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1// Copyright 2015 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package android
16
17import (
18	"fmt"
19	"path/filepath"
20	"reflect"
21	"regexp"
22	"runtime"
23	"sort"
24	"strings"
25)
26
27// CopyOf returns a new slice that has the same contents as s.
28func CopyOf(s []string) []string {
29	return append([]string(nil), s...)
30}
31
32// JoinWithPrefix prepends the prefix to each string in the list and
33// returns them joined together with " " as separator.
34func JoinWithPrefix(strs []string, prefix string) string {
35	if len(strs) == 0 {
36		return ""
37	}
38
39	var buf strings.Builder
40	buf.WriteString(prefix)
41	buf.WriteString(strs[0])
42	for i := 1; i < len(strs); i++ {
43		buf.WriteString(" ")
44		buf.WriteString(prefix)
45		buf.WriteString(strs[i])
46	}
47	return buf.String()
48}
49
50// JoinWithSuffix appends the suffix to each string in the list and
51// returns them joined together with given separator.
52func JoinWithSuffix(strs []string, suffix string, separator string) string {
53	if len(strs) == 0 {
54		return ""
55	}
56
57	var buf strings.Builder
58	buf.WriteString(strs[0])
59	buf.WriteString(suffix)
60	for i := 1; i < len(strs); i++ {
61		buf.WriteString(separator)
62		buf.WriteString(strs[i])
63		buf.WriteString(suffix)
64	}
65	return buf.String()
66}
67
68// SorterStringKeys returns the keys of the given string-keyed map in the ascending order.
69func SortedStringKeys(m interface{}) []string {
70	v := reflect.ValueOf(m)
71	if v.Kind() != reflect.Map {
72		panic(fmt.Sprintf("%#v is not a map", m))
73	}
74	if v.Len() == 0 {
75		return nil
76	}
77	iter := v.MapRange()
78	s := make([]string, 0, v.Len())
79	for iter.Next() {
80		s = append(s, iter.Key().String())
81	}
82	sort.Strings(s)
83	return s
84}
85
86// stringValues returns the values of the given string-valued map in randomized map order.
87func stringValues(m interface{}) []string {
88	v := reflect.ValueOf(m)
89	if v.Kind() != reflect.Map {
90		panic(fmt.Sprintf("%#v is not a map", m))
91	}
92	if v.Len() == 0 {
93		return nil
94	}
95	iter := v.MapRange()
96	s := make([]string, 0, v.Len())
97	for iter.Next() {
98		s = append(s, iter.Value().String())
99	}
100	return s
101}
102
103// SortedStringValues returns the values of the given string-valued map in the ascending order.
104func SortedStringValues(m interface{}) []string {
105	s := stringValues(m)
106	sort.Strings(s)
107	return s
108}
109
110// SortedUniqueStringValues returns the values of the given string-valued map in the ascending order
111// with duplicates removed.
112func SortedUniqueStringValues(m interface{}) []string {
113	s := stringValues(m)
114	return SortedUniqueStrings(s)
115}
116
117// IndexList returns the index of the first occurrence of the given string in the list or -1
118func IndexList(s string, list []string) int {
119	for i, l := range list {
120		if l == s {
121			return i
122		}
123	}
124
125	return -1
126}
127
128// InList checks if the string belongs to the list
129func InList(s string, list []string) bool {
130	return IndexList(s, list) != -1
131}
132
133// Returns true if the given string s is prefixed with any string in the given prefix list.
134func HasAnyPrefix(s string, prefixList []string) bool {
135	for _, prefix := range prefixList {
136		if strings.HasPrefix(s, prefix) {
137			return true
138		}
139	}
140	return false
141}
142
143// Returns true if any string in the given list has the given substring.
144func SubstringInList(list []string, substr string) bool {
145	for _, s := range list {
146		if strings.Contains(s, substr) {
147			return true
148		}
149	}
150	return false
151}
152
153// Returns true if any string in the given list has the given prefix.
154func PrefixInList(list []string, prefix string) bool {
155	for _, s := range list {
156		if strings.HasPrefix(s, prefix) {
157			return true
158		}
159	}
160	return false
161}
162
163// Returns true if any string in the given list has the given suffix.
164func SuffixInList(list []string, suffix string) bool {
165	for _, s := range list {
166		if strings.HasSuffix(s, suffix) {
167			return true
168		}
169	}
170	return false
171}
172
173// IndexListPred returns the index of the element which in the given `list` satisfying the predicate, or -1 if there is no such element.
174func IndexListPred(pred func(s string) bool, list []string) int {
175	for i, l := range list {
176		if pred(l) {
177			return i
178		}
179	}
180
181	return -1
182}
183
184// FilterList divides the string list into two lists: one with the strings belonging
185// to the given filter list, and the other with the remaining ones
186func FilterList(list []string, filter []string) (remainder []string, filtered []string) {
187	// InList is O(n). May be worth using more efficient lookup for longer lists.
188	for _, l := range list {
189		if InList(l, filter) {
190			filtered = append(filtered, l)
191		} else {
192			remainder = append(remainder, l)
193		}
194	}
195
196	return
197}
198
199// FilterListPred returns the elements of the given list for which the predicate
200// returns true. Order is kept.
201func FilterListPred(list []string, pred func(s string) bool) (filtered []string) {
202	for _, l := range list {
203		if pred(l) {
204			filtered = append(filtered, l)
205		}
206	}
207	return
208}
209
210// RemoveListFromList removes the strings belonging to the filter list from the
211// given list and returns the result
212func RemoveListFromList(list []string, filter_out []string) (result []string) {
213	result = make([]string, 0, len(list))
214	for _, l := range list {
215		if !InList(l, filter_out) {
216			result = append(result, l)
217		}
218	}
219	return
220}
221
222// RemoveFromList removes given string from the string list.
223func RemoveFromList(s string, list []string) (bool, []string) {
224	result := make([]string, 0, len(list))
225	var removed bool
226	for _, item := range list {
227		if item != s {
228			result = append(result, item)
229		} else {
230			removed = true
231		}
232	}
233	return removed, result
234}
235
236// FirstUniqueStrings returns all unique elements of a slice of strings, keeping the first copy of
237// each.  It modifies the slice contents in place, and returns a subslice of the original slice.
238func FirstUniqueStrings(list []string) []string {
239	// 128 was chosen based on BenchmarkFirstUniqueStrings results.
240	if len(list) > 128 {
241		return firstUniqueStringsMap(list)
242	}
243	return firstUniqueStringsList(list)
244}
245
246func firstUniqueStringsList(list []string) []string {
247	k := 0
248outer:
249	for i := 0; i < len(list); i++ {
250		for j := 0; j < k; j++ {
251			if list[i] == list[j] {
252				continue outer
253			}
254		}
255		list[k] = list[i]
256		k++
257	}
258	return list[:k]
259}
260
261func firstUniqueStringsMap(list []string) []string {
262	k := 0
263	seen := make(map[string]bool, len(list))
264	for i := 0; i < len(list); i++ {
265		if seen[list[i]] {
266			continue
267		}
268		seen[list[i]] = true
269		list[k] = list[i]
270		k++
271	}
272	return list[:k]
273}
274
275// LastUniqueStrings returns all unique elements of a slice of strings, keeping the last copy of
276// each.  It modifies the slice contents in place, and returns a subslice of the original slice.
277func LastUniqueStrings(list []string) []string {
278	totalSkip := 0
279	for i := len(list) - 1; i >= totalSkip; i-- {
280		skip := 0
281		for j := i - 1; j >= totalSkip; j-- {
282			if list[i] == list[j] {
283				skip++
284			} else {
285				list[j+skip] = list[j]
286			}
287		}
288		totalSkip += skip
289	}
290	return list[totalSkip:]
291}
292
293// SortedUniqueStrings returns what the name says
294func SortedUniqueStrings(list []string) []string {
295	unique := FirstUniqueStrings(list)
296	sort.Strings(unique)
297	return unique
298}
299
300// checkCalledFromInit panics if a Go package's init function is not on the
301// call stack.
302func checkCalledFromInit() {
303	for skip := 3; ; skip++ {
304		_, funcName, ok := callerName(skip)
305		if !ok {
306			panic("not called from an init func")
307		}
308
309		if funcName == "init" || strings.HasPrefix(funcName, "init·") ||
310			strings.HasPrefix(funcName, "init.") {
311			return
312		}
313	}
314}
315
316// A regex to find a package path within a function name. It finds the shortest string that is
317// followed by '.' and doesn't have any '/'s left.
318var pkgPathRe = regexp.MustCompile(`^(.*?)\.([^/]+)$`)
319
320// callerName returns the package path and function name of the calling
321// function.  The skip argument has the same meaning as the skip argument of
322// runtime.Callers.
323func callerName(skip int) (pkgPath, funcName string, ok bool) {
324	var pc [1]uintptr
325	n := runtime.Callers(skip+1, pc[:])
326	if n != 1 {
327		return "", "", false
328	}
329
330	f := runtime.FuncForPC(pc[0]).Name()
331	s := pkgPathRe.FindStringSubmatch(f)
332	if len(s) < 3 {
333		panic(fmt.Errorf("failed to extract package path and function name from %q", f))
334	}
335
336	return s[1], s[2], true
337}
338
339// GetNumericSdkVersion removes the first occurrence of system_ in a string,
340// which is assumed to be something like "system_1.2.3"
341func GetNumericSdkVersion(v string) string {
342	return strings.Replace(v, "system_", "", 1)
343}
344
345// copied from build/kati/strutil.go
346func substPattern(pat, repl, str string) string {
347	ps := strings.SplitN(pat, "%", 2)
348	if len(ps) != 2 {
349		if str == pat {
350			return repl
351		}
352		return str
353	}
354	in := str
355	trimmed := str
356	if ps[0] != "" {
357		trimmed = strings.TrimPrefix(in, ps[0])
358		if trimmed == in {
359			return str
360		}
361	}
362	in = trimmed
363	if ps[1] != "" {
364		trimmed = strings.TrimSuffix(in, ps[1])
365		if trimmed == in {
366			return str
367		}
368	}
369
370	rs := strings.SplitN(repl, "%", 2)
371	if len(rs) != 2 {
372		return repl
373	}
374	return rs[0] + trimmed + rs[1]
375}
376
377// copied from build/kati/strutil.go
378func matchPattern(pat, str string) bool {
379	i := strings.IndexByte(pat, '%')
380	if i < 0 {
381		return pat == str
382	}
383	return strings.HasPrefix(str, pat[:i]) && strings.HasSuffix(str, pat[i+1:])
384}
385
386var shlibVersionPattern = regexp.MustCompile("(?:\\.\\d+(?:svn)?)+")
387
388// splitFileExt splits a file name into root, suffix and ext. root stands for the file name without
389// the file extension and the version number (e.g. "libexample"). suffix stands for the
390// concatenation of the file extension and the version number (e.g. ".so.1.0"). ext stands for the
391// file extension after the version numbers are trimmed (e.g. ".so").
392func SplitFileExt(name string) (string, string, string) {
393	// Extract and trim the shared lib version number if the file name ends with dot digits.
394	suffix := ""
395	matches := shlibVersionPattern.FindAllStringIndex(name, -1)
396	if len(matches) > 0 {
397		lastMatch := matches[len(matches)-1]
398		if lastMatch[1] == len(name) {
399			suffix = name[lastMatch[0]:lastMatch[1]]
400			name = name[0:lastMatch[0]]
401		}
402	}
403
404	// Extract the file name root and the file extension.
405	ext := filepath.Ext(name)
406	root := strings.TrimSuffix(name, ext)
407	suffix = ext + suffix
408
409	return root, suffix, ext
410}
411
412// ShardPaths takes a Paths, and returns a slice of Paths where each one has at most shardSize paths.
413func ShardPaths(paths Paths, shardSize int) []Paths {
414	if len(paths) == 0 {
415		return nil
416	}
417	ret := make([]Paths, 0, (len(paths)+shardSize-1)/shardSize)
418	for len(paths) > shardSize {
419		ret = append(ret, paths[0:shardSize])
420		paths = paths[shardSize:]
421	}
422	if len(paths) > 0 {
423		ret = append(ret, paths)
424	}
425	return ret
426}
427
428// ShardString takes a string and returns a slice of strings where the length of each one is
429// at most shardSize.
430func ShardString(s string, shardSize int) []string {
431	if len(s) == 0 {
432		return nil
433	}
434	ret := make([]string, 0, (len(s)+shardSize-1)/shardSize)
435	for len(s) > shardSize {
436		ret = append(ret, s[0:shardSize])
437		s = s[shardSize:]
438	}
439	if len(s) > 0 {
440		ret = append(ret, s)
441	}
442	return ret
443}
444
445// ShardStrings takes a slice of strings, and returns a slice of slices of strings where each one has at most shardSize
446// elements.
447func ShardStrings(s []string, shardSize int) [][]string {
448	if len(s) == 0 {
449		return nil
450	}
451	ret := make([][]string, 0, (len(s)+shardSize-1)/shardSize)
452	for len(s) > shardSize {
453		ret = append(ret, s[0:shardSize])
454		s = s[shardSize:]
455	}
456	if len(s) > 0 {
457		ret = append(ret, s)
458	}
459	return ret
460}
461
462// CheckDuplicate checks if there are duplicates in given string list.
463// If there are, it returns first such duplicate and true.
464func CheckDuplicate(values []string) (duplicate string, found bool) {
465	seen := make(map[string]string)
466	for _, v := range values {
467		if duplicate, found = seen[v]; found {
468			return duplicate, true
469		}
470		seen[v] = v
471	}
472	return "", false
473}
474