mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-08 20:55:01 +00:00
305 lines
7.1 KiB
Go
305 lines
7.1 KiB
Go
// Copyright 2010 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 suffixarray
|
|
|
|
import (
|
|
"bytes"
|
|
"math/rand"
|
|
"regexp"
|
|
"sort"
|
|
"strings"
|
|
"testing"
|
|
)
|
|
|
|
type testCase struct {
|
|
name string // name of test case
|
|
source string // source to index
|
|
patterns []string // patterns to lookup
|
|
}
|
|
|
|
var testCases = []testCase{
|
|
{
|
|
"empty string",
|
|
"",
|
|
[]string{
|
|
"",
|
|
"foo",
|
|
"(foo)",
|
|
".*",
|
|
"a*",
|
|
},
|
|
},
|
|
|
|
{
|
|
"all a's",
|
|
"aaaaaaaaaa", // 10 a's
|
|
[]string{
|
|
"",
|
|
"a",
|
|
"aa",
|
|
"aaa",
|
|
"aaaa",
|
|
"aaaaa",
|
|
"aaaaaa",
|
|
"aaaaaaa",
|
|
"aaaaaaaa",
|
|
"aaaaaaaaa",
|
|
"aaaaaaaaaa",
|
|
"aaaaaaaaaaa", // 11 a's
|
|
".",
|
|
".*",
|
|
"a+",
|
|
"aa+",
|
|
"aaaa[b]?",
|
|
"aaa*",
|
|
},
|
|
},
|
|
|
|
{
|
|
"abc",
|
|
"abc",
|
|
[]string{
|
|
"a",
|
|
"b",
|
|
"c",
|
|
"ab",
|
|
"bc",
|
|
"abc",
|
|
"a.c",
|
|
"a(b|c)",
|
|
"abc?",
|
|
},
|
|
},
|
|
|
|
{
|
|
"barbara*3",
|
|
"barbarabarbarabarbara",
|
|
[]string{
|
|
"a",
|
|
"bar",
|
|
"rab",
|
|
"arab",
|
|
"barbar",
|
|
"bara?bar",
|
|
},
|
|
},
|
|
|
|
{
|
|
"typing drill",
|
|
"Now is the time for all good men to come to the aid of their country.",
|
|
[]string{
|
|
"Now",
|
|
"the time",
|
|
"to come the aid",
|
|
"is the time for all good men to come to the aid of their",
|
|
"to (come|the)?",
|
|
},
|
|
},
|
|
|
|
{
|
|
"godoc simulation",
|
|
"package main\n\nimport(\n \"rand\"\n ",
|
|
[]string{},
|
|
},
|
|
}
|
|
|
|
// find all occurrences of s in source; report at most n occurrences
|
|
func find(src, s string, n int) []int {
|
|
var res []int
|
|
if s != "" && n != 0 {
|
|
// find at most n occurrences of s in src
|
|
for i := -1; n < 0 || len(res) < n; {
|
|
j := strings.Index(src[i+1:], s)
|
|
if j < 0 {
|
|
break
|
|
}
|
|
i += j + 1
|
|
res = append(res, i)
|
|
}
|
|
}
|
|
return res
|
|
}
|
|
|
|
func testLookup(t *testing.T, tc *testCase, x *Index, s string, n int) {
|
|
res := x.Lookup([]byte(s), n)
|
|
exp := find(tc.source, s, n)
|
|
|
|
// check that the lengths match
|
|
if len(res) != len(exp) {
|
|
t.Errorf("test %q, lookup %q (n = %d): expected %d results; got %d", tc.name, s, n, len(exp), len(res))
|
|
}
|
|
|
|
// if n >= 0 the number of results is limited --- unless n >= all results,
|
|
// we may obtain different positions from the Index and from find (because
|
|
// Index may not find the results in the same order as find) => in general
|
|
// we cannot simply check that the res and exp lists are equal
|
|
|
|
// check that each result is in fact a correct match and there are no duplicates
|
|
sort.Ints(res)
|
|
for i, r := range res {
|
|
if r < 0 || len(tc.source) <= r {
|
|
t.Errorf("test %q, lookup %q, result %d (n = %d): index %d out of range [0, %d[", tc.name, s, i, n, r, len(tc.source))
|
|
} else if !strings.HasPrefix(tc.source[r:], s) {
|
|
t.Errorf("test %q, lookup %q, result %d (n = %d): index %d not a match", tc.name, s, i, n, r)
|
|
}
|
|
if i > 0 && res[i-1] == r {
|
|
t.Errorf("test %q, lookup %q, result %d (n = %d): found duplicate index %d", tc.name, s, i, n, r)
|
|
}
|
|
}
|
|
|
|
if n < 0 {
|
|
// all results computed - sorted res and exp must be equal
|
|
for i, r := range res {
|
|
e := exp[i]
|
|
if r != e {
|
|
t.Errorf("test %q, lookup %q, result %d: expected index %d; got %d", tc.name, s, i, e, r)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func testFindAllIndex(t *testing.T, tc *testCase, x *Index, rx *regexp.Regexp, n int) {
|
|
res := x.FindAllIndex(rx, n)
|
|
exp := rx.FindAllStringIndex(tc.source, n)
|
|
|
|
// check that the lengths match
|
|
if len(res) != len(exp) {
|
|
t.Errorf("test %q, FindAllIndex %q (n = %d): expected %d results; got %d", tc.name, rx, n, len(exp), len(res))
|
|
}
|
|
|
|
// if n >= 0 the number of results is limited --- unless n >= all results,
|
|
// we may obtain different positions from the Index and from regexp (because
|
|
// Index may not find the results in the same order as regexp) => in general
|
|
// we cannot simply check that the res and exp lists are equal
|
|
|
|
// check that each result is in fact a correct match and the result is sorted
|
|
for i, r := range res {
|
|
if r[0] < 0 || r[0] > r[1] || len(tc.source) < r[1] {
|
|
t.Errorf("test %q, FindAllIndex %q, result %d (n == %d): illegal match [%d, %d]", tc.name, rx, i, n, r[0], r[1])
|
|
} else if !rx.MatchString(tc.source[r[0]:r[1]]) {
|
|
t.Errorf("test %q, FindAllIndex %q, result %d (n = %d): [%d, %d] not a match", tc.name, rx, i, n, r[0], r[1])
|
|
}
|
|
}
|
|
|
|
if n < 0 {
|
|
// all results computed - sorted res and exp must be equal
|
|
for i, r := range res {
|
|
e := exp[i]
|
|
if r[0] != e[0] || r[1] != e[1] {
|
|
t.Errorf("test %q, FindAllIndex %q, result %d: expected match [%d, %d]; got [%d, %d]",
|
|
tc.name, rx, i, e[0], e[1], r[0], r[1])
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func testLookups(t *testing.T, tc *testCase, x *Index, n int) {
|
|
for _, pat := range tc.patterns {
|
|
testLookup(t, tc, x, pat, n)
|
|
if rx, err := regexp.Compile(pat); err == nil {
|
|
testFindAllIndex(t, tc, x, rx, n)
|
|
}
|
|
}
|
|
}
|
|
|
|
// index is used to hide the sort.Interface
|
|
type index Index
|
|
|
|
func (x *index) Len() int { return len(x.sa) }
|
|
func (x *index) Less(i, j int) bool { return bytes.Compare(x.at(i), x.at(j)) < 0 }
|
|
func (x *index) Swap(i, j int) { x.sa[i], x.sa[j] = x.sa[j], x.sa[i] }
|
|
func (a *index) at(i int) []byte { return a.data[a.sa[i]:] }
|
|
|
|
func testConstruction(t *testing.T, tc *testCase, x *Index) {
|
|
if !sort.IsSorted((*index)(x)) {
|
|
t.Errorf("failed testConstruction %s", tc.name)
|
|
}
|
|
}
|
|
|
|
func equal(x, y *Index) bool {
|
|
if !bytes.Equal(x.data, y.data) {
|
|
return false
|
|
}
|
|
for i, j := range x.sa {
|
|
if j != y.sa[i] {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
// returns the serialized index size
|
|
func testSaveRestore(t *testing.T, tc *testCase, x *Index) int {
|
|
var buf bytes.Buffer
|
|
if err := x.Write(&buf); err != nil {
|
|
t.Errorf("failed writing index %s (%s)", tc.name, err)
|
|
}
|
|
size := buf.Len()
|
|
var y Index
|
|
if err := y.Read(&buf); err != nil {
|
|
t.Errorf("failed reading index %s (%s)", tc.name, err)
|
|
}
|
|
if !equal(x, &y) {
|
|
t.Errorf("restored index doesn't match saved index %s", tc.name)
|
|
}
|
|
return size
|
|
}
|
|
|
|
func TestIndex(t *testing.T) {
|
|
for _, tc := range testCases {
|
|
x := New([]byte(tc.source))
|
|
testConstruction(t, &tc, x)
|
|
testSaveRestore(t, &tc, x)
|
|
testLookups(t, &tc, x, 0)
|
|
testLookups(t, &tc, x, 1)
|
|
testLookups(t, &tc, x, 10)
|
|
testLookups(t, &tc, x, 2e9)
|
|
testLookups(t, &tc, x, -1)
|
|
}
|
|
}
|
|
|
|
// Of all possible inputs, the random bytes have the least amount of substring
|
|
// repetition, and the repeated bytes have the most. For most algorithms,
|
|
// the running time of every input will be between these two.
|
|
func benchmarkNew(b *testing.B, random bool) {
|
|
b.StopTimer()
|
|
data := make([]byte, 1e6)
|
|
if random {
|
|
for i := range data {
|
|
data[i] = byte(rand.Intn(256))
|
|
}
|
|
}
|
|
b.StartTimer()
|
|
for i := 0; i < b.N; i++ {
|
|
New(data)
|
|
}
|
|
}
|
|
|
|
func BenchmarkNewIndexRandom(b *testing.B) {
|
|
benchmarkNew(b, true)
|
|
}
|
|
func BenchmarkNewIndexRepeat(b *testing.B) {
|
|
benchmarkNew(b, false)
|
|
}
|
|
|
|
func BenchmarkSaveRestore(b *testing.B) {
|
|
b.StopTimer()
|
|
r := rand.New(rand.NewSource(0x5a77a1)) // guarantee always same sequence
|
|
data := make([]byte, 1<<20) // 1MB of data to index
|
|
for i := range data {
|
|
data[i] = byte(r.Intn(256))
|
|
}
|
|
x := New(data)
|
|
size := testSaveRestore(nil, nil, x) // verify correctness
|
|
buf := bytes.NewBuffer(make([]byte, size)) // avoid growing
|
|
b.SetBytes(int64(size))
|
|
b.StartTimer()
|
|
for i := 0; i < b.N; i++ {
|
|
x.Write(buf)
|
|
var y Index
|
|
y.Read(buf)
|
|
}
|
|
}
|