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// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include "cache.h"
#include "lrucache_map.hpp"
namespace vespalib {
template< typename P >
cache<P> &
cache<P>::maxElements(size_t elems) {
Lru::maxElements(elems);
return *this;
}
template< typename P >
cache<P> &
cache<P>::reserveElements(size_t elems) {
Lru::reserve(elems);
return *this;
}
template< typename P >
void
cache<P>::invalidate(const K & key) {
vespalib::LockGuard guard(_hashLock);
invalidate(guard, key);
}
template< typename P >
bool
cache<P>::hasKey(const K & key) const {
vespalib::LockGuard guard(_hashLock);
return hasKey(guard, key);
}
template< typename P >
bool
cache<P>::hasLock() const {
return TryLock(_hashLock).hasLock();
}
template< typename P >
cache<P>::~cache() { }
template< typename P >
cache<P>::cache(BackingStore & b, size_t maxBytes) :
Lru(Lru::UNLIMITED),
_maxBytes(maxBytes),
_sizeBytes(0),
_hit(0),
_miss(0),
_noneExisting(0),
_race(0),
_insert(0),
_write(0),
_erase(0),
_invalidate(0),
_lookup(0),
_store(b)
{ }
template< typename P >
bool
cache<P>::removeOldest(const value_type & v) {
bool remove(Lru::removeOldest(v) || (sizeBytes() >= capacityBytes()));
if (remove) {
_sizeBytes -= calcSize(v.first, v.second._value);
}
return remove;
}
template< typename P >
vespalib::LockGuard
cache<P>::getGuard() {
return vespalib::LockGuard(_hashLock);
}
template< typename P >
typename P::Value
cache<P>::read(const K & key)
{
{
vespalib::LockGuard guard(_hashLock);
if (Lru::hasKey(key)) {
_hit++;
return (*this)[key];
} else {
_miss++;
}
}
vespalib::LockGuard storeGuard(getLock(key));
{
vespalib::LockGuard guard(_hashLock);
if (Lru::hasKey(key)) {
// Somebody else just fetched it ahead of me.
_race++;
return (*this)[key];
}
}
V value;
if (_store.read(key, value)) {
vespalib::LockGuard guard(_hashLock);
Lru::insert(key, value);
_sizeBytes += calcSize(key, value);
_insert++;
} else {
vespalib::Atomic::postInc(&_noneExisting);
}
return value;
}
template< typename P >
void
cache<P>::write(const K & key, const V & value)
{
vespalib::LockGuard storeGuard(getLock(key));
{
vespalib::LockGuard guard(_hashLock);
(*this)[key] = value;
_sizeBytes += calcSize(key, value);
_write++;
}
_store.write(key, value);
}
template< typename P >
void
cache<P>::erase(const K & key)
{
vespalib::LockGuard storeGuard(getLock(key));
invalidate(key);
_store.erase(key);
}
template< typename P >
void
cache<P>::invalidate(const vespalib::LockGuard & guard, const K & key)
{
assert(guard.locks(_hashLock));
(void) guard;
if (Lru::hasKey(key)) {
_sizeBytes -= calcSize(key, (*this)[key]);
_invalidate++;
Lru::erase(key);
}
}
template< typename P >
bool
cache<P>::hasKey(const vespalib::LockGuard & guard, const K & key) const
{
(void) guard;
assert(guard.locks(_hashLock));
_lookup++;
return Lru::hasKey(key);
}
}
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