diff options
Diffstat (limited to 'rdiff-backup/rdiff_backup/journal.py')
| -rw-r--r-- | rdiff-backup/rdiff_backup/journal.py | 119 |
1 files changed, 73 insertions, 46 deletions
diff --git a/rdiff-backup/rdiff_backup/journal.py b/rdiff-backup/rdiff_backup/journal.py index d79875e..53b3ca7 100644 --- a/rdiff-backup/rdiff_backup/journal.py +++ b/rdiff-backup/rdiff_backup/journal.py @@ -17,6 +17,9 @@ # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 # USA +# UPDATE: I have decided not to use journaling and use the regress +# stuff exclusively. This code is left here for posterity. + """Application level journaling for better error recovery This module has routines for maintaining a "journal" to keep track of @@ -49,12 +52,15 @@ Two caveats: """ -import Globals, log, rpath, cPickle, TempFile +import Globals, log, rpath, cPickle, TempFile, os, restore # Holds an rpath of the journal directory, a file object, and then journal_dir_rp = None journal_dir_fp = None +# Set to time in seconds of previous aborted backup +unsuccessful_backup_time = None + def open_journal(): """Make sure the journal dir exists (creating it if necessary)""" global journal_dir_rp, journal_dir_fp @@ -74,7 +80,12 @@ def close_journal(): journal_dir_rp = journal_dir_fp = None def sync_journal(): - """fsync the journal directory""" + """fsync the journal directory. + + Note that fsync'ing a particular entry file may also be required + to guarantee writes have been committed. + + """ journal_dir_rp.fsync(journal_dir_fp) def recover_journal(): @@ -94,74 +105,91 @@ def get_entries_from_journal(): else: entry_list.append(e) return entry_list -def write_entry(test_filename, test_filename_type, - increment_filename, temp_filename): +def write_entry(index, temp_index, testfile_option, testfile_type): """Write new entry given variables into journal, return entry""" e = Entry() - e.test_filename = test_filename - e.test_filename_type = test_filename_type - e.increment_filename = increment_filename - e.temp_filename = temp_filename + e.index = index + e.temp_index = index + e.testfile_option = testfile_option + e.testfile_type = testfile_type e.write() return e -def remove_entry(entry_rp): - """Remove the entry in entry_rp from the journal""" - entry_rp.delete() - sync_journal() - class Entry: """A single journal entry, describing one transaction Although called a journal entry, this is less a description of - what is going happen than a short recipe of what to do if + what is going happen than a short recipe of how to recover if something goes wrong. Currently the recipe needs to be very simple and is determined by - the four variables test_filename, test_filename_type, - increment_filename, and temp_filename. See the recover() method - for details. + the four variables index, temp_index, testfile_option, + testfile_type. See the recover() method for details. """ - test_filename = None - test_filename_type = None # None is a valid value for this variable - increment_filename = None - temp_filename = None + index = None + temp_index = None + testfile_option = None + testfile_type = None # None is a valid value for this variable - # This holds the rpath in the journal dir that holds self + # This points to the rpath in the journal dir that holds this entry entry_rp = None def recover(self): """Recover the current journal entry - See if test_filename matches test_filename_type. If so, - delete increment_filename. Delete temp_filename regardless. + self.testfile_option has 3 possibilities: + 1 - testfile is mirror file + 2 - testfile is increment file + 3 - testfile is temp file + + Either way, see if the type of the testfile matches + testfile_type. If so, delete increment file. Deleted + tempfile regardless. + + We express things in terms of indicies because we need paths + relative to a fixed directory (like Globals.dest_root). + It's OK to recover the same entry multiple times. """ - assert self.test_filename and self.temp_filename - test_rp = rpath.RPath(Globals.local_connection, self.test_filename) - temp_rp = rpath.RPath(Globals.local_connection, self.temp_filename) - inc_rp = rpath.RPath(Globals.local_connection, self.increment_filename) - if test_rp.lstat() == self.test_filename_type: - if inc_rp.lstat(): - inc_rp.delete() - inc_rp.get_parent_rp().fsync() - if temp_rp.lstat(): - temp_rp.delete() - temp_rp.get_parent_rp().fsync() + assert self.index is not None and self.temp_index is not None + mirror_rp = Globals.dest_root.new_index(self.index) + if self.temp_index: + temp_rp = Globals.dest_root.new_index(self.temp_index) + inc_rp = self.get_inc() + + assert 1 <= self.testfile_option <= 3 + if self.testfile_option == 1: test_rp = mirror_rp + elif self.testfile_option == 2: test_rp = inc_rp + else: test_rp = temp_rp + + if test_rp and test_rp.lstat() == self.testfile_type: + if inc_rp and inc_rp.lstat(): inc_rp.sync_delete() + if temp_rp and temp_rp.lstat(): temp_rp.sync_delete() + + def get_inc(self): + """Return inc_rpath, if any, corresponding to self.index""" + incroot = Globals.rbdir.append_path("increments") + incbase = incroot.new_index(self.index) + inclist = restore.get_inclist(incbase) + inclist = filter(lambda inc: + inc.getinctime() == unsuccessful_backup_time, inclist) + assert len(inclist) <= 1 + if inclist: return inclist[0] + else: return None def to_string(self): """Return string form of entry""" - return cPickle.dumps({'test_filename': self.test_filename, - 'test_filename_type': self.test_filename_type, - 'increment_filename': self.increment_filename, - 'temp_filename': self.temp_filename}) + return cPickle.dumps({'index': self.index, + 'testfile_option': self.testfile_option, + 'testfile_type': self.testfile_type, + 'temp_index': self.temp_index}) def write(self): """Write the current entry into the journal""" - entry_rp = TempFile.new(journal_dir_rp.append("foo")) + entry_rp = TempFile.new_in_dir(journal_dir_rp) fp = entry_rp.open("wb") fp.write(self.to_string()) entry_rp.fsync(fp) @@ -174,10 +202,10 @@ class Entry: try: val_dict = cPickle.loads(s) except cPickle.UnpicklingError: return 0 try: - self.test_filename = val_dict['test_filename'] - self.test_filename_type = val_dict['test_filename_type'] - self.increment_filename = val_dict['increment_filename'] - self.temp_filename = val_dict['temp_filename'] + self.index = val_dict['index'] + self.testfile_type = val_dict['testfile_type'] + self.testfile_option = val_dict['testfile_option'] + self.temp_index = val_dict['temp_index'] except TypeError, KeyError: return 0 return 1 @@ -191,5 +219,4 @@ class Entry: def delete(self): """Remove entry from the journal. self.entry_rp must be set""" - self.entry_rp.delete() - sync_journal() + self.entry_rp.sync_delete() |