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go/src/infra/libs/infra_util/stringSet.go

+// Copyright 2014 The Chromium 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 infra_util
+
+import (
+        "bytes"
+        "fmt"
+)
+
+type StringSet map[string]struct{}
+
+func StringSetFrom(elems ...string) StringSet {
+        ret := make(StringSet, len(elems))
+        ret.Add(elems...)
+        return ret
+}
+
+func (s StringSet) Cardinality() int { return len(s) }
+
+func (s StringSet) Add(elems ...string) (ret int) {
+        for _, e := range elems {
+                if !s.Has(e) {
+                        ret++
+                        s[e] = struct{}{}
+                }
+        }
+        return
+}
+
+func (s StringSet) Remove(elems ...string) (ret int) {
+        for _, e := range elems {
+                if s.Has(e) {
+                        delete(s, e)
+                        ret++
+                }
+        }
+        return
+}
+
+func (s StringSet) Has(elem string) bool {
+        _, has := s[elem]
+        return has
+}
+
+func (s StringSet) String() string {
+        buf := &bytes.Buffer{}
+        fmt.Fprintf(buf, "set(")
+        first := true
+        for e := range s {
+                if !first {
+                        fmt.Fprint(buf, ",")
+                }
+                first = false
+                fmt.Fprintf(buf, "%#v", e)
+        }
+        fmt.Fprintf(buf, ")")
+        return buf.String()
+}