dump_schedule utility (#300)

## Description

Adds the `dump_schedule` crate which is a simple tool that writes
valence's schedule graph to a file named ~~`graph.gv`~~ `graph.svg`.

## Test Plan

Steps:
1. `cargo r -p dump_schedule`
2. Paste the contents of `graph.gv` to https://edotor.net/
3. Look at the pretty graph.

.gitignore

@@ -15,4 +15,4 @@ rust-mc-bot
 flamegraph*.svg
 perf.data
 perf.data.old
-/graph.gv
+/graph.svg

crates/dump_schedule/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "dump_schedule"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+bevy_mod_debugdump = "0.7.0"
+valence = { path = "../valence", version = "0.2.0" }

crates/dump_schedule/README.md

@@ -0,0 +1,7 @@
+# dump_schedule
+
+A simple debugging utility for visualizing Valence's main schedule graph. Generates a SVG file.
+
+1. Ensure that [Graphviz](https://graphviz.org/) is installed and the `dot` command is available.
+2. Run the program with `cargo r -p dump_schedule`
+3. Open the generated `graph.svg` in your browser or other program, e.g. `chromium graph.svg`.

crates/dump_schedule/src/main.rs

@@ -0,0 +1,36 @@
+use std::io;
+use std::io::Write;
+use std::process::{Command, Stdio};
+
+use valence::bevy_app::prelude::*;
+use valence::config::ServerPlugin;
+
+fn main() -> io::Result<()> {
+    let mut app = App::new();
+
+    app.add_plugin(ServerPlugin::new(()));
+
+    let dot_graph = bevy_mod_debugdump::schedule_graph_dot(
+        &mut app,
+        CoreSchedule::Main,
+        &bevy_mod_debugdump::schedule_graph::Settings {
+            ambiguity_enable: false,
+            ..Default::default()
+        },
+    );
+
+    let mut child = Command::new("dot")
+        .stdin(Stdio::piped())
+        .arg("-Tsvg")
+        .arg("-o")
+        .arg("graph.svg")
+        .spawn()?;
+
+    if let Some(stdin) = child.stdin.as_mut() {
+        stdin.write_all(dot_graph.as_bytes())?;
+    }
+
+    child.wait_with_output()?;
+
+    Ok(())
+}

crates/valence/Cargo.toml

@@ -12,7 +12,6 @@ build = "build/main.rs"
 authors = ["Ryan Johnson <ryanj00a@gmail.com>"]
 
 [dependencies]
-#bevy_mod_debugdump = "0.7.0"
 anyhow = "1.0.65"
 arrayvec = "0.7.2"
 async-trait = "0.1.60"

crates/valence/src/server.rs

@@ -339,20 +339,6 @@ pub fn build_plugin(
         .add_plugin(PlayerListPlugin)
         .add_plugin(WeatherPlugin);
 
-    /*
-    println!(
-        "{}",
-        bevy_mod_debugdump::schedule_graph_dot(
-            app,
-            CoreSchedule::Main,
-            &bevy_mod_debugdump::schedule_graph::Settings {
-                ambiguity_enable: false,
-                ..Default::default()
-            },
-        )
-    );
-    */
-
     Ok(())
 }