some minor changes

Author: CTTY

crates/iceberg/src/writer/base_writer/data_file_writer.rs

@@ -19,8 +19,9 @@
 
 use arrow_array::RecordBatch;
 use itertools::Itertools;
-use crate::io::OutputFile;
+
 use crate::Result;
+use crate::io::OutputFile;
 use crate::spec::{DataContentType, DataFile, Struct};
 use crate::writer::file_writer::{FileWriter, FileWriterBuilder};
 use crate::writer::{CurrentFileStatus, IcebergWriter, IcebergWriterBuilder};

crates/iceberg/src/writer/base_writer/equality_delete_writer.rs

@@ -26,11 +26,11 @@ use parquet::arrow::PARQUET_FIELD_ID_META_KEY;
 
 use crate::arrow::record_batch_projector::RecordBatchProjector;
 use crate::arrow::schema_to_arrow_schema;
+use crate::io::OutputFile;
 use crate::spec::{DataFile, SchemaRef, Struct};
 use crate::writer::file_writer::{FileWriter, FileWriterBuilder};
 use crate::writer::{IcebergWriter, IcebergWriterBuilder};
 use crate::{Error, ErrorKind, Result};
-use crate::io::OutputFile;
 
 /// Builder for `EqualityDeleteWriter`.
 #[derive(Clone, Debug)]

crates/iceberg/src/writer/file_writer/parquet_writer.rs

@@ -42,8 +42,8 @@ use crate::arrow::{
 use crate::io::{FileIO, FileWrite, OutputFile};
 use crate::spec::{
     DataContentType, DataFileBuilder, DataFileFormat, Datum, ListType, Literal, MapType,
-    NestedFieldRef, PartitionSpec, PrimitiveType, Schema, SchemaRef, SchemaVisitor,
-    Struct, StructType, TableMetadata, Type, visit_schema,
+    NestedFieldRef, PartitionSpec, PrimitiveType, Schema, SchemaRef, SchemaVisitor, Struct,
+    StructType, TableMetadata, Type, visit_schema,
 };
 use crate::transform::create_transform_function;
 use crate::writer::{CurrentFileStatus, DataFile};
@@ -60,10 +60,7 @@ pub struct ParquetWriterBuilder {
 impl ParquetWriterBuilder {
     /// Create a new `ParquetWriterBuilder`
     /// To construct the write result, the schema should contain the `PARQUET_FIELD_ID_META_KEY` metadata for each field.
-    pub fn new(
-        props: WriterProperties,
-        schema: SchemaRef,
-    ) -> Self {
+    pub fn new(props: WriterProperties, schema: SchemaRef) -> Self {
         Self::new_with_match_mode(props, schema, FieldMatchMode::Id)
     }
 

crates/iceberg/src/writer/file_writer/rolling_writer.rs

@@ -42,7 +42,7 @@ where
     file_name_generator: F,
     file_io: FileIO,
     partition_key: Option<PartitionKey>,
-    data_files: Vec<DataFile>, // this should be B::R::O? DefaultOutput?
+    data_files: Vec<DataFile>, // todo this should be B::R::O? DefaultOutput?
 }
 
 impl<B, L, F> RollingWriter<B, L, F>
@@ -122,8 +122,7 @@ where
         if self.should_roll() {
             if let Some(mut inner) = self.inner.take() {
                 // close the current writer, roll to a new file
-                let mut data_files = inner.close().await?;
-                self.data_files.append(&mut data_files);
+                self.data_files.extend(inner.close().await?);
 
                 // start a new writer
                 self.inner = Some(self.create_new_writer().await?);
@@ -145,8 +144,7 @@ where
     pub async fn close(&mut self) -> Result<Vec<DataFile>> {
         // close the current writer and merge the output
         if let Some(mut current_writer) = self.inner.take() {
-            let data_files = current_writer.close().await?;
-            self.data_files.extend(data_files);
+            self.data_files.extend(current_writer.close().await?);
         }
 
         Ok(std::mem::take(&mut self.data_files))