rocksdb

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

Peter (Stig) Edwards 043cb62d63 Fix record_size in log_write_bench, swap args to std::string::assign. (#1373 ) Hello and thank you for RocksDB, I noticed when using log_write_bench that writes were always 88 bytes: > strace -e trace=write ./log_write_bench -num_records 2 2>&1 \| head -n 2 write(3, "\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371"..., 88) = 88 write(3, "\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371\371"..., 88) = 88 > strace -e trace=write ./log_write_bench -record_size 4096 -num_records 2 2>&1 \| head -n 2 write(3, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 88) = 88 write(3, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 88) = 88 I think this should be: << record.assign('X', FLAGS_record_size); >> record.assign(FLAGS_record_size, 'X'); So fill and not buffer. Otherwise I always see writes of size 88 (the decimal value for chr "X"). string& assign (const char* s, size_t n); buffer - Copies the first n characters from the array of characters pointed by s. string& assign (size_t n, char c); fill - Replaces the current value by n consecutive copies of character c. perl -le 'print ord "X"' 88 With the change: > strace -e trace=write ./log_write_bench -record_size 4096 -num_records 2 2>&1 \| head -n 2 write(3, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"..., 4096) = 4096 write(3, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"..., 4096) = 4096 > strace -e trace=write ./log_write_bench -num_records 2 2>&1 \| head -n 2 write(3, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"..., 249) = 249 write(3, "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"..., 249) = 249 Thanks. `01c27be5fb` https://reviews.facebook.net/D16239		8 years ago
arcanist_util	Retry getting arcanist token on failure	8 years ago
build_tools	Support ZSTD with finalized format	8 years ago
cmake/modules	cmake support for linux and osx (#1358 )	8 years ago
coverage	Fix coverage script	10 years ago
db	Support SST files with Global sequence numbers	8 years ago
docs	"Recent Posts" -> "All Posts"	8 years ago
examples	Fix typo (#903 )	8 years ago
hdfs	Fix bug in UnScSigned-off-by: xh931076284 <931076284@qq.com> (#1336 )	8 years ago
include/rocksdb	env_mirror: fix a few leaks (#1363 )	8 years ago
java	Minor fixes around Windows 64 Java Artifacts (#1366 )	8 years ago
memtable	Add SeekForPrev() to Iterator	8 years ago
port	Add NoSpace subcode to IOError (#1320 )	8 years ago
table	Support SST files with Global sequence numbers	8 years ago
third-party	Fix clang analyzer errors	8 years ago
tools	cmake support for linux and osx (#1358 )	8 years ago
util	Fix record_size in log_write_bench, swap args to std::string::assign. (#1373 )	8 years ago
utilities	Support SST files with Global sequence numbers	8 years ago
.arcconfig	Integrate Jenkins with Phabricator	10 years ago
.clang-format	A script that automatically reformat affected lines	11 years ago
.gitignore	Experiments on column-aware encodings	8 years ago
.travis.yml	Fix travis	8 years ago
AUTHORS	Add AUTHORS file. Fix #203	10 years ago
CMakeLists.txt	cmake support for linux and osx (#1358 )	8 years ago
CONTRIBUTING.md	facebook accounts are not required for CLA signers	10 years ago
DEFAULT_OPTIONS_HISTORY.md	Release RocksDB 4.8.0	9 years ago
DUMP_FORMAT.md	First version of rocksdb_dump and rocksdb_undump.	10 years ago
HISTORY.md	DB::GetOptions() reflect dynamic changed options	8 years ago
INSTALL.md	Simple changes to support builds for ppc64[le] consistent with X86	9 years ago
LANGUAGE-BINDINGS.md	Update LANGUAGE-BINDINGS.md	8 years ago
LICENSE	Updated all copyright headers to the new format.	9 years ago
Makefile	Minor fixes around Windows 64 Java Artifacts (#1366 )	8 years ago
PATENTS	Update Patent Grant.	10 years ago
README.md	Appveyor badge to show master branch	8 years ago
ROCKSDB_LITE.md	Optimistic Transactions	10 years ago
USERS.md	Adding Dgraph to list of Users (#1291 )	8 years ago
Vagrantfile	RocksDB on FreeBSD support	10 years ago
WINDOWS_PORT.md	Commit both PR and internal code review changes	9 years ago
appveyor.yml	fix vs generator (#1269 )	8 years ago
src.mk	Add Java API for SstFileWriter	8 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/