Move bin/dump into a debug subcommand, read stdin instead of a file

src/bin/dump.rs

@@ -1,29 +0,0 @@
-extern crate webmetro;
-
-use std::env::args;
-use std::fs::File;
-use std::io::Read;
-use std::path::Path;
-use webmetro::webm::{ parse_webm, SimpleBlock };
-use webmetro::webm::WebmElement::*;
-
-pub fn main() {
-    let mut args = args();
-    let _ = args.next();
-    let filename = args.next().expect("Reading filename");
-
-    let mut buffer = Vec::new();
-    let mut file = File::open(Path::new(&filename)).expect("Opening file");
-
-    file.read_to_end(&mut buffer).expect("Reading file contents");
-
-    for element in parse_webm(buffer.as_slice()) {
-        match element {
-            // suppress printing byte arrays
-            Tracks(slice) => println!("Tracks[{}]", slice.len()),
-            SimpleBlock(SimpleBlock {timecode, ..}) => println!("SimpleBlock@{}", timecode),
-            other => println!("{:?}", other)
-        }
-    }
-
-}

src/commands/dump.rs

@@ -0,0 +1,55 @@
+use std::{
+    error::Error,
+    io::{self, prelude::*}
+};
+
+use clap::{App, AppSettings, ArgMatches, SubCommand};
+use futures::{
+    Async,
+    stream::poll_fn
+};
+
+use webmetro::{
+    stream_parser::StreamEbml,
+    webm::{
+        SimpleBlock,
+        WebmElement::*
+    }
+};
+
+pub fn options() -> App<'static, 'static> {
+    SubCommand::with_name("dump")
+        .setting(AppSettings::Hidden)
+        .about("Dumps WebM parsing events from parsing stdin")
+}
+
+pub fn run(_args: &ArgMatches) -> Result<(), Box<Error>> {
+
+    let stdin = io::stdin();
+    let mut buf_reader = stdin.lock();
+    let mut read_bytes = 0;
+
+    let mut events = poll_fn(|| {
+        buf_reader.consume(read_bytes);
+        buf_reader.fill_buf().map(|slice| {
+            read_bytes = slice.len();
+            if read_bytes > 0 {
+                Async::Ready(Some(Into::<Vec<u8>>::into(slice)))
+            } else {
+                Async::Ready(None)
+            }
+        })
+    }).parse_ebml();
+
+    // stdin is sync so Async::NotReady will never happen
+    while let Ok(Async::Ready(Some(element))) = events.poll_event() {
+        match element {
+            // suppress printing byte arrays
+            Tracks(slice) => println!("Tracks[{}]", slice.len()),
+            SimpleBlock(SimpleBlock {timecode, ..}) => println!("SimpleBlock@{}", timecode),
+            other => println!("{:?}", other)
+        }
+    }
+
+    Ok(())
+}

src/commands/mod.rs

@@ -1 +1,2 @@
+pub mod dump;
 pub mod relay;

src/main.rs

@@ -6,7 +6,10 @@ extern crate webmetro;
 mod commands;
 
 use clap::{App, AppSettings};
-use commands::{relay};
+use commands::{
+    relay,
+    dump
+};
 
 fn options() -> App<'static, 'static> {
     App::new("webmetro")
@@ -14,6 +17,7 @@ fn options() -> App<'static, 'static> {
         .about("Utilities for broadcasting & relaying live WebM video/audio streams")
         .setting(AppSettings::VersionlessSubcommands)
         .subcommand(relay::options())
+        .subcommand(dump::options())
 }
 
 fn main() {
@@ -21,6 +25,7 @@ fn main() {
 
     match args.subcommand() {
         ("relay", Some(sub_args)) => relay::run(sub_args),
+        ("dump", Some(sub_args)) => dump::run(sub_args),
         _ => {
             options().print_help().unwrap();
             println!("");