Method register_file_format

datafusion/core/src/execution/session_state.rs:885–905

Adds or updates a [FileFormatFactory] which can be used with COPY TO or CREATE EXTERNAL TABLE statements for reading and writing files of custom formats.

(
        &mut self,
        file_format: Arc<dyn FileFormatFactory>,
        overwrite: bool,
    )

    /// CREATE EXTERNAL TABLE statements for reading and writing files of custom
    /// formats.
    pub fn register_file_format(
        &mut self,
        file_format: Arc<dyn FileFormatFactory>,
        overwrite: bool,
    ) -> Result<(), DataFusionError> {
        let ext = file_format.get_ext().to_lowercase();
        match (self.file_formats.entry(ext.clone()), overwrite) {
            (Entry::Vacant(e), _) => {
                e.insert(file_format);
            }
            (Entry::Occupied(mut e), true) => {
                e.insert(file_format);
            }
            (Entry::Occupied(_), false) => {
                return config_err!(
                    "File type already registered for extension {ext}. Set overwrite to true to replace this extension."
                );
            }
        };
        Ok(())
    }

    /// Retrieves a [FileFormatFactory] based on file extension which has been registered
    /// via SessionContext::register_file_format. Extensions are not case sensitive.