add top K to vector stores

packages/components/nodes/vectorstores/InMemory/InMemoryVectorStore.ts

@@ -35,6 +35,14 @@ class InMemoryVectorStore_VectorStores implements INode {
                 label: 'Embeddings',
                 name: 'embeddings',
                 type: 'Embeddings'
+            },
+            {
+                label: 'Top K',
+                name: 'topK',
+                description: 'Number of top results to fetch. Default to 4',
+                placeholder: '4',
+                type: 'number',
+                optional: true
             }
         ]
         this.outputs = [
@@ -55,6 +63,8 @@ class InMemoryVectorStore_VectorStores implements INode {
         const docs = nodeData.inputs?.document as Document[]
         const embeddings = nodeData.inputs?.embeddings as Embeddings
         const output = nodeData.outputs?.output as string
+        const topK = nodeData.inputs?.topK as string
+        const k = topK ? parseInt(topK, 10) : 4
 
         const flattenDocs = docs && docs.length ? flatten(docs) : []
         const finalDocs = []
@@ -65,9 +75,10 @@ class InMemoryVectorStore_VectorStores implements INode {
         const vectorStore = await MemoryVectorStore.fromDocuments(finalDocs, embeddings)
 
         if (output === 'retriever') {
-            const retriever = vectorStore.asRetriever()
+            const retriever = vectorStore.asRetriever(k)
             return retriever
         } else if (output === 'vectorStore') {
+            ;(vectorStore as any).k = k
             return vectorStore
         }
         return vectorStore