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Renamed to ParallelAccessStore

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This commit is contained in:
Sebastian Messmer 2015-04-16 14:52:06 +02:00
parent 74381f2cdd
commit d15a355464
7 changed files with 182 additions and 179 deletions
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18
CachingBaseStore.h
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#ifndef MESSMER_CACHINGSTORE_CACHINGBASESTORE_H_
#define MESSMER_CACHINGSTORE_CACHINGBASESTORE_H_
#include <memory>
namespace cachingstore {
template<class Resource, class Key>
class CachingBaseStore {
public:
virtual ~CachingBaseStore() {}
virtual std::unique_ptr<Resource> loadFromBaseStore(const Key &key) = 0;
virtual void removeFromBaseStore(std::unique_ptr<Resource> block) = 0;
};
}
#endif

158
CachingStore.h
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#ifndef MESSMER_BLOCKSTORE_IMPLEMENTATIONS_CACHING_CACHINGSTORE_H_
#define MESSMER_BLOCKSTORE_IMPLEMENTATIONS_CACHING_CACHINGSTORE_H_
#include <mutex>
#include <memory>
#include <map>
#include <future>
#include <cassert>
#include <messmer/cpp-utils/macros.h>
#include "CachingBaseStore.h"
//TODO Refactor
//TODO Test cases
namespace cachingstore {
template<class Resource, class CachedResourceRef, class Key>
class CachingStore {
public:
CachingStore(std::unique_ptr<CachingBaseStore<Resource, Key>> baseStore)
: _mutex(),
_baseStore(std::move(baseStore)),
_openResources(),
_resourcesToRemove() {
}
//TODO Enforce CachedResourceRef inherits from CachedResource
class CachedResource {
public:
//TODO Better way to initialize
CachedResource(): _cachingStore(nullptr), _key(Key::CreateRandom()) {}
void init(CachingStore *cachingStore, const Key &key) {
_cachingStore = cachingStore;
_key = key;
}
virtual ~CachedResource() {
_cachingStore->release(_key);
}
private:
CachingStore *_cachingStore;
//TODO We're storing Key twice (here and in the base resource). Rather use getKey() on the base resource if possible somehow.
Key _key;
};
std::unique_ptr<CachedResourceRef> add(const Key &key, std::unique_ptr<Resource> resource);
std::unique_ptr<CachedResourceRef> load(const Key &key);
void remove(const Key &key, std::unique_ptr<CachedResourceRef> block);
private:
class OpenResource {
public:
OpenResource(std::unique_ptr<Resource> resource): _resource(std::move(resource)), _refCount(0) {}
Resource *getReference() {
++_refCount;
return _resource.get();
}
void releaseReference() {
--_refCount;
}
bool refCountIsZero() const {
return 0 == _refCount;
}
std::unique_ptr<Resource> moveResourceOut() {
return std::move(_resource);
}
private:
std::unique_ptr<Resource> _resource;
uint32_t _refCount;
};
std::mutex _mutex;
std::unique_ptr<CachingBaseStore<Resource, Key>> _baseStore;
std::map<Key, OpenResource> _openResources;
std::map<Key, std::promise<std::unique_ptr<Resource>>> _resourcesToRemove;
std::unique_ptr<CachedResourceRef> _add(const Key &key, std::unique_ptr<Resource> resource);
std::unique_ptr<CachedResourceRef> _createCachedResourceRef(Resource *resource, const Key &key);
void release(const Key &key);
friend class CachedResource;
DISALLOW_COPY_AND_ASSIGN(CachingStore);
};
template<class Resource, class CachedResourceRef, class Key>
std::unique_ptr<CachedResourceRef> CachingStore<Resource, CachedResourceRef, Key>::add(const Key &key, std::unique_ptr<Resource> resource) {
std::lock_guard<std::mutex> lock(_mutex);
return _add(key, std::move(resource));
}
template<class Resource, class CachedResourceRef, class Key>
std::unique_ptr<CachedResourceRef> CachingStore<Resource, CachedResourceRef, Key>::_add(const Key &key, std::unique_ptr<Resource> resource) {
auto insertResult = _openResources.emplace(key, std::move(resource));
assert(true == insertResult.second);
return _createCachedResourceRef(insertResult.first->second.getReference(), key);
}
template<class Resource, class CachedResourceRef, class Key>
std::unique_ptr<CachedResourceRef> CachingStore<Resource, CachedResourceRef, Key>::_createCachedResourceRef(Resource *resource, const Key &key) {
auto resourceRef = std::make_unique<CachedResourceRef>(resource);
resourceRef->init(this, key);
return std::move(resourceRef);
}
template<class Resource, class CachedResourceRef, class Key>
std::unique_ptr<CachedResourceRef> CachingStore<Resource, CachedResourceRef, Key>::load(const Key &key) {
//TODO This lock doesn't allow loading different blocks in parallel. Can we do something with futures maybe?
std::lock_guard<std::mutex> lock(_mutex);
auto found = _openResources.find(key);
if (found == _openResources.end()) {
auto resource = _baseStore->loadFromBaseStore(key);
if (resource.get() == nullptr) {
return nullptr;
}
return _add(key, std::move(resource));
} else {
return _createCachedResourceRef(found->second.getReference(), key);
}
}
template<class Resource, class CachedResourceRef, class Key>
void CachingStore<Resource, CachedResourceRef, Key>::remove(const Key &key, std::unique_ptr<CachedResourceRef> resource) {
auto insertResult = _resourcesToRemove.emplace(key, std::promise<std::unique_ptr<Resource>>());
assert(true == insertResult.second);
resource.reset();
//Wait for last resource user to release it
auto resourceToRemove = insertResult.first->second.get_future().get();
_resourcesToRemove.erase(key); //TODO Is this erase causing a race condition?
_baseStore->removeFromBaseStore(std::move(resourceToRemove));
}
template<class Resource, class CachedResourceRef, class Key>
void CachingStore<Resource, CachedResourceRef, Key>::release(const Key &key) {
std::lock_guard<std::mutex> lock(_mutex);
auto found = _openResources.find(key);
assert (found != _openResources.end());
found->second.releaseReference();
if (found->second.refCountIsZero()) {
auto foundToRemove = _resourcesToRemove.find(key);
if (foundToRemove != _resourcesToRemove.end()) {
foundToRemove->second.set_value(found->second.moveResourceOut());
}
_openResources.erase(found);
}
}
}
#endif

18
ParallelAccessBaseStore.h Normal file
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#ifndef MESSMER_PARALLELACCESSSTORE_PARALLELACCESSBASESTORE_H_
#define MESSMER_PARALLELACCESSSTORE_PARALLELACCESSBASESTORE_H_
#include <memory>
namespace parallelaccessstore {
template<class Resource, class Key>
class ParallelAccessBaseStore {
public:
virtual ~ParallelAccessBaseStore() {}
virtual std::unique_ptr<Resource> loadFromBaseStore(const Key &key) = 0;
virtual void removeFromBaseStore(std::unique_ptr<Resource> block) = 0;
};
}
#endif

161
ParallelAccessStore.h Normal file
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#ifndef MESSMER_PARALLELACCESSSTORE_IMPLEMENTATIONS_PARALLELACCESS_PARALLELACCESSSTORE_H_
#define MESSMER_PARALLELACCESSSTORE_IMPLEMENTATIONS_PARALLELACCESS_PARALLELACCESSSTORE_H_
#include <mutex>
#include <memory>
#include <map>
#include <future>
#include <cassert>
#include <type_traits>
#include <messmer/cpp-utils/macros.h>
#include "ParallelAccessBaseStore.h"
//TODO Refactor
//TODO Test cases
namespace parallelaccessstore {
template<class Resource, class ResourceRef, class Key>
class ParallelAccessStore {
public:
ParallelAccessStore(std::unique_ptr<ParallelAccessBaseStore<Resource, Key>> baseStore);
class ResourceRefBase {
public:
//TODO Better way to initialize
ResourceRefBase(): _cachingStore(nullptr), _key(Key::CreateRandom()) {}
void init(ParallelAccessStore *cachingStore, const Key &key) {
_cachingStore = cachingStore;
_key = key;
}
virtual ~ResourceRefBase() {
_cachingStore->release(_key);
}
private:
ParallelAccessStore *_cachingStore;
//TODO We're storing Key twice (here and in the base resource). Rather use getKey() on the base resource if possible somehow.
Key _key;
};
std::unique_ptr<ResourceRef> add(const Key &key, std::unique_ptr<Resource> resource);
std::unique_ptr<ResourceRef> load(const Key &key);
void remove(const Key &key, std::unique_ptr<ResourceRef> block);
private:
class OpenResource {
public:
OpenResource(std::unique_ptr<Resource> resource): _resource(std::move(resource)), _refCount(0) {}
Resource *getReference() {
++_refCount;
return _resource.get();
}
void releaseReference() {
--_refCount;
}
bool refCountIsZero() const {
return 0 == _refCount;
}
std::unique_ptr<Resource> moveResourceOut() {
return std::move(_resource);
}
private:
std::unique_ptr<Resource> _resource;
uint32_t _refCount;
};
std::mutex _mutex;
std::unique_ptr<ParallelAccessBaseStore<Resource, Key>> _baseStore;
std::map<Key, OpenResource> _openResources;
std::map<Key, std::promise<std::unique_ptr<Resource>>> _resourcesToRemove;
std::unique_ptr<ResourceRef> _add(const Key &key, std::unique_ptr<Resource> resource);
std::unique_ptr<ResourceRef> _createResourceRef(Resource *resource, const Key &key);
void release(const Key &key);
friend class CachedResource;
DISALLOW_COPY_AND_ASSIGN(ParallelAccessStore);
};
template<class Resource, class ResourceRef, class Key>
ParallelAccessStore<Resource, ResourceRef, Key>::ParallelAccessStore(std::unique_ptr<ParallelAccessBaseStore<Resource, Key>> baseStore)
: _mutex(),
_baseStore(std::move(baseStore)),
_openResources(),
_resourcesToRemove() {
static_assert(std::is_base_of<ResourceRefBase, ResourceRef>::value, "ResourceRef must inherit from ResourceRefBase");
}
template<class Resource, class ResourceRef, class Key>
std::unique_ptr<ResourceRef> ParallelAccessStore<Resource, ResourceRef, Key>::add(const Key &key, std::unique_ptr<Resource> resource) {
std::lock_guard<std::mutex> lock(_mutex);
return _add(key, std::move(resource));
}
template<class Resource, class ResourceRef, class Key>
std::unique_ptr<ResourceRef> ParallelAccessStore<Resource, ResourceRef, Key>::_add(const Key &key, std::unique_ptr<Resource> resource) {
auto insertResult = _openResources.emplace(key, std::move(resource));
assert(true == insertResult.second);
return _createResourceRef(insertResult.first->second.getReference(), key);
}
template<class Resource, class ResourceRef, class Key>
std::unique_ptr<ResourceRef> ParallelAccessStore<Resource, ResourceRef, Key>::_createResourceRef(Resource *resource, const Key &key) {
auto resourceRef = std::make_unique<ResourceRef>(resource);
resourceRef->init(this, key);
return std::move(resourceRef);
}
template<class Resource, class ResourceRef, class Key>
std::unique_ptr<ResourceRef> ParallelAccessStore<Resource, ResourceRef, Key>::load(const Key &key) {
//TODO This lock doesn't allow loading different blocks in parallel. Can we do something with futures maybe?
std::lock_guard<std::mutex> lock(_mutex);
auto found = _openResources.find(key);
if (found == _openResources.end()) {
auto resource = _baseStore->loadFromBaseStore(key);
if (resource.get() == nullptr) {
return nullptr;
}
return _add(key, std::move(resource));
} else {
return _createResourceRef(found->second.getReference(), key);
}
}
template<class Resource, class ResourceRef, class Key>
void ParallelAccessStore<Resource, ResourceRef, Key>::remove(const Key &key, std::unique_ptr<ResourceRef> resource) {
auto insertResult = _resourcesToRemove.emplace(key, std::promise<std::unique_ptr<Resource>>());
assert(true == insertResult.second);
resource.reset();
//Wait for last resource user to release it
auto resourceToRemove = insertResult.first->second.get_future().get();
_resourcesToRemove.erase(key); //TODO Is this erase causing a race condition?
_baseStore->removeFromBaseStore(std::move(resourceToRemove));
}
template<class Resource, class ResourceRef, class Key>
void ParallelAccessStore<Resource, ResourceRef, Key>::release(const Key &key) {
std::lock_guard<std::mutex> lock(_mutex);
auto found = _openResources.find(key);
assert (found != _openResources.end());
found->second.releaseReference();
if (found->second.refCountIsZero()) {
auto foundToRemove = _resourcesToRemove.find(key);
if (foundToRemove != _resourcesToRemove.end()) {
foundToRemove->second.set_value(found->second.moveResourceOut());
}
_openResources.erase(found);
}
}
}
#endif

2
README.md
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# cachingstore
# parallelaccessstore

2
biicode.conf
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messmer/cpp-utils: 2
[parent]
messmer/cachingstore: 0
messmer/parallelaccessstore: 0
[paths]
# Local directories to look for headers (within block)
# /

2
test/CachingBaseStoreTest.cpp
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#include "../CachingBaseStore.h"
#include "../ParallelAccessBaseStore.h"
// Test that CachingBaseStore.h can be included without errors