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@@ -1,305 +1,307 b'' | |||||
1 | # transaction.py - simple journaling scheme for mercurial |
|
1 | # transaction.py - simple journaling scheme for mercurial | |
2 | # |
|
2 | # | |
3 | # This transaction scheme is intended to gracefully handle program |
|
3 | # This transaction scheme is intended to gracefully handle program | |
4 | # errors and interruptions. More serious failures like system crashes |
|
4 | # errors and interruptions. More serious failures like system crashes | |
5 | # can be recovered with an fsck-like tool. As the whole repository is |
|
5 | # can be recovered with an fsck-like tool. As the whole repository is | |
6 | # effectively log-structured, this should amount to simply truncating |
|
6 | # effectively log-structured, this should amount to simply truncating | |
7 | # anything that isn't referenced in the changelog. |
|
7 | # anything that isn't referenced in the changelog. | |
8 | # |
|
8 | # | |
9 | # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> |
|
9 | # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> | |
10 | # |
|
10 | # | |
11 | # This software may be used and distributed according to the terms of the |
|
11 | # This software may be used and distributed according to the terms of the | |
12 | # GNU General Public License version 2 or any later version. |
|
12 | # GNU General Public License version 2 or any later version. | |
13 |
|
13 | |||
14 | from i18n import _ |
|
14 | from i18n import _ | |
15 | import errno |
|
15 | import errno | |
16 | import error, util |
|
16 | import error, util | |
17 |
|
17 | |||
18 | def active(func): |
|
18 | def active(func): | |
19 | def _active(self, *args, **kwds): |
|
19 | def _active(self, *args, **kwds): | |
20 | if self.count == 0: |
|
20 | if self.count == 0: | |
21 | raise error.Abort(_( |
|
21 | raise error.Abort(_( | |
22 | 'cannot use transaction when it is already committed/aborted')) |
|
22 | 'cannot use transaction when it is already committed/aborted')) | |
23 | return func(self, *args, **kwds) |
|
23 | return func(self, *args, **kwds) | |
24 | return _active |
|
24 | return _active | |
25 |
|
25 | |||
26 | def _playback(journal, report, opener, entries, backupentries, unlink=True): |
|
26 | def _playback(journal, report, opener, entries, backupentries, unlink=True): | |
27 | for f, o, ignore in entries: |
|
27 | for f, o, ignore in entries: | |
28 | if o or not unlink: |
|
28 | if o or not unlink: | |
29 | try: |
|
29 | try: | |
30 | fp = opener(f, 'a') |
|
30 | fp = opener(f, 'a') | |
31 | fp.truncate(o) |
|
31 | fp.truncate(o) | |
32 | fp.close() |
|
32 | fp.close() | |
33 | except IOError: |
|
33 | except IOError: | |
34 | report(_("failed to truncate %s\n") % f) |
|
34 | report(_("failed to truncate %s\n") % f) | |
35 | raise |
|
35 | raise | |
36 | else: |
|
36 | else: | |
37 | try: |
|
37 | try: | |
38 | opener.unlink(f) |
|
38 | opener.unlink(f) | |
39 | except (IOError, OSError), inst: |
|
39 | except (IOError, OSError), inst: | |
40 | if inst.errno != errno.ENOENT: |
|
40 | if inst.errno != errno.ENOENT: | |
41 | raise |
|
41 | raise | |
42 |
|
42 | |||
43 | backupfiles = [] |
|
43 | backupfiles = [] | |
44 | for f, b, ignore in backupentries: |
|
44 | for f, b, ignore in backupentries: | |
45 | filepath = opener.join(f) |
|
45 | filepath = opener.join(f) | |
46 | backuppath = opener.join(b) |
|
46 | backuppath = opener.join(b) | |
47 | try: |
|
47 | try: | |
48 | util.copyfile(backuppath, filepath) |
|
48 | util.copyfile(backuppath, filepath) | |
49 | backupfiles.append(b) |
|
49 | backupfiles.append(b) | |
50 | except IOError: |
|
50 | except IOError: | |
51 | report(_("failed to recover %s\n") % f) |
|
51 | report(_("failed to recover %s\n") % f) | |
52 | raise |
|
52 | raise | |
53 |
|
53 | |||
54 | opener.unlink(journal) |
|
54 | opener.unlink(journal) | |
55 | backuppath = "%s.backupfiles" % journal |
|
55 | backuppath = "%s.backupfiles" % journal | |
56 | if opener.exists(backuppath): |
|
56 | if opener.exists(backuppath): | |
57 | opener.unlink(backuppath) |
|
57 | opener.unlink(backuppath) | |
58 | for f in backupfiles: |
|
58 | for f in backupfiles: | |
59 | opener.unlink(f) |
|
59 | opener.unlink(f) | |
60 |
|
60 | |||
61 | class transaction(object): |
|
61 | class transaction(object): | |
62 | def __init__(self, report, opener, journal, after=None, createmode=None, |
|
62 | def __init__(self, report, opener, journal, after=None, createmode=None, | |
63 | onclose=None, onabort=None): |
|
63 | onclose=None, onabort=None): | |
64 | """Begin a new transaction |
|
64 | """Begin a new transaction | |
65 |
|
65 | |||
66 | Begins a new transaction that allows rolling back writes in the event of |
|
66 | Begins a new transaction that allows rolling back writes in the event of | |
67 | an exception. |
|
67 | an exception. | |
68 |
|
68 | |||
69 | * `after`: called after the transaction has been committed |
|
69 | * `after`: called after the transaction has been committed | |
70 | * `createmode`: the mode of the journal file that will be created |
|
70 | * `createmode`: the mode of the journal file that will be created | |
71 | * `onclose`: called as the transaction is closing, but before it is |
|
71 | * `onclose`: called as the transaction is closing, but before it is | |
72 | closed |
|
72 | closed | |
73 | * `onabort`: called as the transaction is aborting, but before any files |
|
73 | * `onabort`: called as the transaction is aborting, but before any files | |
74 | have been truncated |
|
74 | have been truncated | |
75 | """ |
|
75 | """ | |
76 | self.count = 1 |
|
76 | self.count = 1 | |
77 | self.usages = 1 |
|
77 | self.usages = 1 | |
78 | self.report = report |
|
78 | self.report = report | |
79 | self.opener = opener |
|
79 | self.opener = opener | |
80 | self.after = after |
|
80 | self.after = after | |
81 | self.onclose = onclose |
|
81 | self.onclose = onclose | |
82 | self.onabort = onabort |
|
82 | self.onabort = onabort | |
83 | self.entries = [] |
|
83 | self.entries = [] | |
84 | self.backupentries = [] |
|
84 | self.backupentries = [] | |
85 | self.map = {} |
|
85 | self.map = {} | |
86 | self.backupmap = {} |
|
86 | self.backupmap = {} | |
87 | self.journal = journal |
|
87 | self.journal = journal | |
88 | self._queue = [] |
|
88 | self._queue = [] | |
89 | # a dict of arguments to be passed to hooks |
|
89 | # a dict of arguments to be passed to hooks | |
90 | self.hookargs = {} |
|
90 | self.hookargs = {} | |
91 |
|
91 | |||
92 | self.backupjournal = "%s.backupfiles" % journal |
|
92 | self.backupjournal = "%s.backupfiles" % journal | |
93 | self.file = opener.open(self.journal, "w") |
|
93 | self.file = opener.open(self.journal, "w") | |
94 | self.backupsfile = opener.open(self.backupjournal, 'w') |
|
94 | self.backupsfile = opener.open(self.backupjournal, 'w') | |
95 | if createmode is not None: |
|
95 | if createmode is not None: | |
96 | opener.chmod(self.journal, createmode & 0666) |
|
96 | opener.chmod(self.journal, createmode & 0666) | |
97 | opener.chmod(self.backupjournal, createmode & 0666) |
|
97 | opener.chmod(self.backupjournal, createmode & 0666) | |
98 |
|
98 | |||
99 | def __del__(self): |
|
99 | def __del__(self): | |
100 | if self.journal: |
|
100 | if self.journal: | |
101 | self._abort() |
|
101 | self._abort() | |
102 |
|
102 | |||
103 | @active |
|
103 | @active | |
104 | def startgroup(self): |
|
104 | def startgroup(self): | |
105 | self._queue.append(([], [])) |
|
105 | self._queue.append(([], [])) | |
106 |
|
106 | |||
107 | @active |
|
107 | @active | |
108 | def endgroup(self): |
|
108 | def endgroup(self): | |
109 | q = self._queue.pop() |
|
109 | q = self._queue.pop() | |
110 | self.entries.extend(q[0]) |
|
110 | self.entries.extend(q[0]) | |
111 | self.backupentries.extend(q[1]) |
|
111 | self.backupentries.extend(q[1]) | |
112 |
|
112 | |||
113 | offsets = [] |
|
113 | offsets = [] | |
114 | backups = [] |
|
114 | backups = [] | |
115 | for f, o, _ in q[0]: |
|
115 | for f, o, _ in q[0]: | |
116 | offsets.append((f, o)) |
|
116 | offsets.append((f, o)) | |
117 |
|
117 | |||
118 | for f, b, _ in q[1]: |
|
118 | for f, b, _ in q[1]: | |
119 | backups.append((f, b)) |
|
119 | backups.append((f, b)) | |
120 |
|
120 | |||
121 | d = ''.join(['%s\0%d\n' % (f, o) for f, o in offsets]) |
|
121 | d = ''.join(['%s\0%d\n' % (f, o) for f, o in offsets]) | |
122 | self.file.write(d) |
|
122 | self.file.write(d) | |
123 | self.file.flush() |
|
123 | self.file.flush() | |
124 |
|
124 | |||
125 | d = ''.join(['%s\0%s\0' % (f, b) for f, b in backups]) |
|
125 | d = ''.join(['%s\0%s\0' % (f, b) for f, b in backups]) | |
126 | self.backupsfile.write(d) |
|
126 | self.backupsfile.write(d) | |
127 | self.backupsfile.flush() |
|
127 | self.backupsfile.flush() | |
128 |
|
128 | |||
129 | @active |
|
129 | @active | |
130 | def add(self, file, offset, data=None): |
|
130 | def add(self, file, offset, data=None): | |
131 | if file in self.map or file in self.backupmap: |
|
131 | if file in self.map or file in self.backupmap: | |
132 | return |
|
132 | return | |
133 | if self._queue: |
|
133 | if self._queue: | |
134 | self._queue[-1][0].append((file, offset, data)) |
|
134 | self._queue[-1][0].append((file, offset, data)) | |
135 | return |
|
135 | return | |
136 |
|
136 | |||
137 | self.entries.append((file, offset, data)) |
|
137 | self.entries.append((file, offset, data)) | |
138 | self.map[file] = len(self.entries) - 1 |
|
138 | self.map[file] = len(self.entries) - 1 | |
139 | # add enough data to the journal to do the truncate |
|
139 | # add enough data to the journal to do the truncate | |
140 | self.file.write("%s\0%d\n" % (file, offset)) |
|
140 | self.file.write("%s\0%d\n" % (file, offset)) | |
141 | self.file.flush() |
|
141 | self.file.flush() | |
142 |
|
142 | |||
143 | @active |
|
143 | @active | |
144 | def addbackup(self, file, hardlink=True): |
|
144 | def addbackup(self, file, hardlink=True): | |
145 | """Adds a backup of the file to the transaction |
|
145 | """Adds a backup of the file to the transaction | |
146 |
|
146 | |||
147 | Calling addbackup() creates a hardlink backup of the specified file |
|
147 | Calling addbackup() creates a hardlink backup of the specified file | |
148 | that is used to recover the file in the event of the transaction |
|
148 | that is used to recover the file in the event of the transaction | |
149 | aborting. |
|
149 | aborting. | |
150 |
|
150 | |||
151 | * `file`: the file path, relative to .hg/store |
|
151 | * `file`: the file path, relative to .hg/store | |
152 | * `hardlink`: use a hardlink to quickly create the backup |
|
152 | * `hardlink`: use a hardlink to quickly create the backup | |
153 | """ |
|
153 | """ | |
154 |
|
154 | |||
155 | if file in self.map or file in self.backupmap: |
|
155 | if file in self.map or file in self.backupmap: | |
156 | return |
|
156 | return | |
157 | backupfile = "journal.%s" % file |
|
157 | backupfile = "journal.%s" % file | |
158 | if self.opener.exists(file): |
|
158 | if self.opener.exists(file): | |
159 | filepath = self.opener.join(file) |
|
159 | filepath = self.opener.join(file) | |
160 | backuppath = self.opener.join(backupfile) |
|
160 | backuppath = self.opener.join(backupfile) | |
161 | util.copyfiles(filepath, backuppath, hardlink=hardlink) |
|
161 | util.copyfiles(filepath, backuppath, hardlink=hardlink) | |
162 | else: |
|
162 | else: | |
163 | self.add(file, 0) |
|
163 | self.add(file, 0) | |
164 | return |
|
164 | return | |
165 |
|
165 | |||
166 | if self._queue: |
|
166 | if self._queue: | |
167 | self._queue[-1][1].append((file, backupfile)) |
|
167 | self._queue[-1][1].append((file, backupfile)) | |
168 | return |
|
168 | return | |
169 |
|
169 | |||
170 | self.backupentries.append((file, backupfile, None)) |
|
170 | self.backupentries.append((file, backupfile, None)) | |
171 | self.backupmap[file] = len(self.backupentries) - 1 |
|
171 | self.backupmap[file] = len(self.backupentries) - 1 | |
172 | self.backupsfile.write("%s\0%s\0" % (file, backupfile)) |
|
172 | self.backupsfile.write("%s\0%s\0" % (file, backupfile)) | |
173 | self.backupsfile.flush() |
|
173 | self.backupsfile.flush() | |
174 |
|
174 | |||
175 | @active |
|
175 | @active | |
176 | def find(self, file): |
|
176 | def find(self, file): | |
177 | if file in self.map: |
|
177 | if file in self.map: | |
178 | return self.entries[self.map[file]] |
|
178 | return self.entries[self.map[file]] | |
179 | if file in self.backupmap: |
|
179 | if file in self.backupmap: | |
180 | return self.backupentries[self.backupmap[file]] |
|
180 | return self.backupentries[self.backupmap[file]] | |
181 | return None |
|
181 | return None | |
182 |
|
182 | |||
183 | @active |
|
183 | @active | |
184 | def replace(self, file, offset, data=None): |
|
184 | def replace(self, file, offset, data=None): | |
185 | ''' |
|
185 | ''' | |
186 | replace can only replace already committed entries |
|
186 | replace can only replace already committed entries | |
187 | that are not pending in the queue |
|
187 | that are not pending in the queue | |
188 | ''' |
|
188 | ''' | |
189 |
|
189 | |||
190 | if file not in self.map: |
|
190 | if file not in self.map: | |
191 | raise KeyError(file) |
|
191 | raise KeyError(file) | |
192 | index = self.map[file] |
|
192 | index = self.map[file] | |
193 | self.entries[index] = (file, offset, data) |
|
193 | self.entries[index] = (file, offset, data) | |
194 | self.file.write("%s\0%d\n" % (file, offset)) |
|
194 | self.file.write("%s\0%d\n" % (file, offset)) | |
195 | self.file.flush() |
|
195 | self.file.flush() | |
196 |
|
196 | |||
197 | @active |
|
197 | @active | |
198 | def nest(self): |
|
198 | def nest(self): | |
199 | self.count += 1 |
|
199 | self.count += 1 | |
200 | self.usages += 1 |
|
200 | self.usages += 1 | |
201 | return self |
|
201 | return self | |
202 |
|
202 | |||
203 | def release(self): |
|
203 | def release(self): | |
204 | if self.count > 0: |
|
204 | if self.count > 0: | |
205 | self.usages -= 1 |
|
205 | self.usages -= 1 | |
206 | # if the transaction scopes are left without being closed, fail |
|
206 | # if the transaction scopes are left without being closed, fail | |
207 | if self.count > 0 and self.usages == 0: |
|
207 | if self.count > 0 and self.usages == 0: | |
208 | self._abort() |
|
208 | self._abort() | |
209 |
|
209 | |||
210 | def running(self): |
|
210 | def running(self): | |
211 | return self.count > 0 |
|
211 | return self.count > 0 | |
212 |
|
212 | |||
213 | @active |
|
213 | @active | |
214 | def close(self): |
|
214 | def close(self): | |
215 | '''commit the transaction''' |
|
215 | '''commit the transaction''' | |
216 | if self.count == 1 and self.onclose is not None: |
|
216 | if self.count == 1 and self.onclose is not None: | |
217 | self.onclose() |
|
217 | self.onclose() | |
218 |
|
218 | |||
219 | self.count -= 1 |
|
219 | self.count -= 1 | |
220 | if self.count != 0: |
|
220 | if self.count != 0: | |
221 | return |
|
221 | return | |
222 | self.file.close() |
|
222 | self.file.close() | |
|
223 | self.backupsfile.close() | |||
223 | self.entries = [] |
|
224 | self.entries = [] | |
224 | if self.after: |
|
225 | if self.after: | |
225 | self.after() |
|
226 | self.after() | |
226 | if self.opener.isfile(self.journal): |
|
227 | if self.opener.isfile(self.journal): | |
227 | self.opener.unlink(self.journal) |
|
228 | self.opener.unlink(self.journal) | |
228 | if self.opener.isfile(self.backupjournal): |
|
229 | if self.opener.isfile(self.backupjournal): | |
229 | self.opener.unlink(self.backupjournal) |
|
230 | self.opener.unlink(self.backupjournal) | |
230 | for f, b, _ in self.backupentries: |
|
231 | for f, b, _ in self.backupentries: | |
231 | self.opener.unlink(b) |
|
232 | self.opener.unlink(b) | |
232 | self.backupentries = [] |
|
233 | self.backupentries = [] | |
233 | self.journal = None |
|
234 | self.journal = None | |
234 |
|
235 | |||
235 | @active |
|
236 | @active | |
236 | def abort(self): |
|
237 | def abort(self): | |
237 | '''abort the transaction (generally called on error, or when the |
|
238 | '''abort the transaction (generally called on error, or when the | |
238 | transaction is not explicitly committed before going out of |
|
239 | transaction is not explicitly committed before going out of | |
239 | scope)''' |
|
240 | scope)''' | |
240 | self._abort() |
|
241 | self._abort() | |
241 |
|
242 | |||
242 | def _abort(self): |
|
243 | def _abort(self): | |
243 | self.count = 0 |
|
244 | self.count = 0 | |
244 | self.usages = 0 |
|
245 | self.usages = 0 | |
245 | self.file.close() |
|
246 | self.file.close() | |
|
247 | self.backupsfile.close() | |||
246 |
|
248 | |||
247 | if self.onabort is not None: |
|
249 | if self.onabort is not None: | |
248 | self.onabort() |
|
250 | self.onabort() | |
249 |
|
251 | |||
250 | try: |
|
252 | try: | |
251 | if not self.entries and not self.backupentries: |
|
253 | if not self.entries and not self.backupentries: | |
252 | if self.journal: |
|
254 | if self.journal: | |
253 | self.opener.unlink(self.journal) |
|
255 | self.opener.unlink(self.journal) | |
254 | if self.backupjournal: |
|
256 | if self.backupjournal: | |
255 | self.opener.unlink(self.backupjournal) |
|
257 | self.opener.unlink(self.backupjournal) | |
256 | return |
|
258 | return | |
257 |
|
259 | |||
258 | self.report(_("transaction abort!\n")) |
|
260 | self.report(_("transaction abort!\n")) | |
259 |
|
261 | |||
260 | try: |
|
262 | try: | |
261 | _playback(self.journal, self.report, self.opener, |
|
263 | _playback(self.journal, self.report, self.opener, | |
262 | self.entries, self.backupentries, False) |
|
264 | self.entries, self.backupentries, False) | |
263 | self.report(_("rollback completed\n")) |
|
265 | self.report(_("rollback completed\n")) | |
264 | except Exception: |
|
266 | except Exception: | |
265 | self.report(_("rollback failed - please run hg recover\n")) |
|
267 | self.report(_("rollback failed - please run hg recover\n")) | |
266 | finally: |
|
268 | finally: | |
267 | self.journal = None |
|
269 | self.journal = None | |
268 |
|
270 | |||
269 |
|
271 | |||
270 | def rollback(opener, file, report): |
|
272 | def rollback(opener, file, report): | |
271 | """Rolls back the transaction contained in the given file |
|
273 | """Rolls back the transaction contained in the given file | |
272 |
|
274 | |||
273 | Reads the entries in the specified file, and the corresponding |
|
275 | Reads the entries in the specified file, and the corresponding | |
274 | '*.backupfiles' file, to recover from an incomplete transaction. |
|
276 | '*.backupfiles' file, to recover from an incomplete transaction. | |
275 |
|
277 | |||
276 | * `file`: a file containing a list of entries, specifying where |
|
278 | * `file`: a file containing a list of entries, specifying where | |
277 | to truncate each file. The file should contain a list of |
|
279 | to truncate each file. The file should contain a list of | |
278 | file\0offset pairs, delimited by newlines. The corresponding |
|
280 | file\0offset pairs, delimited by newlines. The corresponding | |
279 | '*.backupfiles' file should contain a list of file\0backupfile |
|
281 | '*.backupfiles' file should contain a list of file\0backupfile | |
280 | pairs, delimited by \0. |
|
282 | pairs, delimited by \0. | |
281 | """ |
|
283 | """ | |
282 | entries = [] |
|
284 | entries = [] | |
283 | backupentries = [] |
|
285 | backupentries = [] | |
284 |
|
286 | |||
285 | fp = opener.open(file) |
|
287 | fp = opener.open(file) | |
286 | lines = fp.readlines() |
|
288 | lines = fp.readlines() | |
287 | fp.close() |
|
289 | fp.close() | |
288 | for l in lines: |
|
290 | for l in lines: | |
289 | try: |
|
291 | try: | |
290 | f, o = l.split('\0') |
|
292 | f, o = l.split('\0') | |
291 | entries.append((f, int(o), None)) |
|
293 | entries.append((f, int(o), None)) | |
292 | except ValueError: |
|
294 | except ValueError: | |
293 | report(_("couldn't read journal entry %r!\n") % l) |
|
295 | report(_("couldn't read journal entry %r!\n") % l) | |
294 |
|
296 | |||
295 | backupjournal = "%s.backupfiles" % file |
|
297 | backupjournal = "%s.backupfiles" % file | |
296 | if opener.exists(backupjournal): |
|
298 | if opener.exists(backupjournal): | |
297 | fp = opener.open(backupjournal) |
|
299 | fp = opener.open(backupjournal) | |
298 | data = fp.read() |
|
300 | data = fp.read() | |
299 | if len(data) > 0: |
|
301 | if len(data) > 0: | |
300 | parts = data.split('\0') |
|
302 | parts = data.split('\0') | |
301 | for i in xrange(0, len(parts), 2): |
|
303 | for i in xrange(0, len(parts), 2): | |
302 | f, b = parts[i:i + 1] |
|
304 | f, b = parts[i:i + 1] | |
303 | backupentries.append((f, b, None)) |
|
305 | backupentries.append((f, b, None)) | |
304 |
|
306 | |||
305 | _playback(file, report, opener, entries, backupentries) |
|
307 | _playback(file, report, opener, entries, backupentries) |
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