From 25812762c9eb3d01a38fb7dba0fd9d7cde50b53b Mon Sep 17 00:00:00 2001
From: Martin Evans <martindevans@gmail.com>
Date: Wed, 24 Apr 2024 14:54:02 +0100
Subject: [PATCH] Added checks in `Decode` to skip doing anything if the batch
 is empty.

---
 LLama/Native/SafeLLamaContextHandle.cs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/LLama/Native/SafeLLamaContextHandle.cs b/LLama/Native/SafeLLamaContextHandle.cs
index c9e959a09..51568769d 100644
--- a/LLama/Native/SafeLLamaContextHandle.cs
+++ b/LLama/Native/SafeLLamaContextHandle.cs
@@ -368,6 +368,9 @@ public uint TokenToSpan(LLamaToken token, Span<byte> dest)
         /// </returns>
         public DecodeResult Decode(LLamaBatch batch)
         {
+            if (batch.TokenCount == 0)
+                return DecodeResult.Ok;
+
             lock (GlobalInferenceLock)
                 using (batch.ToNativeBatch(out var nb))
                     return (DecodeResult)llama_decode(this, nb);
@@ -383,6 +386,9 @@ public DecodeResult Decode(LLamaBatch batch)
         /// <returns>A tuple, containing the decode result and the number of tokens that have <b>not</b> been decoded yet.</returns>
         internal (DecodeResult, int) Decode(List<LLamaToken> tokens, LLamaSeqId id, LLamaBatch batch, ref int n_past)
         {
+            if (tokens.Count == 0)
+                return (DecodeResult.Ok, 0);
+
             var batchSize = checked((int)BatchSize);
 
             // Evaluate the prompt, in chunks smaller than the max batch size