There are a couple differences between ChromiumEnv and
PosixEnv/WindowsEnv which cause test failures that are fixed (or at
least patched over) in this change:
* NewSequentialFile() and NewRandomAccessFile() return Status::IOError
rather than Status::NotFound when a file is not found, due to
https://crbug.com/760362. This means a few tests need to expect a
different error result.
* GetChildren() never returns the '.' or '..' entries.
* As allowed by the documentation for Env::Schedule(), ChromiumEnv may
execute functions on multiple threads and guarantees no sequencing.
EnvTest.RunMany assumed that functions ran in order. The test has been
updated.
This gives some flexibility to embedders.
Currently, embedders have to build a binary for each test file.
After this CL, embedders can still choose to have a binary for each test
file, by linking each test file with a googletest target that includes
main() (usually "gtest_main"). Embedders can also choose to build a
single binary for almost all test files, and link with a googletest
target that includes main(). The latter is more convenient for projects
that have very few test binaries, like Chromium.
PiperOrigin-RevId: 419470798
key across multiple files.
As reported in Github issue #339, it is incorrect to split the
same user key across multiple compacted files since it causes
tombstones/newer-versions to be dropped, thereby exposing obsolete
data. There was a fix for #339, but it ended up not fully fixing
the problem. (It checked for boundary problems in the first level
being compacted, but not the second). This problem was revealed
by Github issue 887.
We now adjust boundaries to avoid splitting user keys in both the
first level and the second level.
PiperOrigin-RevId: 374921082
This is beneficial when iterators are reused and seeks are not random
but increasing. It is additionally beneficial with larger block sizes and keys with common prefixes.
Add a benchmark "seekordered" to db_bench that reuses iterators across
increasing seeks. Add support to the benchmark to count comparisons made and to support common key prefix length. Change benchmark random seeds to be reproducible for entire benchmark suite executions but unique for threads in different benchmarks runs. This changes a benchmark suite of readrandom,seekrandom from having a 100% found ratio as previously it had the same seed used for fillrandom.
./db_bench --benchmarks=fillrandom,compact,seekordered --block_size=262144 --comparisons=1 --key_prefix=100
without this change (though with benchmark changes):
seekrandom : 55.309 micros/op; (631820 of 1000000 found)
Comparisons: 27001049
seekordered : 1.732 micros/op; (631882 of 1000000 found)
Comparisons: 26998402
with this change:
seekrandom : 55.866 micros/op; (631820 of 1000000 found)
Comparisons: 26952143
seekordered : 1.686 micros/op; (631882 of 1000000 found)
Comparisons: 25549369
For ordered seeking, this is a reduction of 5% comparisons and a 3% speedup. For random seeking (with single use iterators) the comparisons and speed are less than 1% and likely noise.
PiperOrigin-RevId: 351149832
leveldb::Env::DeleteFile was replaced with leveldb::Env::RemoveFile in
all tests. This allows us to remove workarounds for windows.h #defining
DeleteFile.
PiperOrigin-RevId: 289121105
The "DeleteFile" method name causes pain for Windows developers, because
<windows.h> #defines a DeleteFile macro to DeleteFileW or DeleteFileA.
Current code uses workarounds, like #undefining DeleteFile everywhere an
Env is declared, implemented, or used.
This CL removes the need for workarounds by renaming Env::DeleteFile to
Env::RemoveFile. For consistency, Env::DeleteDir is also renamed to
Env::RemoveDir. A few internal methods are also renamed for consistency.
Software that supports Windows is expected to migrate any Env
implementations and usage to Remove{File,Dir}, and never use the name
Env::Delete{File,Dir} in its code.
The renaming is done in a backwards-compatible way, at the risk of
making it slightly more difficult to build a new correct Env
implementation. The backwards compatibility is achieved using the
following hacks:
1) Env::Remove{File,Dir} methods are added, with a default
implementation that calls into Env::Delete{File,Dir}. This makes old
Env implementations compatible with code that calls into the updated
API.
2) The Env::Delete{File,Dir} methods are no longer pure virtuals.
Instead, they gain a default implementation that calls into
Env::Remove{File,Dir}. This makes updated Env implementations
compatible with code that calls into the old API.
The cost of this approach is that it's possible to write an Env without
overriding either Rename{File,Dir} or Delete{File,Dir}, without getting
a compiler warning. However, attempting to run the test suite will
immediately fail with an infinite call stack ending in
{Remove,Delete}{File,Dir}, making developers aware of the problem.
PiperOrigin-RevId: 288710907
Added unreached return at the end of Version::Get::State::Match
to stop this _incorrect_ warning:
version_set.cc:376:5: warning: control reaches end of
non-void function [-Wreturn-type]
This warning was being emitted when building with clang 6.0.1-10
and also emitted by lgtm.com when statically analyzing leveldb even
though all SaverState enumeration values were handled.
PiperOrigin-RevId: 272455474
A recent change (4cb80b7ddce6f) to DBImpl::DeleteObsoleteFiles
unlocked DBImpl::mutex_ while deleting files to allow for
greater concurrency. This change improves on the prior in
a few areas:
1. The table is evicted from the table cache before unlocking
the mutex. This should only improve performance.
2. This implementation is slightly simpler, but at the cost of
a bit more memory usage.
3. A comment adding more detail as to why the mutex is being
unlocked and why it is safe to do so.
PiperOrigin-RevId: 253111645
