@laconia/core - npm Package Compare versions

Comparing version 0.6.0 to 0.7.0

src/SingleCache.js

+module.exports = class SingleCache {
+  constructor(maxAge) {
+    this.maxAge = maxAge;
+  }
+
+  hasExpired() {
+    return Date.now() - this.lastModified > this.maxAge;
+  }
+
+  set(value) {
+    this.lastModified = Date.now();
+    this.value = value;
+  }
+
+  get() {
+    return this.value;
+  }
+
+  isEmpty() {
+    return this.value === undefined;
+  }
+};

package.json

 {
   "name": "@laconia/core",
-  "version": "0.6.0",
+  "version": "0.7.0",
   "description": "Micro dependency injection framework",
@@ -5,0 +5,0 @@ "keywords": [

README.md

@@ -27,3 +27,5 @@ # @laconia/core
 * Dependency injection
-* Reduce boilerplate code that is needed to avoid common Lambda programming error
+* Caching for heavy instance creation
+* Reduce boilerplate code
+* Avoid common Lambda programming error
 
@@ -131,2 +133,9 @@ One of the problem in AWS Lambda is the `UnhandledPromiseRejectionWarning` problem where
 
+#### Cache
+
+When `#register` is called, all of the instances returned by the function specified will be
+cached by default and will expire every 5 minutes. It is therefore a good practice to offload
+some of the heavy operations that don't change on every Lambda run to `LaconiaContext`.
+This feature can be turned off, see API section.
+
 ### API
@@ -150,3 +159,3 @@
 
-#### `register(instanceFn)`
+#### `register(factoryFn, options)`
 
@@ -156,5 +165,11 @@ Registers objects into LaconiaContext. Objects registered here will be made
 
-* `instanceFn(laconiaContext)`
+* `factoryFn(laconiaContext)`
   * This `Function` is called when your Lambda is invoked
   * An object which contains the instances to be registered must be returned
+* `options`:
+  * `cache`
+    * `enabled = true`
+      * Set to false to turn off caching
+    * `maxAge = 300000`
+      * Your factoryFn will be called when the cache has reached its maximum age specified by this option
 
@@ -168,2 +183,17 @@ Example:
 }));
+
+// Reduce maxAge
+const handler = () => {};
+laconia(handler).register(
+  async () => (
+    {
+      /* heavy operations */
+    },
+    {
+      cache: {
+        maxAge: 1000
+      }
+    }
+  )
+);
 ```
@@ -170,0 +200,0 @@

src/CoreLaconiaContext.js

 const LaconiaContext = require("./LaconiaContext");
+const SingleCache = require("./SingleCache");
 
+const cacheResult = (fn, maxAge) => {
+  const cache = new SingleCache(maxAge);
+
+  return async (...args) => {
+    if (cache.isEmpty() || cache.hasExpired()) {
+      cache.set(await fn(...args));
+    }
+    return cache.get();
+  };
+};
+
 module.exports = class CoreLaconiaContext extends LaconiaContext {
@@ -12,2 +24,6 @@ constructor(baseContext) {
   }
+
+  registerFactory(factory, { enabled = true, maxAge = 300000 } = {}) {
+    super.registerFactory(enabled ? cacheResult(factory, maxAge) : factory);
+  }
 };

src/laconia.js

@@ -22,4 +22,4 @@ const CoreLaconiaContext = require("./CoreLaconiaContext");
     },
-    register: factoryFn => {
-      laconiaContext.registerFactory(factoryFn);
+    register: (factoryFn, options = {}) => {
+      laconiaContext.registerFactory(factoryFn, options.cache);
       return laconia;
@@ -26,0 +26,0 @@ }

New alerts

Environment variable access

Supply chain risk

Package accesses environment variables, which may be a sign of credential stuffing or data theft.

Found 1 instance in 1 package

Fixed alerts

Environment variable access

Supply chain risk

Package accesses environment variables, which may be a sign of credential stuffing or data theft.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

11658

15.76%

Number of package files

8

14.29%

Lines of code

130

31.31%

Number of lines in readme file

216

16.13%

No dependency changes