Merge pull request kubernetes#75699 from smarterclayton/fast_encode

Avoid allocations when building SelfLinks and fast path escape

Author: k8s-ci-robot

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/BUILD

@@ -34,6 +34,7 @@ go_test(
         "//staging/src/k8s.io/apiserver/pkg/endpoints/request:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/registry/rest:go_default_library",
         "//vendor/github.com/evanphx/json-patch:go_default_library",
+        "//vendor/github.com/google/gofuzz:go_default_library",
         "//vendor/k8s.io/utils/trace:go_default_library",
     ],
 )

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/namer.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"strings"
 
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -86,6 +87,21 @@ func (n ContextBasedNaming) Name(req *http.Request) (namespace, name string, err
 	return ns, requestInfo.Name, nil
 }
 
+// fastURLPathEncode encodes the provided path as a URL path
+func fastURLPathEncode(path string) string {
+	for _, r := range []byte(path) {
+		switch {
+		case r >= '-' && r <= '9', r >= 'A' && r <= 'Z', r >= 'a' && r <= 'z':
+			// characters within this range do not require escaping
+		default:
+			var u url.URL
+			u.Path = path
+			return u.EscapedPath()
+		}
+	}
+	return path
+}
+
 func (n ContextBasedNaming) GenerateLink(requestInfo *request.RequestInfo, obj runtime.Object) (uri string, err error) {
 	namespace, name, err := n.ObjectName(obj)
 	if err == errEmptyName && len(requestInfo.Name) > 0 {
@@ -101,19 +117,23 @@ func (n ContextBasedNaming) GenerateLink(requestInfo *request.RequestInfo, obj r
 		return n.SelfLinkPathPrefix + url.QueryEscape(name) + n.SelfLinkPathSuffix, nil
 	}
 
-	return n.SelfLinkPathPrefix +
-			url.QueryEscape(namespace) +
-			"/" + url.QueryEscape(requestInfo.Resource) + "/" +
-			url.QueryEscape(name) +
-			n.SelfLinkPathSuffix,
-		nil
+	builder := strings.Builder{}
+	builder.Grow(len(n.SelfLinkPathPrefix) + len(namespace) + len(requestInfo.Resource) + len(name) + len(n.SelfLinkPathSuffix) + 8)
+	builder.WriteString(n.SelfLinkPathPrefix)
+	builder.WriteString(namespace)
+	builder.WriteByte('/')
+	builder.WriteString(requestInfo.Resource)
+	builder.WriteByte('/')
+	builder.WriteString(name)
+	builder.WriteString(n.SelfLinkPathSuffix)
+	return fastURLPathEncode(builder.String()), nil
 }
 
 func (n ContextBasedNaming) GenerateListLink(req *http.Request) (uri string, err error) {
 	if len(req.URL.RawPath) > 0 {
 		return req.URL.RawPath, nil
 	}
-	return req.URL.EscapedPath(), nil
+	return fastURLPathEncode(req.URL.Path), nil
 }
 
 func (n ContextBasedNaming) ObjectName(obj runtime.Object) (namespace, name string, err error) {

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/namer_test.go

@@ -17,9 +17,13 @@ limitations under the License.
 package handlers
 
 import (
+	"math/rand"
+	"net/url"
 	"testing"
 
-	"k8s.io/api/core/v1"
+	fuzz "github.com/google/gofuzz"
+
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -114,3 +118,62 @@ func TestGenerateLink(t *testing.T) {
 		}
 	}
 }
+
+func Test_fastURLPathEncode_fuzz(t *testing.T) {
+	specialCases := []string{"/", "//", ".", "*", "/abc%"}
+	for _, test := range specialCases {
+		got := fastURLPathEncode(test)
+		u := url.URL{Path: test}
+		expected := u.EscapedPath()
+		if got != expected {
+			t.Errorf("%q did not match %q", got, expected)
+		}
+	}
+	f := fuzz.New().Funcs(
+		func(s *string, c fuzz.Continue) {
+			*s = randString(c.Rand)
+		},
+	)
+	for i := 0; i < 2000; i++ {
+		var test string
+		f.Fuzz(&test)
+
+		got := fastURLPathEncode(test)
+		u := url.URL{Path: test}
+		expected := u.EscapedPath()
+		if got != expected {
+			t.Errorf("%q did not match %q", got, expected)
+		}
+	}
+}
+
+// Unicode range fuzzer from github.com/google/gofuzz/fuzz.go
+
+type charRange struct {
+	first, last rune
+}
+
+var unicodeRanges = []charRange{
+	{0x00, 0x255},
+	{' ', '~'},           // ASCII characters
+	{'\u00a0', '\u02af'}, // Multi-byte encoded characters
+	{'\u4e00', '\u9fff'}, // Common CJK (even longer encodings)
+}
+
+// randString makes a random string up to 20 characters long. The returned string
+// may include a variety of (valid) UTF-8 encodings.
+func randString(r *rand.Rand) string {
+	n := r.Intn(20)
+	runes := make([]rune, n)
+	for i := range runes {
+		runes[i] = unicodeRanges[r.Intn(len(unicodeRanges))].choose(r)
+	}
+	return string(runes)
+}
+
+// choose returns a random unicode character from the given range, using the
+// given randomness source.
+func (r *charRange) choose(rand *rand.Rand) rune {
+	count := int64(r.last - r.first)
+	return r.first + rune(rand.Int63n(count))
+}

staging/src/k8s.io/apiserver/pkg/endpoints/watch_test.go

@@ -757,6 +757,30 @@ func TestWatchHTTPTimeout(t *testing.T) {
 func BenchmarkWatchHTTP(b *testing.B) {
 	items := benchmarkItems(b)
 
+	// use ASCII names to capture the cost of handling ASCII only self-links
+	for i := range items {
+		item := &items[i]
+		item.Namespace = fmt.Sprintf("namespace-%d", i)
+		item.Name = fmt.Sprintf("reasonable-name-%d", i)
+	}
+
+	runWatchHTTPBenchmark(b, items)
+}
+
+func BenchmarkWatchHTTP_UTF8(b *testing.B) {
+	items := benchmarkItems(b)
+
+	// use UTF names to capture the cost of handling UTF-8 escaping in self-links
+	for i := range items {
+		item := &items[i]
+		item.Namespace = fmt.Sprintf("躀痢疈蜧í柢-%d", i)
+		item.Name = fmt.Sprintf("翏Ŏ熡韐-%d", i)
+	}
+
+	runWatchHTTPBenchmark(b, items)
+}
+
+func runWatchHTTPBenchmark(b *testing.B, items []example.Pod) {
 	simpleStorage := &SimpleRESTStorage{}
 	handler := handle(map[string]rest.Storage{"simples": simpleStorage})
 	server := httptest.NewServer(handler)