Inefficient file watching

[bpasero]

Came across this code:

vscode/src/vs/platform/extensionManagement/node/extensionsWatcher.ts

Lines 47 to 69 in 1944e5d

	private doesChangeAffects(change: IFileChange, extensionsResource: URI): boolean {
	// Is not immediate child of extensions resource
	if (!this.uriIdentityService.extUri.isEqual(this.uriIdentityService.extUri.dirname(change.resource), extensionsResource)) {
	return false;
	}
	// .obsolete file changed
	if (this.uriIdentityService.extUri.isEqual(change.resource, this.uriIdentityService.extUri.joinPath(extensionsResource, '.obsolete'))) {
	return true;
	}
	// Only interested in added/deleted changes
	if (change.type !== FileChangeType.ADDED && change.type !== FileChangeType.DELETED) {
	return false;
	}
	// Ingore changes to files starting with `.`
	if (this.uriIdentityService.extUri.basename(change.resource).startsWith('.')) {
	return false;
	}
	return true;
	}

I think it can be improved:

• do the cheap checks first (i.e. the change type check)
• do not do a manual check for parent via dirname, there is isEqualOrParent

[sandy081]

do not do a manual check for parent via dirname, there is isEqualOrParent

I want to check if the resource is an immediate child of another resource, for that, isEqualOrParent is not enough, I have to do isEqual check too. Instead I am just checking if parent of the resource is equal to the target resource. I think both shall be equally optimistic.