Get rid of hash function in MapOf factory functions (#108)

Also upgrades library version to v3

.github/workflows/build-32-bit.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [1.21.x]
+        go-version: [1.19.x, 1.20.x, 1.21.x]
     name: Build with Go ${{ matrix.go-version }} 32-bit
     steps:
       - uses: actions/checkout@v3

.github/workflows/build.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [1.21.x]
+        go-version: [1.19.x, 1.20.x, 1.21.x]
     name: Build with Go ${{ matrix.go-version }}
     steps:
       - uses: actions/checkout@v3

README.md

@@ -1,5 +1,5 @@
-[![GoDoc reference](https://img.shields.io/badge/godoc-reference-blue.svg)](https://pkg.go.dev/github.com/puzpuzpuz/xsync/v2)
-[![GoReport](https://goreportcard.com/badge/github.com/puzpuzpuz/xsync/v2)](https://goreportcard.com/report/github.com/puzpuzpuz/xsync/v2)
+[![GoDoc reference](https://img.shields.io/badge/godoc-reference-blue.svg)](https://pkg.go.dev/github.com/puzpuzpuz/xsync/v3)
+[![GoReport](https://goreportcard.com/badge/github.com/puzpuzpuz/xsync/v3)](https://goreportcard.com/report/github.com/puzpuzpuz/xsync/v3)
 [![codecov](https://codecov.io/gh/puzpuzpuz/xsync/branch/main/graph/badge.svg)](https://codecov.io/gh/puzpuzpuz/xsync)
 
 # xsync
@@ -16,15 +16,15 @@ Also, a non-scientific, unfair benchmark comparing Java's [j.u.c.ConcurrentHashM
 
 ## Usage
 
-The latest xsync major version is v2, so `/v2` suffix should be used when importing the library:
+The latest xsync major version is v3, so `/v3` suffix should be used when importing the library:
 
 ```go
 import (
-	"github.com/puzpuzpuz/xsync/v2"
+	"github.com/puzpuzpuz/xsync/v3"
 )
 ```
 
-*Note for v1 users*: v1 support is discontinued, so please upgrade to v2. While the API has some breaking changes, the migration should be trivial.
+*Note for v1 users*: v1 support is discontinued, so please upgrade to v3. While the API has some breaking changes, the migration should be trivial.
 
 ### Counter
 
@@ -35,7 +35,7 @@ c := xsync.NewCounter()
 // increment and decrement the counter
 c.Inc()
 c.Dec()
-// read the current value 
+// read the current value
 v := c.Value()
 ```
 
@@ -58,10 +58,10 @@ CLHT is built around idea to organize the hash table in cache-line-sized buckets
 
 One important difference with `sync.Map` is that only string keys are supported. That's because Golang standard library does not expose the built-in hash functions for `interface{}` values.
 
-`MapOf[K, V]` is an implementation with parametrized value type. It is available for Go 1.18 or later. While it's still a CLHT-inspired hash map, `MapOf`'s design is quite different from `Map`. As a result, less GC pressure and less atomic operations on reads.
+`MapOf[K, V]` is an implementation with parametrized value type. While it's still a CLHT-inspired hash map, `MapOf`'s design is quite different from `Map`. As a result, less GC pressure and less atomic operations on reads.
 
 ```go
-m := xsync.NewMapOf[string]()
+m := xsync.NewMapOf[string, string]()
 m.Store("foo", "bar")
 v, ok := m.Load("foo")
 ```
@@ -73,17 +73,7 @@ type Point struct {
 	x int32
 	y int32
 }
-m := NewTypedMapOf[Point, int](func(seed maphash.Seed, p Point) uint64 {
-	// provide a hash function when creating the MapOf;
-	// we recommend using the hash/maphash package for the function
-	var h maphash.Hash
-	h.SetSeed(seed)
-	binary.Write(&h, binary.LittleEndian, p.x)
-	hash := h.Sum64()
-	h.Reset()
-	binary.Write(&h, binary.LittleEndian, p.y)
-	return 31*hash + h.Sum64()
-})
+m := NewMapOf[Point, int]()
 m.Store(Point{42, 42}, 42)
 v, ok := m.Load(point{42, 42})
 ```

counter.go

@@ -62,7 +62,7 @@ func (c *Counter) Add(delta int64) {
 	t, ok := ptokenPool.Get().(*ptoken)
 	if !ok {
 		t = new(ptoken)
-		t.idx = fastrand()
+		t.idx = runtime_fastrand()
 	}
 	for {
 		stripe := &c.stripes[t.idx&c.mask]
@@ -71,7 +71,7 @@ func (c *Counter) Add(delta int64) {
 			break
 		}
 		// Give a try with another randomly selected stripe.
-		t.idx = fastrand()
+		t.idx = runtime_fastrand()
 	}
 	ptokenPool.Put(t)
 }

counter_test.go

@@ -5,7 +5,7 @@ import (
 	"sync/atomic"
 	"testing"
 
-	. "github.com/puzpuzpuz/xsync/v2"
+	. "github.com/puzpuzpuz/xsync/v3"
 )
 
 func TestCounterInc(t *testing.T) {

example_test.go

@@ -1,42 +1,13 @@
-//go:build go1.18
-// +build go1.18
-
 package xsync_test
 
 import (
-	"encoding/binary"
 	"fmt"
-	"hash/maphash"
-	"time"
 
-	"github.com/puzpuzpuz/xsync/v2"
+	"github.com/puzpuzpuz/xsync/v3"
 )
 
-func ExampleNewTypedMapOf() {
-	type Person struct {
-		GivenName   string
-		FamilyName  string
-		YearOfBirth int16
-	}
-	age := xsync.NewTypedMapOf[Person, int](func(seed maphash.Seed, p Person) uint64 {
-		var h maphash.Hash
-		h.SetSeed(seed)
-		h.WriteString(p.GivenName)
-		hash := h.Sum64()
-		h.Reset()
-		h.WriteString(p.FamilyName)
-		hash = 31*hash + h.Sum64()
-		h.Reset()
-		binary.Write(&h, binary.LittleEndian, p.YearOfBirth)
-		return 31*hash + h.Sum64()
-	})
-	Y := time.Now().Year()
-	age.Store(Person{"Ada", "Lovelace", 1815}, Y-1815)
-	age.Store(Person{"Charles", "Babbage", 1791}, Y-1791)
-}
-
 func ExampleMapOf_Compute() {
-	counts := xsync.NewIntegerMapOf[int, int]()
+	counts := xsync.NewMapOf[int, int]()
 
 	// Store a new value.
 	v, ok := counts.Compute(42, func(oldValue int, loaded bool) (newValue int, delete bool) {

export_test.go

@@ -1,7 +1,5 @@
 package xsync
 
-import "hash/maphash"
-
 const (
 	EntriesPerMapBucket = entriesPerMapBucket
 	MapLoadFactor       = mapLoadFactor
@@ -11,7 +9,8 @@ const (
 )
 
 type (
-	BucketPadded = bucketPadded
+	BucketPadded   = bucketPadded
+	BucketOfPadded = bucketOfPadded
 )
 
 type MapStats struct {
@@ -50,14 +49,33 @@ func DisableAssertions() {
 	assertionsEnabled = false
 }
 
-func HashString(seed maphash.Seed, s string) uint64 {
-	return hashString(seed, s)
-}
-
 func Fastrand() uint32 {
-	return fastrand()
+	return runtime_fastrand()
 }
 
 func NextPowOf2(v uint32) uint32 {
 	return nextPowOf2(v)
 }
+
+func MakeSeed() uint64 {
+	return makeSeed()
+}
+
+func HashString(s string, seed uint64) uint64 {
+	return hashString(s, seed)
+}
+
+func MakeHasher[T comparable]() func(T, uint64) uint64 {
+	return makeHasher[T]()
+}
+
+func CollectMapOfStats[K comparable, V any](m *MapOf[K, V]) MapStats {
+	return MapStats{m.stats()}
+}
+
+func NewMapOfPresizedWithHasher[K comparable, V any](
+	hasher func(K, uint64) uint64,
+	sizeHint int,
+) *MapOf[K, V] {
+	return newMapOfPresized[K, V](hasher, sizeHint)
+}

go.mod

@@ -1,3 +1,3 @@
-module github.com/puzpuzpuz/xsync/v2
+module github.com/puzpuzpuz/xsync/v3
 
-go 1.20
+go 1.18