A library that provides an embeddable, persistent key-value store for fast storage.
Go to file
Dhruba Borthakur e5fe80e4e3 The sharding of the block cache is limited to 2*20 pieces.
Summary:
The numbers of shards that the block cache is divided into is
configurable. However, if the user specifies that he/she wants
the block cache to be divided into more than 2**20 pieces, then
the system will rey to allocate a huge array of that size) that
could fail.

It is better to limit the sharding of the block cache to an
upper bound. The default sharding is 16 shards (i.e. 2**4)
and the maximum is now 2 million shards (i.e. 2**20).

Also, fixed a bug with the LRUCache where the numShardBits
should be a private member of the LRUCache object rather than
a static variable.

Test Plan:
run db_bench with --cache_numshardbits=64.

Task ID: #

Blame Rev:

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5013
2012-08-29 12:17:59 -07:00
db The sharding of the block cache is limited to 2*20 pieces. 2012-08-29 12:17:59 -07:00
doc merge 1.5 2012-08-28 11:43:33 -07:00
hdfs adding a scribe logger in leveldb to log leveldb deploy stats 2012-08-21 11:43:22 -07:00
helpers/memenv A number of fixes: 2011-10-31 17:22:06 +00:00
include/leveldb merge 1.5 2012-08-28 11:43:33 -07:00
port merge 1.5 2012-08-28 11:43:33 -07:00
scribe fix db_test error with scribe logger turned on 2012-08-28 11:22:58 -07:00
snappy Checkin pre-compiled snappy libraries for leveldb. 2012-08-01 16:55:39 -07:00
table add bzip2 compression 2012-06-29 10:27:28 -07:00
thrift Expose new configration variables via the thrift api 2012-08-17 10:29:12 -07:00
tools number to read is not resepected 2012-08-24 18:29:40 -07:00
util The sharding of the block cache is limited to 2*20 pieces. 2012-08-29 12:17:59 -07:00
.arcconfig Support arcdiff. 2012-05-09 23:35:05 -07:00
.gitignore Added bloom filter support. 2012-04-17 08:36:46 -07:00
AUTHORS reverting disastrous MOE commit, returning to r21 2011-04-19 23:11:15 +00:00
build_detect_platform merge 1.5 2012-08-28 11:43:33 -07:00
build_detect_version Record the version of the source repository that was used to build the leveldb library. 2012-08-24 15:18:43 -07:00
fbcode.sh adding a scribe logger in leveldb to log leveldb deploy stats 2012-08-21 11:43:22 -07:00
LICENSE reverting disastrous MOE commit, returning to r21 2011-04-19 23:11:15 +00:00
Makefile merge 1.5 2012-08-28 11:43:33 -07:00
NEWS sync with upstream @ 21409451 2011-05-21 02:17:43 +00:00
README @20776309 2011-04-20 22:48:11 +00:00
README.fb Make leveldb server not exit immediately. 2012-08-03 01:00:35 -07:00
TODO A number of smaller fixes and performance improvements: 2011-06-22 02:36:45 +00:00

leveldb: A key-value store
Authors: Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)

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