split Corpus into base array and spill slice

config.go

@@ -862,7 +862,7 @@ func newConfig(icfg *internalConfig) *Config {
 	var cfg Config
 
 	// origins
-	if icfg.corpus == nil {
+	if icfg.corpus.IsEmpty() {
 		cfg.Origins = []string{"*"}
 	} else {
 		cfg.Origins = icfg.corpus.Elems()

internal/origins/corpus.go

@@ -9,39 +9,75 @@ import (
 // A Corpus represents a set of allowed (tuple) [Web origins].
 //
 // [Web origins]: https://developer.mozilla.org/en-US/docs/Glossary/Origin
-type Corpus []Root
+type Corpus struct {
+	base  [4]Root
+	spill []Root
+	next  int
+}
 
 type Root struct {
 	scheme string
 	tree   radix.Tree
 }
 
+func (c *Corpus) IsEmpty() bool {
+	return c.next == 0
+}
+
 // Add augments c with all Web origins encompassed by pattern.
 func (c *Corpus) Add(pattern *Pattern) {
-	i := slices.IndexFunc(*c, func(r Root) bool { return r.scheme == pattern.Scheme })
-	if i < 0 {
-		var tree radix.Tree
-		tree.Insert(pattern.Value, pattern.Port)
-		root := Root{scheme: pattern.Scheme, tree: tree}
-		*c = append(*c, root)
+	// search array first
+	for i := range c.next {
+		if c.base[i].scheme == pattern.Scheme {
+			c.base[i].tree.Insert(pattern.Value, pattern.Port)
+			return
+		}
+	}
+	if c.next < len(c.base) {
+		c.base[c.next].scheme = pattern.Scheme
+		c.base[c.next].tree.Insert(pattern.Value, pattern.Port)
+		c.next++
 		return
 	}
-	(*c)[i].tree.Insert(pattern.Value, pattern.Port)
+	// search slice
+	for i := range c.spill {
+		if c.spill[i].scheme == pattern.Scheme {
+			c.spill[i].tree.Insert(pattern.Value, pattern.Port)
+			return
+		}
+	}
+	var tree radix.Tree
+	tree.Insert(pattern.Value, pattern.Port)
+	root := Root{scheme: pattern.Scheme, tree: tree}
+	c.spill = append(c.spill, root)
 }
 
 // Contains reports whether c contains origin o.
 func (c Corpus) Contains(o *Origin) bool {
-	i := slices.IndexFunc(c, func(r Root) bool { return r.scheme == o.Scheme })
-	if i < 0 {
-		return false
+	for i := range c.next {
+		if c.base[i].scheme == o.Scheme {
+			return c.base[i].tree.Contains(o.Value, o.Port)
+		}
 	}
-	return c[i].tree.Contains(o.Value, o.Port)
+	for i := range c.spill {
+		if c.spill[i].scheme == o.Scheme {
+			return c.spill[i].tree.Contains(o.Value, o.Port)
+		}
+	}
+	return false
 }
 
 // Elems returns a slice containing textual representations of c's elements.
 func (c Corpus) Elems() []string {
 	var res []string
-	for _, root := range c {
+	for _, root := range c.base {
+		elems := root.tree.Elems()
+		for i := range elems {
+			elems[i] = root.scheme + "://" + elems[i]
+		}
+		res = append(res, elems...)
+	}
+	for _, root := range c.spill {
 		elems := root.tree.Elems()
 		for i := range elems {
 			elems[i] = root.scheme + "://" + elems[i]

middleware.go

@@ -168,7 +168,7 @@ func (icfg *internalConfig) handleNonCORS(resHdrs http.Header, isOPTIONS bool) {
 	if icfg.privateNetworkAccessNoCors {
 		return
 	}
-	if icfg.corpus != nil {
+	if !icfg.corpus.IsEmpty() {
 		// See https://fetch.spec.whatwg.org/#cors-protocol-and-http-caches.
 		// Note that we deliberately list "Origin" in the Vary header of responses
 		// to actual requests even in cases where a single origin is allowed,
@@ -293,7 +293,7 @@ func (icfg *internalConfig) processOriginForPreflight(
 	if !ok {
 		return false
 	}
-	if !icfg.credentialed && icfg.corpus == nil {
+	if !icfg.credentialed && icfg.corpus.IsEmpty() {
 		buf[headers.ACAO] = headers.WildcardSgl
 		return true
 	}
@@ -347,11 +347,11 @@ func (icfg *internalConfig) handleCORSActual(
 	case isOPTIONS:
 		// see the implementation comment in handleCORSPreflight
 		resHdrs.Add(headers.Vary, headers.ValueVaryOptions)
-	case icfg.corpus != nil:
+	case !icfg.corpus.IsEmpty():
 		// See https://fetch.spec.whatwg.org/#cors-protocol-and-http-caches.
 		resHdrs.Add(headers.Vary, headers.Origin)
 	}
-	if !icfg.credentialed && icfg.corpus == nil {
+	if !icfg.credentialed && icfg.corpus.IsEmpty() {
 		// See the last paragraph in
 		// https://fetch.spec.whatwg.org/#cors-protocol-and-http-caches.
 		// Note that we deliberately list "Origin" in the Vary header of responses