pcsx2/3rdparty/google/dense_hash_map

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// Copyright (c) 2005, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// ----
// Author: Craig Silverstein
//
// This is just a very thin wrapper over densehashtable.h, just
// like sgi stl's stl_hash_map is a very thin wrapper over
// stl_hashtable. The major thing we define is operator[], because
// we have a concept of a data_type which stl_hashtable doesn't
// (it only has a key and a value).
//
// NOTE: this is exactly like sparse_hash_map.h, with the word
// "sparse" replaced by "dense", except for the addition of
// set_empty_key().
//
// YOU MUST CALL SET_EMPTY_KEY() IMMEDIATELY AFTER CONSTRUCTION.
//
// Otherwise your program will die in mysterious ways.
//
// In other respects, we adhere mostly to the STL semantics for
// hash-map. One important exception is that insert() invalidates
// iterators entirely. On the plus side, though, erase() doesn't
// invalidate iterators at all, or even change the ordering of elements.
//
// Here are a few "power user" tips:
//
// 1) set_deleted_key():
// If you want to use erase() you must call set_deleted_key(),
// in addition to set_empty_key(), after construction.
// The deleted and empty keys must differ.
//
// 2) resize(0):
// When an item is deleted, its memory isn't freed right
// away. This allows you to iterate over a hashtable,
// and call erase(), without invalidating the iterator.
// To force the memory to be freed, call resize(0).
//
// 3) set_resizing_parameters(0.0, 0.8):
// Setting the shrink_resize_percent to 0.0 guarantees
// that the hash table will never shrink.
//
// Guide to what kind of hash_map to use:
// (1) dense_hash_map: fastest, uses the most memory
// (2) sparse_hash_map: slowest, uses the least memory
// (3) hash_map (STL): in the middle
// Typically I use sparse_hash_map when I care about space and/or when
// I need to save the hashtable on disk. I use hash_map otherwise. I
// don't personally use dense_hash_map ever; the only use of
// dense_hash_map I know of is to work around malloc() bugs in some
// systems (dense_hash_map has a particularly simple allocation scheme).
//
// - dense_hash_map has, typically, a factor of 2 memory overhead (if your
// data takes up X bytes, the hash_map uses X more bytes in overhead).
// - sparse_hash_map has about 2 bits overhead per entry.
// - sparse_hash_map can be 3-7 times slower than the others for lookup and,
// especially, inserts. See time_hash_map.cc for details.
//
// See /usr/(local/)?doc/sparsehash-0.1/dense_hash_map.html
// for information about how to use this class.
#ifndef _DENSE_HASH_MAP_H_
#define _DENSE_HASH_MAP_H_
#include <google/sparsehash/sparseconfig.h>
#include <stdio.h> // for FILE * in read()/write()
#include <algorithm> // for the default template args
#include <functional> // for equal_to
#include <memory> // for alloc<>
#include <utility> // for pair<>
#include HASH_FUN_H // defined in config.h
#include <google/sparsehash/densehashtable.h>
_START_GOOGLE_NAMESPACE_
using STL_NAMESPACE::pair;
template <class Key, class T,
class HashFcn = SPARSEHASH_HASH<Key>, // defined in sparseconfig.h
class EqualKey = STL_NAMESPACE::equal_to<Key>,
class Alloc = STL_NAMESPACE::allocator<T> >
class dense_hash_map {
private:
// Apparently select1st is not stl-standard, so we define our own
struct SelectKey {
const Key& operator()(const pair<const Key, T>& p) const {
return p.first;
}
};
// The actual data
typedef dense_hashtable<pair<const Key, T>, Key, HashFcn,
SelectKey, EqualKey, Alloc> ht;
ht rep;
public:
typedef typename ht::key_type key_type;
typedef T data_type;
typedef T mapped_type;
typedef typename ht::value_type value_type;
typedef typename ht::hasher hasher;
typedef typename ht::key_equal key_equal;
typedef typename ht::size_type size_type;
typedef typename ht::difference_type difference_type;
typedef typename ht::pointer pointer;
typedef typename ht::const_pointer const_pointer;
typedef typename ht::reference reference;
typedef typename ht::const_reference const_reference;
typedef typename ht::iterator iterator;
typedef typename ht::const_iterator const_iterator;
// Iterator functions
iterator begin() { return rep.begin(); }
iterator end() { return rep.end(); }
const_iterator begin() const { return rep.begin(); }
const_iterator end() const { return rep.end(); }
// Accessor functions
hasher hash_funct() const { return rep.hash_funct(); }
key_equal key_eq() const { return rep.key_eq(); }
// Constructors
explicit dense_hash_map(size_type expected_max_items_in_table = 0,
const hasher& hf = hasher(),
const key_equal& eql = key_equal())
: rep(expected_max_items_in_table, hf, eql) { }
template <class InputIterator>
dense_hash_map(InputIterator f, InputIterator l,
size_type expected_max_items_in_table = 0,
const hasher& hf = hasher(),
const key_equal& eql = key_equal())
: rep(expected_max_items_in_table, hf, eql) {
rep.insert(f, l);
}
// We use the default copy constructor
// We use the default operator=()
// We use the default destructor
void clear() { rep.clear(); }
// This clears the hash map without resizing it down to the minimum
// bucket count, but rather keeps the number of buckets constant
void clear_no_resize() { rep.clear_no_resize(); }
void swap(dense_hash_map& hs) { rep.swap(hs.rep); }
// Functions concerning size
size_type size() const { return rep.size(); }
size_type max_size() const { return rep.max_size(); }
bool empty() const { return rep.empty(); }
size_type bucket_count() const { return rep.bucket_count(); }
size_type max_bucket_count() const { return rep.max_bucket_count(); }
void resize(size_type hint) { rep.resize(hint); }
void set_resizing_parameters(float shrink, float grow) {
return rep.set_resizing_parameters(shrink, grow);
}
// Lookup routines
iterator find(const key_type& key) { return rep.find(key); }
const_iterator find(const key_type& key) const { return rep.find(key); }
data_type& operator[](const key_type& key) { // This is our value-add!
iterator it = find(key);
if (it != end()) {
return it->second;
} else {
return insert(value_type(key, data_type())).first->second;
}
}
size_type count(const key_type& key) const { return rep.count(key); }
pair<iterator, iterator> equal_range(const key_type& key) {
return rep.equal_range(key);
}
pair<const_iterator, const_iterator> equal_range(const key_type& key) const {
return rep.equal_range(key);
}
// Insertion routines
pair<iterator, bool> insert(const value_type& obj) { return rep.insert(obj); }
template <class InputIterator>
void insert(InputIterator f, InputIterator l) { rep.insert(f, l); }
void insert(const_iterator f, const_iterator l) { rep.insert(f, l); }
// required for std::insert_iterator; the passed-in iterator is ignored
iterator insert(iterator, const value_type& obj) { return insert(obj).first; }
// Deletion and empty routines
// THESE ARE NON-STANDARD! I make you specify an "impossible" key
// value to identify deleted and empty buckets. You can change the
// deleted key as time goes on, or get rid of it entirely to be insert-only.
void set_empty_key(const key_type& key) { // YOU MUST CALL THIS!
rep.set_empty_key(value_type(key, data_type())); // rep wants a value
}
void set_deleted_key(const key_type& key) {
rep.set_deleted_key(value_type(key, data_type())); // rep wants a value
}
void clear_deleted_key() { rep.clear_deleted_key(); }
// These are standard
size_type erase(const key_type& key) { return rep.erase(key); }
void erase(iterator it) { rep.erase(it); }
void erase(iterator f, iterator l) { rep.erase(f, l); }
// Comparison
bool operator==(const dense_hash_map& hs) const { return rep == hs.rep; }
bool operator!=(const dense_hash_map& hs) const { return rep != hs.rep; }
// I/O -- this is an add-on for writing metainformation to disk
bool write_metadata(FILE *fp) { return rep.write_metadata(fp); }
bool read_metadata(FILE *fp) { return rep.read_metadata(fp); }
bool write_nopointer_data(FILE *fp) { return rep.write_nopointer_data(fp); }
bool read_nopointer_data(FILE *fp) { return rep.read_nopointer_data(fp); }
};
// We need a global swap as well
template <class Key, class T, class HashFcn, class EqualKey, class Alloc>
inline void swap(dense_hash_map<Key, T, HashFcn, EqualKey, Alloc>& hm1,
dense_hash_map<Key, T, HashFcn, EqualKey, Alloc>& hm2) {
hm1.swap(hm2);
}
_END_GOOGLE_NAMESPACE_
#endif /* _DENSE_HASH_MAP_H_ */