Commit Graph

83 Commits

Author SHA1 Message Date
Zun Wang
eb53c05a35 Add comment for GetBackupInfo about returned BackupInfos order
Summary: #title

Test Plan: n/a

Reviewers: uddipta, ldemailly, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60393
2016-07-06 12:54:01 -07:00
Wanning Jiang
95d96eeeb1 remove LockFile
Summary: LockFile is unnecessary in unit test

Test Plan: env_basic_test.cc

Reviewers: andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60285
2016-07-01 15:28:08 -07:00
Wanning Jiang
ff45d1b547 if read only backup engine can't find meta dirs, return NotFound() instead of IOError()
Summary: Read only backup engine return NotFound() on missing meta dir (for e2e test)

Test Plan: backupable_db_test

Reviewers: andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60273
2016-07-01 11:36:33 -07:00
Wanning Jiang
95c192475d writable file close before reset
Summary: during backup, writable file should call close() before reset()

Test Plan: backupable_db_test.cc

Reviewers: andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60195
2016-06-29 15:33:27 -07:00
Wanning Jiang
56887f6cb8 Backup Options
Summary: Backup options file to private directory

Test Plan:
backupable_db_test.cc, BackupOptions
	   Modify DB options by calling OpenDB for 3 times. Check the latest options file is in the right place. Also check no redundent files are backuped.

Reviewers: andrewkr

Reviewed By: andrewkr

Subscribers: leveldb, dhruba, andrewkr

Differential Revision: https://reviews.facebook.net/D59373
2016-06-09 19:03:10 -07:00
Uddipta Maity
1147e5b05a Adding support for sharing throttler between multiple backup and restores
Summary:
Rocksdb backup and restore rate limiting is currently done per backup/restore.
So, it is difficult to control rate across multiple backup/restores. With this
change, a throttler can be provided. If a throttler is provided, it is used.
Otherwise, a new throttler is created based on the actual rate limits specified
in the options.

Test Plan: Added unit tests

Reviewers: ldemailly, andrewkr, sdong

Reviewed By: andrewkr

Subscribers: igor, yiwu, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56265
2016-06-03 17:02:07 -07:00
sdong
0e77246ba9 backupable_db.cc: lambada to explictly caputre "this" when escaping scope
Summary:
Google C++ Style writes: In particular, prefer to write lambda captures explicitly when capturing this or if the lambda will escape the current scope.
Here it is the case for both.

Test Plan: Run all test suites.

Reviewers: andrewkr, dhruba

Reviewed By: andrewkr, dhruba

Subscribers: yhchiang, IslamAbdelRahman, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58515
2016-05-20 10:16:49 -07:00
Andrew Kryczka
1995e34d6a Retrieve file size from proper Env
Summary:
When db_env_ != backup_env_, InsertPathnameToSizeBytes() would
use the wrong Env during backup creation. This happened because this function
used backup_env_ instead of db_env_ to get WAL/data file sizes.

This diff adds an argument to InsertPathnameToSizeBytes() indicating which Env
to use.

Test Plan: ran @anirbanb's BackupTestTool

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57159
2016-04-26 12:33:30 -07:00
Andrew Kryczka
40b840f294 Delete deprecated *BackupableDB interface for backups
Summary:
This interface is redundant and has been deprecated for a while.
It's also unused internally. Let's delete it.

I moved the comments to the corresponding functions in BackupEngine/
BackupEngineReadOnly. This caused the diff tool to not work cleanly.

Test Plan:
unit tests

  $ ./backupable_db_test

Reviewers: yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D56331
2016-04-18 09:04:14 -07:00
sdong
cea8ed9702 Fix backupable_db_test test cases that can't run by itself
Summary:
Several of backupable_db_test fails if running standalone, because of directory missing. Fix it by:
(1) garbage collector skips shared directory if it doesn't exit
(2) BackupableDBTest.Issue921Test to create the parent directory of the backup directory fist.

Test Plan: Run the tests individually and make sure they pass

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56829
2016-04-15 15:48:57 -07:00
Andrew Kryczka
114a1b8792 Fix build errors for windows
Summary:
- Need to use unsigned long long for 64-bit literals on windows
- Need size_t for backup meta-file length since clang doesn't let us assign size_t to int

Test Plan: backupable_db_test and options_test

Reviewers: IslamAbdelRahman, yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D56391
2016-04-08 13:09:19 -07:00
Uddipta Maity
b55e2165be Rocksdb backup can store optional application specific metadata
Summary:
Rocksdb backup engine maintains metadata about backups in separate files. But,
there was no way to add extra application specific data to it. Adding support
for that.
In some use cases, applications decide to restore a backup based on some
metadata. This will help those cases to cheaply decide whether to restore or
not.

Test Plan:
Added a unit test. Existing ones are passing

Sample meta file for BinaryMetadata test-

```

1459454043
0
metadata 6162630A64656600676869
2
private/1/MANIFEST-000001 crc32 1184723444
private/1/CURRENT crc32 3505765120

```

Reviewers: sdong, ldemailly, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, ldemailly

Differential Revision: https://reviews.facebook.net/D56007
2016-04-01 10:56:52 -07:00
SherlockNoMad
58ecd91326 Fix Windows build 2016-03-03 15:08:24 -08:00
Andrew Kryczka
501927ffc4 [backupable db] Remove file size embedded in name workaround
Summary:
Now that we get sizes efficiently, we no longer need the workaround to
embed file size in filename.

Test Plan:
  $ ./backupable_db_test

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55035
2016-03-03 13:32:20 -08:00
Andrew Kryczka
f8e90e8753 Get file attributes in bulk for VerifyBackup and CreateNewBackup
Summary:
For VerifyBackup(), backup files can be spread across "shared/",
"shared_checksum/", and "private/" subdirectories, so we have to
bulk get all three.

For CreateNewBackup(), we make two separate bulk calls: one for the
data files and one for WAL files.

There is also a new helper function, ExtendPathnameToSizeBytes(),
that translates the file attributes vector to a map. I decided to leave
GetChildrenFileAttributes()'s (from D53781) return type as vector to
keep it consistent with GetChildren().

Depends on D53781.

Test Plan:
verified relevant unit tests

  $ ./backupable_db_test

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D53919
2016-03-01 19:33:33 -08:00
Andrew Kryczka
69c471bd9b Handle concurrent manifest update and backup creation
Summary:
Fixed two related race conditions in backup creation.

(1) CreateNewBackup() uses DB::DisableFileDeletions() to prevent table files
from being deleted while it is copying; however, the MANIFEST file could still
rotate during this time. The fix is to stop deleting the old manifest in the
rotation logic. It will be deleted safely later when PurgeObsoleteFiles() runs
(can only happen when file deletions are enabled).

(2) CreateNewBackup() did not account for the CURRENT file being mutable.
This is significant because the files returned by GetLiveFiles() contain a
particular manifest filename, but the manifest to which CURRENT refers can
change at any time. This causes problems when CURRENT changes between the call
to GetLiveFiles() and when it's copied to the backup directory. To workaround this, I
manually forge a CURRENT file referring to the manifest filename returned in
GetLiveFiles().

(2) also applies to the checkpointing code, so let me know if this approach is
good and I'll make the same change there.

Test Plan:
new test for roll manifest during backup creation.

running the test before this change:

  $ ./backupable_db_test --gtest_filter=BackupableDBTest.ChangeManifestDuringBackupCreation
  ...
  IO error: /tmp/rocksdbtest-9383/backupable_db/MANIFEST-000001: No such file or directory

running the test after this change:

  $ ./backupable_db_test --gtest_filter=BackupableDBTest.ChangeManifestDuringBackupCreation
  ...
  [ RUN      ] BackupableDBTest.ChangeManifestDuringBackupCreation
  [       OK ] BackupableDBTest.ChangeManifestDuringBackupCreation (2836 ms)

Reviewers: IslamAbdelRahman, anthony, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54711
2016-02-29 12:56:55 -08:00
Baraa Hamodi
21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
Igor Canadi
e541dcc8fa Fix issue #921
Summary:
See a bug report here: https://github.com/facebook/rocksdb/issues/921
The fix is to not check the shared/ directory if share_table_files is false. We could also check FileExists() before GetChildren(), but that will add extra latency when Env is Hdfs :(

Test Plan: added a unit test

Reviewers: rven, sdong, IslamAbdelRahman, yhchiang, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D52593
2016-01-06 13:05:24 -08:00
Zhipeng Jia
73b175a773 Fix clang warnings regarding unnecessary std::move 2015-12-24 04:10:00 +08:00
SherlockNoMad
b4efaebff0 Fix ms version Appveyor build error 2015-11-30 11:07:47 -08:00
sdong
6bbfa1874b BackupDB to have a mode to use file size in file name
Summary: Getting file size from all the backup files can take a long time. In some cases, the sizes are available in file names. We allow a mode to get those sizes from file name.

Test Plan:
Make some unit tests in backupable_db_test to run in such a mode.
Make sure RocksDB Lite builds too.

Reviewers: IslamAbdelRahman, rven, yhchiang, kradhakrishnan, anthony, igor

Reviewed By: igor

Subscribers: muthu, asameet, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51243
2015-11-25 11:55:37 -08:00
Dmytro Okhonko
31a27a3606 Callback for informing backup downloading added
Summary:
In case of huge db backup infromation about progress of downloading would help.
New callback parameter in CreateNewBackup() function will trigger whenever a some amount of data downloaded.
Task: 8057631

Test Plan:
ProgressCallbackDuringBackup test that cover new functionality added to BackupableDBTest tests.
other test succeed as well.

Reviewers: Guenena, benj, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D46575
2015-09-15 17:08:30 -07:00
Mayank Pundir
d9f42aa60d Adding a verifyBackup method to BackupEngine
Summary: This diff adds a verifyBackup method to BackupEngine. The method verifies the name and size of each file in the backup.

Test Plan: Unit test cases created and passing.

Reviewers: igor, benj

Subscribers: zelaine.fong, yhchiang, sdong, lgalanis, dhruba, AaronFeldman

Differential Revision: https://reviews.facebook.net/D46029
2015-09-03 17:27:21 -07:00
Paul Marinescu
50dc5f0c5a Replace BackupRateLimiter with GenericRateLimiter
Summary: BackupRateLimiter removed and uses replaced with the existing GenericRateLimiter

Test Plan:
make all check

make clean
USE_CLANG=1 make all

make clean
OPT=-DROCKSDB_LITE make release

Reviewers: leveldb, igor

Reviewed By: igor

Subscribers: igor, dhruba

Differential Revision: https://reviews.facebook.net/D46095
2015-09-03 17:00:09 -07:00
Igor Canadi
b42cd6bed5 Remove the need for LATEST_BACKUP in BackupEngine
Summary:
In the first implementation of BackupEngine, LATEST_BACKUP was the commit point. The backup became committed after the write to LATEST_BACKUP completed.

However, we can avoid the need for LATEST_BACKUP. Instead of write to LATEST_BACKUP, the commit point can be the rename from `meta/<backup_id>.tmp` to `meta/<backup_id>`. Once we see that there exists a file `meta/<backup_id>` (without tmp), we can assume that backup is valid.

In this diff, we still write out the file LATEST_BACKUP. We need to do this so that we can maintain backward compatibility. However, the new version doesn't depend on this file anymore. We get the latest backup by `ls`-ing `meta` directory.

This diff depends on D41925

Test Plan: Adjusted backupable_db_test to this new behavior

Reviewers: benj, yhchiang, sdong, AaronFeldman

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42069
2015-09-02 11:49:49 -07:00
Dmitri Smirnov
fbe2c05f59 s/NOEXCEPT/ROCKSDB_NOEXCEPT 2015-08-25 16:34:39 -07:00
Dmitri Smirnov
6924d7582b Address noexcept and const integer lambda capture
VS 2013 does not support noexcept.
   Complains about usage of ineteger constant within lambda requiring explicit capture.
2015-08-25 15:17:14 -07:00
Igor Canadi
53b88784df Add throttling to multi-threaded backups
Summary: See internal task t8056182

Test Plan: Added multi-threading in RateLimiter test

Reviewers: benj, AaronFeldman

Reviewed By: AaronFeldman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D45459
2015-08-25 13:32:46 -07:00
agiardullo
064294081b Improved FileExists API
Summary: Add new CheckFileExists method.  Considered changing the FileExists api but didn't want to break anyone's builds.

Test Plan: unit tests

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42003
2015-07-20 17:20:40 -07:00
sdong
6e9fbeb27c Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env
Summary: We want to keep Env a think layer for better portability. Less platform dependent codes should be moved out of Env. In this patch, I create a wrapper of file readers and writers, and put rate limiting, write buffering, as well as most perf context instrumentation and random kill out of Env. It will make it easier to maintain multiple Env in the future.

Test Plan: Run all existing unit tests.

Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D42321
2015-07-17 16:58:18 -07:00
Dmitri Smirnov
d1a457181d Ensure Windows build w/o port/port.h in public headers
- Remove make file defines from public headers and use _WIN32 because it is compiler defined
 - use __GNUC__ and __clang__ to guard non-portable attributes
 - add #include "port/port.h" to some new .cc files.
 - minor changes in CMakeLists to reflect recent changes
2015-07-16 12:10:16 -07:00
Igor Canadi
8a9fca2619 Better error handling in BackupEngine
Summary:
Couple of changes here:
* NewBackupEngine() and NewReadOnlyBackupEngine() are now removed. They were deprecated since RocksDB 3.8. Changing these to new functions should be pretty straight-forward. As a followup, I'll fix all fbcode callsights
* Instead of initializing backup engine in the constructor, we initialize it in a separate function now. That way, we can catch all errors and return appropriate status code.
* We catch all errors during initializations and return them to the client properly.
* Added new tests to backupable_db_test, to make sure that we can't open BackupEngine when there are Env errors.
* Transitioned backupable_db_test to use BackupEngine rather than BackupableDB. From the two available APIs, judging by the current use-cases, it looks like BackupEngine API won. It's much more flexible since it doesn't require StackableDB.

Test Plan: Added a new unit test to backupable_db_test

Reviewers: yhchiang, sdong, AaronFeldman

Reviewed By: AaronFeldman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D41925
2015-07-14 20:51:36 +02:00
sdong
f9728640f3 "make format" against last 10 commits
Summary: This helps Windows port to format their changes, as discussed. Might have formatted some other codes too becasue last 10 commits include more.

Test Plan: Build it.

Reviewers: anthony, IslamAbdelRahman, kradhakrishnan, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D41961
2015-07-13 13:50:18 -07:00
Dmitri Smirnov
c903ccc4c2 Merge from github/master 2015-07-09 18:01:08 -07:00
Aaron Feldman
e12b403991 Initialize threads later in constructor
Summary: This addresses a test failure where an exception occured in the constructor's call to CreateDirIfMissing(). The existence of unjoined threads prevented this exception from propogating properly. See http://stackoverflow.com/questions/7381757/c-terminate-called-without-an-active-exception

Test Plan: Re-run tests from task #7626266

Reviewers: sdong, anthony, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D41313
2015-07-07 10:49:16 -07:00
Dmitri Smirnov
d2f0912bd3 Merge the latest changes from github/master 2015-07-02 17:23:41 -07:00
Dmitri Smirnov
feb99c31a4 Merge remote-tracking branch 'origin' into ms_win_port 2015-07-02 13:14:18 -07:00
Aaron Feldman
e70115e71b Fix unity build by removing anonymous namespace
Summary: see title

Test Plan: run 'make unity'

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D41079
2015-07-02 12:27:35 -07:00
Aaron Feldman
a69bc91e37 Multithreaded backup and restore in BackupEngineImpl
Summary:
Add a new field: BackupableDBOptions.max_background_copies.
CreateNewBackup() and RestoreDBFromBackup() will use this number of threads to perform copies.
If there is a backup rate limit, then max_background_copies must be 1.
Update backupable_db_test.cc to test multi-threaded backup and restore.
Update backupable_db_test.cc to test backups when the backup environment is not the same as the database environment.

Test Plan:
Run ./backupable_db_test
Run valgrind ./backupable_db_test
Run with TSAN and ASAN

Reviewers: yhchiang, rven, anthony, sdong, igor

Reviewed By: igor

Subscribers: yhchiang, anthony, sdong, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D40725
2015-07-02 11:35:51 -07:00
Dmitri Smirnov
18285c1e2f Windows Port from Microsoft
Summary: Make RocksDb build and run on Windows to be functionally
 complete and performant. All existing test cases run with no
 regressions. Performance numbers are in the pull-request.

 Test plan: make all of the existing unit tests pass, obtain perf numbers.

 Co-authored-by: Praveen Rao praveensinghrao@outlook.com
 Co-authored-by: Sherlock Huang baihan.huang@gmail.com
 Co-authored-by: Alex Zinoviev alexander.zinoviev@me.com
 Co-authored-by: Dmitri Smirnov dmitrism@microsoft.com
2015-07-01 16:13:56 -07:00
Igor Canadi
50eab9cf30 Fix BackupEngine
Summary:
In D28521 we removed GarbageCollect() from BackupEngine's constructor. The reason was that opening BackupEngine on HDFS was very slow and in most cases we didn't have any garbage. We allowed the user to call GarbageCollect() when it detects some garbage files in his backup directory.

Unfortunately, this left us vulnerable to an interesting issue. Let's say we started a backup and copied files {1, 3} but the backup failed. On another host, we restore DB from backup and generate {1, 3, 5}. Since {1, 3} is already there, we will not overwrite. However, these files might be from a different database so their contents might be different. See internal task t6781803 for more info.

Now, when we're copying files and we discover a file already there, we check:
1. if the file is not referenced from any backups, we overwrite the file.
2. if the file is referenced from other backups AND the checksums don't match, we fail the backup. This will only happen if user is using a single backup directory for backing up two different databases.
3. if the file is referenced from other backups AND the checksums match, it's all good. We skip the copy and go copy the next file.

Test Plan: Added new test to backupable_db_test. The test fails before this patch.

Reviewers: sdong, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D37599
2015-05-07 17:39:19 -07:00
clark.kang
6ede020dc4 fix typos 2015-04-25 18:14:27 +09:00
sdong
98a44559d5 Build for CYGWIN
Summary:
Make it build for CYGWIN.
Need to define "-std=gnu++11" instead of "-std=c++11" and use some replacement functions.

Test Plan: Build it and run some unit tests in CYGWIN

Reviewers: yhchiang, rven, anthony, kradhakrishnan, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D37605
2015-04-23 21:33:44 -07:00
Igor Canadi
216a9e16f4 Fix compile
Summary: I was pretty sure I compiled this before landing, sorry :/

Test Plan: compiles

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34173
2015-02-27 14:21:16 -08:00
Igor Canadi
b9ff6b050d Fix a bug in ReadOnlyBackupEngine
Summary:
This diff fixes a bug introduced by D28521. Read-only backup engine can delete a backup that is later than the latest -- we never check the condition.

I also added a bunch of logging that will help with debugging cases like this in the future.

See more discussion at t6218248.

Test Plan: Added a unit test that was failing before the change. Also, see new LOG file contents: https://phabricator.fb.com/P19738984

Reviewers: benj, sanketh, sumeet, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33897
2015-02-27 14:03:56 -08:00
Igor Sugak
62247ffa3b rocksdb: Add missing override
Summary:
When using latest clang (3.6 or 3.7/trunck) rocksdb is failing with many errors. Almost all of them are missing override errors. This diff adds missing override keyword. No manual changes.

Prerequisites: bear and clang 3.5 build with extra tools

```lang=bash
% USE_CLANG=1 bear make all # generate a compilation database http://clang.llvm.org/docs/JSONCompilationDatabase.html
% clang-modernize -p . -include . -add-override
% make format
```

Test Plan:
Make sure all tests are passing.
```lang=bash
% #Use default fb code clang.
% make check
```
Verify less error and no missing override errors.
```lang=bash
% # Have trunk clang present in path.
% ROCKSDB_NO_FBCODE=1 CC=clang CXX=clang++ make
```

Reviewers: igor, kradhakrishnan, rven, meyering, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34077
2015-02-26 11:28:41 -08:00
Igor Canadi
173c52a97f Fix build on older compilers -- emplace() is not available 2015-01-29 13:43:09 -08:00
Igor Canadi
5257c9c42c Merge pull request #452 from robertabcd/backupable-mem
Reduce memory footprint in backupable db.
2015-01-28 10:53:46 -08:00
Igor Canadi
a52dd00243 Fix ASAN failure with backupable DB
Summary: It looks like ASAN with gcc 4.9 works better than 4.8.1. It detected this possibility of heap buffer overflow. This was in our codebase for a year :)

Test Plan: COMPILE_WITH_ASAN=1 make backupable_db && ./backupable_db

Reviewers: yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D32085
2015-01-23 15:02:43 -08:00
Robert
628a67b007 Reduce memory footprint in backupable db.
* Use emplace when possible.
* Make FileInfo shared among all BackupMeta, instead of storing filenames.
* Make checksum_value in FileInfo constant.
* Reserve space beforehand if container size is known.
* Make FileInfo and BackupMeta non-copyable and non-assignable to prevent future logic errors.
  It is very dangerous to copy BackupMeta without careful handling refcounts of FileInfo.
* Remove a copy of BackupMeta when detected corrupt backup.
2015-01-09 16:58:13 +08:00