get_max_sequence_length() warning if user MAX_SEQUENCE_LENGTH > model MAX_SEQUENCE_LENGTH (#105)

- Modify `get_max_sequence_length()` to warn if USER-DEFINED
`MAX_SEQUENCE_LENGTH` is greater than model's config value
- Consolidated multiple return statements into a single return at the
end of the function
- Combined logging into a single `info!()` call
- Introduced variable `result_max_sequence_length` to hold the final
value
- Added concise docstring for function documentation

---------

Signed-off-by: Jefferson Fialho <[email protected]>
Co-authored-by: Joe Runde <[email protected]>

Author: fialhocoelho

launcher/src/main.rs

@@ -491,32 +491,39 @@ fn num_cuda_devices() -> Option<usize> {
     let n_devices = devices.split(',').count();
     Some(n_devices)
 }
+
 /// Finds a max sequence length for the model. In priority order:
 /// 1. MAX_SEQUENCE_LENGTH set by user
 /// 2. The sequence length specified in config.json
-/// 3. A default of 2048
+/// 3. A default of 2048 
+/// ### Arguments
+/// * `max_sequence_length` - Optional user-defined maximum sequence length.
+/// * `config_path` - Path to the model configuration file.
+/// ### Returns
+/// The effective maximum sequence length to be used.
 fn get_max_sequence_length(max_sequence_length: Option<usize>, config_path: &Path) -> usize {
-    if let Some(max_sequence_length) = max_sequence_length {
-        info!(
-            "Using configured max_sequence_length: {}",
-            max_sequence_length
-        );
-        return max_sequence_length;
-    }
+    let mut length: Option<usize> = max_sequence_length;
+    let mut source = "user-defined";
+
     if let Ok(model_config) = get_config_json(config_path) {
-        if let Some(length) = get_max_sequence_length_from_config(&model_config) {
-            info!(
-                "Loaded max_sequence_length from model config.json: {}",
-                length
-            );
-            return length;
+        if let Some(model_length) = get_max_sequence_length_from_config(&model_config) {
+            if length.is_some_and(|length| length > model_length) {
+                warn!("User-defined max_sequence_length ({}) is greater than the model's max_sequence_length ({})",
+                length.unwrap(), model_length
+                );
+            }
+            length.get_or_insert_with(|| {
+                source = "model";
+                model_length
+            });
         }
     }
-    info!(
-        "Using default max_sequence_length: {}",
+    let result = length.unwrap_or_else(|| {
+        source = "default";
         DEFAULT_MAX_SEQUENCE_LENGTH
-    );
-    DEFAULT_MAX_SEQUENCE_LENGTH
+    });
+    info!("Using {} max_sequence_length: {}", source, result);
+    return result;    
 }
 
 /// Opens the model's config.json file and reads into serde_json value