):
        """
        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
        """
        headers_out['user-agent'] = 'obj-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})
        async_dir = os.path.join(self.devices, objdevice, ASYNCDIR)
        ohash = hash_path(account, container, obj)
        self.logger.increment('async_pendings')
        self.threadpools[objdevice].run_in_thread(
            write_pickle,
            {'op': op, 'account': account, 'container': container,
             'obj': obj, 'headers': headers_out},
            os.path.join(async_dir, ohash[-3:], ohash + '-' +
                         normalize_timestamp(headers_out['x-timestamp'])),
            os.path.join(self.devices, objdevice, 'tmp'))

    def container_update(self, op, account, container, obj, request,
                         headers_out, objdevice):
        """
        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
        """
        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: '
                                '"%s" vs "%s"' %
                                (headers_in.get('X-Container-Host', ''),
                                 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()
        for conthost, contdevice in updates:
            self.async_update(op, account, container, obj, conthost,
                              contpartition, contdevice, headers_out,
                              objdevice)

    def delete_at_update(self, op, delete_at, account, container, obj,
                         request, objdevice):
        """
        Update the expiring objects 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 driving the update
        :param objdevice: device name that the object is in
        """
        # Quick cap that will work from now until Sat Nov 20 17:46:39 2286
        # At that time, Swift will be so popular and pervasive I will have
        # created income for thousands of future programmers.
        delete_at = max(min(delete_at, 9999999999), 0)
        updates = [(None, None)]

        partition = None
        hosts = contdevices = [None]
        headers_in = request.headers
        headers_out = HeaderKeyDict({
            'x-timestamp': headers_in['x-timestamp'],
            '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 = str(
                    delete_at / self.expiring_objects_container_divisor *
                    self.expiring_objects_container_divisor)
            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 = str(
                delete_at / self.expiring_objects_container_divisor *
                self.expiring_objects_container_divisor)

        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)

    @public
    @timing_stats()
    def POST(self, request):
        """Handle HTTP POST requests for the Swift Object Server."""
        try:
            device, partition, account, container, obj = \
                split_path(unquote(request.path), 5, 5, True)
            validate_device_partition(device, partition)
        except ValueError, err:
            return HTTPBadRequest(body=str(err), request=request,
                                  content_type='text/plain')
        if 'x-timestamp' not in request.headers or \
                not check_float(request.headers['x-timestamp']):
            return HTTPBadRequest(body='Missing timestamp', request=request,
                                  content_type='text/plain')
        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')
        if self.mount_check and not check_mount(self.devices, device):
            return HTTPInsufficientStorage(drive=device, request=request)
        disk_file = self._diskfile(device, partition, account, container, obj)
        if disk_file.is_deleted() or disk_file.is_expired():
            return HTTPNotFound(request=request)
        try:
            disk_file.get_data_file_size()
        except (DiskFileError, DiskFileNotExist):
            disk_file.quarantine()
            return HTTPNotFound(request=request)
        metadata = {'X-Timestamp': request.headers['x-timestamp']}
        metadata.update(val for val in request.headers.iteritems()
                        if val[0].startswith('X-Object-Meta-'))
        for header_key in self.allowed_headers:
            if header_key in request.headers:
                header_caps = header_key.title()
                metadata[header_caps] = request.headers[header_key]
        old_delete_at = int(disk_file.metadata.get('X-Delete-At') or 0)
        if old_delete_at != new_delete_at:
            if new_delete_at:
                self.delete_at_update('PUT', new_delete_at, account, container,
                                      obj, request, device)
            if old_delete_at:
                self.delete_at_update('DELETE', old_delete_at, account,
                                      container, obj, request, device)
        disk_file.put_metadata(metadata)
        return HTTPAccepted(request=request)

    @public
    @timing_stats()
    def PUT(self, request):
        """Handle HTTP PUT requests for the Swift Object Server."""
        try:
            device, partition, account, container, obj = \
                split_path(unquote(request.path), 5, 5, True)
            validate_device_partition(device, partition)
        except ValueError, err:
            return HTTPBadRequest(body=str(err), request=request,
                                  content_type='text/plain')
        if 'x-timestamp' not in request.headers or \
                not check_float(request.headers['x-timestamp']):
            return HTTPBadRequest(body='Missing timestamp', request=request,
                                  content_type='text/plain')
        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)
        if new_delete_at and new_delete_at < time.time():
            return HTTPBadRequest(body='X-Delete-At in past', request=request,
                                  content_type='text/plain')
        try:
            fsize = request.message_length()
        except ValueError as e:
            return HTTPBadRequest(body=str(e), request=request,
                                  content_type='text/plain')
        if self.mount_check and not check_mount(self.devices, device):
            return HTTPInsufficientStorage(drive=device, request=request)
        disk_file = self._diskfile(device, partition, account, container, obj)
        old_delete_at = int(disk_file.metadata.get('X-Delete-At') or 0)
        orig_timestamp = disk_file.metadata.get('X-Timestamp')
        upload_expiration = time.time() + self.max_upload_time
        etag = md5()
        elapsed_time = 0
        try:
            with disk_file.writer(size=fsize) as writer:
                reader = request.environ['wsgi.input'].read
                for chunk in iter(lambda: reader(self.network_chunk_size), ''):
                    start_time = time.time()
                    if start_time > upload_expiration:
                        self.logger.increment('PUT.timeouts')
                        return HTTPRequestTimeout(request=request)
                    etag.update(chunk)
                    writer.write(chunk)
                    sleep()
                    elapsed_time += time.time() - start_time
                upload_size = writer.upload_size
                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)
                etag = etag.hexdigest()
                if 'etag' in request.headers and \
                        request.headers['etag'].lower() != etag:
                    return HTTPUnprocessableEntity(request=request)
                metadata = {
                    'X-Timestamp': request.headers['x-timestamp'],
                    'Content-Type': request.headers['content-type'],
                    'ETag': etag,
                    'Content-Length': str(upload_size),
                }
                metadata.update(val for val in request.headers.iteritems()
                                if val[0].lower().startswith('x-object-meta-')
                                and len(val[0]) > 14)
                for header_key in self.allowed_headers:
                    if header_key in request.headers:
                        header_caps = header_key.title()
                        metadata[header_caps] = request.headers[header_key]
                writer.put(metadata)
        except DiskFileNoSpace:
            return HTTPInsufficientStorage(drive=device, request=request)
        disk_file.unlinkold(metadata['X-Timestamp'])
        if old_delete_at != new_delete_at:
            if new_delete_at:
                self.delete_at_update(
                    'PUT', new_delete_at, account, container, obj,
                    request, device)
            if old_delete_at:
                self.delete_at_update(
                    'DELETE', old_delete_at, account, container, obj,
                    request, device)
        if not orig_timestamp or \
                orig_timestamp < request.headers['x-timestamp']:
            self.container_update(
                'PUT', account, container, obj, request,
                HeaderKeyDict({
                    'x-size': disk_file.metadata['Content-Length'],
                    'x-content-type': disk_file.metadata['Content-Type'],
                    'x-timestamp': disk_file.metadata['X-Timestamp'],
                    'x-etag': disk_file.metadata['ETag']}),
                device)
        resp = HTTPCreated(request=request, etag=etag)
        return resp

    @public
    @timing_stats()
    def GET(self, request):
        """Handle HTTP GET requests for the Swift Object Server."""
        try:
            device, partition, account, container, obj = \
                split_path(unquote(request.path), 5, 5, True)
            validate_device_partition(device, partition)
        except ValueError, err:
            return HTTPBadRequest(body=str(err), request=request,
                                  content_type='text/plain')
        if self.mount_check and not check_mount(self.devices, device):
            return HTTPInsufficientStorage(drive=device, request=request)
        disk_file = self._diskfile(device, partition, account, container, obj,
                                   keep_data_fp=True, iter_hook=sleep)
        if disk_file.is_deleted() or disk_file.is_expired():
            if request.headers.get('if-match') == '*':
                return HTTPPreconditionFailed(request=request)
            else:
                return HTTPNotFound(request=request)
        try:
            file_size = disk_file.get_data_file_size()
        except (DiskFileError, DiskFileNotExist):
            disk_file.quarantine()
            return HTTPNotFound(request=request)
        if request.headers.get('if-match') not in (None, '*') and \
                disk_file.metadata['ETag'] not in request.if_match:
            disk_file.close()
            return HTTPPreconditionFailed(request=request)
        if request.headers.get('if-none-match') is not None:
            if disk_file.metadata['ETag'] in request.if_none_match:
                resp = HTTPNotModified(request=request)
                resp.etag = disk_file.metadata['ETag']
                disk_file.close()
                return resp
        try:
            if_unmodified_since = request.if_unmodified_since
        except (OverflowError, ValueError):
            # catches timestamps before the epoch
            return HTTPPreconditionFailed(request=request)
        if if_unmodified_since and \
                datetime.fromtimestamp(
                    float(disk_file.metadata['X-Timestamp']), UTC) > \
                if_unmodified_since:
            disk_file.close()
            return HTTPPreconditionFailed(request=request)
        try:
            if_modified_since = request.if_modified_since
        except (OverflowError, ValueError):
            # catches timestamps before the epoch
            return HTTPPreconditionFailed(request=request)
        if if_modified_since and \
                datetime.fromtimestamp(
                    float(disk_file.metadata['X-Timestamp']), UTC) < \
                if_modified_since:
            disk_file.close()
            return HTTPNotModified(request=request)
        response = Response(app_iter=disk_file,
                            request=request, conditional_response=True)
        response.headers['Content-Type'] = disk_file.metadata.get(
            'Content-Type', 'application/octet-stream')
        for key, value in disk_file.metadata.iteritems():
            if key.lower().startswith('x-object-meta-') or \
                    key.lower() in self.allowed_headers:
                response.headers[key] = value
        response.etag = disk_file.metadata['ETag']
        response.last_modified = float(disk_file.metadata['X-Timestamp'])
        response.content_length = file_size
        if response.content_length < self.keep_cache_size and \
                (self.keep_cache_private or
                 ('X-Auth-Token' not in request.headers and
                  'X-Storage-Token' not in request.headers)):
            disk_file.keep_cache = True
        if 'Content-Encoding' in disk_file.metadata:
            response.content_encoding = disk_file.metadata['Content-Encoding']
        response.headers['X-Timestamp'] = disk_file.metadata['X-Timestamp']
        return request.get_response(response)

    @public
    @timing_stats(sample_rate=0.8)
    def HEAD(self, request):
        """Handle HTTP HEAD requests for the Swift Object Server."""
        try:
            device, partition, account, container, obj = \
                split_path(unquote(request.path), 5, 5, True)
            validate_device_partition(device, partition)
        except ValueError, err:
            resp = HTTPBadRequest(request=request)
            resp.content_type = 'text/plain'
            resp.body = str(err)
            return resp
        if self.mount_check and not check_mount(self.devices, device):
            return HTTPInsufficientStorage(drive=device, request=request)
        disk_file = self._diskfile(device, partition, account, container, obj)
        if disk_file.is_deleted() or disk_file.is_expired():
            return HTTPNotFound(request=request)
        try:
            file_size = disk_file.get_data_file_size()
        except (DiskFileError, DiskFileNotExist):
            disk_file.quarantine()
            return HTTPNotFound(request=request)
        response = Response(request=request, conditional_response=True)
        response.headers['Content-Type'] = disk_file.metadata.get(
            'Content-Type', 'application/octet-stream')
        for key, value in disk_file.metadata.iteritems():
            if key.lower().startswith('x-object-meta-') or \
                    key.lower() in self.allowed_headers:
                response.headers[key] = value
        response.etag = disk_file.metadata['ETag']
        response.last_modified = float(disk_file.metadata['X-Timestamp'])
        # Needed for container sync feature
        response.headers['X-Timestamp'] = disk_file.metadata['X-Timestamp']
        response.content_length = file_size
        if 'Content-Encoding' in disk_file.metadata:
            response.content_encoding = disk_file.metadata['Content-Encoding']
        return response

    @public
    @timing_stats()
    def DELETE(self, request):
        """Handle HTTP DELETE requests for the Swift Object Server."""
        try:
            device, partition, account, container, obj = \
                split_path(unquote(request.path), 5, 5, True)
            validate_device_partition(device, partition)
        except ValueError, e:
            return HTTPBadRequest(body=str(e), request=request,
                                  content_type='text/plain')
        if 'x-timestamp' not in request.headers or \
                not check_float(request.headers['x-timestamp']):
            return HTTPBadRequest(body='Missing timestamp', request=request,
                                  content_type='text/plain')
        if self.mount_check and not check_mount(self.devices, device):
            return HTTPInsufficientStorage(drive=device, request=request)
        response_class = HTTPNoContent
        disk_file = self._diskfile(device, partition, account, container, obj)
        if 'x-if-delete-at' in request.headers and \
                int(request.headers['x-if-delete-at']) != \
                int(disk_file.metadata.get('X-Delete-At') or 0):
            return HTTPPreconditionFailed(
                request=request,
                body='X-If-Delete-At and X-Delete-At do not match')
        orig_timestamp = disk_file.metadata.get('X-Timestamp')
        if disk_file.is_deleted() or disk_file.is_expired():
            response_class = HTTPNotFound
        metadata = {
            'X-Timestamp': request.headers['X-Timestamp'], 'deleted': True,
        }
        old_delete_at = int(disk_file.metadata.get('X-Delete-At') or 0)
        if old_delete_at:
            self.delete_at_update('DELETE', old_delete_at, account,
                                  container, obj, request, device)
        disk_file.put_metadata(metadata, tombstone=True)
        disk_file.unlinkold(metadata['X-Timestamp'])
        if not orig_timestamp or \
                orig_timestamp < request.headers['x-timestamp']:
            self.container_update(
                'DELETE', account, container, obj, request,
                HeaderKeyDict({'x-timestamp': metadata['X-Timestamp']}),
                device)
        resp = response_class(request=request)
        return resp

    @public
    @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.
        """
        try:
            device, partition, suffix = split_path(
                unquote(request.path), 2, 3, True)
            validate_device_partition(device, partition)
        except ValueError, e:
            return HTTPBadRequest(body=str(e), request=request,
                                  content_type='text/plain')
        if self.mount_check and not check_mount(self.devices, device):
            return HTTPInsufficientStorage(drive=device, request=request)
        path = os.path.join(self.devices, device, DATADIR, partition)
        if not os.path.exists(path):
            mkdirs(path)
        suffixes = suffix.split('-') if suffix else []
        _junk, hashes = self.threadpools[device].force_run_in_thread(
            get_hashes, path, recalculate=suffixes)
        return Response(body=pickle.dumps(hashes))

    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'
                try:
                    method = getattr(self, req.method)
                    getattr(method, 'publicly_accessible')
                    if req.method not in self.allowed_methods:
                        raise AttributeError('Not allowed method.')
                except AttributeError:
                    res = HTTPMethodNotAllowed()
                else:
                    res = method(req)
            except DiskFileCollision:
                res = HTTPForbidden(request=req)
            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
        if self.log_requests:
            log_line = '%s - - [%s] "%s %s" %s %s "%s" "%s" "%s" %.4f' % (
                req.remote_addr,
                time.strftime('%d/%b/%Y:%H:%M:%S +0000',
                              time.gmtime()),
                req.method, req.path, res.status.split()[0],
                res.content_length or '-', req.referer or '-',
                req.headers.get('x-trans-id', '-'),
                req.user_agent or '-',
                trans_time)
            if req.method == 'REPLICATE':
                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)
        return res(env, start_response)


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)
