A library that provides an embeddable, persistent key-value store for fast storage.
e5fe80e4e3
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 |
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db | ||
doc | ||
hdfs | ||
helpers/memenv | ||
include/leveldb | ||
port | ||
scribe | ||
snappy | ||
table | ||
thrift | ||
tools | ||
util | ||
.arcconfig | ||
.gitignore | ||
AUTHORS | ||
build_detect_platform | ||
build_detect_version | ||
fbcode.sh | ||
LICENSE | ||
Makefile | ||
NEWS | ||
README | ||
README.fb | ||
TODO |
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