fix(performance): reduce memory allocation in containsPath (#3730)

yoav-orca · web-flow · commit 6f70927bccf7 · 2025-03-13T14:39:57.000-04:00
Signed-off-by: Yoav Alon &lt;yoav@orca.security&gt;
diff --git a/syft/internal/fileresolver/path_skipper.go b/syft/internal/fileresolver/path_skipper.go
@@ -143,7 +143,11 @@ func containsPath(p1, p2 string) bool {
 	if p1Clean == p2Clean {
 		return true
 	}
-	return strings.HasPrefix(p1Clean, p2Clean+"/")
+	if !strings.HasPrefix(p1Clean, p2Clean) {
+		return false
+	}
+	// This is done to avoid allocation of a new string
+	return len(p1Clean) > len(p2Clean) && p1Clean[len(p2Clean)] == '/'
 }
 
 func simpleClean(p string) string {

Original file line number	Diff line number	Diff line change
`@@ -143,7 +143,11 @@ func containsPath(p1, p2 string) bool {`
`143`	`143`	`if p1Clean == p2Clean {`
`144`	`144`	`return true`
`145`	`145`	`}`
`146`		`- return strings.HasPrefix(p1Clean, p2Clean+"/")`
	`146`	`+ if !strings.HasPrefix(p1Clean, p2Clean) {`
	`147`	`+ return false`
	`148`	`+ }`
	`149`	`+ // This is done to avoid allocation of a new string`
	`150`	`+ return len(p1Clean) > len(p2Clean) && p1Clean[len(p2Clean)] == '/'`
`147`	`151`	`}`
`148`	`152`
`149`	`153`	`func simpleClean(p string) string {`