perf: avoid cloning content parts in gather_multi_modal_data (#8009)

lib/llm/src/preprocessor.rs

@@ -413,12 +413,14 @@ impl OpenAIPreprocessor {
         formatted_prompt: Option<String>,
     ) -> Result<()> {
         let mut media_map: MultimodalDataMap = HashMap::new();
-        let mut fetch_tasks: Vec<(String, ChatCompletionRequestUserMessageContentPart)> =
+        let mut fetch_tasks: Vec<(String, &ChatCompletionRequestUserMessageContentPart)> =
             Vec::new();
 
         let Some(messages) = request.typed_messages() else {
             return Ok(());
         };
+        let has_media_loader = self.media_loader.is_some();
+
         for message in messages.iter() {
             let content_parts = match message {
                 ChatCompletionRequestMessage::User(u) => match &u.content {
@@ -427,33 +429,35 @@ impl OpenAIPreprocessor {
                 },
                 _ => continue,
             };
-            // Iterate over content parts
             for content_part in content_parts.iter() {
+                if has_media_loader {
+                    let type_str = match content_part {
+                        ChatCompletionRequestUserMessageContentPart::ImageUrl(_) => "image_url",
+                        ChatCompletionRequestUserMessageContentPart::VideoUrl(_) => "video_url",
+                        ChatCompletionRequestUserMessageContentPart::AudioUrl(_) => "audio_url",
+                        _ => continue,
+                    };
+                    fetch_tasks.push((type_str.to_string(), content_part));
+                } else {
                     let (type_str, url) = match content_part {
-                    ChatCompletionRequestUserMessageContentPart::ImageUrl(image_part) => {
-                        ("image_url".to_string(), image_part.image_url.url.clone())
+                        ChatCompletionRequestUserMessageContentPart::ImageUrl(p) => {
+                            ("image_url", p.image_url.url.clone())
                         }
-                    ChatCompletionRequestUserMessageContentPart::VideoUrl(video_part) => {
-                        ("video_url".to_string(), video_part.video_url.url.clone())
+                        ChatCompletionRequestUserMessageContentPart::VideoUrl(p) => {
+                            ("video_url", p.video_url.url.clone())
                         }
-                    ChatCompletionRequestUserMessageContentPart::AudioUrl(audio_part) => {
-                        ("audio_url".to_string(), audio_part.audio_url.url.clone())
+                        ChatCompletionRequestUserMessageContentPart::AudioUrl(p) => {
+                            ("audio_url", p.audio_url.url.clone())
                         }
                         _ => continue,
                     };
-
-                if self.media_loader.is_some() {
-                    fetch_tasks.push((type_str, content_part.clone()));
-                    continue;
-                }
-
-                //Fallback: ust pass the URL through
                     media_map
-                    .entry(type_str)
+                        .entry(type_str.to_string())
                         .or_default()
                         .push(MultimodalData::Url(url));
                 }
             }
+        }
 
         // Execute all fetch tasks
         if !fetch_tasks.is_empty() {