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Viewing changes to lib/lp/codehosting/bzrutils.py

  • Committer: Gary Poster
  • Date: 2011-07-27 15:25:32 UTC
  • mto: This revision was merged to the branch mainline in revision 13541.
  • Revision ID: gary.poster@canonical.com-20110727152532-50akr19c7mgcj5qu
add config option for timeout value

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lib/lp/codehosting/bzrutils.py
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    'read_locked',
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    'remove_exception_logging_hook',
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    'safe_open',
 
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    'UnsafeUrlSeen',
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    ]
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from contextlib import contextmanager
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import os
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import sys
 
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import threading
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from bzrlib import (
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    config,
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    trace,
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    )
 
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from bzrlib.branch import Branch
 
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from bzrlib.bzrdir import BzrDir
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from bzrlib.errors import (
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    NotStacked,
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    UnstackableBranchFormat,
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            get_vfs_format_classes(branch_two))
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checked_open_data = threading.local()
 
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def _install_checked_open_hook():
 
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    """Install `_checked_open_pre_open_hook` as a ``pre_open`` hook.
 
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    This is done at module import time, but _checked_open_pre_open_hook
 
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    doesn't do anything unless the `checked_open_data` threading.Local object
 
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    has a 'checked_opener' attribute in this thread.
 
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    This is in a module-level function rather than performed at module level
 
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    so that it can be called in setUp for testing `checked_open` as
 
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    bzrlib.tests.TestCase.setUp clears hooks.
 
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    """
 
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    BzrDir.hooks.install_named_hook(
 
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        'pre_open', _checked_open_pre_open_hook, 'safe open')
 
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def _checked_open_pre_open_hook(transport):
 
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    """If a checked_open validate function is present in this thread, call it.
 
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    """
 
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    if not getattr(checked_open_data, 'validate', False):
 
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        return
 
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    checked_open_data.validate(transport.base)
 
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_install_checked_open_hook()
 
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def checked_open(validation_function, url, possible_transports=None):
 
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    """Open a branch, calling `validation_function` with any URL thus found.
 
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    This is intended to be used to open a branch ensuring that it's not
 
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    stacked or a reference to something unexpected.
 
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    """
 
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    if hasattr(checked_open_data, 'validate'):
 
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        raise AssertionError("checked_open called recursively")
 
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    checked_open_data.validate = validation_function
 
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    try:
 
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        return Branch.open(url, possible_transports=possible_transports)
 
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    finally:
 
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        del checked_open_data.validate
 
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class UnsafeUrlSeen(Exception):
 
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    """`safe_open` found a URL that was not on the configured scheme."""
 
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def makeURLChecker(allowed_scheme):
 
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    """Make a callable that rejects URLs not on the given scheme."""
 
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    def checkURL(url):
 
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        """Check that `url` is safe to open."""
 
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        if URI(url).scheme != allowed_scheme:
 
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            raise UnsafeUrlSeen(
 
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                "Attempt to open %r which is not a %s URL" % (
 
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                    url, allowed_scheme))
 
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    return checkURL
 
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def safe_open(allowed_scheme, url, possible_transports=None):
 
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    """Open the branch at `url`, only accessing URLs on `allowed_scheme`.
 
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    :raises UnsafeUrlSeen: An attempt was made to open a URL that was not on
 
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        `allowed_scheme`.
 
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    """
 
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    return checked_open(
 
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        makeURLChecker(allowed_scheme), url, possible_transports)
 
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def get_stacked_on_url(branch):
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    """Get the stacked-on URL for 'branch', or `None` if not stacked."""
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    try: