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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 mozilla_dom_localstorage_LSSnapshot_h
#define mozilla_dom_localstorage_LSSnapshot_h
#include <cstdint>
#include <cstdlib>
#include "ErrorList.h"
#include "mozilla/Assertions.h"
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
#include "nsCOMPtr.h"
#include "nsDataHashtable.h"
#include "nsHashKeys.h"
#include "nsIRunnable.h"
#include "nsISupports.h"
#include "nsStringFwd.h"
#include "nsTArrayForwardDeclare.h"
#include "nsTHashtable.h"
class nsITimer;
namespace mozilla {
namespace dom {
class LSDatabase;
class LSNotifyInfo;
class LSSnapshotChild;
class LSSnapshotInitInfo;
class LSWriteAndNotifyInfo;
class SnapshotWriteOptimizer;
template <typename>
class Optional;
class LSSnapshot final : public nsIRunnable {
public:
/**
* The LoadState expresses what subset of information a snapshot has from the
* authoritative Datastore in the parent process. The initial snapshot is
* populated heuristically based on the size of the keys and size of the items
* (inclusive of the key value; item is key+value, not just value) of the
* entire datastore relative to the configured prefill limit (via pref
* "dom.storage.snapshot_prefill" exposed as gSnapshotPrefill in bytes).
*
* If there's less data than the limit, we send both keys and values and end
* up as AllOrderedItems. If there's enough room for all the keys but not
* all the values, we end up as AllOrderedKeys with as many values present as
* would fit. If there's not enough room for all the keys, then we end up as
* Partial with as many key-value pairs as will fit.
*
* The state AllUnorderedItems can only be reached by code getting items one
* by one.
*/
enum class LoadState {
/**
* Class constructed, Init(LSSnapshotInitInfo) has not been invoked yet.
*/
Initial,
/**
* Some keys and their values are known.
*/
Partial,
/**
* All the keys are known in order, but some values are unknown.
*/
AllOrderedKeys,
/**
* All keys and their values are known, but in an arbitrary order.
*/
AllUnorderedItems,
/**
* All keys and their values are known and are present in their canonical
* order. This is everything, and is the preferred case. The initial
* population will send this info when the size of all items is less than
* the prefill threshold.
*
* mValues will contain all keys and values, mLoadedItems and mUnknownItems
* are unused.
*/
AllOrderedItems,
EndGuard
};
private:
RefPtr<LSSnapshot> mSelfRef;
RefPtr<LSDatabase> mDatabase;
nsCOMPtr<nsITimer> mTimer;
LSSnapshotChild* mActor;
nsTHashtable<nsStringHashKey> mLoadedItems;
nsTHashtable<nsStringHashKey> mUnknownItems;
nsDataHashtable<nsStringHashKey, nsString> mValues;
UniquePtr<SnapshotWriteOptimizer> mWriteOptimizer;
UniquePtr<nsTArray<LSWriteAndNotifyInfo>> mWriteAndNotifyInfos;
uint32_t mInitLength;
uint32_t mLength;
int64_t mExactUsage;
int64_t mPeakUsage;
LoadState mLoadState;
bool mHasOtherProcessObservers;
bool mExplicit;
bool mHasPendingStableStateCallback;
bool mHasPendingTimerCallback;
bool mDirty;
#ifdef DEBUG
bool mInitialized;
bool mSentFinish;
#endif
public:
explicit LSSnapshot(LSDatabase* aDatabase);
void AssertIsOnOwningThread() const { NS_ASSERT_OWNINGTHREAD(LSSnapshot); }
void SetActor(LSSnapshotChild* aActor);
void ClearActor() {
AssertIsOnOwningThread();
MOZ_ASSERT(mActor);
mActor = nullptr;
}
bool Explicit() const { return mExplicit; }
nsresult Init(const nsAString& aKey, const LSSnapshotInitInfo& aInitInfo,
bool aExplicit);
nsresult GetLength(uint32_t* aResult);
nsresult GetKey(uint32_t aIndex, nsAString& aResult);
nsresult GetItem(const nsAString& aKey, nsAString& aResult);
nsresult GetKeys(nsTArray<nsString>& aKeys);
nsresult SetItem(const nsAString& aKey, const nsAString& aValue,
LSNotifyInfo& aNotifyInfo);
nsresult RemoveItem(const nsAString& aKey, LSNotifyInfo& aNotifyInfo);
nsresult Clear(LSNotifyInfo& aNotifyInfo);
void MarkDirty();
nsresult End();
private:
~LSSnapshot();
void ScheduleStableStateCallback();
void MaybeScheduleStableStateCallback();
nsresult GetItemInternal(const nsAString& aKey,
const Optional<nsString>& aValue,
nsAString& aResult);
nsresult EnsureAllKeys();
nsresult UpdateUsage(int64_t aDelta);
nsresult Checkpoint();
nsresult Finish();
void CancelTimer();
static void TimerCallback(nsITimer* aTimer, void* aClosure);
NS_DECL_ISUPPORTS
NS_DECL_NSIRUNNABLE
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_localstorage_LSSnapshot_h
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