add Map.GetAndSet, rename Map.{EnsureGet => Use}

Author: ayonli

collections/BiMap_example_test.go

@@ -79,13 +79,13 @@ func ExampleBiMap_GetKey() {
 	//  false
 }
 
-func ExampleBiMap_EnsureGet() {
-	m := collections.NewMap([]collections.MapEntry[string, string]{
+func ExampleBiMap_Use() {
+	m := collections.NewBiMap([]collections.MapEntry[string, string]{
 		{"foo", "Hi"},
 	})
 
-	val1 := m.EnsureGet("foo", func() string { return "Hello" })
-	val2 := m.EnsureGet("bar", func() string { return "World" })
+	val1 := m.Use("foo", func() string { return "Hello" })
+	val2 := m.Use("bar", func() string { return "World" })
 
 	fmt.Println(val1)
 	fmt.Println(val2)
@@ -94,6 +94,22 @@ func ExampleBiMap_EnsureGet() {
 	// World
 }
 
+func ExampleBiMap_GetAndSet() {
+	m := collections.NewBiMap([]collections.MapEntry[string, string]{
+		{"foo", "Hello"},
+		{"bar", "World"},
+	})
+
+	val1, _ := m.GetAndSet("foo", "Hi")
+	val2, _ := m.Get("foo")
+
+	fmt.Println(val1)
+	fmt.Println(val2)
+	// Output:
+	// Hello
+	// Hi
+}
+
 func ExampleBiMap_Has() {
 	m := collections.NewBiMap([]collections.MapEntry[string, string]{
 		{"foo", "Hello"},

collections/CiMap.go

@@ -65,11 +65,9 @@ func (self *CiMap[K, V]) Has(key K) bool {
 	return self.Map.Has(K(strings.ToLower(string(key))))
 }
 
-// Retrieves a value by the given key. If the key doesn't exist yet, invokes the `setter` function
-// to set the value and return it.
-//
-// This function is atomic.
-func (self *CiMap[K, V]) EnsureGet(key K, setter func() V) V {
+// Retrieves a value by the given key. If the key doesn't exist yet, invokes the `init` function
+// for setting the value and return it.
+func (self *CiMap[K, V]) Use(key K, init func() V) V {
 	self.mut.Lock()
 	defer self.mut.Unlock()
 
@@ -78,7 +76,7 @@ func (self *CiMap[K, V]) EnsureGet(key K, setter func() V) V {
 	var value V
 
 	if idx == -1 {
-		value = setter()
+		value = init()
 		self.set(key, value)
 	} else {
 		record := self.records[idx]
@@ -88,6 +86,24 @@ func (self *CiMap[K, V]) EnsureGet(key K, setter func() V) V {
 	return value
 }
 
+// Retrieves the previous value by the given key and set a new value.
+func (self *CiMap[K, V]) GetAndSet(key K, value V) (V, bool) {
+	self.mut.Lock()
+	defer self.mut.Unlock()
+
+	id := strings.ToLower(string(key))
+	idx := self.findIndex(K(id))
+
+	if idx == -1 {
+		self.set(key, value)
+		return *new(V), false
+	} else {
+		record := self.records[idx]
+		self.set(key, value)
+		return record.Value, true
+	}
+}
+
 // Removes the key-value pair by the given key.
 func (self *CiMap[K, V]) Delete(key K) bool {
 	self.mut.Lock()

collections/CiMap_example_test.go

@@ -79,13 +79,13 @@ func ExampleCiMap_Has() {
 	// false
 }
 
-func ExampleCiMap_EnsureGet() {
+func ExampleCiMap_Use() {
 	m := collections.NewCiMap([]collections.MapEntry[string, string]{
 		{"foo", "Hi"},
 	})
 
-	val1 := m.EnsureGet("Foo", func() string { return "Hello" })
-	val2 := m.EnsureGet("Bar", func() string { return "World" })
+	val1 := m.Use("Foo", func() string { return "Hello" })
+	val2 := m.Use("Bar", func() string { return "World" })
 
 	fmt.Println(val1)
 	fmt.Println(val2)
@@ -94,6 +94,22 @@ func ExampleCiMap_EnsureGet() {
 	// World
 }
 
+func ExampleCiMap_GetAndSet() {
+	m := collections.NewCiMap([]collections.MapEntry[string, string]{
+		{"foo", "Hello"},
+		{"bar", "World"},
+	})
+
+	val1, _ := m.GetAndSet("Foo", "Hi")
+	val2, _ := m.Get("foo")
+
+	fmt.Println(val1)
+	fmt.Println(val2)
+	// Output:
+	// Hello
+	// Hi
+}
+
 func ExampleCiMap_Delete() {
 	m := collections.NewCiMap([]collections.MapEntry[string, string]{
 		{"Foo", "Hello"},

collections/Map.go

@@ -97,19 +97,17 @@ func (self *Map[K, V]) Has(key K) bool {
 	return idx != -1
 }
 
-// Retrieves a value by the given key. If the key doesn't exist yet, invokes the `setter` function
-// to set the value and return it.
-//
-// This function is atomic.
-func (self *Map[K, V]) EnsureGet(key K, setter func() V) V {
+// Retrieves a value by the given key. If the key doesn't exist yet, invokes the `init` function
+// for setting the value and return it.
+func (self *Map[K, V]) Use(key K, init func() V) V {
 	self.mut.Lock()
 	defer self.mut.Unlock()
 
 	idx := self.findIndex(key)
 	var value V
 
 	if idx == -1 {
-		value = setter()
+		value = init()
 		self.set(key, value)
 	} else {
 		record := self.records[idx]
@@ -119,6 +117,23 @@ func (self *Map[K, V]) EnsureGet(key K, setter func() V) V {
 	return value
 }
 
+// Retrieves the previous value by the given key and set a new value.
+func (self *Map[K, V]) GetAndSet(key K, value V) (V, bool) {
+	self.mut.Lock()
+	defer self.mut.Unlock()
+
+	idx := self.findIndex(key)
+
+	if idx == -1 {
+		self.set(key, value)
+		return *new(V), false
+	} else {
+		record := self.records[idx]
+		self.set(key, value)
+		return record.Value, true
+	}
+}
+
 func (self *Map[K, V]) deleteAt(idx int) bool {
 	if idx == -1 {
 		return false

collections/Map_example_test.go

@@ -79,13 +79,13 @@ func ExampleMap_Has() {
 	// false
 }
 
-func ExampleMap_EnsureGet() {
+func ExampleMap_Use() {
 	m := collections.NewMap([]collections.MapEntry[string, string]{
 		{"foo", "Hi"},
 	})
 
-	val1 := m.EnsureGet("foo", func() string { return "Hello" })
-	val2 := m.EnsureGet("bar", func() string { return "World" })
+	val1 := m.Use("foo", func() string { return "Hello" })
+	val2 := m.Use("bar", func() string { return "World" })
 
 	fmt.Println(val1)
 	fmt.Println(val2)
@@ -94,6 +94,22 @@ func ExampleMap_EnsureGet() {
 	// World
 }
 
+func ExampleMap_GetAndSet() {
+	m := collections.NewMap([]collections.MapEntry[string, string]{
+		{"foo", "Hello"},
+		{"bar", "World"},
+	})
+
+	val1, _ := m.GetAndSet("foo", "Hi")
+	val2, _ := m.Get("foo")
+
+	fmt.Println(val1)
+	fmt.Println(val2)
+	// Output:
+	// Hello
+	// Hi
+}
+
 func ExampleMap_Delete() {
 	m := collections.NewMap([]collections.MapEntry[string, string]{
 		{"foo", "Hello"},

collections/Set.go

@@ -26,7 +26,7 @@ func NewSet[T comparable](base []T) *Set[T] {
 
 // Adds an item to the set. If the item already exists, the set remains untouched.
 func (self *Set[T]) Add(item T) *Set[T] {
-	self.m.EnsureGet(item, func() int { return self.m.size })
+	self.m.Use(item, func() int { return self.m.size })
 	return self
 }
 

throttle.go

@@ -87,7 +87,7 @@ func Throttle[A any, R any, Fn func(arg A) (R, error)](
 	if forKey == "" {
 		cache = &throttleCache[R]{key: "", mut: &sync.Mutex{}}
 	} else {
-		cache = (throttleCaches.EnsureGet(forKey, func() any {
+		cache = (throttleCaches.Use(forKey, func() any {
 			return any(&throttleCache[R]{key: forKey, mut: &sync.Mutex{}})
 		})).(*throttleCache[R])
 	}