Introduction

Hosted mode currently takes too long to start up. A significant portion of this startup time is in compiling from source. Instant Hosted Mode proposes to make use of existing class files where possible.

Work in progress

Considerations

• JSNI is not preserved in class files, so we will still need to read from source. We can however, save the JSNI to a file and reuse it if the source file has not changed.
• It isn't clear how super-source fits in.
• External bytecode rewriting tools, such as emma, need to be considered.
• The current generator API makes some aspects of this more complicated, so it might be useful to alter the API (and might be combined with other ideas for allowing generators to run outside a GWT compile)
• Method parameter names are not generally available (though it might be possible to use debug information to get them), and some generators require them.

Implementation Plan

Map dataMap = ...; ProgressManager progressManager = new ProgressManager(); progressManager.add(new ProgressTimer<Map>(dataMap, 5, 30, "progress message 1") { public void progressRun() { Map dataMap = getData(); ... } }); progressManager.add(new ProgressTimer<Map>(dataMap, 5, 50, "progress message 2") { public void progressRun() { Map dataMap = getData(); ... } }); progressManager.add(new ProgressTimer(5, 85, "progress message 3") { public void progressRun() { ... } }); progressManager.start();

진행할 과정들을 나눈 후에 ProgressTimer 를 구현하여 progressRun 메소드에서 실행하도록 한후 ProgressManager 에 추가하는 방식으로 추가된 순서대로 실행을 하도록 하는 방식입니다. 약간의 딜레이가 있을 경우에는 프로세스가 화면 렌더링을 하기전에 즉, 화면이 멈춰보이는 상태 전에 MessageBox 의 progress 를 업데이트합니다.

추가적으로 생성할 때 내부에서 사용할 객체를 넘겨주기 때문에 필요한 객체를 효과적으로 사용할 수 있습니다.


[#M_관련 소스|접기|ㅁ ProgressManager.java
public class ProgressManager { /** * 처음 시작할 타이머 */ private ProgressTimer firstTimer; /** * 가장 마지막에 추가된 타이머 */ private ProgressTimer lastTimer; /** * ProgressTimer 를 추가합니다. * @param timer 추가할 타이머 */ public void add(ProgressTimer timer) { if (firstTimer == null) { firstTimer = timer; lastTimer = timer; } else { lastTimer.setNextTimer(timer); lastTimer = timer; } } /** * first ProgressTimer를 시작합니다. */ public void start() { if (firstTimer != null) { firstTimer.schedule(firstTimer.getDelayMillis()); } } }


ㅁ ProgressTimer.java
import com.google.gwt.user.client.Timer; import com.gwtext.client.widgets.MessageBox; public abstract class ProgressTimer<T> extends Timer { /** * 타이머에서 사용할 데이터 */ private T data; /** * 타이머 딜레이 */ private int delayMillis; /** * 진행 퍼센테이지 */ private int percentage; /** * 진행 메세지 */ private String message; /** * 다음번에 진행할 타이머 */ private ProgressTimer nextTimer; public ProgressTimer(int delayMilli, int percentage) { this(null, delayMilli, percentage); } public ProgressTimer(T data, int delayMilli, int percentage) { this(data, delayMilli, percentage, percentage + "%"); } public ProgressTimer(int delayMilli, int percentage, String message) { this(null, delayMilli, percentage, message); } public ProgressTimer(T data, int delayMilli, int percentage, String message) { this.data = data; this.delayMillis = delayMilli; this.percentage = percentage; this.message = message; } public T getData() { return data; } public int getDelayMillis() { return delayMillis; } public void setNextTimer(ProgressTimer nextTimer) { this.nextTimer = nextTimer; } public void run() { progressRun(); if (nextTimer != null) { nextTimer.schedule(nextTimer.getDelayMillis()); } else { MessageBox.hide(); } } public abstract void progressRun(); public void schedule(int delayMillis) { MessageBox.updateProgress(percentage, message); super.schedule(delayMillis); } }

ㅁ 사용법
  - 사용법은 기존의 자바 로깅과 유사하게 구현하였습니다.
    (내부 구현은 GWT-Ext 의 ShowcasePanel 참조...)
   protected static LoggerWindow logger = LoggerWindow.get(); ... logger.info("start initPanel"); ... if (logger.isDebugEnabled()) { logger.debug("before createFormRenderer"); }
   위의 코드같이 로그를 작성합니다.


ㅁ 페이지 실행
  - 실행시 주소 뒤에 파라미터로 로그레벨을 정의합니다.
 

Release 1.6

Anticipated Time Frame - Q1 2009

• New compiled file deployment structure
  • Easily compile into a war file structure, making it easy to deploy your compiled GWT application into standard servlet containers
• Migration from Tomcat to Jetty hosted mode server
  • A more pluggable architecture for the hosted mode server will enable developers to use servlet containers other than Tomcat with the Hosted Mode browser
• Uniform event handlers
  • Event handlers will be implemented in a uniform fashion across all widgets, with listeners deprecated
• DatePicker, LazyPanel migrated in from incubator
  • New widgets from the incubator
• String performance improvements
  • StringBuilder uses deferred binding to optimize string appends per-browser
• Compiler performance improvements
  • 1.6 will introduce parallel permutation compilations and other performance tweaks for faster compiles

Post 1.6

The following are features that are on our roadmap for releases post 1.6, but are in various states of development. As we reach the end of the 1.6 cycle, we'll update the roadmap with which features we are targeting for the next release.

• Developer Guided Code splitting
  • Developer guided code splitting is a mechanism that allows developers to specify asynchronous split points in their code where the code base can be split and downloaded in different chunks. This is currently an R&D project but looks promising.
• Analysis of compiled code, aka Story of your compile (SOYC)
  • Aims to give developers concrete information about their compiled JavaScript, such as which Java classes are generating the most JavaScript code.
• In-browser hosted mode, aka Out-of-process Hosted Mode (OOPHM)
  • In-browser hosted mode will allow GWT developers to debug their apps within a browser rather than GWT's hosted mode browser
• UI Binder
  • The UI Binder will allow the creation of UI elements in a declarative fashion. Watch for UI Binder to land in the GWT incubator soon.
• Client Bundle
  • Client Bundle implements the power of deferred binding used in Image Bundle in a generic fashion so that it can be used on many resources. These include TextResource, ImageResource, and CSSResource
• RPC performance improvements
  • Ongoing work to improve the performance of RPC
    
    
    

RPC 자체도 Callback 기반입니다. 그 것을 잘 이용한다면 callback 으로도 리턴과 같은 효과를 줄 수 있습니다.

아래 메소드들은 일반적인 메소드와 콜백을 이용하여 리턴을 하는 메소드입니다.