#!/usr/bin/env python # # Public Domain 2014-2019 MongoDB, Inc. # Public Domain 2008-2014 WiredTiger, Inc. # # This is free and unencumbered software released into the public domain. # # Anyone is free to copy, modify, publish, use, compile, sell, or # distribute this software, either in source code form or as a compiled # binary, for any purpose, commercial or non-commercial, and by any # means. # # In jurisdictions that recognize copyright laws, the author or authors # of this software dedicate any and all copyright interest in the # software to the public domain. We make this dedication for the benefit # of the public at large and to the detriment of our heirs and # successors. We intend this dedication to be an overt act of # relinquishment in perpetuity of all present and future rights to this # software under copyright law. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. # IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR # OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, # ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR # OTHER DEALINGS IN THE SOFTWARE. import os, struct from suite_subprocess import suite_subprocess import wiredtiger, wttest # test_salvage.py # Utilities: wt salvage class test_salvage(wttest.WiredTigerTestCase, suite_subprocess): tablename = 'test_salvage.a' nentries = 1000 session_params = 'key_format=S,value_format=S' unique = 'SomeUniqueString' def populate(self, tablename): """ Insert some simple entries into the table """ cursor = self.session.open_cursor('table:' + tablename, None, None) key = '' for i in range(0, self.nentries): key += str(i) if i == self.nentries // 2: val = self.unique + '0' else: val = key + key cursor[key] = val cursor.close() def check_populate(self, tablename): """ Verify that items added by populate are still there """ cursor = self.session.open_cursor('table:' + tablename, None, None) wantkey = '' i = 0 for gotkey, gotval in cursor: wantkey += str(i) if i == self.nentries // 2: wantval = self.unique + '0' else: wantval = wantkey + wantkey self.assertEqual(gotkey, wantkey) self.assertTrue(gotval, wantval) i += 1 self.assertEqual(i, self.nentries) cursor.close() def check_damaged(self, tablename): """ Check a damaged table with a lower standard than check_populate. We don't require that all entries are here, just that the ones that are here are correct. """ cursor = self.session.open_cursor('table:' + tablename, None, None) wantkey = '' i = -1 correct = 0 for gotkey, gotval in cursor: i += 1 wantkey += str(i) if gotkey != wantkey: continue if i == self.nentries // 2: wantval = self.unique + '0' else: wantval = wantkey + wantkey self.assertEqual(gotkey, wantkey) self.assertTrue(gotval, wantval) correct += 1 self.assertTrue(correct > 0) self.printVerbose(2, 'after salvaging, file has ' + str(correct) + '/' + str(self.nentries) + ' entries') cursor.close() def check_empty_table(self, tablename): cursor = self.session.open_cursor('table:' + tablename, None, None) for gotkey, gotval in cursor: self.fail(tablename + ': has unexpected entries') cursor.close() def damage(self, tablename): self.damage_inner(tablename, self.unique.encode()) def read_byte(self, fp): """ Return a single byte from a file opened in binary mode. """ c = fp.read(1) if self.is_python3(): c = c[0] # In python3, the read returns bytes (an array). return c def damage_inner(self, tablename, unique): """ Open the file for the table, find the unique string and modify it. """ self.close_conn() self.assertTrue(type(unique) == bytes) # we close the connection to guarantee everything is # flushed and closed from the WT point of view. filename = tablename + ".wt" fp = open(filename, "r+b") found = matchpos = 0 match = unique matchlen = len(match) flen = os.fstat(fp.fileno()).st_size c = self.read_byte(fp) while fp.tell() != flen: if match[matchpos] == c: matchpos += 1 if matchpos == matchlen: # We're already positioned, so alter it fp.seek(-1, 1) fp.write(b'G') matchpos = 0 found = 1 else: matchpos = 0 c = self.read_byte(fp) # Make sure we found the embedded string self.assertTrue(found) fp.close() def test_salvage_process_empty(self): """ Test salvage in a 'wt' process, using an empty table """ self.session.create('table:' + self.tablename, self.session_params) errfile = "salvageerr.out" self.runWt(["salvage", self.tablename + ".wt"], errfilename=errfile) self.check_empty_file(errfile) self.check_empty_table(self.tablename) def test_salvage_process(self): """ Test salvage in a 'wt' process, using a populated table. """ self.session.create('table:' + self.tablename, self.session_params) self.populate(self.tablename) errfile = "salvageerr.out" self.runWt(["salvage", self.tablename + ".wt"], errfilename=errfile) self.check_empty_file(errfile) self.check_populate(self.tablename) def test_salvage_api_empty(self): """ Test salvage via API, using an empty table """ self.session.create('table:' + self.tablename, self.session_params) self.session.salvage('table:' + self.tablename, None) self.check_empty_table(self.tablename) def test_salvage_api(self): """ Test salvage via API, using a populated table. """ self.session.create('table:' + self.tablename, self.session_params) self.populate(self.tablename) self.session.salvage('file:' + self.tablename + ".wt", None) self.check_populate(self.tablename) def test_salvage_api_damaged(self): """ Test salvage via API, on a damaged table. """ self.session.create('table:' + self.tablename, self.session_params) self.populate(self.tablename) self.damage(self.tablename) # damage() closed the session/connection, reopen them now. self.open_conn() self.assertRaisesWithMessage(wiredtiger.WiredTigerError, lambda: self.session.verify('table:' + self.tablename, None), "/read checksum error/") self.session.salvage('file:' + self.tablename + ".wt", None) self.check_damaged(self.tablename) def test_salvage_process_damaged(self): """ Test salvage in a 'wt' process on a table that is purposely damaged. """ self.session.create('table:' + self.tablename, self.session_params) self.populate(self.tablename) self.damage(self.tablename) errfile = "salvageerr.out" self.runWt(["salvage", self.tablename + ".wt"], errfilename=errfile) self.check_empty_file(errfile) # expect no output self.check_no_error_in_file(errfile) self.check_damaged(self.tablename) if __name__ == '__main__': wttest.run()