Clang 10 includes the optimizations described in
https://bugs.llvm.org/show_bug.cgi?id=41761. This means that the
platform-independent implementations of {Decode,Encode}Fixed{32,64}()
compile to one instruction on the most recent Clang and GCC.
PiperOrigin-RevId: 306330166
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
Using CMAKE_INSTALL_INCLUDEDIR before including GNUINstallDirs results
in a broken installation when CMAKE_INSTALL_PREFIX is a non-standard
directory.
Inspired from https://github.com/google/crc32c/pull/39
PiperOrigin-RevId: 278427974
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
Previously used check_cxx_source_compiles to attempt a
build to determine support for clang thread safety checks.
This change is to support static analysis of the leveldb source by
lgtm.com (using Semmle). It failed to build with the following error:
```
[2019-07-04 22:29:58] [build] c++: error: unrecognized command line option ‘-Wthread-safety’; did you mean ‘-fthread-jumps’?
[2019-07-04 22:30:02] [build] make[2]: *** [CMakeFiles/leveldb.dir/build.make:66: CMakeFiles/leveldb.dir/db/builder.cc.o] Error 1
```
PiperOrigin-RevId: 272275528
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
