feat(zkvms_guest_io): Output proof size

In each zkVM we'll write the size to /tmp/proof_size and then guest_io
will read that value and place it inside our metrics output. This is not
the most elegant, and in certain zkVMs the file output is a part of the
benchmark timing, but it will have to do.

1 files changed, 8 insertions, 1 deletions

diff --git a/zkvms/jolt/host/src/main.rs b/zkvms/jolt/host/src/main.rs
index aa6b898..8bb3c86 100644
--- a/zkvms/jolt/host/src/main.rs
+++ b/zkvms/jolt/host/src/main.rs
@@ -1,6 +1,7 @@
 use zkvms_host_io::{
     benchmarkable, read_args,
     RunType::{Execute, Prove, Verify},
+    output_proof_size,
 };
 
 pub fn main() {
@@ -16,11 +17,17 @@ pub fn main() {
     match run_info.run_type {
         Execute => unreachable!(),
         Prove => benchmarkable! {
-            let (output, _) = prove_guest(run_info.input.clone().into());
+            let (output, proof) = prove_guest(run_info.input.clone().into());
+
+            output_proof_size(&proof);
+
             println!("Prove output: {:?}", output);
         },
         Verify => benchmarkable! {
             let (_, proof) = prove_guest(run_info.input.clone().into());
+
+            output_proof_size(&proof);
+
             let is_valid = verify_guest(proof);
             println!("Verify is valid: {:?}", is_valid);
         },