A library that provides an embeddable, persistent key-value store for fast storage.
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Jim Paton 74781a0c49 Add three new MemTableRep's
Summary:
This patch adds three new MemTableRep's: UnsortedRep, PrefixHashRep, and VectorRep.

UnsortedRep stores keys in an std::unordered_map of std::sets. When an iterator is requested, it dumps the keys into an std::set and iterates over that.

VectorRep stores keys in an std::vector. When an iterator is requested, it creates a copy of the vector and sorts it using std::sort. The iterator accesses that new vector.

PrefixHashRep stores keys in an unordered_map mapping prefixes to ordered sets.

I also added one API change. I added a function MemTableRep::MarkImmutable. This function is called when the rep is added to the immutable list. It doesn't do anything yet, but it seems like that could be useful. In particular, for the vectorrep, it means we could elide the extra copy and just sort in place. The only reason I haven't done that yet is because the use of the ArenaAllocator complicates things (I can elaborate on this if needed).

Test Plan:
make -j32 check
./db_stress --memtablerep=vector
./db_stress --memtablerep=unsorted
./db_stress --memtablerep=prefixhash --prefix_size=10

Reviewers: dhruba, haobo, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12117
2013-08-22 23:10:02 -07:00
build_tools Do not use relative paths in build system 2013-08-22 14:53:51 -07:00
coverage Fix the gcov/lcov related issues 2013-08-22 17:01:06 -07:00
db Add three new MemTableRep's 2013-08-22 23:10:02 -07:00
doc merge 1.5 2012-08-28 11:43:33 -07:00
hdfs Ability to configure bufferedio-reads, filesystem-readaheads and mmap-read-write per database. 2013-03-20 23:14:03 -07:00
helpers/memenv [RocksDB] cleanup EnvOptions 2013-06-12 11:17:19 -07:00
include Add three new MemTableRep's 2013-08-22 23:10:02 -07:00
java Pom changes to make relase 1.5.7 for java. 2013-01-10 10:43:43 -08:00
linters/src fixing linters. 2012-12-14 14:05:27 -08:00
port Fix Zlib_Compress and Zlib_Uncompress 2013-06-18 16:57:42 -07:00
scribe fix db_test error with scribe logger turned on 2012-08-28 11:22:58 -07:00
snappy Build with gcc-4.7.1-glibc-2.14.1. 2012-09-17 10:56:26 -07:00
table Add three new MemTableRep's 2013-08-22 23:10:02 -07:00
thrift Implement RowLocks for assoc schema 2012-10-03 23:19:01 -07:00
tools Add three new MemTableRep's 2013-08-22 23:10:02 -07:00
util Add three new MemTableRep's 2013-08-22 23:10:02 -07:00
utilities Made merge_oprator a shared_ptr; and added TTL unit tests 2013-08-20 13:35:28 -07:00
.arcconfig Enable linting in arc. 2013-02-01 11:34:25 -08:00
.gitignore Clean up the Makefile and the build scripts 2013-08-15 12:59:45 -07:00
LICENSE reverting disastrous MOE commit, returning to r21 2011-04-19 23:11:15 +00:00
Makefile Fix the gcov/lcov related issues 2013-08-22 17:01:06 -07:00
README Fix README contents. 2013-07-30 08:30:13 -07:00
README.fb Updating readme to 2.1 2013-08-06 14:43:16 -07:00

rocksdb: A persistent key-value store for flash storage
Authors: * The Facebook Database Engineering Team
         * Build 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 an Log-Stuctured-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.

The core of this code has been derived from open-source leveldb.

The code under this directory implements a system for maintaining a
persistent key/value store.

See doc/index.html for more explanation.
See doc/impl.html for a brief overview of the implementation.

The public interface is in include/*.h.  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.

Guide to header files:

include/db.h
    Main interface to the DB: Start here

include/options.h
    Control over the behavior of an entire database, and also
    control over the behavior of individual reads and writes.

include/comparator.h
    Abstraction for user-specified comparison function.  If you want
    just bytewise comparison of keys, you can use the default comparator,
    but clients can write their own comparator implementations if they
    want custom ordering (e.g. to handle different character
    encodings, etc.)

include/iterator.h
    Interface for iterating over data. You can get an iterator
    from a DB object.

include/write_batch.h
    Interface for atomically applying multiple updates to a database.

include/slice.h
    A simple module for maintaining a pointer and a length into some
    other byte array.

include/status.h
    Status is returned from many of the public interfaces and is used
    to report success and various kinds of errors.

include/env.h
    Abstraction of the OS environment.  A posix implementation of
    this interface is in util/env_posix.cc

include/table_builder.h
    Lower-level modules that most clients probably won't use directly

include/cache.h
    An API for the block cache.

include/compaction_filter.h
    An API for a application filter invoked on every compaction.

include/filter_policy.h
    An API for configuring a bloom filter.

include/memtablerep.h
    An API for implementing a memtable.

include/statistics.h
    An API to retrieve various database statistics.

include/transaction_log_iterator.h
    An API to retrieve transaction logs from a database.