A library that provides an embeddable, persistent key-value store for fast storage.
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Dhruba Borthakur 9b87a2bae8 Avoid doing a exhaustive search when looking for overlapping files.
Summary:
The Version::GetOverlappingInputs() is called multiple times in
the compaction code path. Eack invocation does a binary search
for overlapping files in the specified key range.
This patch remembers the offset of an overlapped file when
GetOverlappingInputs() is called the first time within
a compaction run. Suceeding calls to GetOverlappingInputs()
uses the remembered index to avoid the binary search.

I measured that 1000 iterations of GetOverlappingInputs
takes around 4500 microseconds without this patch. If I use
this patch with the hint on every invocation, then 1000
iterations take about 3900 microsecond.

Test Plan: make check OPT=-g

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6513
2012-11-07 11:47:17 -08:00
db Avoid doing a exhaustive search when looking for overlapping files. 2012-11-07 11:47:17 -08:00
doc merge 1.5 2012-08-28 11:43:33 -07:00
hdfs Allow a configurable number of background threads. 2012-09-19 15:51:08 -07:00
helpers/memenv Fix all warnings generated by -Wall option to the compiler. 2012-11-06 14:07:31 -08:00
include/leveldb Ability to invoke application hook for every key during compaction. 2012-11-05 16:02:13 -08:00
java Add LevelDb's JNI wrapper 2012-10-05 13:13:49 -07:00
port Make compression options configurable. These include window-bits, level and strategy for ZlibCompression 2012-11-02 11:26:39 -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 Fix all warnings generated by -Wall option to the compiler. 2012-11-06 14:07:31 -08:00
thrift Implement RowLocks for assoc schema 2012-10-03 23:19:01 -07:00
tools Fix all warnings generated by -Wall option to the compiler. 2012-11-06 14:07:31 -08:00
util Fix all warnings generated by -Wall option to the compiler. 2012-11-06 14:07:31 -08:00
.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 Keep build_detect_platform portable 2012-10-26 14:20:04 -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.gcc471.sh Enable SSE when building with fbcode support. 2012-10-18 08:43:25 -07:00
LICENSE reverting disastrous MOE commit, returning to r21 2011-04-19 23:11:15 +00:00
Makefile Fix all warnings generated by -Wall option to the compiler. 2012-11-06 14:07:31 -08:00
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 Enable SSE when building with fbcode support. 2012-10-18 08:43:25 -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