Initial orc-metadata CLI tool

Cargo.toml

@@ -19,6 +19,7 @@ rust-version = "1.70"
 [dependencies]
 arrow = { version = "50", features = ["prettyprint"] }
 bytes = "1.4"
+clap = { version = "4.5.3", features = ["derive"], optional = true }
 fallible-streaming-iterator = { version = "0.1" }
 flate2 = "1"
 futures = { version = "0.3", optional = true, default-features = false, features = ["std"] }
@@ -54,6 +55,7 @@ serde_json = { version = "1.0", default-features = false, features = ["std"] }
 default = ["async"]
 
 async = ["futures", "futures-util", "tokio"]
+cli = ["clap"]
 
 [[bench]]
 name = "arrow_reader"
@@ -63,3 +65,7 @@ required-features = ["async"]
 [[example]]
 name = "datafusion_integration"
 required-features = ["async"]
+
+[[bin]]
+name = "orc-metadata"
+required-features = ["cli"]

src/bin/orc-metadata.rs

@@ -0,0 +1,35 @@
+use std::{error::Error, fs::File, path::PathBuf};
+
+use clap::Parser;
+use datafusion_orc::ArrowReaderBuilder;
+
+#[derive(Parser)]
+#[command(version, about, long_about = None)]
+struct Cli {
+    /// ORC file path
+    file: PathBuf,
+}
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let cli = Cli::parse();
+
+    let f = File::open(cli.file)?;
+    let builder = ArrowReaderBuilder::try_new(f)?;
+    let metadata = builder.file_metadata();
+
+    // TODO: better way to handle this printing?
+    // TODO: move this display to actual library
+    println!(
+        "compression: {}",
+        metadata
+            .compression()
+            .map(|c| c.compression_type().to_string())
+            .unwrap_or("None".to_string())
+    );
+    println!("number of rows: {}", metadata.number_of_rows());
+    println!("number of stripes: {}", metadata.stripe_metadatas().len());
+    // TODO: nesting types indentation is messed up
+    println!("schema:\n{}", metadata.root_data_type());
+
+    Ok(())
+}

src/reader/decompress.rs

@@ -22,6 +22,10 @@ pub struct Compression {
 }
 
 impl Compression {
+    pub fn compression_type(&self) -> CompressionType {
+        self.compression_type
+    }
+
     pub fn from_proto(
         kind: proto::CompressionKind,
         compression_block_size: Option<u64>,
@@ -63,6 +67,12 @@ pub enum CompressionType {
     Zstd,
 }
 
+impl std::fmt::Display for CompressionType {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
 /// Indicates length of block and whether it's compressed or not.
 #[derive(Debug, PartialEq, Eq)]
 enum CompressionHeader {