This CL makes it easier to reason about thread safety by:
1) Adding Clang thread safety annotations according to comments.
2) Expanding a couple of variable names, without adding extra lines of code.
3) Adding const in a couple of places.
4) Replacing an always-non-null const pointer with a reference.
5) Fixing style warnings in the modified files.
This CL does not annotate the DBImpl members that claim to be protected
by the instance mutex, but are accessed without the mutex being held.
Those members (and their unprotected accesses) will be addressed in
future CLs.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189354657
This CL removes unused headers included by util/testharness.h, adds
precise includes where the build breaks, and fixes style errors in the
edited files.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189331061
External linkage is the default for function declarations in C++.
This also fixes ClangTidy errors generated by removing the "extern"
keyword as described above.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=188730416
This removes the use of the non-portable headers <sys/types.h> and <unistd.h> in c_test.c.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=188503102
When the max file size option was added in CL 134391640 the C API
was not modified to support this.
This change was contributed by GitHub user @olt and fixes issue #439.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=173466388
Deleted two unused assignments:
1. offset_in_block in Reader::SkipToInitialBlock().
2. in_fragmented_record in Reader::ReadRecord().
Reasons for the change:
1. offset_in_block is not read again after the if condition.
2. The kFullRecordType switch branch returns, so
in_fragmented_record isn't read again.
3. The kFirstType switch branch sets in_fragmented_record to
true after the if, so the write in the if is ignored.
Change contributed by @C0deAi on GitHub.
This fixes https://github.com/google/leveldb/issues/517
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=172763897
env_posix.cc and concurrent application calls to fflush(NULL).
The fix is to avoid using stdio in env_posix.cc but add our own
buffering where we need it.
Added a test to reproduce the bug.
Added a test for Env reads/writes.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=170738066
12 lines above, there is an "if (!s.ok()) { return s; }" block of code.
"s" is never modified between that block and the "if" removed by this
CL, so "s.ok()" must be true.
The code most likely intended to say "if (!builder->ok())", because the
builder->Add() call above can modify the TableBuilder's status, as a
side-effect. However, this approach would have required setting "s =
builder.status()" in the "else" branch, near the "builder.Abandon()"
call. So, removing the "if" outright is simpler than following that line
of thought.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=167326229
The dead code has been in the codebase since the initial commit and is
generating a compiler warning when used in Xcode.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=164174594
BTRFS reorders rename and write operations, so it is possible that a filesystem crash and recovery results in a situation where the file pointed to by CURRENT does not exist. DB::Open currently reports an I/O error in this case. Reporting database corruption is a better hint to the caller, which can attempt to recover the database or erase it and start over.
This issue is not merely theoretical. It was reported as having showed up in the wild at https://github.com/google/leveldb/issues/195 and at https://crbug.com/738961. Also, asides from the BTRFS case described above, incorrect data in CURRENT seems like a possible corruption case that should be handled gracefully.
The Env API changes here can be considered backwards compatible, because an implementation that returns Status::IOError instead of Status::NotFound will still get the same functionality as before.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=161432630
Markdown is more readable in a text editor and when hosted
on GitHub is more readable than HTML.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=148830423
Detailed description:
Suppose an input split is generated between two leveldb record blocks and the preceding block ends with null padding.
A reader that previously read at least 1 record within the first block (before encountering the padding) upon trying to read the next record, will successfully and correctly read the next logical record from the subsequent block, but will return a last record offset pointing to the padding in the first block.
When this happened in a [], it resulted in duplicate records being handled at what appeared to be different offsets that were separated by only a few bytes.
This behavior is only observed when at least 1 record was read from the first block before encountering the padding. If the initial offset for a reader was within the padding, the correct record offset would be reported, namely the offset within the second block.
The tests failed to catch this scenario/bug, because each read test only read a single record with an initial offset. This CL adds an explicit test case for this scenario, and modifies the test structure to read all remaining records in the test case after an initial offset is specified. Thus an initial offset that jumps to record #3, with 5 total records in the test file, will result in reading 2 records, and validating the offset of each of them in order to pass successfully.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=115338487
1. Object files, libraries, and compiled executables are put
into subdirectories.
2. The shared library is linked from individual object files.
This provides for greater parallelism on large desktops
while at the same time making for easier builds on small
(i.e. embedded) systems. Fixes issue #279.
3. One program, db_bench, is compiled using the shared library.
4. The source file for "leveldbutil" was renamed from
leveldb_main.cc to leveldbutil.cc. This provides for simpler
makefile rules.
5. Because all targets placed the library (libleveldb.a) at the top
level, the last platform built (desktop/device) always overwrote
any prior artifact.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=113407013
The write operations in the table happens without holding the mutex
lock, but concurrent writes are avoided using "writers_" queue.
The Arena::MemoryUsage could access the blocks when write happens.
So, the memory usage is cached in atomic word and can be loaded
from any thread safely.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=107573379
The approximate RAM usage of the database is calculated from the memory
allocated for write buffers and the block cache. This is to give an
estimate of memory usage to leveldb clients.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=104222307
Prior implementation would always try to reuse the manifest, even if reuse_logs
was false (the default). This was missed because the stock
Env::NewAppendableFile implementation returns false forcing the creation of a
new log.
(Based on a suggestion by cmumford.)
"open" benchmark on my workstation speeds up significantly since we
can now avoid three fdatasync calls and a compaction per open:
Before: ~80000 microseconds
After: ~130 microseconds
Details:
(1) Added Options::reuse_logs (currently defaults to false) to control
new behavior. The intention is to change the default to true after some
baking.
(2) Added Env::NewAppendableFile() whose default implementation returns
a not-supported error.
(3) VersionSet::Recovery attempts to reuse the MANIFEST from which
it is recovering.
(4) DBImpl recovery attempts to reuse the last log file and memtable.
(5) db_test.cc now tests a new configuration that sets reuse_logs to true.
(6) fault_injection_test also tests a reuse_logs==true config.
(7) Added a new recovery_test.
This test is intended to ensure leveldb properly detects and recovers from
faults - specifically unwritten file data lost as a result of a system reset.
Changes are:
* Update version number to 1.18
* Replace the basic fprintf call with a call to fwrite in order to
work around the apparent compiler optimization/rewrite failure that we are
seeing with the new toolchain/iOS SDKs provided with Xcode6 and iOS8.
* Fix ALL the header guards.
* Createed a README.md with the LevelDB project description.
* A new CONTRIBUTING file.
* Don't implicitly convert uint64_t to size_t or int. Either preserve it as
uint64_t, or explicitly cast. This fixes MSVC warnings about possible value
truncation when compiling this code in Chromium.
* Added a DumpFile() library function that encapsulates the guts of the
"leveldbutil dump" command. This will allow clients to dump
data to their log files instead of stdout. It will also allow clients to
supply their own environment.
* leveldb: Remove unused function 'ConsumeChar'.
* leveldbutil: Remove unused member variables from WriteBatchItemPrinter.
* OpenBSD, NetBSD and DragonflyBSD have _LITTLE_ENDIAN, so define
PLATFORM_IS_LITTLE_ENDIAN like on FreeBSD. This fixes:
* issue #143
* issue #198
* issue #249
* Switch from <cstdatomic> to <atomic>. The former never made it into the
standard and doesn't exist in modern gcc versions at all. The later contains
everything that leveldb was using from the former.
This problem was noticed when porting to Portable Native Client where no memory
barrier is defined. The fact that <cstdatomic> is missing normally goes
unnoticed since memory barriers are defined for most architectures.
* Make Hash() treat its input as unsigned. Before this change LevelDB files
from platforms with different signedness of char were not compatible. This
change fixes: issue #243
* Verify checksums of index/meta/filter blocks when paranoid_checks set.
* Invoke all tools for iOS with xcrun. (This was causing problems with the new
XCode 5.1.1 image on pulse.)
* include <sys/stat.h> only once, and fix the following linter warning:
"Found C system header after C++ system header"
* When encountering a corrupted table file, return Status::Corruption instead of
Status::InvalidArgument.
* Support cygwin as build platform, patch is from https://code.google.com/p/leveldb/issues/detail?id=188
* Fix typo, merge patch from https://code.google.com/p/leveldb/issues/detail?id=159
* Fix typos and comments, and address the following two issues:
* issue #166
* issue #241
* Add missing db synchronize after "fillseq" in the benchmark.
* Removed unused variable in SeekRandom: value (issue #201)
- Cleanup: delete unused IntSetToString
It was added in http://cr/19491949 (and was referenced at the time).
The last reference was removed in http://cr/19507363.
This fixes warning/error with pre-release crosstoolv18:
'std::string leveldb::{anonymous}::IntSetToString(const std::set<long unsigned int>&)' defined but not used [-Werror=unused-function]
- Added arm64 and and armv7s to IOS build as suggested on leveldb mailing list.
- Changed local variable type from int to size_t
This eliminates compiler warning/error and resolves
https://code.google.com/p/leveldb/issues/detail?id=140
- Make Log::Reader not report a corruption when the last record in a
log file is truncated.
- Fix issue 224: variable created but not utilized.
- Remove comment that referenced a removed feature.
- switched from mmap based writing to simpler stdio based writing. Has a
minor impact (0.5 microseconds) on microbenchmarks for asynchronous
writes. Synchronous writes speed up from 30ms to 10ms on linux/ext4.
Should be much more reliable on diverse platforms.
- compaction errors now immediately put the database into a read-only
mode (until it is re-opened). As a downside, a disk going out of
space and then space being created will require a re-open to recover
from, whereas previously that would happen automatically. On the
plus side, many corruption possibilities go away.
- force the DB to enter an error-state so that all future writes fail
when a synchronous log write succeeds but the sync fails.
- repair now regenerates sstables that exhibit problems
- fix issue 218 - Use native memory barriers on OSX
- fix issue 212 - QNX build is broken
- fix build on iOS with xcode 5
- make tests compile and pass on windows
Fix issues 200, 201
Also,
* Fix link to bigtable paper in docs.
* New sstables will have the file extension .ldb. .sst files will
continue to be recognized.
* When building for iOS, use xcrun to execute the compiler. This may
affect issue 177.
Fix issues 77, 87, 182, 190.
Additionally, fix the bug described in
https://groups.google.com/d/msg/leveldb/yL6h1mAOc20/vLU64RylIdMJ
where a large contiguous keyspace of deleted data was not getting
compacted.
Also fix a bug where options.max_open_files was not getting clamped
properly.
Fixes issues
147 - thanks feniksgordonfreeman
153
156
166
Additionally,
* Remove calls to exit(1).
* Fix unused-variable warnings from clang.
* Fix possible overflow error related to num_restart value >= (2^32/4).
* Add leveldbutil to .gitignore.
* Add better log messages when Write is stalled on a compaction.
Details:
* Fix shared library building.
* Reorganize linking commands so flags like --as-needed can be passed.
* C binding exports version numbers.
* Fix small typos in documention.
Highlights
----------
Mmap at most 1000 files on Posix to improve performance for large databases.
Support for more architectures (thanks to Alexander K.)
Building and porting
--------------------
HP/UX support (issue 126)
AtomicPointer for ia64 (issue 123)
Sparc v9 support (issue 124)
Atomic ops for powerpc
Use -fno-builtin-memcmp only when using g++
Simplify IOS build rules (issue 114)
Use CXXFLAGS instead of CFLAGS when invoking C++ compiler (issue 118)
Fix snappy shared library problem (issue 94)
Fix shared library installation path regression
Endian-ness detection tweak for FreeBSD
Bug fixes
---------
Stop ignoring FLAGS_open_files in db_bench
Make bloom test behavior agnostic to endian-ness
Performance
-----------
Limit number of mmapped files to 1000 to improve perf for large dbs
Do not delay for 1 second on shutdown path (issue 125)
Misc
----
Make InMemoryEnv return a no-op logger
C binding now has a wrapper for free (issue 117)
Add thread-safety annotations
Added an in-process lock table (issue 120)
Make RandomAccessFile and SequentialFile non-copyable
various platforms; improve android port speed.
Avoid static initializer by using a new portability interface for
thread-safe lazy initialization. Custom ports will need to be
extended to implement InitOnce/OnceType/LEVELDB_ONCE_INIT.
Fix endian-ness detection (fixes Powerpc builds).
Build related fixes:
- Support platforms that have unversioned shared libraries.
- Fix IOS build rules.
Android improvements
- Speed up atomic pointers
- Share more code with port_posix.
Do not spin in a tight loop attempting compactions if the file system
is inaccessible (e.g., if kerberos tickets have expired or if it is out
of space).
In particular, we add a new FilterPolicy class. An instance
of this class can be supplied in Options when opening a
database. If supplied, the instance is used to generate
summaries of keys (e.g., a bloom filter) which are placed in
sstables. These summaries are consulted by DB::Get() so we
can avoid reading sstable blocks that are guaranteed to not
contain the key we are looking for.
This change provides one implementation of FilterPolicy
based on bloom filters.
Other changes:
- Updated version number to 1.4.
- Some build tweaks.
- C binding for CompactRange.
- A few more benchmarks: deleteseq, deleterandom, readmissing, seekrandom.
- Minor .gitignore update.
costan
cmumford
sanjay
davidair
corrado
Nicholas Westlake
mjwiacek
Bruce Dawson
ssid
Chris Mumford
ideawu
David Grogan