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- Committer: John Arbash Meinel
- Date: 2005-09-29 20:34:25 UTC
- mfrom: (1185.11.24)
- mto: (1393.1.12)
- mto: This revision was merged to the branch mainline in revision 1396.
- Revision ID: john@arbash-meinel.com-20050929203425-7fc2ea87f449dfe8
Merged in split-storage-2 branch. Need to cleanup a little bit more still.
- files added:
- bzrlib/selftest/testtransport.py
- bzrlib/store
- bzrlib/transport
- files removed:
- bzrlib/remotebranch.py
- files renamed:
- bzrlib/store.py => bzrlib/store/__init__.py
- files modified:
- bzrlib/atomicfile.py
added
removed
bzrlib/transport/__init__.py
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# Copyright (C) 2005 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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"""Transport is an abstraction layer to handle file access.
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The abstraction is to allow access from the local filesystem, as well
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as remote (such as http or sftp).
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"""
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from bzrlib.trace import mutter
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from bzrlib.errors import (BzrError,
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TransportError, TransportNotPossible, NonRelativePath,
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NoSuchFile, FileExists, PermissionDenied,
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ConnectionReset)
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_protocol_handlers = {
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}
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def register_transport(prefix, klass, override=True):
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global _protocol_handlers
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if _protocol_handlers.has_key(prefix):
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if override:
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mutter('overriding transport: %s => %s' % (prefix, klass.__name__))
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_protocol_handlers[prefix] = klass
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else:
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mutter('registering transport: %s => %s' % (prefix, klass.__name__))
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_protocol_handlers[prefix] = klass
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class Transport(object):
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"""This class encapsulates methods for retrieving or putting a file
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from/to a storage location.
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Most functions have a _multi variant, which allows you to queue up
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multiple requests. They generally have a dumb base implementation
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which just iterates over the arguments, but smart Transport
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implementations can do pipelining.
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In general implementations should support having a generator or a list
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as an argument (ie always iterate, never index)
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"""
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def __init__(self, base):
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super(Transport, self).__init__()
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self.base = base
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def clone(self, offset=None):
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"""Return a new Transport object, cloned from the current location,
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using a subdirectory or parent directory. This allows connections
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to be pooled, rather than a new one needed for each subdir.
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"""
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raise NotImplementedError
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def should_cache(self):
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"""Return True if the data pulled across should be cached locally.
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"""
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return False
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def _pump(self, from_file, to_file):
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"""Most children will need to copy from one file-like
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object or string to another one.
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This just gives them something easy to call.
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"""
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if isinstance(from_file, basestring):
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to_file.write(from_file)
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else:
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from bzrlib.osutils import pumpfile
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pumpfile(from_file, to_file)
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def _get_total(self, multi):
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"""Try to figure out how many entries are in multi,
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but if not possible, return None.
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"""
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try:
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return len(multi)
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except TypeError: # We can't tell how many, because relpaths is a generator
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return None
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def _update_pb(self, pb, msg, count, total):
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"""Update the progress bar based on the current count
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and total available, total may be None if it was
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not possible to determine.
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"""
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if pb is None:
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return
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if total is None:
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pb.update(msg, count, count+1)
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else:
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pb.update(msg, count, total)
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def _iterate_over(self, multi, func, pb, msg, expand=True):
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"""Iterate over all entries in multi, passing them to func,
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and update the progress bar as you go along.
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:param expand: If True, the entries will be passed to the function
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by expanding the tuple. If False, it will be passed
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as a single parameter.
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"""
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total = self._get_total(multi)
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count = 0
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for entry in multi:
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self._update_pb(pb, msg, count, total)
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if expand:
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func(*entry)
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else:
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func(entry)
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count += 1
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return count
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def abspath(self, relpath):
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"""Return the full url to the given relative path.
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This can be supplied with a string or a list
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"""
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raise NotImplementedError
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def relpath(self, abspath):
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"""Return the local path portion from a given absolute path.
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"""
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raise NotImplementedError
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def has(self, relpath):
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"""Does the target location exist?"""
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raise NotImplementedError
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def has_multi(self, relpaths, pb=None):
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"""Return True/False for each entry in relpaths"""
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total = self._get_total(relpaths)
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count = 0
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for relpath in relpaths:
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self._update_pb(pb, 'has', count, total)
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yield self.has(relpath)
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count += 1
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def get(self, relpath):
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"""Get the file at the given relative path.
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:param relpath: The relative path to the file
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"""
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raise NotImplementedError
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def get_multi(self, relpaths, pb=None):
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"""Get a list of file-like objects, one for each entry in relpaths.
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:param relpaths: A list of relative paths.
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:param pb: An optional ProgressBar for indicating percent done.
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:return: A list or generator of file-like objects
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"""
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# TODO: Consider having this actually buffer the requests,
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# in the default mode, it probably won't give worse performance,
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# and all children wouldn't have to implement buffering
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total = self._get_total(relpaths)
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count = 0
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for relpath in relpaths:
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self._update_pb(pb, 'get', count, total)
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yield self.get(relpath)
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count += 1
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def get_partial(self, relpath, start, length=None):
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"""Get just part of a file.
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:param relpath: Path to the file, relative to base
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:param start: The starting position to read from
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:param length: The length to read. A length of None indicates
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read to the end of the file.
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:return: A file-like object containing at least the specified bytes.
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Some implementations may return objects which can be read
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past this length, but this is not guaranteed.
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"""
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raise NotImplementedError
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def get_partial_multi(self, offsets, pb=None):
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"""Put a set of files or strings into the location.
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Requesting multiple portions of the same file can be dangerous.
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:param offsets: A list of tuples of relpath, start, length
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[(path1, start1, length1),
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(path2, start2, length2),
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(path3, start3), ...]
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length is optional, defaulting to None
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:param pb: An optional ProgressBar for indicating percent done.
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:return: A generator of file-like objects.
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"""
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total = self._get_total(offsets)
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count = 0
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for offset in offsets:
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self._update_pb(pb, 'get_partial', count, total)
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yield self.get_partial(*offset)
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count += 1
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def put(self, relpath, f):
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"""Copy the file-like or string object into the location.
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:param relpath: Location to put the contents, relative to base.
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:param f: File-like or string object.
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"""
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raise NotImplementedError
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def put_multi(self, files, pb=None):
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"""Put a set of files or strings into the location.
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:param files: A list of tuples of relpath, file object [(path1, file1), (path2, file2),...]
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:param pb: An optional ProgressBar for indicating percent done.
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:return: The number of files copied.
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"""
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return self._iterate_over(files, self.put, pb, 'put', expand=True)
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def mkdir(self, relpath):
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"""Create a directory at the given path."""
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raise NotImplementedError
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def mkdir_multi(self, relpaths, pb=None):
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"""Create a group of directories"""
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return self._iterate_over(relpaths, self.mkdir, pb, 'mkdir', expand=False)
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def append(self, relpath, f):
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"""Append the text in the file-like or string object to
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the supplied location.
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"""
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raise NotImplementedError
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def append_multi(self, files, pb=None):
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"""Append the text in each file-like or string object to
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the supplied location.
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:param files: A set of (path, f) entries
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:param pb: An optional ProgressBar for indicating percent done.
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"""
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return self._iterate_over(files, self.append, pb, 'append', expand=True)
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def copy(self, rel_from, rel_to):
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"""Copy the item at rel_from to the location at rel_to"""
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raise NotImplementedError
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def copy_multi(self, relpaths, pb=None):
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"""Copy a bunch of entries.
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:param relpaths: A list of tuples of the form [(from, to), (from, to),...]
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"""
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# This is the non-pipelined implementation, so that
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# implementors don't have to implement everything.
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return self._iterate_over(relpaths, self.copy, pb, 'copy', expand=True)
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def copy_to(self, relpaths, other, pb=None):
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"""Copy a set of entries from self into another Transport.
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:param relpaths: A list/generator of entries to be copied.
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"""
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# The dummy implementation just does a simple get + put
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def copy_entry(path):
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other.put(path, self.get(path))
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return self._iterate_over(relpaths, copy_entry, pb, 'copy_to', expand=False)
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def move(self, rel_from, rel_to):
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"""Move the item at rel_from to the location at rel_to"""
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raise NotImplementedError
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def move_multi(self, relpaths, pb=None):
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"""Move a bunch of entries.
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:param relpaths: A list of tuples of the form [(from1, to1), (from2, to2),...]
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"""
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return self._iterate_over(relpaths, self.move, pb, 'move', expand=True)
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def move_multi_to(self, relpaths, rel_to):
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"""Move a bunch of entries to a single location.
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This differs from move_multi in that you give a list of from, and
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a single destination, rather than multiple destinations.
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:param relpaths: A list of relative paths [from1, from2, from3, ...]
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:param rel_to: A directory where each entry should be placed.
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"""
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# This is not implemented, because you need to do special tricks to
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# extract the basename, and add it to rel_to
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raise NotImplementedError
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def delete(self, relpath):
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"""Delete the item at relpath"""
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raise NotImplementedError
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def delete_multi(self, relpaths, pb=None):
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"""Queue up a bunch of deletes to be done.
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"""
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return self._iterate_over(relpaths, self.delete, pb, 'delete', expand=False)
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def stat(self, relpath):
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"""Return the stat information for a file.
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WARNING: This may not be implementable for all protocols, so use
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sparingly.
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"""
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raise NotImplementedError
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def stat_multi(self, relpaths, pb=None):
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"""Stat multiple files and return the information.
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"""
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#TODO: Is it worth making this a generator instead of a
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# returning a list?
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stats = []
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def gather(path):
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stats.append(self.stat(path))
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count = self._iterate_over(relpaths, gather, pb, 'stat', expand=False)
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return stats
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def list_dir(self, relpath):
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"""Return a list of all files at the given location.
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WARNING: many transports do not support this, so trying avoid using
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it if at all possible.
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"""
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raise NotImplementedError
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def lock_read(self, relpath):
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"""Lock the given file for shared (read) access.
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WARNING: many transports do not support this, so trying avoid using it
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:return: A lock object, which should contain an unlock() function.
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"""
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raise NotImplementedError
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def lock_write(self, relpath):
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"""Lock the given file for exclusive (write) access.
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WARNING: many transports do not support this, so trying avoid using it
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:return: A lock object, which should contain an unlock() function.
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"""
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raise NotImplementedError
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def transport(base):
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global _protocol_handlers
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if base is None:
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base = '.'
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for proto, klass in _protocol_handlers.iteritems():
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if proto is not None and base.startswith(proto):
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return klass(base)
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# The default handler is the filesystem handler
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# which has a lookup of None
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return _protocol_handlers[None](base)
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# Local transport should always be initialized
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import bzrlib.transport.local
Loggerhead is a web-based interface for Breezy
Version: 2.0.1