Merge pull request #8 from uber-go/string
Add String as a type-safe wrapper for atomic.Value
diff --git a/stress_test.go b/stress_test.go
index 83d3e85..9d1b1db 100644
--- a/stress_test.go
+++ b/stress_test.go
@@ -120,3 +120,18 @@
}()
}
}
+
+func TestStressString(t *testing.T) {
+ defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(_parallelism))
+ atom := NewString("")
+ for i := 0; i < _parallelism; i++ {
+ go func() {
+ for j := 0; j < _iterations; j++ {
+ atom.Load()
+ atom.Store("abc")
+ atom.Load()
+ atom.Store("def")
+ }
+ }()
+ }
+}
diff --git a/string.go b/string.go
new file mode 100644
index 0000000..17eb42e
--- /dev/null
+++ b/string.go
@@ -0,0 +1,47 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+import "sync/atomic"
+
+// String is an atomic type-safe wrapper around atomic.Value for strings.
+type String struct{ atomic.Value }
+
+// NewString creates a String.
+func NewString(s string) *String {
+ return &String{}
+}
+
+// Load atomically loads the wrapped string.
+func (s *String) Load() string {
+ v := s.Value.Load()
+ if v == nil {
+ return ""
+ }
+ return v.(string)
+}
+
+// Store atomically stores the passed string.
+// Note: Converting the string to an interface{} to store in the atomic.Value
+// requires an allocation.
+func (s *String) Store(str string) {
+ s.Value.Store(str)
+}
diff --git a/string_test.go b/string_test.go
new file mode 100644
index 0000000..1c4ab8b
--- /dev/null
+++ b/string_test.go
@@ -0,0 +1,43 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+import (
+ "testing"
+
+ "github.com/stretchr/testify/require"
+)
+
+func TestStringNoInitialValue(t *testing.T) {
+ atom := &String{}
+ require.Equal(t, "", atom.Load(), "Initial value should be blank string")
+}
+
+func TestString(t *testing.T) {
+ atom := NewString("")
+ require.Equal(t, "", atom.Load(), "Expected Load to return initialized value")
+
+ atom.Store("abc")
+ require.Equal(t, "abc", atom.Load(), "Unexpected value after Store")
+
+ atom = NewString("bcd")
+ require.Equal(t, "", atom.Load(), "Expected Load to return initialized value")
+}
