Document more functions, minor cleanup
Fixes: 173745248
Test: treehugger
Change-Id: I075cc5197fff79179ea976927701290078e4d9ac
diff --git a/android/util.go b/android/util.go
index 65c5f1b..8e4c0f4 100644
--- a/android/util.go
+++ b/android/util.go
@@ -29,56 +29,44 @@
return append([]string(nil), s...)
}
+// JoinWithPrefix prepends the prefix to each string in the list and
+// returns them joined together with " " as separator.
func JoinWithPrefix(strs []string, prefix string) string {
if len(strs) == 0 {
return ""
}
- if len(strs) == 1 {
- return prefix + strs[0]
+ var buf strings.Builder
+ buf.WriteString(prefix)
+ buf.WriteString(strs[0])
+ for i := 1; i < len(strs); i++ {
+ buf.WriteString(" ")
+ buf.WriteString(prefix)
+ buf.WriteString(strs[i])
}
-
- n := len(" ") * (len(strs) - 1)
- for _, s := range strs {
- n += len(prefix) + len(s)
- }
-
- ret := make([]byte, 0, n)
- for i, s := range strs {
- if i != 0 {
- ret = append(ret, ' ')
- }
- ret = append(ret, prefix...)
- ret = append(ret, s...)
- }
- return string(ret)
+ return buf.String()
}
+// JoinWithSuffix appends the suffix to each string in the list and
+// returns them joined together with given separator.
func JoinWithSuffix(strs []string, suffix string, separator string) string {
if len(strs) == 0 {
return ""
}
- if len(strs) == 1 {
- return strs[0] + suffix
+ var buf strings.Builder
+ buf.WriteString(strs[0])
+ buf.WriteString(suffix)
+ for i := 1; i < len(strs); i++ {
+ buf.WriteString(separator)
+ buf.WriteString(strs[i])
+ buf.WriteString(suffix)
}
-
- n := len(" ") * (len(strs) - 1)
- for _, s := range strs {
- n += len(suffix) + len(s)
- }
-
- ret := make([]byte, 0, n)
- for i, s := range strs {
- if i != 0 {
- ret = append(ret, separator...)
- }
- ret = append(ret, s...)
- ret = append(ret, suffix...)
- }
- return string(ret)
+ return buf.String()
}
+// SortedIntKeys returns the keys of the given integer-keyed map in the ascending order
+// TODO(asmundak): once Go has generics, combine this with SortedStringKeys below.
func SortedIntKeys(m interface{}) []int {
v := reflect.ValueOf(m)
if v.Kind() != reflect.Map {
@@ -93,6 +81,7 @@
return s
}
+// SorterStringKeys returns the keys of the given string-keyed map in the ascending order
func SortedStringKeys(m interface{}) []string {
v := reflect.ValueOf(m)
if v.Kind() != reflect.Map {
@@ -107,6 +96,7 @@
return s
}
+// SortedStringMapValues returns the values of the string-values map in the ascending order
func SortedStringMapValues(m interface{}) []string {
v := reflect.ValueOf(m)
if v.Kind() != reflect.Map {
@@ -121,6 +111,7 @@
return s
}
+// IndexList returns the index of the first occurrence of the given string in the list or -1
func IndexList(s string, list []string) int {
for i, l := range list {
if l == s {
@@ -131,6 +122,7 @@
return -1
}
+// InList checks if the string belongs to the list
func InList(s string, list []string) bool {
return IndexList(s, list) != -1
}
@@ -176,7 +168,10 @@
return -1
}
+// FilterList divides the string list into two lists: one with the strings belonging
+// to the given filter list, and the other with the remaining ones
func FilterList(list []string, filter []string) (remainder []string, filtered []string) {
+ // InList is O(n). May be worth using more efficient lookup for longer lists.
for _, l := range list {
if InList(l, filter) {
filtered = append(filtered, l)
@@ -188,6 +183,8 @@
return
}
+// RemoveListFromList removes the strings belonging to the filter list from the
+// given list and returns the result
func RemoveListFromList(list []string, filter_out []string) (result []string) {
result = make([]string, 0, len(list))
for _, l := range list {
@@ -198,20 +195,18 @@
return
}
+// RemoveFromList removes given string from the string list.
func RemoveFromList(s string, list []string) (bool, []string) {
- i := IndexList(s, list)
- if i == -1 {
- return false, list
- }
-
- result := make([]string, 0, len(list)-1)
- result = append(result, list[:i]...)
- for _, l := range list[i+1:] {
- if l != s {
- result = append(result, l)
+ result := make([]string, 0, len(list))
+ var removed bool
+ for _, item := range list {
+ if item != s {
+ result = append(result, item)
+ } else {
+ removed = true
}
}
- return true, result
+ return removed, result
}
// FirstUniqueStrings returns all unique elements of a slice of strings, keeping the first copy of
@@ -317,11 +312,10 @@
return s[1], s[2], true
}
+// GetNumericSdkVersion removes the first occurrence of system_ in a string,
+// which is assumed to be something like "system_1.2.3"
func GetNumericSdkVersion(v string) string {
- if strings.Contains(v, "system_") {
- return strings.Replace(v, "system_", "", 1)
- }
- return v
+ return strings.Replace(v, "system_", "", 1)
}
// copied from build/kati/strutil.go
@@ -334,17 +328,17 @@
return str
}
in := str
- trimed := str
+ trimmed := str
if ps[0] != "" {
- trimed = strings.TrimPrefix(in, ps[0])
- if trimed == in {
+ trimmed = strings.TrimPrefix(in, ps[0])
+ if trimmed == in {
return str
}
}
- in = trimed
+ in = trimmed
if ps[1] != "" {
- trimed = strings.TrimSuffix(in, ps[1])
- if trimed == in {
+ trimmed = strings.TrimSuffix(in, ps[1])
+ if trimmed == in {
return str
}
}
@@ -353,7 +347,7 @@
if len(rs) != 2 {
return repl
}
- return rs[0] + trimed + rs[1]
+ return rs[0] + trimmed + rs[1]
}
// copied from build/kati/strutil.go
@@ -424,13 +418,15 @@
return ret
}
+// CheckDuplicate checks if there are duplicates in given string list.
+// If there are, it returns first such duplicate and true.
func CheckDuplicate(values []string) (duplicate string, found bool) {
seen := make(map[string]string)
for _, v := range values {
if duplicate, found = seen[v]; found {
- return
+ return duplicate, true
}
seen[v] = v
}
- return
+ return "", false
}