arrow_file_to_stream/
arrow-file-to-stream.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18// The unused_crate_dependencies lint does not work well for crates defining additional examples/bin targets
19#![allow(unused_crate_dependencies)]
20
21use arrow::error::Result;
22use arrow::ipc::reader::FileReader;
23use arrow::ipc::writer::StreamWriter;
24use clap::Parser;
25use std::fs::File;
26use std::io::{self, BufReader};
27
28#[derive(Debug, Parser)]
29#[clap(author, version, about("Read an arrow file and stream to stdout"), long_about = None)]
30struct Args {
31    file_name: String,
32}
33
34fn main() -> Result<()> {
35    let args = Args::parse();
36    let f = File::open(args.file_name)?;
37    let reader = BufReader::new(f);
38    let mut reader = FileReader::try_new(reader, None)?;
39    let schema = reader.schema();
40
41    let mut writer = StreamWriter::try_new(io::stdout(), &schema)?;
42
43    reader.try_for_each(|batch| {
44        let batch = batch?;
45        writer.write(&batch)
46    })?;
47    writer.finish()?;
48
49    Ok(())
50}