description
A simple implementation of the CHD perfect hash algorithm.
Implemented in C++ with C interfaces. Templatized interfaces for 32-bit, 64-bit, and string keys.
Builds Lua module API with -DPHF_LUALIB.
news
2019-02-15
Fix Rabin-Miller witness limit typo which documented 2047 but actually used 2027. Harmless but confusing and wrong nonetheless.
Don't return 1 as prime, which is more conventional and makes it easier to compare output of the command-line utility -p mode with BSD primes(3) utility.
Tag rel-20190215 (74c77b2664f88489ab230588cf7c4ff7d92b5c1e).
2019-02-14
For non-trivial types like std::string don't use realloc. Fixes crashes with C++ standard libraries where std::string lacks trivial move construction semantics, leading to corrupt string object state. Memory management remains non-idiomatic to avoid too much duplicative code for the PHF_NO_LIBCXX=1 case.
Inline Valgrind suppression for CoreCrypto CSPRNG uninitialized value access. On macOS use of arc4random(3) in the command-line utility for the function generation seed indirectly tainted all the critical paths in PHF::init, causing Valgrind to emit copious but misleading warnings about those paths depending on uninitialized values.
Tag rel-20190214 (d649b6ae550793a63a1c6cfd58d78bcbc5ba0918).
2014-11-20
Public release.
usage
From C++: PHF::init and PHF:hash.
From C: phf_init_uint32, phf_init_uin64, and phf_init_string. With a C11 or GCC-compatible compiler phf_init works like PHF::init in C++.
From Lua: phf.new, and the return value is the hash function.
license
Copyright (c) 2014-2015, 2019 William Ahern
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
source
git clone http://25thandClement.com/~william/projects/phf.git