Add a clear cache function to the t5 model. (#919)

candle-transformers/src/models/t5.rs

@@ -495,6 +495,10 @@ impl T5Attention {
         let attn_output = self.o.forward(&attn_output)?;
         Ok((attn_output, position_bias))
     }
+
+    fn clear_kv_cache(&mut self) {
+        self.kv_cache = None
+    }
 }
 
 #[derive(Debug)]
@@ -530,6 +534,10 @@ impl T5LayerSelfAttention {
         let ys = (xs + ys)?;
         Ok((ys, position_bias))
     }
+
+    fn clear_kv_cache(&mut self) {
+        self.self_attention.clear_kv_cache()
+    }
 }
 
 #[derive(Debug)]
@@ -568,6 +576,10 @@ impl T5LayerCrossAttention {
         let ys = (hidden_states + ys)?;
         Ok((ys, position_bias))
     }
+
+    fn clear_kv_cache(&mut self) {
+        self.cross_attention.clear_kv_cache()
+    }
 }
 
 #[derive(Debug)]
@@ -634,6 +646,11 @@ impl T5Block {
         // TODO: clamp for f16?
         Ok((xs, position_bias))
     }
+
+    fn clear_kv_cache(&mut self) {
+        self.self_attn.clear_kv_cache();
+        self.cross_attn.iter_mut().for_each(|c| c.clear_kv_cache());
+    }
 }
 
 #[derive(Debug)]
@@ -680,6 +697,10 @@ impl T5Stack {
         }
         self.final_layer_norm.forward(&hidden_states)
     }
+
+    fn clear_kv_cache(&mut self) {
+        self.block.iter_mut().for_each(|b| b.clear_kv_cache())
+    }
 }
 
 #[derive(Debug)]
@@ -709,6 +730,10 @@ impl T5EncoderModel {
     pub fn device(&self) -> &Device {
         &self.device
     }
+
+    pub fn clear_kv_cache(&mut self) {
+        self.encoder.clear_kv_cache()
+    }
 }
 
 #[derive(Debug)]
@@ -808,4 +833,9 @@ impl T5ForConditionalGeneration {
     pub fn device(&self) -> &Device {
         &self.device
     }
+
+    pub fn clear_kv_cache(&mut self) {
+        self.encoder.clear_kv_cache();
+        self.decoder.clear_kv_cache();
+    }
 }