ags

home/ags/node_modules/eslint-plugin-n/lib/util/cache.js

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+/**
+ * @author Toru Nagashima
+ * See LICENSE file in root directory for full license.
+ */
+"use strict"
+
+const SKIP_TIME = 5000
+
+/**
+ * The class of cache.
+ * The cache will dispose of each value if the value has not been accessed
+ * during 5 seconds.
+ */
+module.exports = class Cache {
+    /**
+     * Initialize this cache instance.
+     */
+    constructor() {
+        this.map = new Map()
+    }
+
+    /**
+     * Get the cached value of the given key.
+     * @param {any} key The key to get.
+     * @returns {any} The cached value or null.
+     */
+    get(key) {
+        const entry = this.map.get(key)
+        const now = Date.now()
+
+        if (entry) {
+            if (entry.expire > now) {
+                entry.expire = now + SKIP_TIME
+                return entry.value
+            }
+            this.map.delete(key)
+        }
+        return null
+    }
+
+    /**
+     * Set the value of the given key.
+     * @param {any} key The key to set.
+     * @param {any} value The value to set.
+     * @returns {void}
+     */
+    set(key, value) {
+        const entry = this.map.get(key)
+        const expire = Date.now() + SKIP_TIME
+
+        if (entry) {
+            entry.value = value
+            entry.expire = expire
+        } else {
+            this.map.set(key, { value, expire })
+        }
+    }
+}