From 27a817b517d8c42465d0ce6add444a64531d2818 Mon Sep 17 00:00:00 2001
From: buhe <bugu1986@126.com>
Date: Sun, 21 Jan 2024 11:17:23 +0800
Subject: [PATCH] "Update cache only if llmResult has non-nil llm_output."

---
 Sources/LangChain/llms/LLM.swift | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Sources/LangChain/llms/LLM.swift b/Sources/LangChain/llms/LLM.swift
index c958772..538fa00 100644
--- a/Sources/LangChain/llms/LLM.swift
+++ b/Sources/LangChain/llms/LLM.swift
@@ -36,7 +36,9 @@ public class LLM {
             }
             let llmResult = try await _send(text: text, stops: stops)
             if let cache = self.cache {
-                await cache.update(prompt: text, return_val: llmResult)
+                if llmResult.llm_output != nil {
+                    await cache.update(prompt: text, return_val: llmResult)
+                }
             }
             cost = Date.now.timeIntervalSince1970 - now
             if !llmResult.stream {