Merge pull request #1036 from FlowiseAI/feature/InMemoryCache

Feature/In-Mem LLMcache

packages/components/credentials/UpstashRedisApi.credential.ts

@@ -4,12 +4,15 @@ class UpstashRedisApi implements INodeCredential {
     label: string
     name: string
     version: number
+    description: string
     inputs: INodeParams[]
 
     constructor() {
         this.label = 'Upstash Redis API'
         this.name = 'upstashRedisApi'
         this.version = 1.0
+        this.description =
+            'Refer to <a target="_blank" href="https://upstash.com/docs/redis/overall/getstarted">official guide</a> on how to create redis instance and get redis REST URL and Token'
         this.inputs = [
             {
                 label: 'Upstash Redis REST URL',

packages/components/nodes/cache/InMemoryCache/InMemoryCache.ts

@@ -0,0 +1,65 @@
+import { getBaseClasses, ICommonObject, INode, INodeData, INodeParams } from '../../../src'
+import { BaseCache } from 'langchain/schema'
+import hash from 'object-hash'
+
+class InMemoryCache implements INode {
+    label: string
+    name: string
+    version: number
+    description: string
+    type: string
+    icon: string
+    category: string
+    baseClasses: string[]
+    inputs: INodeParams[]
+    credential: INodeParams
+
+    constructor() {
+        this.label = 'InMemory Cache'
+        this.name = 'inMemoryCache'
+        this.version = 1.0
+        this.type = 'InMemoryCache'
+        this.description = 'Cache LLM response in memory, will be cleared once app restarted'
+        this.icon = 'inmemorycache.png'
+        this.category = 'Cache'
+        this.baseClasses = [this.type, ...getBaseClasses(InMemoryCacheExtended)]
+        this.inputs = []
+    }
+
+    async init(nodeData: INodeData, _: string, options: ICommonObject): Promise<any> {
+        const memoryMap = options.cachePool.getLLMCache(options.chatflowid) ?? new Map()
+        const inMemCache = new InMemoryCacheExtended(memoryMap)
+
+        inMemCache.lookup = async (prompt: string, llmKey: string): Promise<any | null> => {
+            const memory = options.cachePool.getLLMCache(options.chatflowid) ?? inMemCache.cache
+            return Promise.resolve(memory.get(getCacheKey(prompt, llmKey)) ?? null)
+        }
+
+        inMemCache.update = async (prompt: string, llmKey: string, value: any): Promise<void> => {
+            inMemCache.cache.set(getCacheKey(prompt, llmKey), value)
+            options.cachePool.addLLMCache(options.chatflowid, inMemCache.cache)
+        }
+        return inMemCache
+    }
+}
+
+const getCacheKey = (...strings: string[]): string => hash(strings.join('_'))
+
+class InMemoryCacheExtended extends BaseCache {
+    cache: Map<string, any>
+
+    constructor(map: Map<string, any>) {
+        super()
+        this.cache = map
+    }
+
+    lookup(prompt: string, llmKey: string): Promise<any | null> {
+        return Promise.resolve(this.cache.get(getCacheKey(prompt, llmKey)) ?? null)
+    }
+
+    async update(prompt: string, llmKey: string, value: any): Promise<void> {
+        this.cache.set(getCacheKey(prompt, llmKey), value)
+    }
+}
+
+module.exports = { nodeClass: InMemoryCache }

packages/components/nodes/cache/MomentoCache/MomentoCache.ts

@@ -19,6 +19,7 @@ class MomentoCache implements INode {
         this.name = 'momentoCache'
         this.version = 1.0
         this.type = 'MomentoCache'
+        this.description = 'Cache LLM response using Momento, a distributed, serverless cache'
         this.icon = 'momento.png'
         this.category = 'Cache'
         this.baseClasses = [this.type, ...getBaseClasses(LangchainMomentoCache)]

packages/components/nodes/cache/RedisCache/RedisCache.ts

@@ -19,6 +19,7 @@ class RedisCache implements INode {
         this.name = 'redisCache'
         this.version = 1.0
         this.type = 'RedisCache'
+        this.description = 'Cache LLM response in Redis, useful for sharing cache across multiple processes or servers'
         this.icon = 'redis.svg'
         this.category = 'Cache'
         this.baseClasses = [this.type, ...getBaseClasses(LangchainRedisCache)]

packages/components/nodes/cache/UpstashRedisCache/UpstashRedisCache.ts

@@ -18,6 +18,7 @@ class UpstashRedisCache implements INode {
         this.name = 'upstashRedisCache'
         this.version = 1.0
         this.type = 'UpstashRedisCache'
+        this.description = 'Cache LLM response in Upstash Redis, serverless data for Redis and Kafka'
         this.icon = 'upstash.png'
         this.category = 'Cache'
         this.baseClasses = [this.type, ...getBaseClasses(LangchainUpstashRedisCache)]

packages/components/package.json

@@ -57,6 +57,7 @@
         "node-fetch": "^2.6.11",
         "node-html-markdown": "^1.3.0",
         "notion-to-md": "^3.1.1",
+        "object-hash": "^3.0.0",
         "pdf-parse": "^1.1.1",
         "pdfjs-dist": "^3.7.107",
         "pg": "^8.11.2",
@@ -73,6 +74,7 @@
     "devDependencies": {
         "@types/gulp": "4.0.9",
         "@types/node-fetch": "2.6.2",
+        "@types/object-hash": "^3.0.2",
         "@types/pg": "^8.10.2",
         "@types/ws": "^8.5.3",
         "gulp": "^4.0.2",

packages/server/src/CachePool.ts

@@ -0,0 +1,53 @@
+import { IActiveCache } from './Interface'
+
+/**
+ * This pool is to keep track of in-memory cache used for LLM and Embeddings
+ */
+export class CachePool {
+    activeLLMCache: IActiveCache = {}
+    activeEmbeddingCache: IActiveCache = {}
+
+    /**
+     * Add to the llm cache pool
+     * @param {string} chatflowid
+     * @param {Map<any, any>} value
+     */
+    addLLMCache(chatflowid: string, value: Map<any, any>) {
+        this.activeLLMCache[chatflowid] = value
+    }
+
+    /**
+     * Add to the embedding cache pool
+     * @param {string} chatflowid
+     * @param {Map<any, any>} value
+     */
+    addEmbeddingCache(chatflowid: string, value: Map<any, any>) {
+        this.activeEmbeddingCache[chatflowid] = value
+    }
+
+    /**
+     * Get item from llm cache pool
+     * @param {string} chatflowid
+     */
+    getLLMCache(chatflowid: string): Map<any, any> | undefined {
+        return this.activeLLMCache[chatflowid]
+    }
+
+    /**
+     * Get item from embedding cache pool
+     * @param {string} chatflowid
+     */
+    getEmbeddingCache(chatflowid: string): Map<any, any> | undefined {
+        return this.activeEmbeddingCache[chatflowid]
+    }
+}
+
+let cachePoolInstance: CachePool | undefined
+
+export function getInstance(): CachePool {
+    if (cachePoolInstance === undefined) {
+        cachePoolInstance = new CachePool()
+    }
+
+    return cachePoolInstance
+}

packages/server/src/Interface.ts

@@ -157,6 +157,10 @@ export interface IActiveChatflows {
     }
 }
 
+export interface IActiveCache {
+    [key: string]: Map<any, any>
+}
+
 export interface IOverrideConfig {
     node: string
     nodeId: string

packages/server/src/index.ts

@@ -53,13 +53,15 @@ import { ChatMessage } from './database/entities/ChatMessage'
 import { Credential } from './database/entities/Credential'
 import { Tool } from './database/entities/Tool'
 import { ChatflowPool } from './ChatflowPool'
+import { CachePool } from './CachePool'
 import { ICommonObject, INodeOptionsValue } from 'flowise-components'
 import { createRateLimiter, getRateLimiter, initializeRateLimiter } from './utils/rateLimit'
 
 export class App {
     app: express.Application
     nodesPool: NodesPool
     chatflowPool: ChatflowPool
+    cachePool: CachePool
     AppDataSource = getDataSource()
 
     constructor() {
@@ -91,6 +93,9 @@ export class App {
                 // Initialize Rate Limit
                 const AllChatFlow: IChatFlow[] = await getAllChatFlow()
                 await initializeRateLimiter(AllChatFlow)
+
+                // Initialize cache pool
+                this.cachePool = new CachePool()
             })
             .catch((err) => {
                 logger.error('❌ [server]: Error during Data Source initialization:', err)
@@ -944,8 +949,10 @@ export class App {
                     incomingInput.question,
                     incomingInput.history,
                     chatId,
+                    chatflowid,
                     this.AppDataSource,
-                    incomingInput?.overrideConfig
+                    incomingInput?.overrideConfig,
+                    this.cachePool
                 )
 
                 const nodeToExecute = reactFlowNodes.find((node: IReactFlowNode) => node.id === endingNodeId)

packages/server/src/utils/index.ts

@@ -35,6 +35,7 @@ import { ChatMessage } from '../database/entities/ChatMessage'
 import { Credential } from '../database/entities/Credential'
 import { Tool } from '../database/entities/Tool'
 import { DataSource } from 'typeorm'
+import { CachePool } from '../CachePool'
 
 const QUESTION_VAR_PREFIX = 'question'
 const CHAT_HISTORY_VAR_PREFIX = 'chat_history'
@@ -197,8 +198,10 @@ export const getEndingNode = (nodeDependencies: INodeDependencies, graph: INodeD
  * @param {IComponentNodes} componentNodes
  * @param {string} question
  * @param {string} chatId
+ * @param {string} chatflowid
  * @param {DataSource} appDataSource
  * @param {ICommonObject} overrideConfig
+ * @param {CachePool} cachePool
  */
 export const buildLangchain = async (
     startingNodeIds: string[],
@@ -209,8 +212,10 @@ export const buildLangchain = async (
     question: string,
     chatHistory: IMessage[],
     chatId: string,
+    chatflowid: string,
     appDataSource: DataSource,
-    overrideConfig?: ICommonObject
+    overrideConfig?: ICommonObject,
+    cachePool?: CachePool
 ) => {
     const flowNodes = cloneDeep(reactFlowNodes)
 
@@ -245,9 +250,11 @@ export const buildLangchain = async (
             logger.debug(`[server]: Initializing ${reactFlowNode.data.label} (${reactFlowNode.data.id})`)
             flowNodes[nodeIndex].data.instance = await newNodeInstance.init(reactFlowNodeData, question, {
                 chatId,
+                chatflowid,
                 appDataSource,
                 databaseEntities,
-                logger
+                logger,
+                cachePool
             })
             logger.debug(`[server]: Finished initializing ${reactFlowNode.data.label} (${reactFlowNode.data.id})`)
         } catch (e: any) {