Add default traits and open function to CompressionEngine

src/compression/program.rs

@@ -1,6 +1,6 @@
 use anyhow::{Context, Result, anyhow};
 use std::fs::File;
-use std::io::Write;
+use std::io::{Read,Write};
 use std::process::{Command,Stdio};
 use std::path::PathBuf;
 use std::env;
@@ -39,29 +39,23 @@ impl CompressionEngine for CompressionEngineProgram {
         self.supported
     }
 
-    fn cat(&self, file_path: PathBuf) -> Result<()> {
-        debug!("COMPRESSION: Outputting {:?} to STDOUT using {:?}", file_path, *self);
+    fn open(&self, file_path: PathBuf) -> Result<Box<dyn Read>> {
+        debug!("COMPRESSION: Opening {:?} using {:?}", file_path, *self);
+
         let program = self.program.clone();
         let args = self.decompress.clone();
 
-        debug!("COMPRESSION: Executing command: {:?} {:?} writing to {:?}", program, args, file_path);
+        debug!("COMPRESSION: Executing command: {:?} {:?} reading from {:?}", program, args, file_path);
 
         let file = File::open(file_path).context("Unable to open file for reading")?;
 
-        let mut process = Command::new(program.clone())
+        let process = Command::new(program.clone())
             .args(args.clone())
             .stdin(file)
+            .stdout(Stdio::piped())
             .spawn()
             .context(anyhow!("Unable to spawn child process: {:?} {:?}", program, args))?;
-
-        let result = process.wait()
-            .context(anyhow!("Unable to wait for child process: {:?} {:?}", program, args))?;
-
-        if result.success() {
-            Ok(())
-        } else {
-            Err(anyhow!("Decompression program returned {}", result))
-        }
+        Ok(Box::new(process.stdout.unwrap()))
     }
 
     fn create(&self, file_path: PathBuf) -> Result<Box<dyn Write>> {