Support cache system instructs for Google GenAI (#4148)

* Support cache system instructs for Google GenAI

* format code

* Update FlowiseGoogleAICacheManager.ts

---------

Co-authored-by: Henry Heng <henryheng@flowiseai.com>

packages/components/nodes/chatmodels/ChatGoogleGenerativeAI/FlowiseChatGoogleGenerativeAI.ts

@@ -25,6 +25,7 @@ import { StructuredToolInterface } from '@langchain/core/tools'
 import { isStructuredTool } from '@langchain/core/utils/function_calling'
 import { zodToJsonSchema } from 'zod-to-json-schema'
 import { BaseLanguageModelCallOptions } from '@langchain/core/language_models/base'
+import type FlowiseGoogleAICacheManager from '../../cache/GoogleGenerativeAIContextCache/FlowiseGoogleAICacheManager'
 
 const DEFAULT_IMAGE_MAX_TOKEN = 8192
 const DEFAULT_IMAGE_MODEL = 'gemini-1.5-flash-latest'
@@ -86,6 +87,8 @@ class LangchainChatGoogleGenerativeAI
 
     private client: GenerativeModel
 
+    private contextCache?: FlowiseGoogleAICacheManager
+
     get _isMultimodalModel() {
         return this.modelName.includes('vision') || this.modelName.startsWith('gemini-1.5')
     }
@@ -147,7 +150,7 @@ class LangchainChatGoogleGenerativeAI
         this.getClient()
     }
 
-    getClient(tools?: Tool[]) {
+    async getClient(prompt?: Content[], tools?: Tool[]) {
         this.client = new GenerativeAI(this.apiKey ?? '').getGenerativeModel({
             model: this.modelName,
             tools,
@@ -161,6 +164,14 @@ class LangchainChatGoogleGenerativeAI
                 topK: this.topK
             }
         })
+        if (this.contextCache) {
+            const cachedContent = await this.contextCache.lookup({
+                contents: prompt ? [{ ...prompt[0], parts: prompt[0].parts.slice(0, 1) }] : [],
+                model: this.modelName,
+                tools
+            })
+            this.client.cachedContent = cachedContent as any
+        }
     }
 
     _combineLLMOutput() {
@@ -209,6 +220,10 @@ class LangchainChatGoogleGenerativeAI
         }
     }
 
+    setContextCache(contextCache: FlowiseGoogleAICacheManager): void {
+        this.contextCache = contextCache
+    }
+
     async getNumTokens(prompt: BaseMessage[]) {
         const contents = convertBaseMessagesToContent(prompt, this._isMultimodalModel)
         const { totalTokens } = await this.client.countTokens({ contents })
@@ -226,9 +241,9 @@ class LangchainChatGoogleGenerativeAI
         this.convertFunctionResponse(prompt)
 
         if (tools.length > 0) {
-            this.getClient(tools as Tool[])
+            await this.getClient(prompt, tools as Tool[])
         } else {
-            this.getClient()
+            await this.getClient(prompt)
         }
         const res = await this.caller.callWithOptions({ signal: options?.signal }, async () => {
             let output
@@ -296,9 +311,9 @@ class LangchainChatGoogleGenerativeAI
 
         const tools = options.tools ?? []
         if (tools.length > 0) {
-            this.getClient(tools as Tool[])
+            await this.getClient(prompt, tools as Tool[])
         } else {
-            this.getClient()
+            await this.getClient(prompt)
         }
 
         const stream = await this.caller.callWithOptions({ signal: options?.signal }, async () => {