Merge pull request #132 from icey-yu/add-cache

feat: cache

db/cacheutil/cache.go

@@ -0,0 +1,72 @@
+package cacheutil
+
+import "sync"
+
+// Cache is a Generic sync.Map structure.
+type Cache[K comparable, V any] struct {
+	m sync.Map
+}
+
+func NewCache[K comparable, V any]() *Cache[K, V] {
+	return &Cache[K, V]{}
+}
+
+// Load returns the value stored in the map for a key, or nil if no value is present.
+func (c *Cache[K, V]) Load(key K) (value V, ok bool) {
+	rawValue, ok := c.m.Load(key)
+	if !ok {
+		return
+	}
+	return rawValue.(V), ok
+}
+
+// Store sets the value for a key.
+func (c *Cache[K, V]) Store(key K, value V) {
+	c.m.Store(key, value)
+}
+
+// StoreAll sets all value by f's key.
+func (c *Cache[K, V]) StoreAll(f func(value V) K, values []V) {
+	for _, v := range values {
+		c.m.Store(f(v), v)
+	}
+}
+
+// LoadOrStore returns the existing value for the key if present.
+func (c *Cache[K, V]) LoadOrStore(key K, value V) (actual V, loaded bool) {
+	rawValue, loaded := c.m.LoadOrStore(key, value)
+	return rawValue.(V), loaded
+}
+
+// Delete deletes the value for a key.
+func (c *Cache[K, V]) Delete(key K) {
+	c.m.Delete(key)
+}
+
+// DeleteAll deletes all values.
+func (c *Cache[K, V]) DeleteAll() {
+	c.m.Range(func(key, value interface{}) bool {
+		c.m.Delete(key)
+		return true
+	})
+}
+
+// RangeAll returns all values in the map.
+func (c *Cache[K, V]) RangeAll() (values []V) {
+	c.m.Range(func(rawKey, rawValue interface{}) bool {
+		values = append(values, rawValue.(V))
+		return true
+	})
+	return values
+}
+
+// RangeCon returns values in the map that satisfy condition f.
+func (c *Cache[K, V]) RangeCon(f func(key K, value V) bool) (values []V) {
+	c.m.Range(func(rawKey, rawValue interface{}) bool {
+		if f(rawKey.(K), rawValue.(V)) {
+			values = append(values, rawValue.(V))
+		}
+		return true
+	})
+	return values
+}