Bug 135663 (ReplaySavepoints)

Summary:	Web Replay: support replaying to arbitrary debugger positions
Product:	WebKit	Reporter:	Brian Burg <burg>
Component:	Web Inspector	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED LATER
Severity:	Normal	CC:	graouts, inspector-bugzilla-changes, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	528+ (Nightly build)
Hardware:	All
OS:	All
Bug Depends on:	135690, 135830
Bug Blocks:	136290

Description Brian Burg 2014-08-06 12:05:00 PDT

We should be able to revert back to any position that the debugger is in.
In past prototypes, we have called this concept "savepoints", "bookmarks", or "checkpoints".

Savepoints have coordinates of <event loop input, breakpoint, debugger walk>.


The algorithm is:
0. During normal replay, keep records of how many times a breakpoint is hit per event loop input.
1. replay to the preceding event loop input and pause playback
2. enable the debugger and set the preceding breakpoint which was hit
3. unpause playback, then that breakpoint
4. replay the series of debugger commands that led to the terminal state.


This feature may be split into smaller bugs. It requires no new backend support.

Comment 1 Radar WebKit Bug Importer 2014-08-06 12:05:10 PDT

<rdar://problem/17934582>

Comment 2 Brian Burg 2014-08-11 22:45:57 PDT

This could possibly be messed up by promises not working when the inspected page is paused.

Comment 3 BJ Burg 2017-07-10 14:01:25 PDT

Closing web replay-related bugs until we resume working on the feature again.