mirror of
https://github.com/golang/go
synced 2024-11-05 16:56:16 -07:00
ac8637e9fa
Just reading through intsets and decided to knock out a few TODOs. Change-Id: I677dbcc5ff934fbe0f0af09a4741e708a893f8db Reviewed-on: https://go-review.googlesource.com/2733 Reviewed-by: Alan Donovan <adonovan@google.com>
639 lines
14 KiB
Go
639 lines
14 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
|
||
// Use of this source code is governed by a BSD-style
|
||
// license that can be found in the LICENSE file.
|
||
|
||
package intsets_test
|
||
|
||
import (
|
||
"fmt"
|
||
"log"
|
||
"math/rand"
|
||
"sort"
|
||
"strings"
|
||
"testing"
|
||
|
||
"golang.org/x/tools/container/intsets"
|
||
)
|
||
|
||
func TestBasics(t *testing.T) {
|
||
var s intsets.Sparse
|
||
if len := s.Len(); len != 0 {
|
||
t.Errorf("Len({}): got %d, want 0", len)
|
||
}
|
||
if s := s.String(); s != "{}" {
|
||
t.Errorf("String({}): got %q, want \"{}\"", s)
|
||
}
|
||
if s.Has(3) {
|
||
t.Errorf("Has(3): got true, want false")
|
||
}
|
||
if err := s.Check(); err != nil {
|
||
t.Error(err)
|
||
}
|
||
|
||
if !s.Insert(3) {
|
||
t.Errorf("Insert(3): got false, want true")
|
||
}
|
||
if max := s.Max(); max != 3 {
|
||
t.Errorf("Max: got %d, want 3", max)
|
||
}
|
||
|
||
if !s.Insert(435) {
|
||
t.Errorf("Insert(435): got false, want true")
|
||
}
|
||
if s := s.String(); s != "{3 435}" {
|
||
t.Errorf("String({3 435}): got %q, want \"{3 435}\"", s)
|
||
}
|
||
if max := s.Max(); max != 435 {
|
||
t.Errorf("Max: got %d, want 435", max)
|
||
}
|
||
if len := s.Len(); len != 2 {
|
||
t.Errorf("Len: got %d, want 2", len)
|
||
}
|
||
|
||
if !s.Remove(435) {
|
||
t.Errorf("Remove(435): got false, want true")
|
||
}
|
||
if s := s.String(); s != "{3}" {
|
||
t.Errorf("String({3}): got %q, want \"{3}\"", s)
|
||
}
|
||
}
|
||
|
||
// Insert, Len, IsEmpty, Hash, Clear, AppendTo.
|
||
func TestMoreBasics(t *testing.T) {
|
||
set := new(intsets.Sparse)
|
||
set.Insert(456)
|
||
set.Insert(123)
|
||
set.Insert(789)
|
||
if set.Len() != 3 {
|
||
t.Errorf("%s.Len: got %d, want 3", set, set.Len())
|
||
}
|
||
if set.IsEmpty() {
|
||
t.Errorf("%s.IsEmpty: got true", set)
|
||
}
|
||
if !set.Has(123) {
|
||
t.Errorf("%s.Has(123): got false", set)
|
||
}
|
||
if set.Has(1234) {
|
||
t.Errorf("%s.Has(1234): got true", set)
|
||
}
|
||
got := set.AppendTo([]int{-1})
|
||
if want := []int{-1, 123, 456, 789}; fmt.Sprint(got) != fmt.Sprint(want) {
|
||
t.Errorf("%s.AppendTo: got %v, want %v", set, got, want)
|
||
}
|
||
|
||
set.Clear()
|
||
|
||
if set.Len() != 0 {
|
||
t.Errorf("Clear: got %d, want 0", set.Len())
|
||
}
|
||
if !set.IsEmpty() {
|
||
t.Errorf("IsEmpty: got false")
|
||
}
|
||
if set.Has(123) {
|
||
t.Errorf("%s.Has: got false", set)
|
||
}
|
||
}
|
||
|
||
func TestTakeMin(t *testing.T) {
|
||
var set intsets.Sparse
|
||
set.Insert(456)
|
||
set.Insert(123)
|
||
set.Insert(789)
|
||
set.Insert(-123)
|
||
var got int
|
||
for i, want := range []int{-123, 123, 456, 789} {
|
||
if !set.TakeMin(&got) || got != want {
|
||
t.Errorf("TakeMin #%d: got %d, want %d", i, got, want)
|
||
}
|
||
}
|
||
if set.TakeMin(&got) {
|
||
t.Errorf("%s.TakeMin returned true", &set)
|
||
}
|
||
if err := set.Check(); err != nil {
|
||
t.Fatalf("check: %s: %#v", err, &set)
|
||
}
|
||
}
|
||
|
||
func TestMinAndMax(t *testing.T) {
|
||
values := []int{0, 456, 123, 789, -123} // elt 0 => empty set
|
||
wantMax := []int{intsets.MinInt, 456, 456, 789, 789}
|
||
wantMin := []int{intsets.MaxInt, 456, 123, 123, -123}
|
||
|
||
var set intsets.Sparse
|
||
for i, x := range values {
|
||
if i != 0 {
|
||
set.Insert(x)
|
||
}
|
||
if got, want := set.Min(), wantMin[i]; got != want {
|
||
t.Errorf("Min #%d: got %d, want %d", i, got, want)
|
||
}
|
||
if got, want := set.Max(), wantMax[i]; got != want {
|
||
t.Errorf("Max #%d: got %d, want %d", i, got, want)
|
||
}
|
||
}
|
||
|
||
set.Insert(intsets.MinInt)
|
||
if got, want := set.Min(), intsets.MinInt; got != want {
|
||
t.Errorf("Min: got %d, want %d", got, want)
|
||
}
|
||
|
||
set.Insert(intsets.MaxInt)
|
||
if got, want := set.Max(), intsets.MaxInt; got != want {
|
||
t.Errorf("Max: got %d, want %d", got, want)
|
||
}
|
||
}
|
||
|
||
func TestEquals(t *testing.T) {
|
||
var setX intsets.Sparse
|
||
setX.Insert(456)
|
||
setX.Insert(123)
|
||
setX.Insert(789)
|
||
|
||
if !setX.Equals(&setX) {
|
||
t.Errorf("Equals(%s, %s): got false", &setX, &setX)
|
||
}
|
||
|
||
var setY intsets.Sparse
|
||
setY.Insert(789)
|
||
setY.Insert(456)
|
||
setY.Insert(123)
|
||
|
||
if !setX.Equals(&setY) {
|
||
t.Errorf("Equals(%s, %s): got false", &setX, &setY)
|
||
}
|
||
|
||
setY.Insert(1)
|
||
if setX.Equals(&setY) {
|
||
t.Errorf("Equals(%s, %s): got true", &setX, &setY)
|
||
}
|
||
|
||
var empty intsets.Sparse
|
||
if setX.Equals(&empty) {
|
||
t.Errorf("Equals(%s, %s): got true", &setX, &empty)
|
||
}
|
||
|
||
// Edge case: some block (with offset=0) appears in X but not Y.
|
||
setY.Remove(123)
|
||
if setX.Equals(&setY) {
|
||
t.Errorf("Equals(%s, %s): got true", &setX, &setY)
|
||
}
|
||
}
|
||
|
||
// A pset is a parallel implementation of a set using both an intsets.Sparse
|
||
// and a built-in hash map.
|
||
type pset struct {
|
||
hash map[int]bool
|
||
bits intsets.Sparse
|
||
}
|
||
|
||
func makePset() *pset {
|
||
return &pset{hash: make(map[int]bool)}
|
||
}
|
||
|
||
func (set *pset) add(n int) {
|
||
prev := len(set.hash)
|
||
set.hash[n] = true
|
||
grewA := len(set.hash) > prev
|
||
|
||
grewB := set.bits.Insert(n)
|
||
|
||
if grewA != grewB {
|
||
panic(fmt.Sprintf("add(%d): grewA=%t grewB=%t", n, grewA, grewB))
|
||
}
|
||
}
|
||
|
||
func (set *pset) remove(n int) {
|
||
prev := len(set.hash)
|
||
delete(set.hash, n)
|
||
shrankA := len(set.hash) < prev
|
||
|
||
shrankB := set.bits.Remove(n)
|
||
|
||
if shrankA != shrankB {
|
||
panic(fmt.Sprintf("remove(%d): shrankA=%t shrankB=%t", n, shrankA, shrankB))
|
||
}
|
||
}
|
||
|
||
func (set *pset) check(t *testing.T, msg string) {
|
||
var eltsA []int
|
||
for elt := range set.hash {
|
||
eltsA = append(eltsA, int(elt))
|
||
}
|
||
sort.Ints(eltsA)
|
||
|
||
eltsB := set.bits.AppendTo(nil)
|
||
|
||
if a, b := fmt.Sprint(eltsA), fmt.Sprint(eltsB); a != b {
|
||
t.Errorf("check(%s): hash=%s bits=%s (%s)", msg, a, b, &set.bits)
|
||
}
|
||
|
||
if err := set.bits.Check(); err != nil {
|
||
t.Fatalf("Check(%s): %s: %#v", msg, err, &set.bits)
|
||
}
|
||
}
|
||
|
||
// randomPset returns a parallel set of random size and elements.
|
||
func randomPset(prng *rand.Rand, maxSize int) *pset {
|
||
set := makePset()
|
||
size := int(prng.Int()) % maxSize
|
||
for i := 0; i < size; i++ {
|
||
// TODO(adonovan): benchmark how performance varies
|
||
// with this sparsity parameter.
|
||
n := int(prng.Int()) % 10000
|
||
set.add(n)
|
||
}
|
||
return set
|
||
}
|
||
|
||
// TestRandomMutations performs the same random adds/removes on two
|
||
// set implementations and ensures that they compute the same result.
|
||
func TestRandomMutations(t *testing.T) {
|
||
const debug = false
|
||
|
||
set := makePset()
|
||
prng := rand.New(rand.NewSource(0))
|
||
for i := 0; i < 10000; i++ {
|
||
n := int(prng.Int())%2000 - 1000
|
||
if i%2 == 0 {
|
||
if debug {
|
||
log.Printf("add %d", n)
|
||
}
|
||
set.add(n)
|
||
} else {
|
||
if debug {
|
||
log.Printf("remove %d", n)
|
||
}
|
||
set.remove(n)
|
||
}
|
||
if debug {
|
||
set.check(t, "post mutation")
|
||
}
|
||
}
|
||
set.check(t, "final")
|
||
if debug {
|
||
log.Print(&set.bits)
|
||
}
|
||
}
|
||
|
||
// TestSetOperations exercises classic set operations: ∩ , ∪, \.
|
||
func TestSetOperations(t *testing.T) {
|
||
prng := rand.New(rand.NewSource(0))
|
||
|
||
// Use random sets of sizes from 0 to about 1000.
|
||
// For each operator, we test variations such as
|
||
// Z.op(X, Y), Z.op(X, Z) and Z.op(Z, Y) to exercise
|
||
// the degenerate cases of each method implementation.
|
||
for i := uint(0); i < 12; i++ {
|
||
X := randomPset(prng, 1<<i)
|
||
Y := randomPset(prng, 1<<i)
|
||
|
||
// TODO(adonovan): minimise dependencies between stanzas below.
|
||
|
||
// Copy(X)
|
||
C := makePset()
|
||
C.bits.Copy(&Y.bits) // no effect on result
|
||
C.bits.Copy(&X.bits)
|
||
C.hash = X.hash
|
||
C.check(t, "C.Copy(X)")
|
||
C.bits.Copy(&C.bits)
|
||
C.check(t, "C.Copy(C)")
|
||
|
||
// U.Union(X, Y)
|
||
U := makePset()
|
||
U.bits.Union(&X.bits, &Y.bits)
|
||
for n := range X.hash {
|
||
U.hash[n] = true
|
||
}
|
||
for n := range Y.hash {
|
||
U.hash[n] = true
|
||
}
|
||
U.check(t, "U.Union(X, Y)")
|
||
|
||
// U.Union(X, X)
|
||
U.bits.Union(&X.bits, &X.bits)
|
||
U.hash = X.hash
|
||
U.check(t, "U.Union(X, X)")
|
||
|
||
// U.Union(U, Y)
|
||
U = makePset()
|
||
U.bits.Copy(&X.bits)
|
||
U.bits.Union(&U.bits, &Y.bits)
|
||
for n := range X.hash {
|
||
U.hash[n] = true
|
||
}
|
||
for n := range Y.hash {
|
||
U.hash[n] = true
|
||
}
|
||
U.check(t, "U.Union(U, Y)")
|
||
|
||
// U.Union(X, U)
|
||
U.bits.Copy(&Y.bits)
|
||
U.bits.Union(&X.bits, &U.bits)
|
||
U.check(t, "U.Union(X, U)")
|
||
|
||
// U.UnionWith(U)
|
||
U.bits.UnionWith(&U.bits)
|
||
U.check(t, "U.UnionWith(U)")
|
||
|
||
// I.Intersection(X, Y)
|
||
I := makePset()
|
||
I.bits.Intersection(&X.bits, &Y.bits)
|
||
for n := range X.hash {
|
||
if Y.hash[n] {
|
||
I.hash[n] = true
|
||
}
|
||
}
|
||
I.check(t, "I.Intersection(X, Y)")
|
||
|
||
// I.Intersection(X, X)
|
||
I.bits.Intersection(&X.bits, &X.bits)
|
||
I.hash = X.hash
|
||
I.check(t, "I.Intersection(X, X)")
|
||
|
||
// I.Intersection(I, X)
|
||
I.bits.Intersection(&I.bits, &X.bits)
|
||
I.check(t, "I.Intersection(I, X)")
|
||
|
||
// I.Intersection(X, I)
|
||
I.bits.Intersection(&X.bits, &I.bits)
|
||
I.check(t, "I.Intersection(X, I)")
|
||
|
||
// I.Intersection(I, I)
|
||
I.bits.Intersection(&I.bits, &I.bits)
|
||
I.check(t, "I.Intersection(I, I)")
|
||
|
||
// D.Difference(X, Y)
|
||
D := makePset()
|
||
D.bits.Difference(&X.bits, &Y.bits)
|
||
for n := range X.hash {
|
||
if !Y.hash[n] {
|
||
D.hash[n] = true
|
||
}
|
||
}
|
||
D.check(t, "D.Difference(X, Y)")
|
||
|
||
// D.Difference(D, Y)
|
||
D.bits.Copy(&X.bits)
|
||
D.bits.Difference(&D.bits, &Y.bits)
|
||
D.check(t, "D.Difference(D, Y)")
|
||
|
||
// D.Difference(Y, D)
|
||
D.bits.Copy(&X.bits)
|
||
D.bits.Difference(&Y.bits, &D.bits)
|
||
D.hash = make(map[int]bool)
|
||
for n := range Y.hash {
|
||
if !X.hash[n] {
|
||
D.hash[n] = true
|
||
}
|
||
}
|
||
D.check(t, "D.Difference(Y, D)")
|
||
|
||
// D.Difference(X, X)
|
||
D.bits.Difference(&X.bits, &X.bits)
|
||
D.hash = nil
|
||
D.check(t, "D.Difference(X, X)")
|
||
|
||
// D.DifferenceWith(D)
|
||
D.bits.Copy(&X.bits)
|
||
D.bits.DifferenceWith(&D.bits)
|
||
D.check(t, "D.DifferenceWith(D)")
|
||
|
||
// SD.SymmetricDifference(X, Y)
|
||
SD := makePset()
|
||
SD.bits.SymmetricDifference(&X.bits, &Y.bits)
|
||
for n := range X.hash {
|
||
if !Y.hash[n] {
|
||
SD.hash[n] = true
|
||
}
|
||
}
|
||
for n := range Y.hash {
|
||
if !X.hash[n] {
|
||
SD.hash[n] = true
|
||
}
|
||
}
|
||
SD.check(t, "SD.SymmetricDifference(X, Y)")
|
||
|
||
// X.SymmetricDifferenceWith(Y)
|
||
SD.bits.Copy(&X.bits)
|
||
SD.bits.SymmetricDifferenceWith(&Y.bits)
|
||
SD.check(t, "X.SymmetricDifference(Y)")
|
||
|
||
// Y.SymmetricDifferenceWith(X)
|
||
SD.bits.Copy(&Y.bits)
|
||
SD.bits.SymmetricDifferenceWith(&X.bits)
|
||
SD.check(t, "Y.SymmetricDifference(X)")
|
||
|
||
// SD.SymmetricDifference(X, X)
|
||
SD.bits.SymmetricDifference(&X.bits, &X.bits)
|
||
SD.hash = nil
|
||
SD.check(t, "SD.SymmetricDifference(X, X)")
|
||
|
||
// SD.SymmetricDifference(X, Copy(X))
|
||
X2 := makePset()
|
||
X2.bits.Copy(&X.bits)
|
||
SD.bits.SymmetricDifference(&X.bits, &X2.bits)
|
||
SD.check(t, "SD.SymmetricDifference(X, Copy(X))")
|
||
|
||
// Copy(X).SymmetricDifferenceWith(X)
|
||
SD.bits.Copy(&X.bits)
|
||
SD.bits.SymmetricDifferenceWith(&X.bits)
|
||
SD.check(t, "Copy(X).SymmetricDifferenceWith(X)")
|
||
}
|
||
}
|
||
|
||
func TestIntersectionWith(t *testing.T) {
|
||
// Edge cases: the pairs (1,1), (1000,2000), (8000,4000)
|
||
// exercise the <, >, == cases in IntersectionWith that the
|
||
// TestSetOperations data is too dense to cover.
|
||
var X, Y intsets.Sparse
|
||
X.Insert(1)
|
||
X.Insert(1000)
|
||
X.Insert(8000)
|
||
Y.Insert(1)
|
||
Y.Insert(2000)
|
||
Y.Insert(4000)
|
||
X.IntersectionWith(&Y)
|
||
if got, want := X.String(), "{1}"; got != want {
|
||
t.Errorf("IntersectionWith: got %s, want %s", got, want)
|
||
}
|
||
}
|
||
|
||
func TestIntersects(t *testing.T) {
|
||
prng := rand.New(rand.NewSource(0))
|
||
|
||
for i := uint(0); i < 12; i++ {
|
||
X, Y := randomPset(prng, 1<<i), randomPset(prng, 1<<i)
|
||
x, y := &X.bits, &Y.bits
|
||
|
||
// test the slow way
|
||
var z intsets.Sparse
|
||
z.Copy(x)
|
||
z.IntersectionWith(y)
|
||
|
||
if got, want := x.Intersects(y), !z.IsEmpty(); got != want {
|
||
t.Errorf("Intersects: got %v, want %v", got, want)
|
||
}
|
||
|
||
// make it false
|
||
a := x.AppendTo(nil)
|
||
for _, v := range a {
|
||
y.Remove(v)
|
||
}
|
||
|
||
if got, want := x.Intersects(y), false; got != want {
|
||
t.Errorf("Intersects: got %v, want %v", got, want)
|
||
}
|
||
|
||
// make it true
|
||
if x.IsEmpty() {
|
||
continue
|
||
}
|
||
i := prng.Intn(len(a))
|
||
y.Insert(a[i])
|
||
|
||
if got, want := x.Intersects(y), true; got != want {
|
||
t.Errorf("Intersects: got %v, want %v", got, want)
|
||
}
|
||
}
|
||
}
|
||
|
||
func TestSubsetOf(t *testing.T) {
|
||
prng := rand.New(rand.NewSource(0))
|
||
|
||
for i := uint(0); i < 12; i++ {
|
||
X, Y := randomPset(prng, 1<<i), randomPset(prng, 1<<i)
|
||
x, y := &X.bits, &Y.bits
|
||
|
||
// test the slow way
|
||
var z intsets.Sparse
|
||
z.Copy(x)
|
||
z.DifferenceWith(y)
|
||
|
||
if got, want := x.SubsetOf(y), z.IsEmpty(); got != want {
|
||
t.Errorf("SubsetOf: got %v, want %v", got, want)
|
||
}
|
||
|
||
// make it true
|
||
y.UnionWith(x)
|
||
|
||
if got, want := x.SubsetOf(y), true; got != want {
|
||
t.Errorf("SubsetOf: got %v, want %v", got, want)
|
||
}
|
||
|
||
// make it false
|
||
if x.IsEmpty() {
|
||
continue
|
||
}
|
||
a := x.AppendTo(nil)
|
||
i := prng.Intn(len(a))
|
||
y.Remove(a[i])
|
||
|
||
if got, want := x.SubsetOf(y), false; got != want {
|
||
t.Errorf("SubsetOf: got %v, want %v", got, want)
|
||
}
|
||
}
|
||
}
|
||
|
||
func TestBitString(t *testing.T) {
|
||
for _, test := range []struct {
|
||
input []int
|
||
want string
|
||
}{
|
||
{nil, "0"},
|
||
{[]int{0}, "1"},
|
||
{[]int{0, 4, 5}, "110001"},
|
||
{[]int{0, 7, 177}, "1" + strings.Repeat("0", 169) + "10000001"},
|
||
{[]int{-3, 0, 4, 5}, "110001.001"},
|
||
{[]int{-3}, "0.001"},
|
||
} {
|
||
var set intsets.Sparse
|
||
for _, x := range test.input {
|
||
set.Insert(x)
|
||
}
|
||
if got := set.BitString(); got != test.want {
|
||
t.Errorf("BitString(%s) = %s, want %s", set.String(), got, test.want)
|
||
}
|
||
}
|
||
}
|
||
|
||
func TestFailFastOnShallowCopy(t *testing.T) {
|
||
var x intsets.Sparse
|
||
x.Insert(1)
|
||
|
||
y := x // shallow copy (breaks representation invariants)
|
||
defer func() {
|
||
got := fmt.Sprint(recover())
|
||
want := "A Sparse has been copied without (*Sparse).Copy()"
|
||
if got != want {
|
||
t.Errorf("shallow copy: recover() = %q, want %q", got, want)
|
||
}
|
||
}()
|
||
y.String() // panics
|
||
t.Error("didn't panic as expected")
|
||
}
|
||
|
||
// -- Benchmarks -------------------------------------------------------
|
||
|
||
// TODO(adonovan):
|
||
// - Add benchmarks of each method.
|
||
// - Gather set distributions from pointer analysis.
|
||
// - Measure memory usage.
|
||
|
||
func BenchmarkSparseBitVector(b *testing.B) {
|
||
prng := rand.New(rand.NewSource(0))
|
||
for tries := 0; tries < b.N; tries++ {
|
||
var x, y, z intsets.Sparse
|
||
for i := 0; i < 1000; i++ {
|
||
n := int(prng.Int()) % 100000
|
||
if i%2 == 0 {
|
||
x.Insert(n)
|
||
} else {
|
||
y.Insert(n)
|
||
}
|
||
}
|
||
z.Union(&x, &y)
|
||
z.Difference(&x, &y)
|
||
}
|
||
}
|
||
|
||
func BenchmarkHashTable(b *testing.B) {
|
||
prng := rand.New(rand.NewSource(0))
|
||
for tries := 0; tries < b.N; tries++ {
|
||
x, y, z := make(map[int]bool), make(map[int]bool), make(map[int]bool)
|
||
for i := 0; i < 1000; i++ {
|
||
n := int(prng.Int()) % 100000
|
||
if i%2 == 0 {
|
||
x[n] = true
|
||
} else {
|
||
y[n] = true
|
||
}
|
||
}
|
||
// union
|
||
for n := range x {
|
||
z[n] = true
|
||
}
|
||
for n := range y {
|
||
z[n] = true
|
||
}
|
||
// difference
|
||
z = make(map[int]bool)
|
||
for n := range y {
|
||
if !x[n] {
|
||
z[n] = true
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
func BenchmarkAppendTo(b *testing.B) {
|
||
prng := rand.New(rand.NewSource(0))
|
||
var x intsets.Sparse
|
||
for i := 0; i < 1000; i++ {
|
||
x.Insert(int(prng.Int()) % 10000)
|
||
}
|
||
var space [1000]int
|
||
for tries := 0; tries < b.N; tries++ {
|
||
x.AppendTo(space[:0])
|
||
}
|
||
}
|