perf(aws_role): compile ARN regexp once at package level

[b-wulan]

File changed:

aws_role.go

Optimization:

Moved regexp.Compile(...) from inside parseRole() (called once per role) to a package-level regexp.MustCompile variable awsRoleRe. The pattern is identical — only the compilation site moved.

+var awsRoleRe = regexp.MustCompile(`arn:([^:\n]*):([^:\n]*):([^:\n]*):([^:\n]*):(([^:/\n]*)[:/])?([^:,\n]*)`)

 func parseRole(role string) (*AWSRole, error) {
-    r, _ := regexp.Compile("arn:([^:\n]*):([^:\n]*):([^:\n]*):([^:\n]*):(([^:/\n]*)[:/])?([^:,\n]*)")
-    tokens := r.FindAllString(role, -1)
+    tokens := awsRoleRe.FindAllString(role, -1)

Why it improves the project:

parseRole is called once per AWS role in the SAML response — a typical multi-account SSO session may return dozens of roles. Compiling a regexp involves NFA/DFA construction, which allocates and is CPU-intensive. Doing this once at startup instead of on every call eliminates that overhead entirely.

The original code also silently discarded the regexp.Compile error (r, _ := ...). If the pattern were somehow invalid, r would be nil and r.FindAllString would panic mid-execution. regexp.MustCompile at package level converts any such failure into a startup-time panic, which is the correct Go convention for static patterns.