perf: use Aho-Corasick for string matching

go.mod

@@ -4,5 +4,6 @@ go 1.13
 
 require (
 	github.com/gin-gonic/gin v1.5.0
+	github.com/signalsciences/ac v1.1.0
 	github.com/stretchr/testify v1.4.0
 )

go.sum

@@ -24,6 +24,8 @@ github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 h1:Esafd1046DLD
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/signalsciences/ac v1.1.0 h1:3PS8uD5khoTgnnF10aCswUAVDgW8o30SGcN6XUv27yU=
+github.com/signalsciences/ac v1.1.0/go.mod h1:jnlGjtNM8dyGcnOdZjY35vHmUtOn5M5K4U+BzcVPjN0=
 github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=

requestfilters.go

@@ -4,6 +4,8 @@ import (
 	"net/http"
 	"path"
 	"strings"
+
+	"github.com/signalsciences/ac/acascii"
 )
 
 // RequestFilter decide whether or not to compress response judging by request
@@ -39,14 +41,14 @@ func (c *CommonRequestFilter) ShouldCompress(req *http.Request) bool {
 //
 // Omit this filter if you want to compress all extension.
 type ExtensionFilter struct {
-	Exts       Set
+	Exts       *acascii.Matcher
 	AllowEmpty bool
 }
 
-// NewExtensionFilter ...
+// NewExtensionFilter returns a extension or panics
 func NewExtensionFilter(extensions []string) *ExtensionFilter {
 	var (
-		exts       = make(Set)
+		exts       = make([]string, 0, len(extensions))
 		allowEmpty bool
 	)
 
@@ -55,10 +57,13 @@ func NewExtensionFilter(extensions []string) *ExtensionFilter {
 			allowEmpty = true
 			continue
 		}
-		exts.Add(item)
+		exts = append(exts, item)
 	}
 
-	return &ExtensionFilter{Exts: exts, AllowEmpty: allowEmpty}
+	return &ExtensionFilter{
+		Exts:       acascii.MustCompileString(exts),
+		AllowEmpty: allowEmpty,
+	}
 }
 
 // ShouldCompress implements RequestFilter interface
@@ -67,7 +72,7 @@ func (e *ExtensionFilter) ShouldCompress(req *http.Request) bool {
 	if ext == "" {
 		return e.AllowEmpty
 	}
-	return e.Exts.Contains(ext)
+	return e.Exts.MatchString(ext)
 }
 
 // defaultExtensions is the list of default extensions for which to enable gzip.

responsefilters.go

@@ -2,7 +2,8 @@ package gzip
 
 import (
 	"net/http"
-	"strings"
+
+	"github.com/signalsciences/ac/acascii"
 )
 
 // ResponseHeaderFilter decide whether or not to compress response
@@ -39,14 +40,14 @@ func (s *SkipCompressedFilter) ShouldCompress(header http.Header) bool {
 //
 // Omit this filter if you want to compress all content type.
 type ContentTypeFilter struct {
-	Types      Set
+	Types      *acascii.Matcher
 	AllowEmpty bool
 }
 
 // NewContentTypeFilter ...
 func NewContentTypeFilter(types []string) *ContentTypeFilter {
 	var (
-		set        = make(Set)
+		nonEmpty   = make([]string, 0, len(types))
 		allowEmpty bool
 	)
 
@@ -55,14 +56,16 @@ func NewContentTypeFilter(types []string) *ContentTypeFilter {
 			allowEmpty = true
 			continue
 		}
-		set.Add(item)
+		nonEmpty = append(nonEmpty, item)
 	}
 
-	return &ContentTypeFilter{Types: set, AllowEmpty: allowEmpty}
+	return &ContentTypeFilter{
+		Types:      acascii.MustCompileString(nonEmpty),
+		AllowEmpty: allowEmpty,
+	}
 }
 
 // ShouldCompress implements RequestFilter interface
-// TODO: optimize with ahocorasick
 func (e *ContentTypeFilter) ShouldCompress(header http.Header) bool {
 	contentType := header.Get("Content-Type")
 
@@ -70,9 +73,7 @@ func (e *ContentTypeFilter) ShouldCompress(header http.Header) bool {
 		return e.AllowEmpty
 	}
 
-	return e.Types.ContainsFunc(func(s string) bool {
-		return strings.Contains(contentType, s)
-	})
+	return e.Types.MatchString(contentType)
 }
 
 // defaultContentType is the list of default content types for which to enable gzip.

set.go

@@ -1,34 +0,0 @@
-package gzip
-
-// Set stores distinct strings.
-// Original source:
-// https://github.com/caddyserver/caddy/blob/7fa90f08aee0861187236b2fbea16b4fa69c5a28/caddyhttp/gzip/requestfilter.go#L76-L105
-type Set map[string]struct{}
-
-// Add adds an element to the set.
-func (s Set) Add(value string) {
-	s[value] = struct{}{}
-}
-
-// Remove removes an element from the set.
-func (s Set) Remove(value string) {
-	delete(s, value)
-}
-
-// Contains check if the set contains value.
-func (s Set) Contains(value string) bool {
-	_, ok := s[value]
-	return ok
-}
-
-// ContainsFunc is similar to Contains. It iterates all the
-// elements in the set and passes each to f. It returns true
-// on the first call to f that returns true and false otherwise.
-func (s Set) ContainsFunc(f func(string) bool) bool {
-	for k := range s {
-		if f(k) {
-			return true
-		}
-	}
-	return false
-}

set_test.go

@@ -1,38 +0,0 @@
-package gzip
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestSet(t *testing.T) {
-	var set = make(Set)
-
-	assert.False(t, set.Contains("a"))
-	set.Add("a")
-	assert.True(t, set.Contains("a"))
-
-	assert.False(t, set.Contains("b"))
-	set.Add("b")
-	assert.True(t, set.Contains("b"))
-
-	assert.True(t, set.ContainsFunc(func(s string) bool {
-		return s == "a"
-	}))
-	assert.True(t, set.ContainsFunc(func(s string) bool {
-		return s == "b"
-	}))
-	assert.False(t, set.ContainsFunc(func(s string) bool {
-		return s == "c"
-	}))
-
-	set.Remove("a")
-	assert.False(t, set.Contains("a"))
-	set.Remove("b")
-	assert.False(t, set.Contains("b"))
-
-	assert.False(t, set.Contains("c"))
-	set.Remove("c")
-	assert.False(t, set.Contains("c"))
-}