database_context.cc | Explore in Territory

/*
 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
 * Copyright (C) 2011 Google, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "third_party/blink/renderer/modules/webdatabase/database_context.h"

#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/execution_context/execution_context.h"
#include "third_party/blink/renderer/core/frame/local_dom_window.h"
#include "third_party/blink/renderer/core/inspector/console_message.h"
#include "third_party/blink/renderer/modules/webdatabase/database.h"
#include "third_party/blink/renderer/modules/webdatabase/database_client.h"
#include "third_party/blink/renderer/modules/webdatabase/database_task.h"
#include "third_party/blink/renderer/modules/webdatabase/database_thread.h"
#include "third_party/blink/renderer/modules/webdatabase/database_tracker.h"
#include "third_party/blink/renderer/modules/webdatabase/storage_log.h"
#include "third_party/blink/renderer/platform/weborigin/scheme_registry.h"
#include "third_party/blink/renderer/platform/weborigin/security_origin.h"

namespace blink {

// How the DatabaseContext Life-Cycle works?
// ========================================
// ... in other words, who's keeping the DatabaseContext alive and how long does
// it need to stay alive?
//
// The DatabaseContext is referenced from
// 1. Supplement<ExecutionContext>
// 2. Database
//
// At Birth:
// ========
// We create a DatabaseContext only when there is a need i.e. the script tries
// to open a Database via DatabaseContext::OpenDatabase().
//
// The DatabaseContext constructor will register itself to ExecutionContext as
// a supplement. This lets DatabaseContext keep itself alive until it is
// cleared after ContextDestroyed().
//
// Once a DatabaseContext is associated with a ExecutionContext, it will
// live until after the ExecutionContext destructs. This is true even if
// we don't succeed in opening any Databases for that context. When we do
// succeed in opening Databases for this ExecutionContext, the Database
// will re-use the same DatabaseContext.
//
// At Shutdown:
// ===========
// During shutdown, the DatabaseContext needs to:
// 1. "outlive" the ExecutionContext.
//    - This is needed because the DatabaseContext needs to remove itself from
//    the
//      ExecutionContext's ExecutionContextLifecycleObserver list and
//      ExecutionContextLifecycleObserver
//      list. This removal needs to be executed on the script's thread. Hence,
//      we
//      rely on the ExecutionContext's shutdown process to call
//      Stop() and ContextDestroyed() to give us a chance to clean these up from
//      the script thread.
//
// 2. "outlive" the Databases.
//    - This is because they may make use of the DatabaseContext to execute a
//      close task and shutdown in an orderly manner. When the Databases are
//      destructed, they will release the DatabaseContext reference from the
//      DatabaseThread.
//
// During shutdown, the ExecutionContext is shutting down on the script thread
// while the Databases are shutting down on the DatabaseThread. Hence, there can
// be a race condition as to whether the ExecutionContext or the Databases
// destruct first.
//
// The Members in the Databases and Supplement<ExecutionContext> will ensure
// that the DatabaseContext will outlive Database and ExecutionContext
// regardless of which of the 2 destructs first.

DatabaseContext* DatabaseContext::From(ExecutionContext& context) { … }

const char DatabaseContext::kSupplementName[] = …;

DatabaseContext::DatabaseContext(ExecutionContext& context,
                                 base::PassKey<DatabaseContext> passkey)
    : … { … }

DatabaseContext::~DatabaseContext() = default;

void DatabaseContext::Trace(Visitor* visitor) const { … }

// This is called if the associated ExecutionContext is destructing while
// we're still associated with it. That's our cue to disassociate and shutdown.
// To do this, we stop the database and let everything shutdown naturally
// because the database closing process may still make use of this context.
// It is not safe to just delete the context here.
void DatabaseContext::ContextDestroyed() { … }

DatabaseThread* DatabaseContext::GetDatabaseThread() { … }

bool DatabaseContext::DatabaseThreadAvailable() { … }

void DatabaseContext::StopDatabases() { … }

bool DatabaseContext::AllowDatabaseAccess() const { … }

const SecurityOrigin* DatabaseContext::GetSecurityOrigin() const { … }

bool DatabaseContext::IsContextThread() const { … }

static void LogOpenDatabaseError(ExecutionContext* context,
                                 const String& name) { … }

Database* DatabaseContext::OpenDatabaseInternal(
    const String& name,
    const String& expected_version,
    const String& display_name,
    V8DatabaseCallback* creation_callback,
    bool set_version_in_new_database,
    DatabaseError& error,
    String& error_message) { … }

Database* DatabaseContext::OpenDatabase(const String& name,
                                        const String& expected_version,
                                        const String& display_name,
                                        V8DatabaseCallback* creation_callback,
                                        DatabaseError& error,
                                        String& error_message) { … }

void DatabaseContext::ThrowExceptionForDatabaseError(
    DatabaseError error,
    const String& error_message,
    ExceptionState& exception_state) { … }

void DatabaseContext::LogErrorMessage(ExecutionContext* context,
                                      const String& message) { … }

}  // namespace blink
chromium/third_party/blink/renderer/modules/webdatabase/database_context.cc
