mirror of
https://github.com/dart-lang/sdk
synced 2024-11-05 18:22:09 +00:00
109 lines
3.1 KiB
C++
109 lines
3.1 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
|
|
// for details. All rights reserved. Use of this source code is governed by a
|
|
// BSD-style license that can be found in the LICENSE file.
|
|
|
|
#ifndef RUNTIME_PLATFORM_HASHMAP_H_
|
|
#define RUNTIME_PLATFORM_HASHMAP_H_
|
|
|
|
#include "platform/globals.h"
|
|
|
|
namespace dart {
|
|
|
|
class HashMap {
|
|
public:
|
|
typedef bool (*MatchFun)(void* key1, void* key2);
|
|
|
|
typedef void (*ClearFun)(void* value);
|
|
|
|
// initial_capacity is the size of the initial hash map;
|
|
// it must be a power of 2 (and thus must not be 0).
|
|
HashMap(MatchFun match, uint32_t initial_capacity);
|
|
|
|
~HashMap();
|
|
|
|
static bool SamePointerValue(void* key1, void* key2) { return key1 == key2; }
|
|
|
|
static uint32_t StringHash(char* key) {
|
|
uint32_t hash_ = 0;
|
|
if (key == NULL) return hash_;
|
|
int len = strlen(key);
|
|
for (int i = 0; i < len; i++) {
|
|
hash_ += key[i];
|
|
hash_ += hash_ << 10;
|
|
hash_ ^= hash_ >> 6;
|
|
}
|
|
hash_ += hash_ << 3;
|
|
hash_ ^= hash_ >> 11;
|
|
hash_ += hash_ << 15;
|
|
return hash_ == 0 ? 1 : hash_;
|
|
}
|
|
|
|
static bool SameStringValue(void* key1, void* key2) {
|
|
return strcmp(reinterpret_cast<char*>(key1),
|
|
reinterpret_cast<char*>(key2)) == 0;
|
|
}
|
|
|
|
// HashMap entries are (key, value, hash) triplets.
|
|
// Some clients may not need to use the value slot
|
|
// (e.g. implementers of sets, where the key is the value).
|
|
struct Entry {
|
|
Entry() : key(NULL), value(NULL), hash(0) {}
|
|
void* key;
|
|
void* value;
|
|
uint32_t hash; // The full hash value for key.
|
|
};
|
|
|
|
// If an entry with matching key is found, Lookup()
|
|
// returns that entry. If no matching entry is found,
|
|
// but insert is set, a new entry is inserted with
|
|
// corresponding key, key hash, and NULL value.
|
|
// Otherwise, NULL is returned.
|
|
Entry* Lookup(void* key, uint32_t hash, bool insert);
|
|
|
|
// Removes the entry with matching key.
|
|
//
|
|
// WARNING: This method cannot be called while iterating a `HashMap`
|
|
// otherwise the iteration might step over elements!
|
|
void Remove(void* key, uint32_t hash);
|
|
|
|
// Empties the hash map (occupancy() == 0), and calls the function 'clear' on
|
|
// each of the values if given.
|
|
void Clear(ClearFun clear = NULL);
|
|
|
|
// The number of entries stored in the table.
|
|
intptr_t size() const { return occupancy_; }
|
|
|
|
// The capacity of the table. The implementation
|
|
// makes sure that occupancy is at most 80% of
|
|
// the table capacity.
|
|
intptr_t capacity() const { return capacity_; }
|
|
|
|
// Iteration
|
|
//
|
|
// for (Entry* p = map.Start(); p != NULL; p = map.Next(p)) {
|
|
// ...
|
|
// }
|
|
//
|
|
// If entries are inserted during iteration, the effect of
|
|
// calling Next() is undefined.
|
|
Entry* Start() const;
|
|
Entry* Next(Entry* p) const;
|
|
|
|
private:
|
|
MatchFun match_;
|
|
Entry* map_;
|
|
uint32_t capacity_;
|
|
uint32_t occupancy_;
|
|
|
|
Entry* map_end() const { return map_ + capacity_; }
|
|
Entry* Probe(void* key, uint32_t hash);
|
|
void Initialize(uint32_t capacity);
|
|
void Resize();
|
|
|
|
friend class IntSet; // From hashmap_test.cc
|
|
DISALLOW_COPY_AND_ASSIGN(HashMap);
|
|
};
|
|
|
|
} // namespace dart
|
|
|
|
#endif // RUNTIME_PLATFORM_HASHMAP_H_
|