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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include "cache.h"
#include "cache_stats.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>::setCapacityBytes(size_t sz) {
_maxBytes.store(sz, std::memory_order_relaxed);
return *this;
}
template< typename P >
void
cache<P>::invalidate(const K & key) {
UniqueLock guard(_hashLock);
invalidate(guard, key);
}
template< typename P >
bool
cache<P>::hasKey(const K & key) const {
UniqueLock guard(_hashLock);
return hasKey(guard, key);
}
template< typename P >
cache<P>::~cache() = default;
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),
_update(0),
_invalidate(0),
_lookup(0),
_store(b)
{ }
template< typename P >
MemoryUsage
cache<P>::getStaticMemoryUsage() const {
MemoryUsage usage;
auto cacheGuard = getGuard();
usage.incAllocatedBytes(sizeof(*this));
usage.incUsedBytes(sizeof(*this));
return usage;
}
template< typename P >
bool
cache<P>::removeOldest(const value_type & v) {
bool remove(Lru::removeOldest(v) || (sizeBytes() >= capacityBytes()));
if (remove) {
_sizeBytes.store(sizeBytes() - calcSize(v.first, v.second._value), std::memory_order_relaxed);
}
return remove;
}
template< typename P >
std::unique_lock<std::mutex>
cache<P>::getGuard() const {
return UniqueLock(_hashLock);
}
template< typename P >
typename P::Value
cache<P>::read(const K & key)
{
{
std::lock_guard guard(_hashLock);
if (Lru::hasKey(key)) {
increment_stat(_hit, guard);
return (*this)[key];
} else {
increment_stat(_miss, guard);
}
}
std::lock_guard storeGuard(getLock(key));
{
std::lock_guard guard(_hashLock);
if (Lru::hasKey(key)) {
// Somebody else just fetched it ahead of me.
increment_stat(_race, guard);
return (*this)[key];
}
}
V value;
if (_store.read(key, value)) {
std::lock_guard guard(_hashLock);
Lru::insert(key, value);
_sizeBytes.store(sizeBytes() + calcSize(key, value), std::memory_order_relaxed);
increment_stat(_insert, guard);
} else {
_noneExisting.fetch_add(1);
}
return value;
}
template< typename P >
void
cache<P>::write(const K & key, V value)
{
size_t newSize = calcSize(key, value);
std::lock_guard storeGuard(getLock(key));
{
std::lock_guard guard(_hashLock);
if (Lru::hasKey(key)) {
_sizeBytes.store(sizeBytes() - calcSize(key, (*this)[key]), std::memory_order_relaxed);
increment_stat(_update, guard);
}
}
_store.write(key, value);
{
std::lock_guard guard(_hashLock);
(*this)[key] = std::move(value);
_sizeBytes.store(sizeBytes() + newSize, std::memory_order_relaxed);
increment_stat(_write, guard);
}
}
template< typename P >
void
cache<P>::erase(const K & key)
{
std::lock_guard storeGuard(getLock(key));
invalidate(key);
_store.erase(key);
}
template< typename P >
void
cache<P>::invalidate(const UniqueLock & guard, const K & key)
{
verifyHashLock(guard);
if (Lru::hasKey(key)) {
_sizeBytes.store(sizeBytes() - calcSize(key, (*this)[key]), std::memory_order_relaxed);
increment_stat(_invalidate, guard);
Lru::erase(key);
}
}
template< typename P >
bool
cache<P>::hasKey(const UniqueLock & guard, const K & key) const
{
verifyHashLock(guard);
increment_stat(_lookup, guard);
return Lru::hasKey(key);
}
template< typename P >
void
cache<P>::verifyHashLock(const UniqueLock & guard) const {
assert(guard.mutex() == & _hashLock);
assert(guard.owns_lock());
}
template <typename P>
CacheStats
cache<P>::get_stats() const
{
std::lock_guard guard(_hashLock);
return CacheStats(getHit(), getMiss(), Lru::size(), sizeBytes(), getInvalidate());
}
}
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