48
class ImmutableStore(object):
49
"""Store that holds files indexed by unique names.
42
"""This class represents the abstract storage layout for saving information.
51
44
Files can be added, but not modified once they are in. Typically
52
45
the hash is used as the name, or something else known to be unique,
55
>>> st = ImmutableScratchStore()
57
>>> st.add(StringIO('hello'), 'aa')
63
You are not allowed to add an id that is already present.
65
Entries can be retrieved as files, which may then be read.
67
>>> st.add(StringIO('goodbye'), '123123')
68
>>> st['123123'].read()
71
TODO: Atomic add by writing to a temporary file and renaming.
73
In bzr 0.0.5 and earlier, files within the store were marked
74
readonly on disk. This is no longer done but existing stores need
78
def __init__(self, basedir):
79
self._basedir = basedir
81
def _path(self, entry_id):
82
if not isinstance(entry_id, basestring):
83
raise TypeError(type(entry_id))
84
if '\\' in entry_id or '/' in entry_id:
85
raise ValueError("invalid store id %r" % entry_id)
86
return os.path.join(self._basedir, entry_id)
89
return "%s(%r)" % (self.__class__.__name__, self._basedir)
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def add(self, f, fileid, compressed=True):
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"""Add contents of a file into the store.
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f -- An open file, or file-like object."""
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# FIXME: Only works on files that will fit in memory
97
from bzrlib.atomicfile import AtomicFile
99
mutter("add store entry %r" % (fileid))
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if isinstance(f, types.StringTypes):
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p = self._path(fileid)
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if os.access(p, os.F_OK) or os.access(p + '.gz', os.F_OK):
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raise BzrError("store %r already contains id %r" % (self._basedir, fileid))
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af = AtomicFile(fn, 'wb')
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gf = gzip.GzipFile(mode='wb', fileobj=af)
50
raise NotImplementedError('Children should define their length')
52
def __getitem__(self, fileid):
53
"""Returns a file reading from a particular entry."""
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raise NotImplementedError
56
def __contains__(self, fileid):
58
raise NotImplementedError
61
raise NotImplementedError
63
def add(self, f, fileid):
64
"""Add a file object f to the store accessible from the given fileid"""
65
raise NotImplementedError('Children of Store must define their method of adding entries.')
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def add_multi(self, entries):
68
"""Add a series of file-like or string objects to the store with the given
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:param entries: A list of tuples of file,id pairs [(file1, id1), (file2, id2), ...]
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This could also be a generator yielding (file,id) pairs.
74
for f, fileid in entries:
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def has(self, fileids):
78
"""Return True/False for each entry in fileids.
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:param fileids: A List or generator yielding file ids.
81
:return: A generator or list returning True/False for each entry.
83
for fileid in fileids:
126
def copy_multi(self, other, ids, permit_failure=False):
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def get(self, fileids, permit_failure=False, pb=None):
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"""Return a set of files, one for each requested entry.
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:param permit_failure: If true, return None for entries which do not
94
:return: A list or generator of file-like objects, one for each id.
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for fileid in fileids:
105
def copy_multi(self, other, ids, pb=None, permit_failure=False):
127
106
"""Copy texts for ids from other into self.
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If an id is present in self, it is skipped.
108
If an id is present in self, it is skipped. A count of copied
109
ids is returned, which may be less than len(ids).
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Returns (count_copied, failed), where failed is a collection of ids
132
that could not be copied.
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:param other: Another Store object
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:param ids: A list of entry ids to be copied
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:param pb: A ProgressBar object, if none is given, the default will be created.
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:param permit_failure: Allow missing entries to be ignored
115
:return: (n_copied, [failed]) The number of entries copied successfully,
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followed by a list of entries which could not be copied (because they
134
pb = bzrlib.ui.ui_factory.progress_bar()
120
pb = bzrlib.ui.ui_factory.progress_bar()
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# XXX: Is there any reason why we couldn't make this accept a generator
123
# and build a list as it finds things to copy?
124
ids = list(ids) # Make sure we don't have a generator, since we iterate 2 times
136
125
pb.update('preparing to copy')
137
to_copy = [id for id in ids if id not in self]
138
if isinstance(other, ImmutableStore):
139
return self.copy_multi_immutable(other, to_copy, pb,
140
permit_failure=permit_failure)
127
for file_id, has in zip(ids, self.has(ids)):
129
to_copy.append(file_id)
130
return self._do_copy(other, to_copy, pb, permit_failure=permit_failure)
132
def _do_copy(self, other, to_copy, pb, permit_failure=False):
133
"""This is the standard copying mechanism, just get them one at
134
a time from remote, and store them locally.
136
:param other: Another Store object
137
:param to_copy: A list of entry ids to copy
138
:param pb: A ProgressBar object to display completion status.
139
:param permit_failure: Allow missing entries to be ignored
140
:return: (n_copied, [failed])
141
The number of entries copied, and a list of failed entries.
143
# This should be updated to use add_multi() rather than
144
# the current methods of buffering requests.
145
# One question, is it faster to queue up 1-10 and then copy 1-10
146
# then queue up 11-20, copy 11-20
147
# or to queue up 1-10, copy 1, queue 11, copy 2, etc?
148
# sort of pipeline versus batch.
150
# We can't use self._transport.copy_to because we don't know
151
# whether the local tree is in the same format as other
145
pb.update('copy', count, len(to_copy))
146
if not permit_failure:
147
self.add(other[id], id)
153
def buffer_requests():
155
buffered_requests = []
156
for fileid in to_copy:
156
if not permit_failure:
166
buffered_requests.append((f, fileid))
167
if len(buffered_requests) > self._max_buffered_requests:
168
yield buffered_requests.pop(0)
170
pb.update('copy', count, len(to_copy))
172
for req in buffered_requests:
175
pb.update('copy', count, len(to_copy))
157
177
assert count == len(to_copy)
161
def copy_multi_immutable(self, other, to_copy, pb, permit_failure=False):
166
other_p = other._path(id)
168
osutils.link_or_copy(other_p, p)
169
except (IOError, OSError), e:
170
if e.errno == errno.ENOENT:
171
if not permit_failure:
172
osutils.link_or_copy(other_p+".gz", p+".gz")
175
osutils.link_or_copy(other_p+".gz", p+".gz")
177
if e.errno == errno.ENOENT:
185
pb.update('copy', count, len(to_copy))
186
assert count == len(to_copy)
179
self.add_multi(buffer_requests())
182
return len(to_copy), failed
185
class TransportStore(Store):
186
"""A TransportStore is a Store superclass for Stores that use Transports."""
188
_max_buffered_requests = 10
190
def __init__(self, transport):
191
assert isinstance(transport, bzrlib.transport.Transport)
192
super(TransportStore, self).__init__()
193
self._transport = transport
196
if self._transport is None:
197
return "%s(None)" % (self.__class__.__name__)
199
return "%s(%r)" % (self.__class__.__name__, self._transport.base)
204
class ImmutableMemoryStore(Store):
205
"""A memory only store."""
191
207
def __contains__(self, fileid):
193
p = self._path(fileid)
194
return (os.access(p, os.R_OK)
195
or os.access(p + '.gz', os.R_OK))
197
# TODO: Guard against the same thing being stored twice,
198
# compressed and uncompressed
201
for f in os.listdir(self._basedir):
203
# TODO: case-insensitive?
209
return len(os.listdir(self._basedir))
208
return self._contents.has_key(fileid)
211
super(ImmutableMemoryStore, self).__init__()
214
def add(self, stream, fileid, compressed=True):
215
if self._contents.has_key(fileid):
216
raise StoreError("fileid %s already in the store" % fileid)
217
self._contents[fileid] = stream.read()
212
219
def __getitem__(self, fileid):
213
220
"""Returns a file reading from a particular entry."""
214
p = self._path(fileid)
216
return gzip.GzipFile(p + '.gz', 'rb')
218
if e.errno != errno.ENOENT:
224
if e.errno != errno.ENOENT:
227
raise KeyError(fileid)
221
if not self._contents.has_key(fileid):
223
return StringIO(self._contents[fileid])
225
def _item_size(self, fileid):
226
return len(self._contents[fileid])
229
return iter(self._contents.keys())
230
231
def total_size(self):
231
"""Return (count, bytes)
233
This is the (compressed) size stored on disk, not the size of
241
total += os.stat(p)[ST_SIZE]
243
total += os.stat(p + '.gz')[ST_SIZE]
250
class ImmutableScratchStore(ImmutableStore):
251
"""Self-destructing test subclass of ImmutableStore.
253
The Store only exists for the lifetime of the Python object.
254
Obviously you should not put anything precious in it.
236
result += self._item_size(fileid)
240
class CachedStore(Store):
241
"""A store that caches data locally, to avoid repeated downloads.
242
The precacache method should be used to avoid server round-trips for
257
ImmutableStore.__init__(self, tempfile.mkdtemp())
260
for f in os.listdir(self._basedir):
261
fpath = os.path.join(self._basedir, f)
262
# needed on windows, and maybe some other filesystems
263
os.chmod(fpath, 0600)
265
os.rmdir(self._basedir)
266
mutter("%r destroyed" % self)
246
def __init__(self, store, cache_dir):
247
super(CachedStore, self).__init__()
248
self.source_store = store
249
# This clones the source store type with a locally bound
250
# transport. FIXME: it assumes a constructor is == cloning.
251
# clonable store - it might be nicer to actually have a clone()
252
# or something. RBC 20051003
253
self.cache_store = store.__class__(LocalTransport(cache_dir))
255
def __getitem__(self, id):
256
mutter("Cache add %s" % id)
257
if id not in self.cache_store:
258
self.cache_store.add(self.source_store[id], id)
259
return self.cache_store[id]
261
def __contains__(self, fileid):
262
if fileid in self.cache_store:
264
if fileid in self.source_store:
265
# We could copy at this time
269
def get(self, fileids, permit_failure=False, pb=None):
270
fileids = list(fileids)
271
hasids = self.cache_store.has(fileids)
273
for has, fileid in zip(hasids, fileids):
277
self.cache_store.copy_multi(self.source_store, needs,
278
permit_failure=permit_failure)
279
return self.cache_store.get(fileids,
280
permit_failure=permit_failure, pb=pb)
282
def prefetch(self, ids):
283
"""Copy a series of ids into the cache, before they are used.
284
For remote stores that support pipelining or async downloads, this can
285
increase speed considerably.
287
Failures while prefetching are ignored.
289
mutter("Prefetch of ids %s" % ",".join(ids))
290
self.cache_store.copy_multi(self.source_store, ids,
268
294
def copy_all(store_from, store_to):
269
295
"""Copy all ids from one store to another."""
296
# TODO: Optional progress indicator
270
297
if not hasattr(store_from, "__iter__"):
271
298
raise UnlistableStore(store_from)
272
ids = [f for f in store_from]
300
ids = [f for f in store_from]
301
except (NotImplementedError, TransportNotPossible):
302
raise UnlistableStore(store_from)
273
303
store_to.copy_multi(store_from, ids)