gecko-dev/dom/storage/DOMStorageCache.h

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/* -*- 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 nsDOMStorageCache_h___
#define nsDOMStorageCache_h___
#include "nsIPrincipal.h"
#include "nsITimer.h"
#include "nsString.h"
#include "nsDataHashtable.h"
#include "nsHashKeys.h"
#include "mozilla/Monitor.h"
#include "mozilla/Telemetry.h"
#include "nsAutoPtr.h"
namespace mozilla {
namespace dom {
class DOMStorage;
class DOMStorageUsage;
class DOMStorageManager;
class DOMStorageDBBridge;
// Interface class on which only the database or IPC may call.
// Used to populate the cache with DB data.
class DOMStorageCacheBridge
{
public:
NS_IMETHOD_(MozExternalRefCountType) AddRef(void);
NS_IMETHOD_(void) Release(void);
// The scope (origin) in the database usage format (reversed)
virtual const nsCString& Scope() const = 0;
// Whether the cache is already fully loaded
virtual bool Loaded() = 0;
// How many items has so far been loaded into the cache, used
// for optimization purposes
virtual uint32_t LoadedCount() = 0;
// Called by the database to load a key and its value to the cache
virtual bool LoadItem(const nsAString& aKey, const nsString& aValue) = 0;
// Called by the database after all keys and values has been loaded
// to this cache
virtual void LoadDone(nsresult aRv) = 0;
// Use to synchronously wait until the cache gets fully loaded with data,
// this method exits after LoadDone has been called
virtual void LoadWait() = 0;
protected:
virtual ~DOMStorageCacheBridge() {}
ThreadSafeAutoRefCnt mRefCnt;
NS_DECL_OWNINGTHREAD
};
// Implementation of scope cache that is responsible for preloading data
// for persistent storage (localStorage) and hold data for non-private,
// private and session-only cookie modes. It is also responsible for
// persisting data changes using the database, works as a write-back cache.
class DOMStorageCache : public DOMStorageCacheBridge
{
public:
NS_IMETHOD_(void) Release(void);
explicit DOMStorageCache(const nsACString* aScope);
protected:
virtual ~DOMStorageCache();
public:
void Init(DOMStorageManager* aManager, bool aPersistent, nsIPrincipal* aPrincipal,
const nsACString& aQuotaScope);
// Copies all data from the other storage.
void CloneFrom(const DOMStorageCache* aThat);
// Starts async preload of this cache if it persistent and not loaded.
void Preload();
// Keeps the cache alive (i.e. present in the manager's hash table) for a time.
void KeepAlive();
// The set of methods that are invoked by DOM storage web API.
// We are passing the DOMStorage object just to let the cache
// read properties like mPrivate and mSessionOnly.
// Get* methods return error when load from the database has failed.
nsresult GetLength(const DOMStorage* aStorage, uint32_t* aRetval);
nsresult GetKey(const DOMStorage* aStorage, uint32_t index, nsAString& aRetval);
nsresult GetItem(const DOMStorage* aStorage, const nsAString& aKey, nsAString& aRetval);
nsresult SetItem(const DOMStorage* aStorage, const nsAString& aKey, const nsString& aValue, nsString& aOld);
nsresult RemoveItem(const DOMStorage* aStorage, const nsAString& aKey, nsString& aOld);
nsresult Clear(const DOMStorage* aStorage);
void GetKeys(const DOMStorage* aStorage, nsTArray<nsString>& aKeys);
// Whether the principal equals principal the cache was created for
bool CheckPrincipal(nsIPrincipal* aPrincipal) const;
nsIPrincipal* Principal() const { return mPrincipal; }
// Starts the database engine thread or the IPC bridge
static DOMStorageDBBridge* StartDatabase();
static DOMStorageDBBridge* GetDatabase();
// Stops the thread and flushes all uncommited data
static nsresult StopDatabase();
// DOMStorageCacheBridge
virtual const nsCString& Scope() const { return mScope; }
virtual bool Loaded() { return mLoaded; }
virtual uint32_t LoadedCount();
virtual bool LoadItem(const nsAString& aKey, const nsString& aValue);
virtual void LoadDone(nsresult aRv);
virtual void LoadWait();
// Cache keeps 3 sets of data: regular, private and session-only.
// This class keeps keys and values for a set and also caches
// size of the data for quick per-origin quota checking.
class Data
{
public:
Data() : mOriginQuotaUsage(0) {}
int64_t mOriginQuotaUsage;
nsDataHashtable<nsStringHashKey, nsString> mKeys;
};
public:
// Number of data sets we keep: default, private, session
static const uint32_t kDataSetCount = 3;
private:
// API to clear the cache data, this is invoked by chrome operations
// like cookie deletion.
friend class DOMStorageManager;
static const uint32_t kUnloadDefault = 1 << 0;
static const uint32_t kUnloadPrivate = 1 << 1;
static const uint32_t kUnloadSession = 1 << 2;
static const uint32_t kUnloadComplete =
kUnloadDefault | kUnloadPrivate | kUnloadSession;
#ifdef DOM_STORAGE_TESTS
static const uint32_t kTestReload = 1 << 15;
#endif
void UnloadItems(uint32_t aUnloadFlags);
private:
// Synchronously blocks until the cache is fully loaded from the database
void WaitForPreload(mozilla::Telemetry::ID aTelemetryID);
// Helper to get one of the 3 data sets (regular, private, session)
Data& DataSet(const DOMStorage* aStorage);
// Whether the storage change is about to persist
bool Persist(const DOMStorage* aStorage) const;
// Changes the quota usage on the given data set if it fits the quota.
// If not, then false is returned and no change to the set must be done.
bool ProcessUsageDelta(uint32_t aGetDataSetIndex, const int64_t aDelta);
bool ProcessUsageDelta(const DOMStorage* aStorage, const int64_t aDelta);
private:
// When a cache is reponsible for its life time (in case of localStorage data
// cache) we need to refer our manager since removal of the cache from the hash
// table is handled in the destructor by call to the manager.
// Cache could potentially overlive the manager, hence the hard ref.
nsRefPtr<DOMStorageManager> mManager;
// Reference to the usage counter object we check on for eTLD+1 quota limit.
// Obtained from the manager during initialization (Init method).
nsRefPtr<DOMStorageUsage> mUsage;
// Timer that holds this cache alive for a while after it has been preloaded.
nsCOMPtr<nsITimer> mKeepAliveTimer;
// Principal the cache has been initially created for, this is used only
// for sessionStorage access checks since sessionStorage objects are strictly
// scoped by a principal. localStorage objects on the other hand are scoped by
// origin only.
nsCOMPtr<nsIPrincipal> mPrincipal;
// The scope this cache belongs to in the "DB format", i.e. reversed
nsCString mScope;
// The eTLD+1 scope used to count quota usage.
nsCString mQuotaScope;
// Non-private Browsing, Private Browsing and Session Only sets.
Data mData[kDataSetCount];
// This monitor is used to wait for full load of data.
mozilla::Monitor mMonitor;
// Flag that is initially false. When the cache is about to work with
// the database (i.e. it is persistent) this flags is set to true after
// all keys and coresponding values are loaded from the database.
// This flag never goes from true back to false.
bool mLoaded;
// Result of load from the database. Valid after mLoaded flag has been set.
nsresult mLoadResult;
// Init() method has been called
bool mInitialized : 1;
// This cache is about to be bound with the database (i.e. it has
// to load from the DB first and has to persist when modifying the
// default data set.)
bool mPersistent : 1;
// - False when the session-only data set was never used.
// - True after access to session-only data has been made for the first time.
// We also fill session-only data set with the default one at that moment.
// Drops back to false when session-only data are cleared from chrome.
bool mSessionOnlyDataSetActive : 1;
// Whether we have already captured state of the cache preload on our first access.
bool mPreloadTelemetryRecorded : 1;
// DOMStorageDBThread on the parent or single process,
// DOMStorageDBChild on the child process.
static DOMStorageDBBridge* sDatabase;
// False until we shut the database down.
static bool sDatabaseDown;
};
// DOMStorageUsage
// Infrastructure to manage and check eTLD+1 quota
class DOMStorageUsageBridge
{
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(DOMStorageUsageBridge)
virtual const nsCString& Scope() = 0;
virtual void LoadUsage(const int64_t aUsage) = 0;
protected:
// Protected destructor, to discourage deletion outside of Release():
virtual ~DOMStorageUsageBridge() {}
};
class DOMStorageUsage : public DOMStorageUsageBridge
{
public:
explicit DOMStorageUsage(const nsACString& aScope);
bool CheckAndSetETLD1UsageDelta(uint32_t aDataSetIndex, int64_t aUsageDelta);
private:
virtual const nsCString& Scope() { return mScope; }
virtual void LoadUsage(const int64_t aUsage);
nsCString mScope;
int64_t mUsage[DOMStorageCache::kDataSetCount];
};
} // namespace dom
} // namespace mozilla
#endif