Store old lock projects and lookup new look project in that map

Author: zmackie

cmd/dep/root_analyzer.go

@@ -168,17 +168,20 @@ func (a *rootAnalyzer) DeriveManifestAndLock(dir string, pr gps.ProjectRoot) (gp
 func (a *rootAnalyzer) FinalizeRootManifestAndLock(m *dep.Manifest, l *dep.Lock, ol dep.Lock) {
 	// Iterate through the new projects in solved lock and add them to manifest
 	// if they are direct deps and log feedback for all the new projects.
-	sl := gps.SortedLockedProjects(l.Projects())
-	sol := gps.SortedLockedProjects(ol.Projects())
-	for i, y := range sl {
+	//
+	// IDEA: Make a lookup map of ProjectRoot ->projects in the old lock
+	// use that data structure to simplify these loops
+	olLookup := make(map[gps.ProjectRoot]gps.LockedProject)
+	for _, op := range ol.Projects() {
+		olLookup[op.Ident().ProjectRoot] = op
+	}
+	for _, y := range l.Projects() {
 		var f *fb.ConstraintFeedback
 		pr := y.Ident().ProjectRoot
-		if i < len(sol) {
-			op := sol[i]
-			if same := y.Ident().Eq(op.Ident()); same {
-				if diff := gps.DiffProjects(y, op); diff != nil {
-					fmt.Printf("Some changes: \nImported: %v\nRevised: %v\nDiff: %v\n", y, op, diff)
-				}
+
+		if op, ok := olLookup[pr]; ok {
+			if diff := gps.DiffProjects(y, op); diff != nil {
+				fmt.Printf("Some changes: \nImported: %v\nRevised: %v\nDiff: %v\n", y, op, diff)
 			}
 		}
 		// New constraints: in new lock and dir dep but not in manifest