Pre-release comments.
This commit is contained in:
parent
0d7a176458
commit
cc42ab3b74
14
README
14
README
@ -84,6 +84,18 @@ The CMPH Library encapsulates the newest and more efficient algorithms in an eas
|
|||||||
----------------------------------------
|
----------------------------------------
|
||||||
|
|
||||||
|
|
||||||
|
News for version 2.0
|
||||||
|
====================
|
||||||
|
|
||||||
|
Cleaned up most warnings for the c code.
|
||||||
|
|
||||||
|
Experimental C++ interface (--enable-cxxmph) implementing the BDZ algorithm in
|
||||||
|
a convenient SimpleMPHIndex interface, which serves as the basis
|
||||||
|
for drop-in replacements for std::unordered_map, sparsehash::sparse_hash_map
|
||||||
|
and sparsehash::dense_hash_map. Faster lookup time at the expense of insertion
|
||||||
|
time. See cxxmpph/mph_map.h and cxxmph/mph_index.h for details.
|
||||||
|
|
||||||
|
|
||||||
News for version 1.1
|
News for version 1.1
|
||||||
====================
|
====================
|
||||||
|
|
||||||
@ -310,5 +322,5 @@ Fabiano Cupertino Botelho (fc_botelho@users.sourceforge.net)
|
|||||||
|
|
||||||
Nivio Ziviani (nivio@dcc.ufmg.br)
|
Nivio Ziviani (nivio@dcc.ufmg.br)
|
||||||
|
|
||||||
Last Updated: Fri Jun 1 19:04:40 2012
|
Last Updated: Sun Jun 3 04:09:55 2012
|
||||||
|
|
||||||
|
10
README.t2t
10
README.t2t
@ -88,6 +88,16 @@ The CMPH Library encapsulates the newest and more efficient algorithms in an eas
|
|||||||
|
|
||||||
----------------------------------------
|
----------------------------------------
|
||||||
|
|
||||||
|
==News for version 2.0==
|
||||||
|
|
||||||
|
Cleaned up most warnings for the c code.
|
||||||
|
|
||||||
|
Experimental C++ interface (--enable-cxxmph) implementing the BDZ algorithm in
|
||||||
|
a convenient interface, which serves as the basis
|
||||||
|
for drop-in replacements for std::unordered_map, sparsehash::sparse_hash_map
|
||||||
|
and sparsehash::dense_hash_map. Potentially faster lookup time at the expense
|
||||||
|
of insertion time. See cxxmpph/mph_map.h and cxxmph/mph_index.h for details.
|
||||||
|
|
||||||
==News for version 1.1==
|
==News for version 1.1==
|
||||||
|
|
||||||
Fixed a bug in the chd_pc algorithm and reorganized tests.
|
Fixed a bug in the chd_pc algorithm and reorganized tests.
|
||||||
|
@ -10,16 +10,12 @@
|
|||||||
// This is a pretty uncommon data structure, and if you application has a real
|
// This is a pretty uncommon data structure, and if you application has a real
|
||||||
// use case for it, chances are that it is a real win. If all you are doing is
|
// use case for it, chances are that it is a real win. If all you are doing is
|
||||||
// a straightforward implementation of an in-memory associative mapping data
|
// a straightforward implementation of an in-memory associative mapping data
|
||||||
// structure, then it will probably be slower, since that the
|
// structure, then it will probably be slower. Take a look at mph_map.h
|
||||||
// evaluation of index() is typically slower than the total cost of running a
|
|
||||||
// traditional hash function over a key and doing 2-3 conflict resolutions on
|
|
||||||
// 100byte-ish strings. If you still want to do, take a look at mph_map.h
|
|
||||||
// instead.
|
// instead.
|
||||||
//
|
//
|
||||||
// Thesis presenting this and similar algorithms:
|
// Thesis presenting this and similar algorithms:
|
||||||
// http://homepages.dcc.ufmg.br/~fbotelho/en/talks/thesis2008/thesis.pdf
|
// http://homepages.dcc.ufmg.br/~fbotelho/en/talks/thesis2008/thesis.pdf
|
||||||
//
|
//
|
||||||
//
|
|
||||||
// Notes:
|
// Notes:
|
||||||
//
|
//
|
||||||
// Most users can use the SimpleMPHIndex wrapper instead of the MPHIndex which
|
// Most users can use the SimpleMPHIndex wrapper instead of the MPHIndex which
|
||||||
|
@ -3,15 +3,25 @@
|
|||||||
// Implementation of the unordered associative mapping interface using a
|
// Implementation of the unordered associative mapping interface using a
|
||||||
// minimal perfect hash function.
|
// minimal perfect hash function.
|
||||||
//
|
//
|
||||||
// This class not necessarily faster than unordered_map (or ext/hash_map).
|
// Since these are header-mostly libraries, make sure you compile your code
|
||||||
// Benchmark your code before using it. If you do not call rehash() before
|
// with -DNDEBUG and -O3. The code requires a modern C++11 compiler.
|
||||||
// starting your reads, it will be very likely slower than unordered_map.
|
//
|
||||||
|
// The container comes in 3 flavors, all in the cxxmph namespace and drop-in
|
||||||
|
// replacement for the popular classes with the same names.
|
||||||
|
// * dense_hash_map
|
||||||
|
// -> fast, uses more memory, 2.93 bits per bucket, ~50% occupation
|
||||||
|
// * unordered_map (aliases: hash_map, mph_map)
|
||||||
|
// -> middle ground, uses 2.93 bits per bucket, ~81% occupation
|
||||||
|
// * sparse_hash_map -> slower, uses 3.6 bits per bucket
|
||||||
|
// -> less fast, uses 3.6 bits per bucket, 100% occupation
|
||||||
|
//
|
||||||
|
// Those classes are not necessarily faster than their existing counterparts.
|
||||||
|
// Benchmark your code before using it. The larger the key, the larger the
|
||||||
|
// number of elements inserted, and the bigger the number of failed searches,
|
||||||
|
// the more likely those classes will outperform existing code.
|
||||||
//
|
//
|
||||||
// For large sets of urls (>100k), which are a somewhat expensive to compare, I
|
// For large sets of urls (>100k), which are a somewhat expensive to compare, I
|
||||||
// found this class to be about 10%-30% faster than unordered_map.
|
// found those class to be about 10%-50% faster than unordered_map.
|
||||||
//
|
|
||||||
// The space overhead of this map is 2.6 bits per bucket and it achieves 100%
|
|
||||||
// occupation with a rehash call.
|
|
||||||
|
|
||||||
#include <algorithm>
|
#include <algorithm>
|
||||||
#include <iostream>
|
#include <iostream>
|
||||||
|
Loading…
Reference in New Issue
Block a user