#-------------------------------------------------------------------------------
# Copyright (c) 2012-2014 by European Organization for Nuclear Research (CERN)
# Author: Justin Salmon <jsalmon@cern.ch>
#-------------------------------------------------------------------------------
# This file is part of the XRootD software suite.
#
# XRootD is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# XRootD is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with XRootD. If not, see <http://www.gnu.org/licenses/>.
#
# In applying this licence, CERN does not waive the privileges and immunities
# granted to it by virtue of its status as an Intergovernmental Organization
# or submit itself to any jurisdiction.
#-------------------------------------------------------------------------------
from __future__ import absolute_import, division, print_function
from pyxrootd import client
from XRootD.client.responses import XRootDStatus, StatInfo, VectorReadInfo
from XRootD.client.utils import CallbackWrapper
class File(object):
"""Interact with an ``xrootd`` server to perform file-based operations such
as reading, writing, vector reading, etc."""
def __init__(self):
self.__file = client.File()
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
self.__file.__exit__()
def __iter__(self):
return self
def __next__(self):
return self.__file.next()
# Python 2 compatibility
next = __next__
def open(self, url, flags=0, mode=0, timeout=0, callback=None):
"""Open the file pointed to by the given URL.
:param url: url of the file to be opened
:type url: string
:param flags: An `ORed` combination of :mod:`XRootD.client.flags.OpenFlags`
where the default is `OpenFlags.NONE`
:param mode: access mode for new files, an `ORed` combination of
:mod:`XRootD.client.flags.AccessMode` where the default is
`AccessMode.NONE`
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and None
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.open(url, flags, mode, timeout, callback))
status, response = self.__file.open(url, flags, mode, timeout)
return XRootDStatus(status), None
def close(self, timeout=0, callback=None):
"""Close the file.
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and None
As of Python 2.5, you can avoid having to call this method explicitly if you
use the `with` statement. For example, the following code will
automatically close *f* when the `with` block is exited::
from __future__ import with_statement # This isn't required in Python 2.6
with client.File() as f:
f.open("root://someserver//somefile")
for line in f:
print line,
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.close(timeout, callback))
status, response = self.__file.close(timeout)
return XRootDStatus(status), None
def stat(self, force=False, timeout=0, callback=None):
"""Obtain status information for this file.
:param force: do not use the cached information, force re-stating
:type force: boolean
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and :mod:`XRootD.client.responses.StatInfo` object
"""
if callback:
callback = CallbackWrapper(callback, StatInfo)
return XRootDStatus(self.__file.stat(force, timeout, callback))
status, response = self.__file.stat(force, timeout)
if response: response = StatInfo(response)
return XRootDStatus(status), response
def read(self, offset=0, size=0, timeout=0, callback=None):
"""Read a data chunk from a given offset.
:param offset: offset from the beginning of the file
:type offset: integer
:param size: number of bytes to be read
:type size: integer
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and the data that was read
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.read(offset, size, timeout, callback))
status, response = self.__file.read(offset, size, timeout)
return XRootDStatus(status), response
def readline(self, offset=0, size=0, chunksize=0):
"""Read a data chunk from a given offset, until the first newline or EOF
encountered.
:param offset: offset from the beginning of the file
:type offset: integer
:param size: maximum number of bytes to be read
:type size: integer
:param chunksize: size of chunk used for reading, in bytes
:type chunksize: integer
:returns: data that was read, including the trailing newline
:rtype: string
"""
return self.__file.readline(offset, size, chunksize)
def readlines(self, offset=0, size=0, chunksize=0):
"""Read lines from a given offset until EOF encountered. Return list of
lines read.
:param offset: offset from the beginning of the file
:type offset: integer
:param size: maximum number of bytes to be read
:type size: integer
:param chunksize: size of chunk used for reading, in bytes
:type chunksize: integer
:returns: data that was read, including trailing newlines
:rtype: list of strings
.. warning:: This method will read the whole file into memory if you don't
specify an offset. Think twice about using it if your files
are big.
"""
return self.__file.readlines(offset, size, chunksize)
def readchunks(self, offset=0, chunksize=1024 * 1024 * 2):
"""Return an iterator object which will read data chunks from a given
offset of the given chunksize until EOF.
:param offset: offset from the beginning of the file
:type offset: integer
:param chunksize: size of chunk to read, in bytes
:type chunksize: integer
:returns: iterator object
"""
return self.__file.readchunks(offset, chunksize)
def write(self, buffer, offset=0, size=0, timeout=0, callback=None):
"""Write a data chunk at a given offset.
:param buffer: data to be written
:param offset: offset from the beginning of the file
:type offset: integer
:param size: number of bytes to be written
:type size: integer
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and None
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.write(buffer, offset, size, timeout, callback))
status, response = self.__file.write(buffer, offset, size, timeout)
return XRootDStatus(status), None
def sync(self, timeout=0, callback=None):
"""Commit all pending disk writes.
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and None
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.sync(timeout, callback))
status, response = self.__file.sync(timeout)
return XRootDStatus(status), None
def truncate(self, size, timeout=0, callback=None):
"""Truncate the file to a particular size.
:param size: desired size of the file
:type size: integer
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and None
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.truncate(size, timeout, callback))
status, response = self.__file.truncate(size, timeout)
return XRootDStatus(status), None
def vector_read(self, chunks, timeout=0, callback=None):
"""Read scattered data chunks in one operation.
:param chunks: list of the chunks to be read. The default maximum
chunk size is 2097136 bytes and the default maximum
number of chunks per request is 1024. The server may
be queried using :func:`XRootD.client.FileSystem.query`
for the actual settings.
:type chunks: list of 2-tuples of the form (offset, size)
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and :mod:`XRootD.client.responses.VectorReadInfo`
object
"""
if callback:
callback = CallbackWrapper(callback, VectorReadInfo)
return XRootDStatus(self.__file.vector_read(chunks, timeout, callback))
status, response = self.__file.vector_read(chunks, timeout)
if response: response = VectorReadInfo(response)
return XRootDStatus(status), response
def fcntl(self, arg, timeout=0, callback=None):
"""Perform a custom operation on an open file.
:param arg: argument
:type arg: string
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and a string
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.fcntl( arg, timeout, callback))
status, response = self.__file.fcntl( arg, timeout )
return XRootDStatus(status), response
def visa(self, timeout=0, callback=None):
"""Get access token to a file.
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and a string
"""
if callback:
callback = CallbackWrapper(callback, None)
return XRootDStatus(self.__file.visa(timeout, callback))
status, response = self.__file.visa(timeout)
return XRootDStatus(status), response
def is_open(self):
"""Check if the file is open.
:rtype: boolean
"""
return self.__file.is_open()
def set_property(self, name, value):
"""Set file property.
:param name: name of the property to set
:type name: string
:returns: boolean denoting if property setting was successful
:rtype: boolean
"""
return self.__file.set_property(name, value)
def get_property(self, name):
"""Get file property.
:param name: name of the property
:type name: string
"""
return self.__file.get_property(name)
def set_xattr(self, attrs, timeout=0, callback=None):
"""Set extended file attributes.
:param attrs: extended attributes to be set on the file
:type attrs: list of tuples of name/value pairs
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and :mod:`list of touples (string, XRootD.client.responses.XRootDStatus)` object
"""
if callback:
callback = CallbackWrapper(callback, list)
return XRootDStatus(self.__file.set_xattr(attrs, timeout, callback))
status, response = self.__file.set_xattr(attrs, timeout)
return XRootDStatus(status), response
def get_xattr(self, attrs, timeout=0, callback=None):
"""Get extended file attributes.
:param attrs: list of extended attribute names to be retrived
:type attrs: list of strings
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and :mod:`list of touples (string, string, XRootD.client.responses.XRootDStatus)` object
"""
if callback:
callback = CallbackWrapper(callback, list)
return XRootDStatus(self.__file.get_xattr(attrs, timeout, callback))
status, response = self.__file.get_xattr(attrs, timeout)
return XRootDStatus(status), response
def del_xattr(self, attrs, timeout=0, callback=None):
"""Delete extended file attributes.
:param attrs: list of extended attribute names to be deleted
:type attrs: list of strings
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and :mod:`list of touples (string, XRootD.client.responses.XRootDStatus)` object
"""
if callback:
callback = CallbackWrapper(callback, list)
return XRootDStatus(self.__file.del_xattr(attrs, timeout, callback))
status, response = self.__file.del_xattr(attrs, timeout)
return XRootDStatus(status), response
def list_xattr(self, timeout=0, callback=None):
"""List all extended file attributes.
:returns: tuple containing :mod:`XRootD.client.responses.XRootDStatus`
object and :mod:`list of touples (string, string, XRootD.client.responses.XRootDStatus)` object
"""
if callback:
callback = CallbackWrapper(callback, list)
return XRootDStatus(self.__file.list_xattr(timeout, callback))
status, response = self.__file.list_xattr(timeout)
return XRootDStatus(status), response