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/cache/GoogleGenerativeAIContextCache/FlowiseGoogleAICacheManager.ts

@@ -0,0 +1,44 @@
+import type { CachedContentBase, CachedContent, Content } from '@google/generative-ai'
+import { GoogleAICacheManager as GoogleAICacheManagerBase } from '@google/generative-ai/server'
+import hash from 'object-hash'
+
+type CacheContentOptions = Omit<CachedContentBase, 'contents'> & { contents?: Content[] }
+
+export class GoogleAICacheManager extends GoogleAICacheManagerBase {
+    private ttlSeconds: number
+    private cachedContents: Map<string, CachedContent> = new Map()
+
+    setTtlSeconds(ttlSeconds: number) {
+        this.ttlSeconds = ttlSeconds
+    }
+
+    async lookup(options: CacheContentOptions): Promise<CachedContent | undefined> {
+        const { model, tools, contents } = options
+        if (!contents?.length) {
+            return undefined
+        }
+        const hashKey = hash({
+            model,
+            tools,
+            contents
+        })
+        if (this.cachedContents.has(hashKey)) {
+            return this.cachedContents.get(hashKey)
+        }
+        const { cachedContents } = await this.list()
+        const cachedContent = (cachedContents ?? []).find((cache) => cache.displayName === hashKey)
+        if (cachedContent) {
+            this.cachedContents.set(hashKey, cachedContent)
+            return cachedContent
+        }
+        const res = await this.create({
+            ...(options as CachedContentBase),
+            displayName: hashKey,
+            ttlSeconds: this.ttlSeconds
+        })
+        this.cachedContents.set(hashKey, res)
+        return res
+    }
+}
+
+export default GoogleAICacheManager