feat: implemented the convert command in runtime_tracing_cli - capable of conversion between binary and json trace formats

Author: nickysn

runtime_tracing/src/tracer.rs

@@ -4,7 +4,7 @@ use std::collections::HashMap;
 use std::env;
 use std::error::Error;
 use std::fs;
-use std::io::stdout;
+use std::io::{stdout, BufReader};
 use std::path::{Path, PathBuf};
 
 use crate::types::{
@@ -300,6 +300,21 @@ impl Tracer {
         Ok(())
     }
 
+    pub fn load_trace_events(&mut self, path: &Path, format: TraceEventsFileFormat) -> Result<(), Box<dyn Error>> {
+        match format {
+            TraceEventsFileFormat::Json => {
+                let json = std::fs::read_to_string(path)?;
+                self.events = serde_json::from_str(&json)?;
+            }
+            TraceEventsFileFormat::Binary => {
+                let file = fs::File::open(path)?;
+                let mut buf_reader = BufReader::new(file);
+                self.events = crate::capnptrace::read_trace(&mut buf_reader)?;
+            }
+        }
+        Ok(())
+    }
+
     pub fn store_trace_events(&self, path: &Path, format: TraceEventsFileFormat) -> Result<(), Box<dyn Error>> {
         match format {
             TraceEventsFileFormat::Json => {

runtime_tracing_cli/src/main.rs

@@ -1,3 +1,50 @@
+use std::path::Path;
+
+use clap::{Args, Parser, Subcommand};
+use runtime_tracing::{TraceEventsFileFormat, Tracer};
+
+#[derive(Debug, Clone, Args)]
+struct ConvertCommand {
+    input_file: String,
+    output_file: String,
+}
+
+#[non_exhaustive]
+#[derive(Subcommand, Clone, Debug)]
+enum RuntimeTracingCliCommand {
+    /// Convert from one trace file format to another
+    Convert(ConvertCommand),
+}
+
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+struct RuntimeTracingCli {
+    #[command(subcommand)]
+    command: RuntimeTracingCliCommand,
+}
+
+fn determine_file_format_from_name(s: &str) -> Option<TraceEventsFileFormat> {
+    if s.ends_with(".json") {
+        Some(TraceEventsFileFormat::Json)
+    } else {
+        if s.ends_with(".bin") {
+            Some(TraceEventsFileFormat::Binary)
+        } else {
+            None
+        }
+    }
+}
+
 fn main() {
-    println!("Hello, world!");
+    let args = RuntimeTracingCli::parse();
+
+    match args.command {
+        RuntimeTracingCliCommand::Convert(convert_command) => {
+            let input_file_format = determine_file_format_from_name(&convert_command.input_file).unwrap();
+            let output_file_format = determine_file_format_from_name(&convert_command.output_file).unwrap();
+            let mut trace = Tracer::new("", &[]);
+            trace.load_trace_events(Path::new(&convert_command.input_file), input_file_format).unwrap();
+            trace.store_trace_events(Path::new(&convert_command.output_file), output_file_format).unwrap();
+        }
+    }
 }