Fix missed splits

all_test.go

@@ -218,8 +218,8 @@ func TestSetGet0(t *testing.T) {
 }
 
 func TestSetGet1(t *testing.T) {
-	const N = 50000
-	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x314259} {
+	const N = 60000
+	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x333333, 0xcccccc, 0x314259} {
 		r := TreeNew(cmp)
 		set := r.Set
 		a := make([]int, N)
@@ -253,10 +253,6 @@ func TestSetGet1(t *testing.T) {
 	}
 }
 
-func BenchmarkSetSeq1e2(b *testing.B) {
-	benchmarkSetSeq(b, 1e2)
-}
-
 func BenchmarkSetSeq1e3(b *testing.B) {
 	benchmarkSetSeq(b, 1e3)
 }
@@ -287,10 +283,6 @@ func benchmarkSetSeq(b *testing.B, n int) {
 	b.StopTimer()
 }
 
-func BenchmarkGetSeq1e2(b *testing.B) {
-	benchmarkGetSeq(b, 1e2)
-}
-
 func BenchmarkGetSeq1e3(b *testing.B) {
 	benchmarkGetSeq(b, 1e3)
 }
@@ -322,10 +314,6 @@ func benchmarkGetSeq(b *testing.B, n int) {
 	b.StopTimer()
 }
 
-func BenchmarkSetRnd1e2(b *testing.B) {
-	benchmarkSetRnd(b, 1e2)
-}
-
 func BenchmarkSetRnd1e3(b *testing.B) {
 	benchmarkSetRnd(b, 1e3)
 }
@@ -361,10 +349,6 @@ func benchmarkSetRnd(b *testing.B, n int) {
 	b.StopTimer()
 }
 
-func BenchmarkGetRnd1e2(b *testing.B) {
-	benchmarkGetRnd(b, 1e2)
-}
-
 func BenchmarkGetRnd1e3(b *testing.B) {
 	benchmarkGetRnd(b, 1e3)
 }
@@ -402,8 +386,8 @@ func benchmarkGetRnd(b *testing.B, n int) {
 }
 
 func TestSetGet2(t *testing.T) {
-	const N = 50000
-	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x314259} {
+	const N = 60000
+	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x333333, 0xcccccc, 0x314259} {
 		r := TreeNew(cmp)
 		set := r.Set
 		a := make([]int, N)
@@ -548,8 +532,8 @@ func TestDelete0(t *testing.T) {
 }
 
 func TestDelete1(t *testing.T) {
-	const N = 60000
-	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x314259} {
+	const N = 70000
+	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x333333, 0xcccccc, 0x314259} {
 		r := TreeNew(cmp)
 		set := r.Set
 		a := make([]int, N)
@@ -573,10 +557,6 @@ func TestDelete1(t *testing.T) {
 	}
 }
 
-func benchmarkDelSeq1e2(b *testing.B) {
-	benchmarkDelSeq(b, 1e2)
-}
-
 func benchmarkDelSeq1e3(b *testing.B) {
 	benchmarkDelSeq(b, 1e3)
 }
@@ -610,10 +590,6 @@ func benchmarkDelSeq(b *testing.B, n int) {
 	b.StopTimer()
 }
 
-func BenchmarkDelRnd1e2(b *testing.B) {
-	benchmarkDelRnd(b, 1e2)
-}
-
 func BenchmarkDelRnd1e3(b *testing.B) {
 	benchmarkDelRnd(b, 1e3)
 }
@@ -653,8 +629,8 @@ func benchmarkDelRnd(b *testing.B, n int) {
 }
 
 func TestDelete2(t *testing.T) {
-	const N = 50000
-	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x314259} {
+	const N = 60000
+	for _, x := range []int{0, -1, 0x555555, 0xaaaaaa, 0x333333, 0xcccccc, 0x314259} {
 		r := TreeNew(cmp)
 		set := r.Set
 		a := make([]int, N)
@@ -819,10 +795,6 @@ func TestEnumeratorPrev(t *testing.T) {
 	}
 }
 
-func BenchmarkSeekSeq1e2(b *testing.B) {
-	benchmarkSeekSeq(b, 1e2)
-}
-
 func BenchmarkSeekSeq1e3(b *testing.B) {
 	benchmarkSeekSeq(b, 1e3)
 }
@@ -855,10 +827,6 @@ func benchmarkSeekSeq(b *testing.B, n int) {
 	b.StopTimer()
 }
 
-func BenchmarkSeekRnd1e2(b *testing.B) {
-	benchmarkSeekRnd(b, 1e2)
-}
-
 func BenchmarkSeekRnd1e3(b *testing.B) {
 	benchmarkSeekRnd(b, 1e3)
 }
@@ -894,10 +862,6 @@ func benchmarkSeekRnd(b *testing.B, n int) {
 	}
 }
 
-func BenchmarkNext1e2(b *testing.B) {
-	benchmarkNext(b, 1e2)
-}
-
 func BenchmarkNext1e3(b *testing.B) {
 	benchmarkNext(b, 1e3)
 }
@@ -940,10 +904,6 @@ func benchmarkNext(b *testing.B, n int) {
 	}
 }
 
-func BenchmarkPrev1e2(b *testing.B) {
-	benchmarkPrev(b, 1e2)
-}
-
 func BenchmarkPrev1e3(b *testing.B) {
 	benchmarkPrev(b, 1e3)
 }

btree.go

@@ -36,34 +36,46 @@
 //
 // No other changes to int.go are (strictly) necessary, it compiles just fine.
 //
-// Running the benchmarks for 1000 keys on a machine with Intel X5450 CPU @ 3
-// GHz, Go release 1.3.
+// Running the benchmarks for 1000 keys on a machine with Intel i5-4670 CPU @
+// 3.4GHz, Go release 1.3.
 //
 //	$ go test -bench 1e3 example/all_test.go example/int.go
 //	PASS
-//	BenchmarkSetSeq1e3	   10000	    263951 ns/op
-//	BenchmarkGetSeq1e3	   10000	    154410 ns/op
-//	BenchmarkSetRnd1e3	    5000	    392690 ns/op
-//	BenchmarkGetRnd1e3	   10000	    181776 ns/op
-//	BenchmarkDelRnd1e3	    5000	    323795 ns/op
-//	BenchmarkSeekSeq1e3	   10000	    235939 ns/op
-//	BenchmarkSeekRnd1e3	    5000	    299997 ns/op
-//	BenchmarkNext1e3	  200000	     14202 ns/op
-//	BenchmarkPrev1e3	  200000	     13842 ns/op
-//	ok  	command-line-arguments	30.620s
+//	BenchmarkSetSeq1e3	   10000	    146740 ns/op
+//	BenchmarkGetSeq1e3	   10000	    108261 ns/op
+//	BenchmarkSetRnd1e3	   10000	    254359 ns/op
+//	BenchmarkGetRnd1e3	   10000	    134621 ns/op
+//	BenchmarkDelRnd1e3	   10000	    211864 ns/op
+//	BenchmarkSeekSeq1e3	   10000	    148628 ns/op
+//	BenchmarkSeekRnd1e3	   10000	    215166 ns/op
+//	BenchmarkNext1e3	  200000	      9211 ns/op
+//	BenchmarkPrev1e3	  200000	      8843 ns/op
+//	ok  	command-line-arguments	25.071s
+//	$
 package b
 
 import (
+	"fmt"
 	"io"
 )
 
 //TODO check vs orig initialize/finalize
 
 const (
-	kx = 128 // min 2 //TODO benchmark tune this number if using custom key/value type(s).
-	kd = 64  // min 1 //TODO benchmark tune this number if using custom key/value type(s).
+	kx = 32 //TODO benchmark tune this number if using custom key/value type(s).
+	kd = 32 //TODO benchmark tune this number if using custom key/value type(s).
 )
 
+func init() {
+	if kd < 1 {
+		panic(fmt.Errorf("kd %d: out of range", kd))
+	}
+
+	if kx < 2 {
+		panic(fmt.Errorf("kx %d: out of range", kx))
+	}
+}
+
 type (
 	// Cmp compares a and b. Return value is:
 	//
@@ -529,6 +541,11 @@ func (t *Tree) Set(k interface{} /*K*/, v interface{} /*V*/) {
 		if ok {
 			switch x := q.(type) {
 			case *x:
+				if x.c > 2*kx {
+					t.splitX(p, &x, pi, &i)
+				}
+				pi = i + 1
+				p = x
 				q = x.x[i+1].ch
 				continue
 			case *d:
@@ -580,6 +597,11 @@ func (t *Tree) Put(k interface{} /*K*/, upd func(oldV interface{} /*V*/, exists
 			if ok {
 				switch x := q.(type) {
 				case *x:
+					if x.c > 2*kx {
+						t.splitX(p, &x, pi, &i)
+					}
+					pi = i + 1
+					p = x
 					q = x.x[i+1].ch
 					continue
 				case *d:

example/int.go

@@ -2,68 +2,31 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package b implements a B+tree.
-//
-// Changelog
-//
-// 2014-04-18: Added new method Put.
-//
-// Generic types
-//
-// Keys and their associated values are interface{} typed, similar to all of
-// the containers in the standard library.
-//
-// Semiautomatic production of a type specific variant of this package is
-// supported via
-//
-//	$ make generic
-//
-// This command will write to stdout a version of the btree.go file where
-// every key type occurrence is replaced by the word 'key' (written in all
-// CAPS) and every value type occurrence is replaced by the word 'value'
-// (written in all CAPS). Then you have to replace these tokens with your
-// desired type(s), using any technique you're comfortable with.
-//
-// This is how, for example, 'example/int.go' was created:
-//
-//	$ mkdir example
-//	$
-//	$ # Note: the command bellow must be actually written using the words
-//	$ # 'key' and 'value' in all CAPS. The proper form is avoided in this
-//	$ # documentation to not confuse any text replacement mechanism.
-//	$
-//	$ make generic | sed -e 's/key/int/g' -e 's/value/int/g' > example/int.go
-//
-// No other changes to int.go are (strictly) necessary, it compiles just fine.
-//
-// Running the benchmarks for 1000 keys on a machine with Intel X5450 CPU @ 3
-// GHz, Go release 1.3.
-//
-//	$ go test -bench 1e3 example/all_test.go example/int.go
-//	PASS
-//	BenchmarkSetSeq1e3	   10000	    263951 ns/op
-//	BenchmarkGetSeq1e3	   10000	    154410 ns/op
-//	BenchmarkSetRnd1e3	    5000	    392690 ns/op
-//	BenchmarkGetRnd1e3	   10000	    181776 ns/op
-//	BenchmarkDelRnd1e3	    5000	    323795 ns/op
-//	BenchmarkSeekSeq1e3	   10000	    235939 ns/op
-//	BenchmarkSeekRnd1e3	    5000	    299997 ns/op
-//	BenchmarkNext1e3	  200000	     14202 ns/op
-//	BenchmarkPrev1e3	  200000	     13842 ns/op
-//	ok  	command-line-arguments	30.620s
+// Package b implements a int->int B+tree.
 package b
 
 import (
+	"fmt"
 	"io"
 )
 
 //TODO check vs orig initialize/finalize
 
 const (
-	kx = 128 // min 2 //TODO benchmark tune this number if using custom key/value type(s).
-	kd = 64  // min 1 //TODO benchmark tune this number if using custom key/value type(s).
+	kx = 32 //TODO benchmark tune this number if using custom key/value type(s).
+	kd = 32 //TODO benchmark tune this number if using custom key/value type(s).
 )
 
+func init() {
+	if kd < 1 {
+		panic(fmt.Errorf("kd %d: out of range", kd))
+	}
+
+	if kx < 2 {
+		panic(fmt.Errorf("kx %d: out of range", kx))
+	}
+}
+
 type (
 	// Cmp compares a and b. Return value is:
 	//
@@ -363,15 +326,15 @@ func (t *Tree) find(q interface{}, k int) (i int, ok bool) {
 	return l, false
 }
 
-//A // First returns the first item of the tree in the key collating order, or
-//A // (zero-value, zero-value) if the tree is empty.
-//A func (t *Tree) First() (k int, v int) {
-//A 	if q := t.first; q != nil {
-//A 		q := &q.d[0]
-//A 		k, v = q.k, q.v
-//A 	}
-//A 	return
-//A }
+// First returns the first item of the tree in the key collating order, or
+// (zero-value, zero-value) if the tree is empty.
+func (t *Tree) First() (k int, v int) {
+	if q := t.first; q != nil {
+		q := &q.d[0]
+		k, v = q.k, q.v
+	}
+	return
+}
 
 // Get returns the value associated with k and true if it exists. Otherwise Get
 // returns (zero-value, false).
@@ -414,15 +377,15 @@ func (t *Tree) insert(q *d, i int, k int, v int) *d {
 	return q
 }
 
-//A // Last returns the last item of the tree in the key collating order, or
-//A // (zero-value, zero-value) if the tree is empty.
-//A func (t *Tree) Last() (k int, v int) {
-//A 	if q := t.last; q != nil {
-//A 		q := &q.d[q.c-1]
-//A 		k, v = q.k, q.v
-//A 	}
-//A 	return
-//A }
+// Last returns the last item of the tree in the key collating order, or
+// (zero-value, zero-value) if the tree is empty.
+func (t *Tree) Last() (k int, v int) {
+	if q := t.last; q != nil {
+		q := &q.d[q.c-1]
+		k, v = q.k, q.v
+	}
+	return
+}
 
 // Len returns the number of items in the tree.
 func (t *Tree) Len() int {
@@ -529,6 +492,11 @@ func (t *Tree) Set(k int, v int) {
 		if ok {
 			switch x := q.(type) {
 			case *x:
+				if x.c > 2*kx {
+					t.splitX(p, &x, pi, &i)
+				}
+				pi = i + 1
+				p = x
 				q = x.x[i+1].ch
 				continue
 			case *d:
@@ -580,6 +548,11 @@ func (t *Tree) Put(k int, upd func(oldV int, exists bool) (newV int, write bool)
 			if ok {
 				switch x := q.(type) {
 				case *x:
+					if x.c > 2*kx {
+						t.splitX(p, &x, pi, &i)
+					}
+					pi = i + 1
+					p = x
 					q = x.x[i+1].ch
 					continue
 				case *d: