gecko-dev/dom/media/mediacapabilities/KeyValueStorage.h

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1.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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_KEY_VALUE_STORAGE_H
#define MOZILLA_KEY_VALUE_STORAGE_H
#include "mozilla/MozPromise.h"
#include "nsIKeyValue.h"
namespace mozilla {
/* A wrapper class around kv store service, which allows storing a pair of key
* value permanently. The class must be used from the parent process, where
* there is no sandbox because it requires access to the directory that the
* database is located. */
class KeyValueStorage final {
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(KeyValueStorage)
/* Store permanently the value in the Key. */
RefPtr<GenericPromise> Put(const nsACString& aName, const nsACString& aKey,
int32_t aValue);
/* Get the value stored in the aKey. If the aKey does not exist the promise is
* resolved with the value -1. */
typedef MozPromise<int32_t, nsresult, true> GetPromise;
RefPtr<GetPromise> Get(const nsACString& aName, const nsACString& aKey);
/* Clear all the key/value pairs from the aName database. */
RefPtr<GenericPromise> Clear(const nsACString& aName);
private:
/* Create, if doesn't exist, and initialize the database with a given name. */
RefPtr<GenericPromise> Init();
RefPtr<GenericPromise> Put(const nsACString& aKey, int32_t aValue);
RefPtr<GetPromise> Get(const nsACString& aKey);
RefPtr<GenericPromise> Clear();
~KeyValueStorage() = default;
RefPtr<nsIKeyValueDatabase> mDatabase;
nsCString mDatabaseName;
};
} // namespace mozilla
#endif // MOZILLA_KEY_VALUE_STORAGE_H