rocksdb

fork of https://github.com/oxigraph/rocksdb and https://github.com/facebook/rocksdb for nextgraph and oxigraph

Nikhil Benesch c0208dffbe arena: derive alignment unit from std::max_align_t Summary: As raised in #2265, the arena allocator will return memory that is improperly aligned to store a `std::function` on macOS. Oddly, I'm unable to tickle this bug without adding a `std::function` field to `struct ReadOptions`—but my proposal in #2265 does exactly that. In any case, here's a simple reproduction. Apply this bogus patch to get a `std::function` into `struct ReadOptions` ``` --- a/include/rocksdb/options.h +++ b/include/rocksdb/options.h @@ -1035,6 +1035,8 @@ struct ReadOptions { // Default: 0 uint64_t max_skippable_internal_keys; + std::function<void()> foo; + ReadOptions(); ReadOptions(bool cksum, bool cache); }; ``` then compile `db_properties_test` with ubsan and run `ReadLatencyHistogramByLevel`: ``` $ make COMPILE_WITH_UBSAN=1 db_properties_test $ ./db_properties_test --gtest_filter=DBPropertiesTest.ReadLatencyHistogramByLevel ``` ubsan will complain about several misaligned accesses: ``` Note: Google Test filter = DBPropertiesTest.ReadLatencyHistogramByLevel [==========] Running 1 test from 1 test case. [----------] Global test environment set-up. [----------] 1 test from DBPropertiesTest [ RUN ] DBPropertiesTest.ReadLatencyHistogramByLevel util/coding.h:372:12: runtime error: load of misaligned address 0x00010d85516c for type 'const unsigned long', which requires 8 byte alignment 0x00010d85516c: note: pointer points here 01 00 34 57 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 78 24 82 0a 01 00 00 00 ^ util/coding.h:362:3: runtime error: store to misaligned address 0x7fff5733fac4 for type 'unsigned long', which requires 8 byte alignment 0x7fff5733fac4: note: pointer points here 01 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80 1d 96 0d 01 00 00 00 ^ util/coding.h:372:12: runtime error: load of misaligned address 0x00010d85516c for type 'const unsigned long', which requires 8 byte alignment 0x00010d85516c: note: pointer points here 01 00 34 57 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 78 24 82 0a 01 00 00 00 ^ version_set.cc:854: runtime error: constructor call on misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ version_set.cc:512: runtime error: constructor call on misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ version_set.cc:505: runtime error: constructor call on misaligned address 0x00010dbfa5e8 for type 'rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ options.h:931: runtime error: constructor call on misaligned address 0x00010dbfa5e8 for type 'rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ options.h:931: runtime error: constructor call on misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ functional:1583: runtime error: constructor call on misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1585:9: runtime error: member access within misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1585:9: runtime error: store to misaligned address 0x00010dbfa648 for type '__base ' (aka '__base<void ()> '), which requires 16 byte alignment 0x00010dbfa648: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ db/version_set.cc:864:29: runtime error: upcast of misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:521:12: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:521:12: runtime error: load of misaligned address 0x00010dbfa5d8 for type 'rocksdb::TableCache ', which requires 16 byte alignment 0x00010dbfa5d8: note: pointer points here 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 ^ db/version_set.cc:522:9: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:522:9: runtime error: reference binding to misaligned address 0x00010dbfa5e8 for type 'const rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ db/version_set.cc:522:24: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:522:38: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:522:57: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:522:57: runtime error: load of misaligned address 0x00010dbfa678 for type 'rocksdb::RangeDelAggregator ', which requires 16 byte alignment 0x00010dbfa678: note: pointer points here 01 00 00 00 d0 a1 bf 0d 01 00 00 00 00 00 00 00 00 00 00 00 f8 db 70 0a 01 00 00 00 00 00 00 00 ^ db/version_set.cc:523:54: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:523:54: runtime error: load of misaligned address 0x00010dbfa668 for type 'rocksdb::HistogramImpl ', which requires 16 byte alignment 0x00010dbfa668: note: pointer points here 01 00 00 00 c8 88 a5 0d 01 00 00 00 00 00 00 00 01 00 00 00 d0 a1 bf 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:524:9: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:524:47: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:524:62: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/table_cache.cc:228:33: runtime error: reference binding to misaligned address 0x00010dbfa5e8 for type 'const rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ table/block_based_table_reader.cc:1554:41: runtime error: reference binding to misaligned address 0x00010dbfa5e8 for type 'const rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ table/block_based_table_reader.cc:1396:21: runtime error: reference binding to misaligned address 0x00010dbfa5e8 for type 'const rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ include/rocksdb/options.h:931:8: runtime error: reference binding to misaligned address 0x00010dbfa628 for type 'const std::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1584:13: runtime error: load of misaligned address 0x00010dbfa648 for type '__base const' (aka '__base<void ()> const'), which requires 16 byte alignment 0x00010dbfa648: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c8 a5 97 0d 01 00 00 00 38 36 9b 0d ^ table/block_based_table_reader.cc:1555:24: runtime error: reference binding to misaligned address 0x00010dbfa5e8 for type 'const rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ db/table_cache.cc:244:54: runtime error: load of misaligned address 0x00010dbfa618 for type 'const bool', which requires 16 byte alignment 0x00010dbfa618: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ db/table_cache.cc:246:49: runtime error: reference binding to misaligned address 0x00010dbfa5e8 for type 'const rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ db/version_set.cc:532:12: runtime error: member access within misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ db/version_set.cc:532:12: runtime error: member access within misaligned address 0x00010dbfa5e8 for type 'const rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ db/version_set.cc:532:26: runtime error: load of misaligned address 0x00010dbfa5f8 for type 'const rocksdb::Slice const', which requires 16 byte alignment 0x00010dbfa5f8: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ version_set.cc:493: runtime error: member call on misaligned address 0x00010dbfa5c8 for type 'rocksdb::(anonymous namespace)::LevelFileIteratorState', which requires 16 byte alignment 0x00010dbfa5c8: note: pointer points here 00 00 00 00 a0 db 70 0a 01 00 00 00 00 00 00 00 00 00 00 00 90 14 98 0d 01 00 00 00 00 00 00 00 ^ version_set.cc:493: runtime error: member call on misaligned address 0x00010dbfa5e8 for type 'rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ options.h:931: runtime error: member call on misaligned address 0x00010dbfa5e8 for type 'rocksdb::ReadOptions', which requires 16 byte alignment 0x00010dbfa5e8: note: pointer points here 00 00 00 00 01 01 ff ff ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ options.h:931: runtime error: member call on misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ functional:1765: runtime error: member call on misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1766:9: runtime error: member access within misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1766:9: runtime error: load of misaligned address 0x00010dbfa648 for type '__base ' (aka '__base<void ()> '), which requires 16 byte alignment 0x00010dbfa648: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c8 a5 97 0d 01 00 00 00 38 36 9b 0d ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1766:27: runtime error: member access within misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1768:14: runtime error: member access within misaligned address 0x00010dbfa628 for type 'std::__1::function<void ()>', which requires 16 byte alignment 0x00010dbfa628: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/functional:1768:14: runtime error: load of misaligned address 0x00010dbfa648 for type '__base ' (aka '__base<void ()> '), which requires 16 byte alignment 0x00010dbfa648: note: pointer points here 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c8 a5 97 0d 01 00 00 00 38 36 9b 0d ^ [ OK ] DBPropertiesTest.ReadLatencyHistogramByLevel (1599 ms) [----------] 1 test from DBPropertiesTest (1599 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test case ran. (1599 ms total) [ PASSED ] 1 test. ``` So it seems the root cause is that the internal implementation of `std::function` on macOS (and perhaps with libc++ generally?) requires 16-byte aligned memory, but the arena allocator only guarantees that the returned memory will be `sizeof(void)` aligned, which is only 8-byte alignment on my machine. This patch solves the problem by adjusting the allocator to derive the necessary alignment from `alignof(std::max_align_t)`, which is properly 16 bytes on my machine. As I mentioned in #2265, none of RocksDB's tests will cause this unaligned access to actually abort the process, but, on macOS, linking CockroachDB against a version of RocksDB with the above patch and letting it run for just a few seconds will cause a SIGABRT. ``` Process 19792 stopped thread #2, stop reason = EXC_BAD_ACCESS (code=EXC_I386_GPFLT) frame #0: 0x0000000004f5e78f cockroach`DBNewIter + 95 cockroach`DBNewIter: -> 0x4f5e78f <+95>: callq 0x28(%rax) 0x4f5e792 <+98>: jmp 0x4f5e79e ; <+110> 0x4f5e794 <+100>: movq -0x50(%rbp), %rcx 0x4f5e798 <+104>: movq %rax, %rdi (lldb) bt thread #2, stop reason = EXC_BAD_ACCESS (code=EXC_I386_GPFLT) * frame #0: 0x0000000004f5e78f cockroach`DBNewIter + 95 ``` I'd get you a backtrace, but [Go doesn't include cgo debug information on macOS](https://github.com/golang/go/issues/6942). I've also tried building against libc++ on Linux, where debug information would be available, but I can't seem to trigger the bug there. In any case, this PR both fixes the segfault in CockroachDB and fixes the warnings reported by ubsan. Closes https://github.com/facebook/rocksdb/pull/2347 Differential Revision: D5108596 Pulled By: yiwu-arbug fbshipit-source-id: bd5e4323b2ce915ed4fe78e123cb8996aec75a00		7 years ago
buckifier	rocksdb: make buildable on aarch64	7 years ago
build_tools	fix lite build	7 years ago
cache	Add -DPORTABLE=1 to MSVC CI build	7 years ago
cmake	CMake: Add support for CMake packages	7 years ago
coverage	Fix /bin/bash shebangs	7 years ago
db	arena: derive alignment unit from std::max_align_t	7 years ago
docs	Blog post for 5.8 release	7 years ago
env	Repair DBs with trailing slash in name	7 years ago
examples	Pinnableslice examples and blog post	7 years ago
hdfs	Revert "comment out unused parameters"	8 years ago
include/rocksdb	Move ~Comparator define to comparator.h	7 years ago
java	Add OptionsUtil class to java/CMakeLists.txt	7 years ago
memtable	Added CPU prefetch for skiplist	7 years ago
monitoring	Use RAII instead of pointers in cf_info_map	7 years ago
options	fix lite build	7 years ago
port	Fix MinGW build	7 years ago
table	print more table_options to info log	7 years ago
third-party	Revert "comment out unused parameters"	8 years ago
tools	db_bench randomtransaction print throughput	7 years ago
util	arena: derive alignment unit from std::max_align_t	7 years ago
utilities	Blob DB: Move BlobFile definition to a separate file	7 years ago
.clang-format	A script that automatically reformat affected lines	11 years ago
.gitignore	Remove leftover references to phutil_module_cache	7 years ago
.travis.yml	fix lite build	7 years ago
AUTHORS	Add AUTHORS file. Fix #203	10 years ago
CMakeLists.txt	PinnableSlice move assignment	7 years ago
CONTRIBUTING.md	Remove the licensing description in CONTRIBUTING.md	8 years ago
COPYING	Add GPLv2 as an alternative license.	8 years ago
DEFAULT_OPTIONS_HISTORY.md	options.delayed_write_rate use the rate of rate_limiter by default.	8 years ago
DUMP_FORMAT.md	First version of rocksdb_dump and rocksdb_undump.	10 years ago
HISTORY.md	rate limit auto-tuning	7 years ago
INSTALL.md	Default one to rocksdb:x64-windows	7 years ago
LANGUAGE-BINDINGS.md	add Erlang to the list of language bindings	7 years ago
LICENSE.Apache	Change RocksDB License	8 years ago
LICENSE.leveldb	Add back the LevelDB license file	8 years ago
Makefile	PinnableSlice move assignment	7 years ago
README.md	Appveyor badge to show master branch	9 years ago
ROCKSDB_LITE.md	Optimistic Transactions	10 years ago
TARGETS	PinnableSlice move assignment	7 years ago
USERS.md	Add LogDevice to USERS.md	7 years ago
Vagrantfile	Update Vagrant file (test internal phabricator workflow)	8 years ago
WINDOWS_PORT.md	Commit both PR and internal code review changes	10 years ago
appveyor.yml	Add -DPORTABLE=1 to MSVC CI build	7 years ago
issue_template.md	Add a template for issues	7 years ago
src.mk	PinnableSlice move assignment	7 years ago
thirdparty.inc	Introduce XPRESS compresssion on Windows. (#1081 )	9 years ago

README.md

RocksDB: A Persistent Key-Value Store for Flash and RAM Storage

RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)

This code is a library that forms the core building block for a fast key value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it specially suitable for storing multiple terabytes of data in a single database.

Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples

See the github wiki for more explanation.

The public interface is in include/. Callers should not include or rely on the details of any other header files in this package. Those internal APIs may be changed without warning.

Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/