Re: [PATCH] Reset the graph plotter internals when HEAD has changed.

From: Shawn O. Pearce <spearce@spearce.org>
Date: Jun 10, 2008, 00:40 UTC
Message-ID: <20080610004046.GE4389@spearce.org>
In-Reply-To: <1213051816-4046-2-git-send-email-robin.rosenberg.lists@dewire.com>

Robin Rosenberg <robin.rosenberg.lists@dewire.com> wrote:

> When we reset HEAD to an old revision it becomes more visible than when
> we add a new commit. This is an intermediate solution.

Hmm.

Show 18 quoted lines

> @@ -521,8 +524,18 @@ public class GitHistoryPage extends HistoryPage {
>  		if (db == null)
>  			return false;
>  
> +		final AnyObjectId headId;
> +		try {
> +			headId = db.resolve("HEAD");
> +		} catch (IOException e) {
> +			Activator.logError("Cannot parse HEAD in: "
> +					+ db.getDirectory().getAbsolutePath(), e);
> +			return false;
> +		}
> +
>  		if (currentWalk == null || currentWalk.getRepository() != db
> -				|| pathChange(pathFilters, paths)) {
> +				|| pathChange(pathFilters, paths)
> +				|| headId != null && !headId.equals(currentHeadId)) {
>  			currentWalk = new SWTWalk(db);

Tossing the currentWalk just because HEAD changed to a different commit shouldn't be necessary. Its very heavy-handed. Clearly there is a bug in the plotter code where the reset does not clear state right.

For now this is a reasonable work around. I'll try to remember to come back and debug this case in the future as tossing the entire SWTWalk does reduce redraw performance.

Thanks for at least coming up with the work-around.

-- 
Shawn.