mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-10-31 06:05:44 +00:00
245 lines
9.5 KiB
C++
245 lines
9.5 KiB
C++
/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
|
|
/* vim: set ts=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_FileSystemTaskBase_h
|
|
#define mozilla_dom_FileSystemTaskBase_h
|
|
|
|
#include "mozilla/ErrorResult.h"
|
|
#include "mozilla/dom/FileSystemRequestParent.h"
|
|
#include "mozilla/dom/PFileSystemRequestChild.h"
|
|
|
|
class nsIDOMFile;
|
|
|
|
namespace mozilla {
|
|
namespace dom {
|
|
|
|
class BlobParent;
|
|
class FileSystemBase;
|
|
class FileSystemParams;
|
|
class Promise;
|
|
|
|
/*
|
|
* The base class to implement a Task class.
|
|
* The task is used to handle the OOP (out of process) operations.
|
|
* The file system operations can only be performed in the parent process. When
|
|
* performing such a parent-process-only operation, a task will delivered the
|
|
* operation to the parent process if needed.
|
|
*
|
|
* The following diagram illustrates the how a API call from the content page
|
|
* starts a task and gets call back results.
|
|
*
|
|
* The left block is the call sequence inside the child process, while the
|
|
* right block is the call sequence inside the parent process.
|
|
*
|
|
* There are two types of API call. One is from the content page of the child
|
|
* process and we mark the steps as (1) to (8). The other is from the content
|
|
* page of the parent process and we mark the steps as (1') to (4').
|
|
*
|
|
* Page Page
|
|
* | |
|
|
* | (1) | (1')
|
|
* ______|________________ | _____________________|_____________
|
|
* | | | | | | |
|
|
* | | Task in | | | Task in | |
|
|
* | | Child Process | | | Parent Process | |
|
|
* | V | IPC | V |
|
|
* [new FileSystemTaskBase()] | | [new FileSystemTaskBase()] |
|
|
* | | | | | | |
|
|
* | | (2) | | | (2') |
|
|
* | V | (3) | | |
|
|
* | [GetRequestParams]------------->[new FileSystemTaskBase(...)] |
|
|
* | | | | | |
|
|
* | | | | | (4) | |
|
|
* | | | | | V |
|
|
* | | | | -----------> [Work] |
|
|
* | | IPC | | |
|
|
* | | | | (5) | (3') |
|
|
* | | | | V |
|
|
* | | | | --------[HandleResult] |
|
|
* | | | | | | |
|
|
* | | | | (6) | |
|
|
* | | (7) | V | |
|
|
* | [SetRequestResult]<-------------[GetRequestResult] | |
|
|
* | | | | | (4') |
|
|
* | | (8) | | | | |
|
|
* | V | | | V |
|
|
* |[HandlerCallback] | IPC | [HandlerCallback] |
|
|
* |_______|_______________| | |_________________________|_________|
|
|
* | | |
|
|
* V V
|
|
* Page Page
|
|
*
|
|
* 1. From child process page
|
|
* Child:
|
|
* (1) Call FileSystem API from content page with JS. Create a task and run.
|
|
* The base constructor [FileSystemTaskBase()] of the task should be called.
|
|
* (2) Forward the task to the parent process through the IPC and call
|
|
* [GetRequestParams] to prepare the parameters of the IPC.
|
|
* Parent:
|
|
* (3) The parent process receives IPC and handle it in
|
|
* FileystemRequestParent.
|
|
* Get the IPC parameters and create a task to run the IPC task. The base
|
|
* constructor [FileSystemTaskBase(aParam, aParent)] of the task should be
|
|
* called to set the task as an IPC task.
|
|
* (4) The task operation will be performed in the member function of [Work].
|
|
* A worker thread will be created to run that function. If error occurs
|
|
* during the operation, call [SetError] to record the error and then abort.
|
|
* (5) After finishing the task operation, call [HandleResult] to send the
|
|
* result back to the child process though the IPC.
|
|
* (6) Call [GetRequestResult] request result to prepare the parameters of the
|
|
* IPC. Because the formats of the error result for different task are the
|
|
* same, FileSystemTaskBase can handle the error message without interfering.
|
|
* Each task only needs to implement its specific success result preparation
|
|
* function -[GetSuccessRequestResult].
|
|
* Child:
|
|
* (7) The child process receives IPC and calls [SetRequestResult] to get the
|
|
* task result. Each task needs to implement its specific success result
|
|
* parsing function [SetSuccessRequestResult] to get the success result.
|
|
* (8) Call [HandlerCallback] to send the task result to the content page.
|
|
* 2. From parent process page
|
|
* We don't need to send the task parameters and result to other process. So
|
|
* there are less steps, but their functions are the same. The correspondence
|
|
* between the two types of steps is:
|
|
* (1') = (1),
|
|
* (2') = (4),
|
|
* (3') = (5),
|
|
* (4') = (8).
|
|
*/
|
|
class FileSystemTaskBase
|
|
: public nsRunnable
|
|
, public PFileSystemRequestChild
|
|
{
|
|
public:
|
|
/*
|
|
* Start the task. If the task is running the child process, it will be
|
|
* forwarded to parent process by IPC, or else, creates a worker thread to
|
|
* do the task work.
|
|
*/
|
|
void
|
|
Start();
|
|
|
|
/*
|
|
* The error codes are defined in xpcom/base/ErrorList.h and their
|
|
* corresponding error name and message are defined in dom/base/domerr.msg.
|
|
*/
|
|
void
|
|
SetError(const nsresult& aErrorCode);
|
|
|
|
FileSystemBase*
|
|
GetFileSystem() const;
|
|
|
|
/*
|
|
* Get the type of permission access required to perform this task.
|
|
*/
|
|
virtual void
|
|
GetPermissionAccessType(nsCString& aAccess) const = 0;
|
|
|
|
NS_DECL_NSIRUNNABLE
|
|
protected:
|
|
/*
|
|
* To create a task to handle the page content request.
|
|
*/
|
|
explicit FileSystemTaskBase(FileSystemBase* aFileSystem);
|
|
|
|
/*
|
|
* To create a parent process task delivered from the child process through
|
|
* IPC.
|
|
*/
|
|
FileSystemTaskBase(FileSystemBase* aFileSystem,
|
|
const FileSystemParams& aParam,
|
|
FileSystemRequestParent* aParent);
|
|
|
|
virtual
|
|
~FileSystemTaskBase();
|
|
|
|
/*
|
|
* The function to perform task operation. It will be run on the worker
|
|
* thread of the parent process.
|
|
* Overrides this function to define the task operation for individual task.
|
|
*/
|
|
virtual nsresult
|
|
Work() = 0;
|
|
|
|
/*
|
|
* After the task is completed, this function will be called to pass the task
|
|
* result to the content page.
|
|
* Override this function to handle the call back to the content page.
|
|
*/
|
|
virtual void
|
|
HandlerCallback() = 0;
|
|
|
|
/*
|
|
* Wrap the task parameter to FileSystemParams for sending it through IPC.
|
|
* It will be called when we need to forward a task from the child process to
|
|
* the prarent process.
|
|
* @param filesystem The string representation of the file system.
|
|
*/
|
|
virtual FileSystemParams
|
|
GetRequestParams(const nsString& aFileSystem) const = 0;
|
|
|
|
/*
|
|
* Wrap the task success result to FileSystemResponseValue for sending it
|
|
* through IPC.
|
|
* It will be called when the task is completed successfully and we need to
|
|
* send the task success result back to the child process.
|
|
*/
|
|
virtual FileSystemResponseValue
|
|
GetSuccessRequestResult() const = 0;
|
|
|
|
/*
|
|
* Unwrap the IPC message to get the task success result.
|
|
* It will be called when the task is completed successfully and an IPC
|
|
* message is received in the child process and we want to get the task
|
|
* success result.
|
|
*/
|
|
virtual void
|
|
SetSuccessRequestResult(const FileSystemResponseValue& aValue) = 0;
|
|
|
|
bool
|
|
HasError() const { return mErrorValue != NS_OK; }
|
|
|
|
// Overrides PFileSystemRequestChild
|
|
virtual bool
|
|
Recv__delete__(const FileSystemResponseValue& value) MOZ_OVERRIDE;
|
|
|
|
BlobParent*
|
|
GetBlobParent(nsIDOMFile* aFile) const;
|
|
|
|
nsresult mErrorValue;
|
|
|
|
nsRefPtr<FileSystemBase> mFileSystem;
|
|
nsRefPtr<FileSystemRequestParent> mRequestParent;
|
|
private:
|
|
/*
|
|
* After finishing the task operation, handle the task result.
|
|
* If it is an IPC task, send back the IPC result. Or else, send the result
|
|
* to the content page.
|
|
*/
|
|
void
|
|
HandleResult();
|
|
|
|
/*
|
|
* Wrap the task result to FileSystemResponseValue for sending it through IPC.
|
|
* It will be called when the task is completed and we need to
|
|
* send the task result back to the child process.
|
|
*/
|
|
FileSystemResponseValue
|
|
GetRequestResult() const;
|
|
|
|
/*
|
|
* Unwrap the IPC message to get the task result.
|
|
* It will be called when the task is completed and an IPC message is received
|
|
* in the child process and we want to get the task result.
|
|
*/
|
|
void
|
|
SetRequestResult(const FileSystemResponseValue& aValue);
|
|
};
|
|
|
|
} // namespace dom
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_dom_FileSystemTaskBase_h
|