stratis-dumpmetadata: add struct based dispatch

Signed-off-by: mulhern <[email protected]>

src/bin/stratis-dumpmetadata.rs

@@ -26,63 +26,94 @@ fn initialize_log() {
     builder.init()
 }
 
-fn parse_args() -> Command {
-    Command::new("stratis-dumpmetadata")
-        .next_line_help(true)
-        .arg(
-            Arg::new("dev")
-                .required(true)
-                .help("Print metadata of given device"),
-        )
-        .arg(
-            Arg::new("print_bytes")
-                .long("print-bytes")
-                .action(ArgAction::SetTrue)
-                .num_args(0)
-                .short('b')
-                .help("Print byte buffer of signature block"),
-        )
-        .arg(
-            Arg::new("only")
-                .long("only")
-                .action(ArgAction::Set)
-                .value_name("PORTION")
-                .value_parser(["pool"])
-                .help("Only print specified portion of the metadata"),
+pub trait ToolCommand<'a> {
+    fn name(&self) -> &'a str;
+    fn run(&self, command_line_args: Vec<String>) -> Result<(), String>;
+}
+
+struct StratisDumpMetadata;
+
+impl StratisDumpMetadata {
+    fn cmd() -> Command {
+        Command::new("stratis-dumpmetadata")
+            .next_line_help(true)
+            .arg(
+                Arg::new("dev")
+                    .required(true)
+                    .help("Print metadata of given device"),
+            )
+            .arg(
+                Arg::new("print_bytes")
+                    .long("print-bytes")
+                    .action(ArgAction::SetTrue)
+                    .num_args(0)
+                    .short('b')
+                    .help("Print byte buffer of signature block"),
+            )
+            .arg(
+                Arg::new("only")
+                    .long("only")
+                    .action(ArgAction::Set)
+                    .value_name("PORTION")
+                    .value_parser(["pool"])
+                    .help("Only print specified portion of the metadata"),
+            )
+    }
+}
+
+impl<'a> ToolCommand<'a> for StratisDumpMetadata {
+    fn name(&self) -> &'a str {
+        "stratis-dumpmetadata"
+    }
+
+    fn run(&self, command_line_args: Vec<String>) -> Result<(), String> {
+        let matches = StratisDumpMetadata::cmd().get_matches_from(command_line_args);
+        let devpath = matches
+            .get_one::<String>("dev")
+            .map(|s| s.as_str())
+            .expect("'dev' is a mandatory argument");
+
+        dump_metadata::run(
+            devpath,
+            matches.get_flag("print_bytes"),
+            matches
+                .get_one::<String>("only")
+                .map(|v| v == "pool")
+                .unwrap_or(false),
         )
+    }
+}
+
+fn cmds<'a>() -> Vec<Box<dyn ToolCommand<'a>>> {
+    vec![Box::new(StratisDumpMetadata)]
 }
 
 fn main() {
-    let matches = parse_args().get_matches();
-    let devpath = matches
-        .get_one::<String>("dev")
-        .map(|s| s.as_str())
-        .expect("'dev' is a mandatory argument");
+    let args = env::args().collect::<Vec<_>>();
+    let argv1 = args[0].as_str();
 
     initialize_log();
 
-    match dump_metadata::run(
-        devpath,
-        matches.get_flag("print_bytes"),
-        matches
-            .get_one::<String>("only")
-            .map(|v| v == "pool")
-            .unwrap_or(false),
-    ) {
-        Ok(()) => {}
-        Err(e) => {
-            eprintln!("Error encountered: {}", e);
-            process::exit(1);
+    if let Some(c) = cmds().iter().find(|x| argv1.ends_with(x.name())) {
+        match c.run(args) {
+            Ok(()) => {}
+            Err(e) => {
+                eprintln!("Error encountered: {}", e);
+                process::exit(1);
+            }
         }
+    } else {
+        process::exit(2);
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::parse_args;
+
+    use super::StratisDumpMetadata;
 
     #[test]
     fn test_dumpmetadata_parse_args() {
-        parse_args().debug_assert();
+        StratisDumpMetadata::cmd().debug_assert();
     }
 }