Merge pull request #70 from tabkram/feature/cache

fix: add bypass argument to cache execution

Author: tabkram

src/common/models/executionCache.model.ts

@@ -24,24 +24,33 @@ export interface CacheContext<O = unknown> {
   /** Unique key identifying the cache entry. */
   cacheKey: string;
 
+
   /** The time-to-live (TTL) for the cache entry. */
   ttl: number;
 
-  /** Flag indicating whether the value is cached. */
+  /**  Flag indicating whether the cached value is bypassed and a fresh computation is triggered. */
+  isBypassed: boolean;
+
+  /**
+   *  Flag indicating whether the value is found in the cache.
+   * @remarks: To confirm it was retrieved from cache, ensure `isBypassed` is `false`.
+   * */
   isCached: boolean;
 
   /** The cached value, if any. */
   value?: O;
 }
 
-
 /**
  * Configuration options for caching behavior.
  */
 export interface CacheOptions<O = unknown> {
   /** Time-to-live (TTL) for cache items. Can be static (number) or dynamic (function that returns a number). */
   ttl: number | ((params: { metadata: FunctionMetadata; inputs: unknown[] }) => number);
 
+  /** A function that returns `true` to ignore existing cache and force a fresh computation. Defaults to `false`. */
+  bypass?: (params: { metadata: FunctionMetadata; inputs: unknown[] }) => boolean;
+
   /** Function to generate a custom cache key based on method metadata and arguments. */
   cacheKey?: (params: { metadata: FunctionMetadata; inputs: unknown[] }) => string;
 

src/execution/cache.decorator.spec.ts

@@ -5,13 +5,13 @@ describe('cache decorator', () => {
     let memoizationCheckCount = 0;
     let memoizedCalls = 0;
     let totalFunctionCalls = 0;
-
+    let bypassCache= false;
     class DataService {
       @cache({
         ttl: 3000,
         onCacheEvent: (cacheContext) => {
           memoizationCheckCount++;
-          if (cacheContext.isCached) {
+          if (cacheContext.isCached && !cacheContext.isBypassed) {
             memoizedCalls++;
           }
         }
@@ -21,6 +21,21 @@ describe('cache decorator', () => {
         return new Promise((resolve) => setTimeout(() => resolve(`Data for ID: ${id}`), 100));
       }
 
+      @cache({
+        ttl: 3000,
+        bypass: () => bypassCache,
+        onCacheEvent: (cacheContext) => {
+          memoizationCheckCount++;
+          if (cacheContext.isCached && !cacheContext.isBypassed) {
+            memoizedCalls++;
+          }
+        }
+      })
+      async fetchDataWithByPassedCacheFunction(id: number): Promise<string> {
+        totalFunctionCalls++;
+        return new Promise((resolve) => setTimeout(() => resolve(`Data for ID: ${id}`), 100));
+      }
+
       @cache({
         ttl: 3000,
         onCacheEvent: (cacheContext) => {
@@ -66,6 +81,32 @@ describe('cache decorator', () => {
     expect(totalFunctionCalls).toBe(2); // No extra new calls
     expect(memoizationCheckCount).toBe(4); // 4 checks in total
 
+    // test NO cache for a Bypassed cache function
+    memoizationCheckCount = 0;
+    memoizedCalls = 0;
+    totalFunctionCalls = 0;
+    const result21 = await service.fetchDataWithByPassedCacheFunction(2);
+    expect(result21).toBe('Data for ID: 2');
+    expect(memoizedCalls).toBe(0); // ID 2 result is now memoized
+    expect(totalFunctionCalls).toBe(1); // extra new call
+    expect(memoizationCheckCount).toBe(1); // 5 checks in total
+
+    bypassCache = false;
+    const result22 = await service.fetchDataWithByPassedCacheFunction(2);
+    expect(result22).toBe('Data for ID: 2');
+    expect(memoizedCalls).toBe(1); // ID 2 result is now memoized
+    expect(totalFunctionCalls).toBe(1); // NO extra new call
+    expect(memoizationCheckCount).toBe(2); // 2 checks in total
+
+    bypassCache = true;
+    const result23 = await service.fetchDataWithByPassedCacheFunction(2);
+    expect(result23).toBe('Data for ID: 2');
+    expect(memoizedCalls).toBe(1); // ID 2 result is NOT RETRIEVED FROM CACHE AS THEY ARE BYPASSED
+    expect(totalFunctionCalls).toBe(2); // extra new call as  bypassCache = true
+    expect(memoizationCheckCount).toBe(3); // 5 checks in total
+
+
+
     // test NO cache for a throwing async method
     memoizationCheckCount = 0;
     memoizedCalls = 0;

src/execution/cache.decorator.ts

@@ -23,6 +23,7 @@ export function cache(options: CacheOptions): MethodDecorator {
         functionId: thisMethodMetadata.methodSignature as string,
         ...options,
         cacheKey: attachFunctionMetadata.bind(this)(options.cacheKey, thisMethodMetadata),
+        bypass: attachFunctionMetadata.bind(this)(options.bypass, thisMethodMetadata),
         ttl: attachFunctionMetadata.bind(this)(options.ttl, thisMethodMetadata),
         onCacheEvent: attachFunctionMetadata.bind(this)(options.onCacheEvent, thisMethodMetadata)
       });

src/execution/cache.ts

@@ -21,21 +21,31 @@ export async function executeCache<O>(
 ): Promise<Promise<O> | O> {
   const functionMetadata = extractFunctionMetadata(blockFunction);
   const cacheKey = options.cacheKey?.({ metadata: functionMetadata, inputs }) ?? generateHashId(...inputs);
+  const bypass = typeof options.bypass === 'function' && !!options.bypass?.({ metadata: functionMetadata, inputs });
   const ttl = typeof options.ttl === 'function' ? options.ttl({ metadata: functionMetadata, inputs }) : options.ttl;
-
   let cacheStore: CacheStore | MapCacheStore<O>;
+
   if (options.cacheManager) {
     cacheStore = typeof options.cacheManager === 'function' ? options.cacheManager(this) : options.cacheManager;
   } else {
     cacheStore = new MapCacheStore<O>(this[cacheStoreKey], options.functionId);
   }
-  const cachedValue: O = (await cacheStore.get(cacheKey)) as O;
+  const cachedValue: O | undefined = (await cacheStore.get(cacheKey)) as O;
+
 
   if (typeof options.onCacheEvent === 'function') {
-    options.onCacheEvent({ ttl, metadata: functionMetadata, inputs, cacheKey, isCached: !!cachedValue, value: cachedValue });
+    options.onCacheEvent({
+      ttl,
+      metadata: functionMetadata,
+      inputs,
+      cacheKey,
+      isBypassed: !!bypass,
+      isCached: !!cachedValue,
+      value: cachedValue
+    });
   }
 
-  if (cachedValue) {
+  if (!bypass && cachedValue) {
     return cachedValue;
   } else {
     return (execute.bind(this) as typeof execute)(
@@ -44,7 +54,7 @@ export async function executeCache<O>(
       [],
       (res) => {
         cacheStore.set(cacheKey, res as O, ttl);
-        if((cacheStore as MapCacheStore<O>).fullStorage) {
+        if ((cacheStore as MapCacheStore<O>).fullStorage) {
           this[cacheStoreKey] = (cacheStore as MapCacheStore<O>).fullStorage;
         }
         return res;

src/execution/trace.decorator.spec.ts

@@ -172,8 +172,8 @@ describe('trace decorator', () => {
         url: string,
         traceContext: Record<string, unknown> = {}
       ): Promise<{
-        data: string;
-      }> {
+          data: string;
+        }> {
         return this.fetchDataFunction(url, traceContext);
       }