Revamp of the library with state support (#6)

* Changed iterator

* generic state

* add state notification

* tests

* faster store

* final refactoring

* update readme

grid_test.go

@@ -4,6 +4,9 @@
 package tile
 
 import (
+	"fmt"
+	"io"
+	"sync"
 	"testing"
 	"unsafe"
 
@@ -12,24 +15,24 @@ import (
 
 /*
 cpu: Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz
-BenchmarkGrid/each-8         	     698	   1694002 ns/op	       0 B/op	       0 allocs/op
-BenchmarkGrid/neighbors-8    	19652220	        66.16 ns/op	       0 B/op	       0 allocs/op
-BenchmarkGrid/within-8       	   26200	     47040 ns/op	       0 B/op	       0 allocs/op
-BenchmarkGrid/at-8           	59190276	        16.96 ns/op	       0 B/op	       0 allocs/op
-BenchmarkGrid/write-8        	100000000	        15.40 ns/op	       0 B/op	       0 allocs/op
-BenchmarkGrid/merge-8        	52110926	        23.06 ns/op	       0 B/op	       0 allocs/op
+BenchmarkGrid/each-8         	     862	   1365740 ns/op	       0 B/op	       0 allocs/op
+BenchmarkGrid/neighbors-8    	66562384	        17.94 ns/op	       0 B/op	       0 allocs/op
+BenchmarkGrid/within-8       	   30012	     40112 ns/op	       0 B/op	       0 allocs/op
+BenchmarkGrid/at-8           	396362580	         3.025 ns/op	       0 B/op	       0 allocs/op
+BenchmarkGrid/write-8        	127712601	         9.256 ns/op	       0 B/op	       0 allocs/op
+BenchmarkGrid/merge-8        	125377372	         9.410 ns/op	       0 B/op	       0 allocs/op
 */
 func BenchmarkGrid(b *testing.B) {
-	var d [6]byte
+	var d Tile[uint32]
 	var p Point
 	defer assert.NotNil(b, d)
-	m := NewGrid(768, 768)
+	m := NewGridOf[uint32](768, 768)
 
 	b.Run("each", func(b *testing.B) {
 		b.ReportAllocs()
 		b.ResetTimer()
 		for n := 0; n < b.N; n++ {
-			m.Each(func(point Point, tile Tile) {
+			m.Each(func(point Point, tile Tile[uint32]) {
 				p = point
 				d = tile
 			})
@@ -40,7 +43,7 @@ func BenchmarkGrid(b *testing.B) {
 		b.ReportAllocs()
 		b.ResetTimer()
 		for n := 0; n < b.N; n++ {
-			m.Neighbors(300, 300, func(point Point, tile Tile) {
+			m.Neighbors(300, 300, func(point Point, tile Tile[uint32]) {
 				p = point
 				d = tile
 			})
@@ -51,7 +54,7 @@ func BenchmarkGrid(b *testing.B) {
 		b.ReportAllocs()
 		b.ResetTimer()
 		for n := 0; n < b.N; n++ {
-			m.Within(At(100, 100), At(200, 200), func(point Point, tile Tile) {
+			m.Within(At(100, 100), At(200, 200), func(point Point, tile Tile[uint32]) {
 				p = point
 				d = tile
 			})
@@ -71,28 +74,85 @@ func BenchmarkGrid(b *testing.B) {
 		b.ReportAllocs()
 		b.ResetTimer()
 		for n := 0; n < b.N; n++ {
-			m.WriteAt(100, 100, Tile{})
+			m.WriteAt(100, 100, Value(0))
 		}
 	})
 
 	b.Run("merge", func(b *testing.B) {
 		b.ReportAllocs()
 		b.ResetTimer()
 		for n := 0; n < b.N; n++ {
-			m.MergeAt(100, 100, Tile{}, Tile{0, 1, 0, 0, 0})
+			m.MergeAt(100, 100, func(v Value) Value {
+				v += 1
+				return v
+			})
+		}
+	})
+
+	b.Run("mask", func(b *testing.B) {
+		b.ReportAllocs()
+		b.ResetTimer()
+		for n := 0; n < b.N; n++ {
+			m.MaskAt(100, 100, Value(0), Value(1))
+		}
+	})
+}
+
+/*
+cpu: Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz
+BenchmarkState/range-8         	11211600	       103.4 ns/op	       0 B/op	       0 allocs/op
+BenchmarkState/add-8           	41380593	        29.00 ns/op	       0 B/op	       0 allocs/op
+BenchmarkState/del-8           	54474884	        21.79 ns/op	       0 B/op	       0 allocs/op
+*/
+func BenchmarkState(b *testing.B) {
+	m := NewGridOf[int](768, 768)
+	m.Each(func(p Point, c Tile[int]) {
+		for i := 0; i < 10; i++ {
+			c.Add(i)
+		}
+	})
+
+	b.Run("range", func(b *testing.B) {
+		b.ReportAllocs()
+		b.ResetTimer()
+		for n := 0; n < b.N; n++ {
+			cursor, _ := m.At(100, 100)
+			cursor.Range(func(v int) error {
+				return nil
+			})
+		}
+	})
+
+	b.Run("add", func(b *testing.B) {
+		b.ReportAllocs()
+		b.ResetTimer()
+		for n := 0; n < b.N; n++ {
+			cursor, _ := m.At(100, 100)
+			cursor.Add(100)
+		}
+	})
+
+	b.Run("del", func(b *testing.B) {
+		b.ReportAllocs()
+		b.ResetTimer()
+		for n := 0; n < b.N; n++ {
+			cursor, _ := m.At(100, 100)
+			cursor.Del(100)
 		}
 	})
 }
 
 func TestPageSize(t *testing.T) {
-	assert.LessOrEqual(t, int(unsafe.Sizeof(page{})), 64)
+	assert.Equal(t, 8, int(unsafe.Sizeof(map[uintptr]Point{})))
+	assert.Equal(t, 64, int(unsafe.Sizeof(page[string]{})))
+	assert.Equal(t, 36, int(unsafe.Sizeof([9]Value{})))
 }
 
 func TestWithin(t *testing.T) {
 	m := NewGrid(9, 9)
 
 	var path []string
-	m.Within(At(1, 1), At(5, 5), func(p Point, tile Tile) {
+	m.Within(At(1, 1), At(5, 5), func(p Point, tile Tile[string]) {
 		path = append(path, p.String())
 	})
 	assert.Equal(t, 25, len(path))
@@ -109,7 +169,7 @@ func TestWithinCorner(t *testing.T) {
 	m := NewGrid(9, 9)
 
 	var path []string
-	m.Within(At(7, 6), At(10, 10), func(p Point, tile Tile) {
+	m.Within(At(7, 6), At(10, 10), func(p Point, tile Tile[string]) {
 		path = append(path, p.String())
 	})
 	assert.Equal(t, 6, len(path))
@@ -119,10 +179,25 @@ func TestWithinCorner(t *testing.T) {
 	}, path)
 }
 
+func TestWithinOneSide(t *testing.T) {
+	m := NewGrid(9, 9)
+
+	var path []string
+	m.Within(At(1, 6), At(4, 10), func(p Point, tile Tile[string]) {
+		path = append(path, p.String())
+	})
+	assert.Equal(t, 12, len(path))
+	assert.ElementsMatch(t, []string{
+		"1,6", "2,6", "3,6", "4,6",
+		"1,7", "2,7", "3,7", "4,7",
+		"1,8", "2,8", "3,8", "4,8",
+	}, path)
+}
+
 func TestWithinInvalid(t *testing.T) {
 	m := NewGrid(9, 9)
 	count := 0
-	m.Within(At(10, 10), At(20, 20), func(p Point, tile Tile) {
+	m.Within(At(10, 10), At(20, 20), func(p Point, tile Tile[string]) {
 		count++
 	})
 	assert.Equal(t, 0, count)
@@ -132,7 +207,7 @@ func TestEach(t *testing.T) {
 	m := NewGrid(9, 9)
 
 	var path []string
-	m.Each(func(p Point, tile Tile) {
+	m.Each(func(p Point, tile Tile[string]) {
 		path = append(path, p.String())
 	})
 	assert.Equal(t, 81, len(path))
@@ -163,16 +238,16 @@ func TestNeighbors(t *testing.T) {
 
 	// Create a 9x9 map with labeled tiles
 	m := NewGrid(9, 9)
-	m.Each(func(p Point, tile Tile) {
-		copy(tile[:], p.String()[:3])
-		m.WriteAt(p.X, p.Y, tile)
+	m.Each(func(p Point, tile Tile[string]) {
+		m.WriteAt(p.X, p.Y, Value(p.Integer()))
 	})
 
 	// Run all the tests
 	for _, tc := range tests {
 		var out []string
-		m.Neighbors(tc.x, tc.y, func(_ Point, tile Tile) {
-			out = append(out, string(tile[:3]))
+		m.Neighbors(tc.x, tc.y, func(_ Point, tile Tile[string]) {
+			loc := unpackPoint(uint32(tile.Value()))
+			out = append(out, loc.String())
 		})
 		assert.ElementsMatch(t, tc.expect, out)
 	}
@@ -182,22 +257,21 @@ func TestAt(t *testing.T) {
 
 	// Create a 9x9 map with labeled tiles
 	m := NewGrid(9, 9)
-	m.Each(func(p Point, tile Tile) {
-		copy(tile[:], p.String()[:3])
-		m.WriteAt(p.X, p.Y, tile)
+	m.Each(func(p Point, tile Tile[string]) {
+		m.WriteAt(p.X, p.Y, Value(p.Integer()))
 	})
 
 	// Make sure our At() and the position matches
-	m.Each(func(p Point, tile Tile) {
+	m.Each(func(p Point, tile Tile[string]) {
 		at, _ := m.At(p.X, p.Y)
-		assert.Equal(t, p.String(), string(at[:3]))
+		assert.Equal(t, p.String(), unpackPoint(uint32(at.Value())).String())
 	})
 
 	// Make sure that points match
 	for y := int16(0); y < 9; y++ {
 		for x := int16(0); x < 9; x++ {
 			at, _ := m.At(x, y)
-			assert.Equal(t, At(x, y).String(), string(at[:3]))
+			assert.Equal(t, At(x, y).String(), unpackPoint(uint32(at.Value())).String())
 		}
 	}
 }
@@ -207,22 +281,111 @@ func TestUpdate(t *testing.T) {
 	// Create a 9x9 map with labeled tiles
 	m := NewGrid(9, 9)
 	i := 0
-	m.Each(func(p Point, tile Tile) {
+	m.Each(func(p Point, _ Tile[string]) {
 		i++
-		tile[0] = byte(i)
-		m.WriteAt(p.X, p.Y, tile)
+		m.WriteAt(p.X, p.Y, Value(i))
 	})
 
 	// Assert the update
-	tile, _ := m.At(8, 8)
-	assert.Equal(t, 81, int(tile[0]))
+	cursor, _ := m.At(8, 8)
+	assert.Equal(t, 81, int(cursor.Value()))
 
 	// 81 = 0b01010001
-	tile[0] = 0b00101110 // change last 2 bits and should ignore other bits
-	m.MergeAt(8, 8, tile, Tile{
-		0b00000011, 0, 0, 0, 0, 0,
+	delta := Value(0b00101110) // change last 2 bits and should ignore other bits
+	m.MaskAt(8, 8, delta, Value(0b00000011))
+
+	// original: 0101 0001
+	// delta:    0010 1110
+	// mask:     0000 0011
+	// result:   0101 0010
+	cursor, _ = m.At(8, 8)
+	assert.Equal(t, 0b01010010, int(cursor.Value()))
+}
+
+func TestState(t *testing.T) {
+	m := NewGrid(9, 9)
+	m.Each(func(p Point, c Tile[string]) {
+		c.Add(p.String())
+		c.Add(p.String()) // duplicate
+	})
+
+	m.Each(func(p Point, c Tile[string]) {
+		assert.Equal(t, 1, c.Count())
+		assert.NoError(t, c.Range(func(s string) error {
+			assert.Equal(t, p.String(), s)
+			return nil
+		}))
+
+		c.Del(p.String())
+		assert.Equal(t, 0, c.Count())
 	})
+}
+
+func TestStateRangeErr(t *testing.T) {
+	m := NewGrid(9, 9)
+	m.Each(func(p Point, c Tile[string]) {
+		c.Add(p.String())
+	})
+
+	m.Each(func(p Point, c Tile[string]) {
+		assert.Error(t, c.Range(func(s string) error {
+			return io.EOF
+		}))
+	})
+}
+
+func TestPointOf(t *testing.T) {
+	truthTable := func(x, y int16, idx uint8) (int16, int16) {
+		switch idx {
+		case 0:
+			return x, y
+		case 1:
+			return x + 1, y
+		case 2:
+			return x + 2, y
+		case 3:
+			return x, y + 1
+		case 4:
+			return x + 1, y + 1
+		case 5:
+			return x + 2, y + 1
+		case 6:
+			return x, y + 2
+		case 7:
+			return x + 1, y + 2
+		case 8:
+			return x + 2, y + 2
+		default:
+			return x, y
+		}
+	}
+
+	for i := 0; i < 9; i++ {
+		at := pointOf(At(0, 0), uint8(i))
+		x, y := truthTable(0, 0, uint8(i))
+		assert.Equal(t, x, at.X, fmt.Sprintf("idx=%v", i))
+		assert.Equal(t, y, at.Y, fmt.Sprintf("idx=%v", i))
+	}
+}
+
+func TestConcurrentMerge(t *testing.T) {
+	const count = 10000
+	var wg sync.WaitGroup
+	wg.Add(count)
+
+	m := NewGrid(9, 9)
+	for i := 0; i < count; i++ {
+		go func() {
+			m.MergeAt(1, 1, func(v Value) Value {
+				v += 1
+				return v
+			})
+			wg.Done()
+		}()
+	}
 
-	tile, _ = m.At(8, 8)
-	assert.Equal(t, 0b01010010, int(tile[0]))
+	wg.Wait()
+	tile, ok := m.At(1, 1)
+	assert.True(t, ok)
+	assert.Equal(t, uint32(count), tile.Value())
 }