[feature request] lazy load object variables while attach debug

[nghduc97]

In attach debug, if there are a lot of local variables containing array of objects, the extension fetch a deep copy back to the editor making each step very slow. IntelliJ run fast by only showing the variable's name and type and only fetch the content when I unfold it in watch panel. I would like to have this on the extension.

Environment

• Operating System: Arch
• JDK version: 9.0.4
• Visual Studio Code version: 1.24.1
• Java extension version: 0.26.0
• Java Debugger extension version: 0.9.0

[yaohaizh]

@testforstephen Could you help investigate this issue on the debug protocol?

[andxu]

That is possibly caused by we hint vscode a cheap local scope
https://github.com/Microsoft/java-debug/blob/master/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/ScopesRequestHandler.java#L50

We can hint vscode expensive fetching on attach mode.