ladybird/AK/HashMap.h
Andreas Kling fdc782c1d1 Add a very naive block cache to the DiskBackedFileSystem.
This would be a lot better as an LRU. Right now it's a 32-slot
hash table with random eviction.
2018-10-25 12:36:50 +02:00

114 lines
2.5 KiB
C++

#pragma once
#include "HashTable.h"
#include "StdLib.h"
#include "kstdio.h"
namespace AK {
template<typename K, typename V>
class HashMap {
private:
struct Entry {
K key;
V value;
bool operator==(const Entry& other)
{
return key == other.key;
}
};
struct EntryTraits {
static unsigned hash(const Entry& entry) { return Traits<K>::hash(entry.key); }
static void dump(const Entry& entry)
{
kprintf("key=");
Traits<K>::dump(entry.key);
kprintf(" value=");
Traits<V>::dump(entry.value);
}
};
public:
HashMap() { }
HashMap(HashMap&& other)
: m_table(move(other.m_table))
{
}
HashMap& operator=(HashMap&& other)
{
if (this != &other) {
m_table = move(other.m_table);
}
return *this;
}
bool isEmpty() const { return m_table.isEmpty(); }
unsigned size() const { return m_table.size(); }
unsigned capacity() const { return m_table.capacity(); }
void clear() { m_table.clear(); }
void set(const K&, const V&);
void set(const K&, V&&);
void remove(const K&);
void removeOneRandomly() { m_table.remove(m_table.begin()); }
typedef HashTable<Entry, EntryTraits> HashTableType;
typedef typename HashTableType::Iterator IteratorType;
typedef typename HashTableType::ConstIterator ConstIteratorType;
IteratorType begin() { return m_table.begin(); }
IteratorType end() { return m_table.end(); }
IteratorType find(const K&);
ConstIteratorType begin() const { return m_table.begin(); }
ConstIteratorType end() const { return m_table.end(); }
ConstIteratorType find(const K&) const;
void dump() const { m_table.dump(); }
private:
HashTable<Entry, EntryTraits> m_table;
};
template<typename K, typename V>
void HashMap<K, V>::set(const K& key, V&& value)
{
m_table.set(Entry{key, move(value)});
}
template<typename K, typename V>
void HashMap<K, V>::set(const K& key, const V& value)
{
m_table.set(Entry{key, value});
}
template<typename K, typename V>
void HashMap<K, V>::remove(const K& key)
{
Entry dummy { key, V() };
m_table.remove(dummy);
}
template<typename K, typename V>
auto HashMap<K, V>::find(const K& key) -> IteratorType
{
Entry dummy { key, V() };
return m_table.find(dummy);
}
template<typename K, typename V>
auto HashMap<K, V>::find(const K& key) const -> ConstIteratorType
{
Entry dummy { key, V() };
return m_table.find(dummy);
}
}
using AK::HashMap;