gecko-dev/dom/storage/DOMStorageManager.h

145 lines
4.8 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsDOMStorageManager_h__
#define nsDOMStorageManager_h__
#include "nsIDOMStorageManager.h"
#include "DOMStorageObserver.h"
#include "DOMStorageCache.h"
#include "mozilla/dom/DOMStorage.h"
#include "nsTHashtable.h"
#include "nsDataHashtable.h"
#include "nsHashKeys.h"
class nsIDOMWindow;
namespace mozilla {
namespace dom {
const DOMStorage::StorageType SessionStorage = DOMStorage::SessionStorage;
const DOMStorage::StorageType LocalStorage = DOMStorage::LocalStorage;
class DOMStorageManager : public nsIDOMStorageManager
, public DOMStorageObserverSink
{
NS_DECL_ISUPPORTS
NS_DECL_NSIDOMSTORAGEMANAGER
public:
virtual DOMStorage::StorageType Type() { return mType; }
// Reads the preference for DOM storage quota
static uint32_t GetQuota();
// Gets (but not ensures) cache for the given scope
DOMStorageCache* GetCache(const nsACString& aScope) const;
// Returns object keeping usage cache for the scope.
already_AddRefed<DOMStorageUsage> GetScopeUsage(const nsACString& aScope);
protected:
explicit DOMStorageManager(DOMStorage::StorageType aType);
virtual ~DOMStorageManager();
private:
// DOMStorageObserverSink, handler to various chrome clearing notification
virtual nsresult Observe(const char* aTopic, const nsACString& aScopePrefix) override;
// Since nsTHashtable doesn't like multiple inheritance, we have to aggregate
// DOMStorageCache into the entry.
class DOMStorageCacheHashKey : public nsCStringHashKey
{
public:
explicit DOMStorageCacheHashKey(const nsACString* aKey)
: nsCStringHashKey(aKey)
, mCache(new DOMStorageCache(aKey))
{}
DOMStorageCacheHashKey(const DOMStorageCacheHashKey& aOther)
: nsCStringHashKey(aOther)
{
NS_ERROR("Shouldn't be called");
}
DOMStorageCache* cache() { return mCache; }
// Keep the cache referenced forever, used for sessionStorage.
void HardRef() { mCacheRef = mCache; }
private:
// weak ref only since cache references its manager.
DOMStorageCache* mCache;
// hard ref when this is sessionStorage to keep it alive forever.
nsRefPtr<DOMStorageCache> mCacheRef;
};
// Ensures cache for a scope, when it doesn't exist it is created and initalized,
// this also starts preload of persistent data.
already_AddRefed<DOMStorageCache> PutCache(const nsACString& aScope,
nsIPrincipal* aPrincipal);
// Helper for creation of DOM storage objects
nsresult GetStorageInternal(bool aCreate,
nsIDOMWindow* aWindow,
nsIPrincipal* aPrincipal,
const nsAString& aDocumentURI,
bool aPrivate,
nsIDOMStorage** aRetval);
// Scope->cache map
nsTHashtable<DOMStorageCacheHashKey> mCaches;
const DOMStorage::StorageType mType;
// If mLowDiskSpace is true it indicates a low device storage situation and
// so no localStorage writes are allowed. sessionStorage writes are still
// allowed.
bool mLowDiskSpace;
bool IsLowDiskSpace() const { return mLowDiskSpace; };
void ClearCaches(uint32_t aUnloadFlags, const nsACString& aKeyPrefix);
protected:
// Keeps usage cache objects for eTLD+1 scopes we have touched.
nsDataHashtable<nsCStringHashKey, nsRefPtr<DOMStorageUsage> > mUsages;
friend class DOMStorageCache;
// Releases cache since it is no longer referrered by any DOMStorage object.
virtual void DropCache(DOMStorageCache* aCache);
};
// Derived classes to allow two different contract ids, one for localStorage and
// one for sessionStorage management. localStorage manager is used as service
// scoped to the application while sessionStorage managers are instantiated by each
// top doc shell in the application since sessionStorages are isolated per top level
// browsing context. The code may easily by shared by both.
class DOMLocalStorageManager final : public DOMStorageManager
{
public:
DOMLocalStorageManager();
virtual ~DOMLocalStorageManager();
// Global getter of localStorage manager service
static DOMLocalStorageManager* Self() { return sSelf; }
// Like Self, but creates an instance if we're not yet initialized.
static DOMLocalStorageManager* Ensure();
private:
static DOMLocalStorageManager* sSelf;
};
class DOMSessionStorageManager final : public DOMStorageManager
{
public:
DOMSessionStorageManager();
};
} // namespace dom
} // namespace mozilla
#endif /* nsDOMStorageManager_h__ */