port Trace definition to rust

.gitignore

@@ -4,4 +4,5 @@ node_modules/**
 **/.DS_Store
 .DS_Store
 performance.db.ndjson
-performance.ndjson
+performance.ndjson
+target/

crates/Cargo.toml

@@ -0,0 +1,16 @@
+[workspace]
+members = ["replay_gen"]
+resolver = "2"
+
+[profile.release]
+# Optimize all the things!
+opt-level = 3
+lto = "fat"
+overflow-checks = true
+# Some debug info for profiling.
+debug = 1
+
+[profile.test]
+# Speed-up test execution and avoid stack overflow with deeply-nested ASTs.
+opt-level = 2
+lto = "thin"

crates/replay_gen/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "replay_gen"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+tempfile = "3.2.0"

crates/replay_gen/src/lib.rs

@@ -0,0 +1 @@
+pub mod trace;

crates/replay_gen/src/main.rs

@@ -0,0 +1,29 @@
+use std::env;
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::path::Path;
+
+use replay_gen::trace;
+
+fn main() -> io::Result<()> {
+    // FIXME: use clap to parse args. currently just panics.
+    let args: Vec<String> = env::args().collect();
+    let newline = &args[1];
+    let path = Path::new(newline);
+    let file = File::open(&path)?;
+    let reader = io::BufReader::new(file);
+
+    let mut lines = reader.lines().peekable();
+
+    while let Some(line) = lines.next() {
+        let line = line?;
+        let event = line.parse::<trace::WasmEvent>()?;
+        // hack to print the last event without a newline that matches the current behavior.
+        if lines.peek().is_some() {
+            println!("{:?}", event);
+        } else {
+            print!("{:?}", event);
+        }
+    }
+    Ok(())
+}