Addressing comments.

ratelimits/limiter.go

@@ -307,7 +307,7 @@ func (l *Limiter) initialize(ctx context.Context, rl limit, name Name, id string
 // the limit specified by name is returned. If no default limit exists for the
 // specified name, ErrLimitDisabled is returned.
 func (l *Limiter) getLimit(name Name, id string) (limit, error) {
-	if !isNameValid(name) {
+	if !name.isValid() {
 		// This should never happen. Callers should only be specifying the limit
 		// Name enums defined in this package.
 		return limit{}, fmt.Errorf("specified name enum %q, is invalid", name)

ratelimits/names.go

@@ -53,10 +53,15 @@ const (
 	CertificatesPerFQDNSetPerAccount
 )
 
+// isValid returns true if the Name is a valid rate limit name.
+func (n Name) isValid() bool {
+	return n > Unknown && n < Name(len(nameToString))
+}
+
 // String returns the string representation of the Name. It allows Name to
 // satisfy the fmt.Stringer interface.
 func (n Name) String() string {
-	if !isNameValid(n) {
+	if !n.isValid() {
 		return nameToString[Unknown]
 	}
 	return nameToString[n]
@@ -215,9 +220,3 @@ func nameToEnumString(s Name) string {
 func bucketKey(name Name, id string) string {
 	return nameToEnumString(name) + ":" + id
 }
-
-// isLimitNameValid returns true if the provided Name is a valid rate limit
-// name.
-func isNameValid(name Name) bool {
-	return name > Unknown && name < Name(len(nameToString))
-}

ratelimits/names_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/letsencrypt/boulder/test"
 )
 
-func TestIsNameValid(t *testing.T) {
+func TestNameIsValid(t *testing.T) {
 	t.Parallel()
 	type args struct {
 		name Name
@@ -22,7 +22,7 @@ func TestIsNameValid(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := isNameValid(tt.args.name)
+			got := tt.args.name.isValid()
 			test.AssertEquals(t, tt.want, got)
 		})
 	}

ratelimits/source.go

@@ -12,19 +12,27 @@ var ErrBucketNotFound = fmt.Errorf("bucket not found")
 
 // source is an interface for creating and modifying TATs.
 type source interface {
-	// Set stores the TAT at the specified bucketKey ('name:id'). Contexts
-	// passed to this method should have a timeout or deadline set to prevent
-	// the operation from blocking indefinitely.
+	// Set stores the TAT at the specified bucketKey (formatted as 'name:id').
+	// Implementations MUST ensure non-blocking operations by either:
+	//   a) applying a deadline or timeout to the context WITHIN the method, or
+	//   b) guaranteeing the operation will not block indefinitely (e.g. via
+	//    the underlying storage client implementation).
 	Set(ctx context.Context, bucketKey string, tat time.Time) error
 
-	// Get retrieves the TAT at the specified bucketKey ('name:id'). Contexts
-	// passed to this method should have a timeout or deadline set to prevent
-	// the operation from blocking indefinitely.
+	// Get retrieves the TAT associated with the specified bucketKey (formatted
+	// as 'name:id'). Implementations MUST ensure non-blocking operations by
+	// either:
+	//   a) applying a deadline or timeout to the context WITHIN the method, or
+	//   b) guaranteeing the operation will not block indefinitely (e.g. via
+	//    the underlying storage client implementation).
 	Get(ctx context.Context, bucketKey string) (time.Time, error)
 
-	// Delete deletes the TAT at the specified bucketKey ('name:id'). Contexts
-	// passed to this method should have a timeout or deadline set to prevent
-	// the operation from blocking indefinitely.
+	// Delete removes the TAT associated with the specified bucketKey (formatted
+	// as 'name:id'). Implementations MUST ensure non-blocking operations by
+	// either:
+	//   a) applying a deadline or timeout to the context WITHIN the method, or
+	//   b) guaranteeing the operation will not block indefinitely (e.g. via
+	//    the underlying storage client implementation).
 	Delete(ctx context.Context, bucketKey string) error
 }