add more tests for encoding using the static table

integrationtests/self/integration_test.go

@@ -2,6 +2,8 @@ package self
 
 import (
 	"bytes"
+	"fmt"
+	"math/rand"
 
 	"github.com/marten-seemann/qpack"
 
@@ -28,8 +30,21 @@ var _ = Describe("Self Tests", func() {
 		})
 	})
 
+	randomString := func(l int) string {
+		const charset = "abcdefghijklmnopqrstuvwxyz" +
+			"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+		s := make([]byte, l)
+		for i := range s {
+			s[i] = charset[rand.Intn(len(charset))]
+		}
+		return string(s)
+	}
+
 	It("encodes and decodes a single header field", func() {
-		hf := qpack.HeaderField{Name: "foo", Value: "bar"}
+		hf := qpack.HeaderField{
+			Name:  randomString(15),
+			Value: randomString(15),
+		}
 		Expect(encoder.WriteField(hf)).To(Succeed())
 		_, err := decoder.Write(output.Bytes())
 		Expect(err).ToNot(HaveOccurred())
@@ -40,7 +55,7 @@ var _ = Describe("Self Tests", func() {
 		hfs := []qpack.HeaderField{
 			{Name: "foo", Value: "bar"},
 			{Name: "lorem", Value: "ipsum"},
-			{Name: "name", Value: "value"},
+			{Name: randomString(15), Value: randomString(20)},
 		}
 		for _, hf := range hfs {
 			Expect(encoder.WriteField(hf)).To(Succeed())
@@ -54,7 +69,7 @@ var _ = Describe("Self Tests", func() {
 		hfs1 := []qpack.HeaderField{{Name: "foo", Value: "bar"}}
 		hfs2 := []qpack.HeaderField{
 			{Name: "lorem", Value: "ipsum"},
-			{Name: "name", Value: "value"},
+			{Name: randomString(15), Value: randomString(20)},
 		}
 		for _, hf := range hfs1 {
 			Expect(encoder.WriteField(hf)).To(Succeed())
@@ -74,4 +89,121 @@ var _ = Describe("Self Tests", func() {
 		Expect(err).ToNot(HaveOccurred())
 		Expect(headerFields).To(Equal(hfs2))
 	})
+
+	// replace one character by a random character at a random position
+	replaceRandomCharacter := func(s string) string {
+		pos := rand.Intn(len(s))
+		new := s[:pos]
+		for {
+			if c := randomString(1); c != string(s[pos]) {
+				new += c
+				break
+			}
+		}
+		new += s[pos+1:]
+		return new
+	}
+
+	check := func(encoded []byte, hf qpack.HeaderField) {
+		hfs, err := decoder.DecodeFull(encoded)
+		ExpectWithOffset(1, err).ToNot(HaveOccurred())
+		Expect(hfs).To(HaveLen(1))
+		Expect(hfs[0]).To(Equal(hf))
+	}
+
+	// use an entry with a value, for example "set-cookie"
+	It("uses the static table for field names, for fields without values", func() {
+		var hf qpack.HeaderField
+		for {
+			if entry := staticTable[rand.Intn(len(staticTable))]; len(entry.Value) == 0 {
+				hf = qpack.HeaderField{Name: entry.Name}
+				break
+			}
+		}
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		encodedLen := output.Len()
+		check(output.Bytes(), hf)
+		output.Reset()
+		oldName := hf.Name
+		hf.Name = replaceRandomCharacter(hf.Name)
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		fmt.Fprintf(GinkgoWriter, "Encoding field name:\n\t%s: %d bytes\n\t%s: %d bytes\n", oldName, encodedLen, hf.Name, output.Len())
+		Expect(output.Len()).To(BeNumerically(">", encodedLen))
+	})
+
+	// use an entry with a value, for example "set-cookie",
+	// but now use a custom value
+	It("uses the static table for field names, for fields without values", func() {
+		var hf qpack.HeaderField
+		for {
+			if entry := staticTable[rand.Intn(len(staticTable))]; len(entry.Value) == 0 {
+				hf = qpack.HeaderField{
+					Name:  entry.Name,
+					Value: randomString(5),
+				}
+				break
+			}
+		}
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		encodedLen := output.Len()
+		check(output.Bytes(), hf)
+		output.Reset()
+		oldName := hf.Name
+		hf.Name = replaceRandomCharacter(hf.Name)
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		fmt.Fprintf(GinkgoWriter, "Encoding field name:\n\t%s: %d bytes\n\t%s: %d bytes\n", oldName, encodedLen, hf.Name, output.Len())
+		Expect(output.Len()).To(BeNumerically(">", encodedLen))
+	})
+
+	// use an entry with a value, for example
+	//   cache-control -> Value: "max-age=0"
+	// but encode a different value
+	//   cache-control -> xyz
+	It("uses the static table for field names, for fields with values", func() {
+		var hf qpack.HeaderField
+		for {
+			if entry := staticTable[rand.Intn(len(staticTable))]; len(entry.Value) > 0 {
+				hf = qpack.HeaderField{
+					Name:  entry.Name,
+					Value: randomString(20),
+				}
+				break
+			}
+		}
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		encodedLen := output.Len()
+		check(output.Bytes(), hf)
+		output.Reset()
+		oldName := hf.Name
+		hf.Name = replaceRandomCharacter(hf.Name)
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		fmt.Fprintf(GinkgoWriter, "Encoding field name:\n\t%s: %d bytes\n\t%s: %d bytes\n", oldName, encodedLen, hf.Name, output.Len())
+		Expect(output.Len()).To(BeNumerically(">", encodedLen))
+	})
+
+	It("uses the static table for field values", func() {
+		var hf qpack.HeaderField
+		for {
+			if entry := staticTable[rand.Intn(len(staticTable))]; len(entry.Value) > 0 {
+				hf = qpack.HeaderField{
+					Name:  entry.Name,
+					Value: entry.Value,
+				}
+				break
+			}
+		}
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		encodedLen := output.Len()
+		check(output.Bytes(), hf)
+		output.Reset()
+		oldValue := hf.Value
+		hf.Value = replaceRandomCharacter(hf.Value)
+		Expect(encoder.WriteField(hf)).To(Succeed())
+		fmt.Fprintf(GinkgoWriter,
+			"Encoding field value:\n\t%s: %s -> %d bytes\n\t%s: %s -> %d bytes\n",
+			hf.Name, oldValue, encodedLen,
+			hf.Name, hf.Value, output.Len(),
+		)
+		Expect(output.Len()).To(BeNumerically(">", encodedLen))
+	})
 })

integrationtests/self/self_suite_test.go

@@ -1,7 +1,11 @@
 package self
 
 import (
+	"math/rand"
 	"testing"
+	_ "unsafe"
+
+	"github.com/marten-seemann/qpack"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -11,3 +15,16 @@ func TestSelf(t *testing.T) {
 	RegisterFailHandler(Fail)
 	RunSpecs(t, "Self Suite")
 }
+
+var _ = BeforeSuite(func() {
+	rand.Seed(GinkgoRandomSeed())
+})
+
+var staticTable []qpack.HeaderField
+
+//go:linkname getStaticTable github.com/marten-seemann/qpack.getStaticTable
+func getStaticTable() []qpack.HeaderField
+
+func init() {
+	staticTable = getStaticTable()
+}

static_table.go

@@ -102,6 +102,13 @@ var staticTableEntries = [...]HeaderField{
 	{Name: "x-frame-options", Value: "sameorigin"},
 }
 
+// Only needed for tests.
+// use go:linkname to retrieve the static table.
+//nolint:deadcode,unused
+func getStaticTable() []HeaderField {
+	return staticTableEntries[:]
+}
+
 type indexAndValues struct {
 	idx    uint8
 	values map[string]uint8

static_table_test.go

@@ -6,8 +6,7 @@ import (
 )
 
 var _ = Describe("StaticTable", func() {
-
-	It("verifies that encoderMap and staticTableEntries are coherent", func() {
+	It("verifies that encoderMap has a value for every staticTableEntries entry", func() {
 		for idx, hf := range staticTableEntries {
 			if len(hf.Value) == 0 {
 				Expect(encoderMap[hf.Name].idx).To(Equal(uint8(idx)))
@@ -17,4 +16,18 @@ var _ = Describe("StaticTable", func() {
 		}
 	})
 
+	It("verifies that staticTableEntries has a value for every encoderMap entry", func() {
+		for name, indexAndVal := range encoderMap {
+			if len(indexAndVal.values) == 0 {
+				id := indexAndVal.idx
+				Expect(staticTableEntries[id].Name).To(Equal(name))
+				Expect(staticTableEntries[id].Value).To(BeEmpty())
+			} else {
+				for value, id := range indexAndVal.values {
+					Expect(staticTableEntries[id].Name).To(Equal(name))
+					Expect(staticTableEntries[id].Value).To(Equal(value))
+				}
+			}
+		}
+	})
 })