1 files changed, 66 insertions, 1 deletions
diff --git a/zkvms_host_io/src/lib.rs b/zkvms_host_io/src/lib.rs
index b2049f5..da1e2df 100644
--- a/zkvms_host_io/src/lib.rs
+++ b/zkvms_host_io/src/lib.rs
@@ -5,7 +5,15 @@ pub use input_macros::{
 };
 use num_traits::NumCast;
 use serde::{Deserialize, Serialize};
-use std::{collections::*, env, fs::read_to_string, option::Option};
+use std::{
+    collections::*,
+    env,
+    fs::{read_to_string, OpenOptions},
+    option::Option,
+    time::{Duration, Instant},
+    io::Write,
+    path::Path
+};
 
 static DEFAULT_PUBLIC_INPUT: &str =
     include_str!(concat!(env!("INPUTS_DIR"), "/default_public_input.toml"));
@@ -143,3 +151,60 @@ pub fn read_args() -> RunWith {
         default_env,
     }
 }
+
+/// Used by the "benchmarkable" macro. Takes run_info and two vectors of start and
+/// end instants for each benchmark iteration.
+pub fn emit_benchmark_results(run_info: RunWith, starts: Vec<Instant>, ends: Vec<Instant>) {
+    let info_row = format!("name,guest,total duration,repeats,average\n");
+    let mut output = format!("{},{},", env!("ZKVM"), env!("GUEST"));
+
+    let duration = *ends.last().unwrap() - *starts.first().unwrap();
+    if run_info.millis {
+       output += &format!("{},", duration.as_millis());
+    } else {
+       output += &format!("{:.3},", duration.as_secs_f32());
+    }
+
+    let durations = starts
+        .into_iter()
+        .zip(ends.into_iter())
+        .map(|(s,e)| e - s )
+        .collect::<Vec<Duration>>();
+    let average = durations.iter().sum::<Duration>() / durations.len() as u32;
+
+    if run_info.millis {
+       output += &format!("{},{}\n", run_info.repeats, average.as_millis());
+    } else {
+       output += &format!("{},{:.3}\n", run_info.repeats, average.as_secs_f32());
+    }
+
+    if let Some(file) = run_info.output_file {
+
+       let file_exists = Path::new(&file).exists();
+
+       let mut outfile = match OpenOptions::new()
+           .write(true)
+           .create(true)
+           .append(run_info.append)
+           .open(&file)
+       {
+           Ok(file) => file,
+           Err(e) => {
+               panic!("Failed to open file: {}", e);
+           }
+       };
+
+       if !file_exists {
+           if let Err(e) = write!(outfile, "{}", info_row) {
+               panic!("Failed to write info_row: {}", e);
+           }
+       }
+
+       if let Err(e) = write!(outfile, "{}", output) {
+           panic!("Failed to write output: {}", e);
+       }
+    }
+    else {
+        print!("{}", output);
+    }
+}