hash/maphash: move bytes/hash to hash/maphash

Fixes #34778

Change-Id: If8225a7c41cb2af3f67157fb9670eef86272e85e
Reviewed-on: https://go-review.googlesource.com/c/go/+/204997
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/go/build/deps_test.go

@@ -86,7 +86,6 @@ var pkgDeps = map[string][]string{
 	// L2 adds Unicode and strings processing.
 	"bufio":   {"L0", "unicode/utf8", "bytes"},
 	"bytes":   {"L0", "unicode", "unicode/utf8"},
-	"bytes/hash": {"L0"},
 	"path":    {"L0", "unicode/utf8", "strings"},
 	"strings": {"L0", "unicode", "unicode/utf8"},
 	"unicode": {},
@@ -95,7 +94,6 @@ var pkgDeps = map[string][]string{
 		"L1",
 		"bufio",
 		"bytes",
-		"bytes/hash",
 		"path",
 		"strings",
 		"unicode",
@@ -116,6 +114,7 @@ var pkgDeps = map[string][]string{
 	"hash/crc32":             {"L2", "hash"},
 	"hash/crc64":             {"L2", "hash"},
 	"hash/fnv":               {"L2", "hash"},
+	"hash/maphash":           {"L2", "hash"},
 	"image":                  {"L2", "image/color"}, // interfaces
 	"image/color":            {"L2"},                // interfaces
 	"image/color/palette":    {"L2", "image/color"},

src/bytes/hash/hash.go → src/hash/maphash/maphash.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package bytes/hash provides hash functions on byte sequences. These
+// Package hash/maphash provides hash functions on byte sequences. These
 // hash functions are intended to be used to implement hash tables or
 // other data structures that need to map arbitrary strings or byte
 // sequences to a uniform distribution of integers. The hash functions
@@ -29,7 +29,7 @@
 // All bits of the Hash result are close to uniformly and
 // independently distributed, so can be safely restricted to a range
 // using bit masking, shifting, or modular arithmetic.
-package hash
+package maphash
 
 import (
 	"unsafe"
@@ -161,7 +161,7 @@ func rthash(b []byte, seed uint64) uint64 {
 //go:linkname runtime_memhash runtime.memhash
 func runtime_memhash(p unsafe.Pointer, seed, s uintptr) uintptr
 
-// Wrapper functions so that a bytes/hash.Hash implements
+// Wrapper functions so that a hash/maphash.Hash implements
 // the hash.Hash and hash.Hash64 interfaces.
 
 func (h *Hash) Write(b []byte) (int, error) {

src/bytes/hash/hash_test.go → src/hash/maphash/maphash_test.go

@@ -2,18 +2,18 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package hash_test
+package maphash_test
 
 import (
-	"bytes/hash"
-	basehash "hash"
+	"hash"
+	"hash/maphash"
 	"testing"
 )
 
 func TestUnseededHash(t *testing.T) {
 	m := map[uint64]struct{}{}
 	for i := 0; i < 1000; i++ {
-		h := hash.New()
+		h := maphash.New()
 		m[h.Hash()] = struct{}{}
 	}
 	if len(m) < 900 {
@@ -22,10 +22,10 @@ func TestUnseededHash(t *testing.T) {
 }
 
 func TestSeededHash(t *testing.T) {
-	s := hash.MakeSeed(1234)
+	s := maphash.MakeSeed(1234)
 	m := map[uint64]struct{}{}
 	for i := 0; i < 1000; i++ {
-		h := hash.New()
+		h := maphash.New()
 		h.SetSeed(s)
 		m[h.Hash()] = struct{}{}
 	}
@@ -36,8 +36,8 @@ func TestSeededHash(t *testing.T) {
 
 func TestHashGrouping(t *testing.T) {
 	b := []byte("foo")
-	h1 := hash.New()
-	h2 := hash.New()
+	h1 := maphash.New()
+	h2 := maphash.New()
 	h2.SetSeed(h1.Seed())
 	h1.AddBytes(b)
 	for _, x := range b {
@@ -51,8 +51,8 @@ func TestHashGrouping(t *testing.T) {
 func TestHashBytesVsString(t *testing.T) {
 	s := "foo"
 	b := []byte(s)
-	h1 := hash.New()
-	h2 := hash.New()
+	h1 := maphash.New()
+	h2 := maphash.New()
 	h2.SetSeed(h1.Seed())
 	h1.AddString(s)
 	h2.AddBytes(b)
@@ -66,7 +66,7 @@ func TestHashHighBytes(t *testing.T) {
 	const N = 10
 	m := map[uint64]struct{}{}
 	for i := 0; i < N; i++ {
-		h := hash.New()
+		h := maphash.New()
 		h.AddString("foo")
 		m[h.Hash()>>32] = struct{}{}
 	}
@@ -76,5 +76,5 @@ func TestHashHighBytes(t *testing.T) {
 }
 
 // Make sure a Hash implements the hash.Hash and hash.Hash64 interfaces.
-var _ basehash.Hash = &hash.Hash{}
-var _ basehash.Hash64 = &hash.Hash{}
+var _ hash.Hash = &maphash.Hash{}
+var _ hash.Hash64 = &maphash.Hash{}

src/bytes/hash/smhasher_test.go → src/hash/maphash/smhasher_test.go

@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package hash_test
+package maphash_test
 
 import (
-	"bytes/hash"
 	"fmt"
+	"hash/maphash"
 	"math"
 	"math/rand"
 	"runtime"
@@ -45,14 +45,14 @@ func TestSmhasherSanity(t *testing.T) {
 }
 
 func bytesHash(b []byte, seed uint64) uint64 {
-	h := hash.New()
-	h.SetSeed(hash.MakeSeed(seed))
+	h := maphash.New()
+	h.SetSeed(maphash.MakeSeed(seed))
 	h.AddBytes(b)
 	return h.Hash()
 }
 func stringHash(s string, seed uint64) uint64 {
-	h := hash.New()
-	h.SetSeed(hash.MakeSeed(seed))
+	h := maphash.New()
+	h.SetSeed(maphash.MakeSeed(seed))
 	h.AddString(s)
 	return h.Hash()
 }