Note to existing users: the iterator implementation has changed significantly
since we introduced the
locked_table in this
Please see the
information and examples of how to use iterators.
libcuckoo provides a high-performance, compact hash table that allows multiple concurrent reader and writer threads.
The Doxygen-generated documentation is available at the project page.
Authors: Manu Goyal, Bin Fan, Xiaozhou Li, David G. Andersen, and Michael Kaminsky
For details about this algorithm and citations, please refer to our papers in NSDI 2013 and EuroSys 2014. Some of the details of the hashing algorithm have been improved since that work (e.g., the previous algorithm in 1 serializes all writer threads, while our current implementation supports multiple concurrent writers), however, and this source code is now the definitive reference.
This library has been tested on Mac OSX >= 10.8 and Ubuntu >= 12.04.
It compiles with clang++ >= 3.3 and g++ >= 4.7, however we strongly suggest using the latest versions of both compilers, as they have greatly improved support for atomic operations. Building the library requires the autotools. Install them on Ubuntu
$ sudo apt-get update && sudo apt-get install build-essential autoconf libtool
$ autoreconf -fis $ ./configure $ make $ make install
To build a program with the hash table, include
libcuckoo/cuckoohash_map.hh into your source file. If you want to
use CityHash, which we recommend, we have provided a wrapper
compatible with the
std::hash type around it in the
libcuckoo/city_hasher.hh file. If compiling with CityHash, add the
-lcityhash flag. You must also enable C++11 features on your
compiler. Compiling the file
examples/count_freq.cc with g++
might look like this:
$ g++ -std=c++11 examples/count_freq.cc -lcityhash
The examples directory contains some simple demonstrations of some of the basic features of the hash table.
The tests directory
directory contains a number of tests and benchmarks of the hash table, which
also can serve as useful examples of how to use the table's various features.
make all, the entire test suite can be run with the
command. This will not run the benchmarks, which must be run individually. The
test executables, which have the suffix
.out, can be run individually as well.
Copyright (C) 2013, Carnegie Mellon University and Intel Corporation
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
CityHash (lib/city.h, lib/city.cc) is Copyright (c) Google, Inc. and has its own license, as detailed in the source files.