Add close method to RecordBatchWriter trait

arrow-array/src/record_batch.rs

@@ -47,6 +47,9 @@ pub trait RecordBatchReader: Iterator<Item = Result<RecordBatch, ArrowError>> {
 pub trait RecordBatchWriter {
     /// Write a single batch to the writer.
     fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError>;
+
+    /// Write footer or termination data, then mark the writer as done.
+    fn close(self) -> Result<(), ArrowError>;
 }
 
 /// A two-dimensional batch of column-oriented data with a defined

arrow-csv/src/writer.rs

@@ -197,6 +197,10 @@ impl<W: Write> RecordBatchWriter for Writer<W> {
     fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError> {
         self.write(batch)
     }
+
+    fn close(self) -> Result<(), ArrowError> {
+        Ok(())
+    }
 }
 
 /// A CSV writer builder

arrow-ipc/src/writer.rs

@@ -861,6 +861,10 @@ impl<W: Write> RecordBatchWriter for FileWriter<W> {
     fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError> {
         self.write(batch)
     }
+
+    fn close(mut self) -> Result<(), ArrowError> {
+        self.finish()
+    }
 }
 
 pub struct StreamWriter<W: Write> {
@@ -1001,6 +1005,10 @@ impl<W: Write> RecordBatchWriter for StreamWriter<W> {
     fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError> {
         self.write(batch)
     }
+
+    fn close(mut self) -> Result<(), ArrowError> {
+        self.finish()
+    }
 }
 
 /// Stores the encoded data, which is an crate::Message, and optional Arrow data

arrow-json/src/writer.rs

@@ -594,6 +594,10 @@ where
     fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError> {
         self.write(batch)
     }
+
+    fn close(mut self) -> Result<(), ArrowError> {
+        self.finish()
+    }
 }
 
 #[cfg(test)]
@@ -1265,6 +1269,7 @@ mod tests {
         writer.finish().unwrap();
         assert_eq!(String::from_utf8(writer.into_inner()).unwrap(), "");
     }
+
     #[test]
     fn json_writer_one_row() {
         let mut writer = ArrayWriter::new(vec![] as Vec<u8>);

parquet/src/arrow/arrow_writer/mod.rs

@@ -250,6 +250,11 @@ impl<W: Write> RecordBatchWriter for ArrowWriter<W> {
     fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError> {
         self.write(batch).map_err(|e| e.into())
     }
+
+    fn close(self) -> std::result::Result<(), ArrowError> {
+        self.close()?;
+        Ok(())
+    }
 }
 
 fn write_leaves<W: Write>(