~bzr-pqm/bzr/bzr.dev

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
# Copyright (C) 2005 Canonical Ltd

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program 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 General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
"""Transport is an abstraction layer to handle file access.

The abstraction is to allow access from the local filesystem, as well
as remote (such as http or sftp).
"""

from bzrlib.trace import mutter
import bzrlib.errors as errors
import errno

_protocol_handlers = {
}

def register_transport(prefix, klass, override=True):
    global _protocol_handlers
    # trace messages commented out because they're typically 
    # run during import before trace is set up
    if _protocol_handlers.has_key(prefix):
        if override:
            ## mutter('overriding transport: %s => %s' % (prefix, klass.__name__))
            _protocol_handlers[prefix] = klass
    else:
        ## mutter('registering transport: %s => %s' % (prefix, klass.__name__))
        _protocol_handlers[prefix] = klass


class Transport(object):
    """This class encapsulates methods for retrieving or putting a file
    from/to a storage location.

    Most functions have a _multi variant, which allows you to queue up
    multiple requests. They generally have a dumb base implementation 
    which just iterates over the arguments, but smart Transport
    implementations can do pipelining.
    In general implementations should support having a generator or a list
    as an argument (ie always iterate, never index)
    """

    def __init__(self, base):
        super(Transport, self).__init__()
        self.base = base

    def _translate_error(self, e, path, raise_generic=True):
        """Translate an IOError or OSError into an appropriate bzr error.

        This handles things like ENOENT, ENOTDIR, EEXIST, and EACCESS
        """
        if hasattr(e, 'errno'):
            if e.errno in (errno.ENOENT, errno.ENOTDIR):
                raise errors.NoSuchFile(path, extra=e)
            if e.errno == errno.EEXIST:
                raise errors.FileExists(path, extra=e)
            if e.errno == errno.EACCES:
                raise errors.PermissionDenied(path, extra=e)
        if raise_generic:
            raise errors.TransportError(orig_error=e)

    def clone(self, offset=None):
        """Return a new Transport object, cloned from the current location,
        using a subdirectory or parent directory. This allows connections 
        to be pooled, rather than a new one needed for each subdir.
        """
        raise NotImplementedError

    def should_cache(self):
        """Return True if the data pulled across should be cached locally.
        """
        return False

    def _pump(self, from_file, to_file):
        """Most children will need to copy from one file-like 
        object or string to another one.
        This just gives them something easy to call.
        """
        if isinstance(from_file, basestring):
            to_file.write(from_file)
        else:
            from bzrlib.osutils import pumpfile
            pumpfile(from_file, to_file)

    def _get_total(self, multi):
        """Try to figure out how many entries are in multi,
        but if not possible, return None.
        """
        try:
            return len(multi)
        except TypeError: # We can't tell how many, because relpaths is a generator
            return None

    def _update_pb(self, pb, msg, count, total):
        """Update the progress bar based on the current count
        and total available, total may be None if it was
        not possible to determine.
        """
        if pb is None:
            return
        if total is None:
            pb.update(msg, count, count+1)
        else:
            pb.update(msg, count, total)

    def _iterate_over(self, multi, func, pb, msg, expand=True):
        """Iterate over all entries in multi, passing them to func,
        and update the progress bar as you go along.

        :param expand:  If True, the entries will be passed to the function
                        by expanding the tuple. If False, it will be passed
                        as a single parameter.
        """
        total = self._get_total(multi)
        count = 0
        for entry in multi:
            self._update_pb(pb, msg, count, total)
            if expand:
                func(*entry)
            else:
                func(entry)
            count += 1
        return count

    def abspath(self, relpath):
        """Return the full url to the given relative path.
        This can be supplied with a string or a list

        XXX: Robert Collins 20051016 - is this really needed in the public
             interface ?
        """
        raise NotImplementedError

    def relpath(self, abspath):
        """Return the local path portion from a given absolute path.

        This default implementation is not suitable for filesystems with
        aliasing, such as that given by symlinks, where a path may not 
        start with our base, but still be a relpath once aliasing is 
        resolved.
        """
        # TODO: This might want to use bzrlib.osutils.relpath
        #       but we have to watch out because of the prefix issues
        if not abspath.startswith(self.base):
            raise errors.PathNotChild(abspath, self.base)
        pl = len(self.base)
        return abspath[pl:].lstrip('/')


    def has(self, relpath):
        """Does the file relpath exist?
        
        Note that some transports MAY allow querying on directories, but this
        is not part of the protocol.
        """
        raise NotImplementedError

    def has_multi(self, relpaths, pb=None):
        """Return True/False for each entry in relpaths"""
        total = self._get_total(relpaths)
        count = 0
        for relpath in relpaths:
            self._update_pb(pb, 'has', count, total)
            yield self.has(relpath)
            count += 1

    def has_any(self, relpaths):
        """Return True if any of the paths exist."""
        for relpath in relpaths:
            if self.has(relpath):
                return True
        return False

    def iter_files_recursive(self):
        """Iter the relative paths of files in the transports sub-tree.
        
        As with other listing functions, only some transports implement this,.
        you may check via is_listable to determine if it will.
        """
        raise NotImplementedError

    def get(self, relpath):
        """Get the file at the given relative path.

        :param relpath: The relative path to the file
        """
        raise NotImplementedError

    def get_multi(self, relpaths, pb=None):
        """Get a list of file-like objects, one for each entry in relpaths.

        :param relpaths: A list of relative paths.
        :param pb:  An optional ProgressBar for indicating percent done.
        :return: A list or generator of file-like objects
        """
        # TODO: Consider having this actually buffer the requests,
        # in the default mode, it probably won't give worse performance,
        # and all children wouldn't have to implement buffering
        total = self._get_total(relpaths)
        count = 0
        for relpath in relpaths:
            self._update_pb(pb, 'get', count, total)
            yield self.get(relpath)
            count += 1

    def put(self, relpath, f):
        """Copy the file-like or string object into the location.

        :param relpath: Location to put the contents, relative to base.
        :param f:       File-like or string object.
        """
        raise NotImplementedError

    def put_multi(self, files, pb=None):
        """Put a set of files or strings into the location.

        :param files: A list of tuples of relpath, file object [(path1, file1), (path2, file2),...]
        :param pb:  An optional ProgressBar for indicating percent done.
        :return: The number of files copied.
        """
        return self._iterate_over(files, self.put, pb, 'put', expand=True)

    def mkdir(self, relpath):
        """Create a directory at the given path."""
        raise NotImplementedError

    def mkdir_multi(self, relpaths, pb=None):
        """Create a group of directories"""
        return self._iterate_over(relpaths, self.mkdir, pb, 'mkdir', expand=False)

    def append(self, relpath, f):
        """Append the text in the file-like or string object to 
        the supplied location.
        """
        raise NotImplementedError

    def append_multi(self, files, pb=None):
        """Append the text in each file-like or string object to
        the supplied location.

        :param files: A set of (path, f) entries
        :param pb:  An optional ProgressBar for indicating percent done.
        """
        return self._iterate_over(files, self.append, pb, 'append', expand=True)

    def copy(self, rel_from, rel_to):
        """Copy the item at rel_from to the location at rel_to"""
        raise NotImplementedError

    def copy_multi(self, relpaths, pb=None):
        """Copy a bunch of entries.
        
        :param relpaths: A list of tuples of the form [(from, to), (from, to),...]
        """
        # This is the non-pipelined implementation, so that
        # implementors don't have to implement everything.
        return self._iterate_over(relpaths, self.copy, pb, 'copy', expand=True)

    def copy_to(self, relpaths, other, pb=None):
        """Copy a set of entries from self into another Transport.

        :param relpaths: A list/generator of entries to be copied.
        TODO: This interface needs to be updated so that the target location
              can be different from the source location.
        """
        # The dummy implementation just does a simple get + put
        def copy_entry(path):
            other.put(path, self.get(path))

        return self._iterate_over(relpaths, copy_entry, pb, 'copy_to', expand=False)


    def move(self, rel_from, rel_to):
        """Move the item at rel_from to the location at rel_to"""
        raise NotImplementedError

    def move_multi(self, relpaths, pb=None):
        """Move a bunch of entries.
        
        :param relpaths: A list of tuples of the form [(from1, to1), (from2, to2),...]
        """
        return self._iterate_over(relpaths, self.move, pb, 'move', expand=True)

    def move_multi_to(self, relpaths, rel_to):
        """Move a bunch of entries to a single location.
        This differs from move_multi in that you give a list of from, and
        a single destination, rather than multiple destinations.

        :param relpaths: A list of relative paths [from1, from2, from3, ...]
        :param rel_to: A directory where each entry should be placed.
        """
        # This is not implemented, because you need to do special tricks to
        # extract the basename, and add it to rel_to
        raise NotImplementedError

    def delete(self, relpath):
        """Delete the item at relpath"""
        raise NotImplementedError

    def delete_multi(self, relpaths, pb=None):
        """Queue up a bunch of deletes to be done.
        """
        return self._iterate_over(relpaths, self.delete, pb, 'delete', expand=False)

    def stat(self, relpath):
        """Return the stat information for a file.
        WARNING: This may not be implementable for all protocols, so use
        sparingly.
        NOTE: This returns an object with fields such as 'st_size'. It MAY
        or MAY NOT return the literal result of an os.stat() call, so all
        access should be via named fields.
        ALSO NOTE: Stats of directories may not be supported on some 
        transports.
        """
        raise NotImplementedError

    def stat_multi(self, relpaths, pb=None):
        """Stat multiple files and return the information.
        """
        #TODO:  Is it worth making this a generator instead of a
        #       returning a list?
        stats = []
        def gather(path):
            stats.append(self.stat(path))

        count = self._iterate_over(relpaths, gather, pb, 'stat', expand=False)
        return stats

    def listable(self):
        """Return True if this store supports listing."""
        raise NotImplementedError

    def list_dir(self, relpath):
        """Return a list of all files at the given location.
        WARNING: many transports do not support this, so trying avoid using
        it if at all possible.
        """
        raise errors.TransportNotPossible("This transport has not "
                                          "implemented list_dir.")

    def lock_read(self, relpath):
        """Lock the given file for shared (read) access.
        WARNING: many transports do not support this, so trying avoid using it

        :return: A lock object, which should contain an unlock() function.
        """
        raise NotImplementedError

    def lock_write(self, relpath):
        """Lock the given file for exclusive (write) access.
        WARNING: many transports do not support this, so trying avoid using it

        :return: A lock object, which should contain an unlock() function.
        """
        raise NotImplementedError


def get_transport(base):
    global _protocol_handlers
    if base is None:
        base = u'.'
    for proto, klass in _protocol_handlers.iteritems():
        if proto is not None and base.startswith(proto):
            return klass(base)
    # The default handler is the filesystem handler
    # which has a lookup of None
    return _protocol_handlers[None](base)


def register_lazy_transport(scheme, module, classname):
    """Register lazy-loaded transport class.

    When opening a URL with the given scheme, load the module and then
    instantiate the particular class.  
    """
    def _loader(base):
        mod = __import__(module, globals(), locals(), [classname])
        klass = getattr(mod, classname)
        return klass(base)
    register_transport(scheme, _loader)


def urlescape(relpath):
    """Escape relpath to be a valid url."""
    # TODO utf8 it first. utf8relpath = relpath.encode('utf8')
    import urllib
    return urllib.quote(relpath)


# None is the default transport, for things with no url scheme
register_lazy_transport(None, 'bzrlib.transport.local', 'LocalTransport')
register_lazy_transport('file://', 'bzrlib.transport.local', 'LocalTransport')
register_lazy_transport('sftp://', 'bzrlib.transport.sftp', 'SFTPTransport')
register_lazy_transport('http://', 'bzrlib.transport.http', 'HttpTransport')
register_lazy_transport('https://', 'bzrlib.transport.http', 'HttpTransport')
register_lazy_transport('ftp://', 'bzrlib.transport.ftp', 'FtpTransport')
register_lazy_transport('aftp://', 'bzrlib.transport.ftp', 'FtpTransport')