From 0b06eaec6f0673ba20f9e20720534c01fe9550a0 Mon Sep 17 00:00:00 2001
From: Joshua Barretto <joshua.s.barretto@gmail.com>
Date: Tue, 9 Aug 2022 14:44:02 +0100
Subject: [PATCH] Use MessagePack for more compact rtsim state persistence

---
 Cargo.lock               | 29 +++++++++++++++++++++++++++++
 rtsim/Cargo.toml         |  1 +
 rtsim/src/data/mod.rs    | 12 +++++++-----
 server/src/rtsim2/mod.rs | 11 ++++++-----
 4 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 2ce962ac5c..4915092e2c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4318,6 +4318,12 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "paste"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9423e2b32f7a043629287a536f21951e8c6a82482d0acb1eeebfc90bc2225b22"
+
 [[package]]
 name = "peeking_take_while"
 version = "0.1.2"
@@ -5096,6 +5102,28 @@ dependencies = [
  "syn 1.0.100",
 ]
 
+[[package]]
+name = "rmp"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44519172358fd6d58656c86ab8e7fbc9e1490c3e8f14d35ed78ca0dd07403c9f"
+dependencies = [
+ "byteorder",
+ "num-traits",
+ "paste",
+]
+
+[[package]]
+name = "rmp-serde"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25786b0d276110195fa3d6f3f31299900cf71dfbd6c28450f3f58a0e7f7a347e"
+dependencies = [
+ "byteorder",
+ "rmp",
+ "serde",
+]
+
 [[package]]
 name = "rodio"
 version = "0.15.0"
@@ -6913,6 +6941,7 @@ version = "0.10.0"
 dependencies = [
  "enum-map",
  "hashbrown 0.12.3",
+ "rmp-serde",
  "ron 0.8.0",
  "serde",
  "vek 0.15.8",
diff --git a/rtsim/Cargo.toml b/rtsim/Cargo.toml
index 504d1d50cd..96fccf251e 100644
--- a/rtsim/Cargo.toml
+++ b/rtsim/Cargo.toml
@@ -11,3 +11,4 @@ serde = { version = "1.0.110", features = ["derive"] }
 hashbrown = { version = "0.12", features = ["rayon", "serde", "nightly"] }
 enum-map = { version = "2.4", features = ["serde"] }
 vek = { version = "0.15.8", features = ["serde"] }
+rmp-serde = "1.1.0"
diff --git a/rtsim/src/data/mod.rs b/rtsim/src/data/mod.rs
index d4dd3d97e9..4e8622f294 100644
--- a/rtsim/src/data/mod.rs
+++ b/rtsim/src/data/mod.rs
@@ -7,7 +7,6 @@ pub use self::{
 };
 
 use self::helper::Latest;
-use ron::error::SpannedResult;
 use serde::{Serialize, Deserialize};
 use std::io::{Read, Write};
 
@@ -17,12 +16,15 @@ pub struct Data {
     pub actors: Actors,
 }
 
+pub type ReadError = rmp_serde::decode::Error;
+pub type WriteError = rmp_serde::encode::Error;
+
 impl Data {
-    pub fn from_reader<R: Read>(reader: R) -> SpannedResult<Self> {
-        ron::de::from_reader(reader)
+    pub fn from_reader<R: Read>(reader: R) -> Result<Self, ReadError> {
+        rmp_serde::decode::from_read(reader)
     }
 
-    pub fn write_to<W: Write>(&self, writer: W) -> Result<(), ron::Error> {
-        ron::ser::to_writer(writer, self)
+    pub fn write_to<W: Write>(&self, mut writer: W) -> Result<(), WriteError> {
+        rmp_serde::encode::write(&mut writer, self)
     }
 }
diff --git a/server/src/rtsim2/mod.rs b/server/src/rtsim2/mod.rs
index 515c0dbd7b..2cf6b2b337 100644
--- a/server/src/rtsim2/mod.rs
+++ b/server/src/rtsim2/mod.rs
@@ -8,7 +8,7 @@ use common::{
     vol::RectRasterableVol,
 };
 use common_ecs::{dispatch, System};
-use rtsim2::{data::Data, RtState};
+use rtsim2::{data::{Data, ReadError}, RtState};
 use specs::{DispatcherBuilder, WorldExt};
 use std::{
     fs::{self, File},
@@ -16,6 +16,7 @@ use std::{
     sync::Arc,
     time::Instant,
     io::{self, Write},
+    error::Error,
 };
 use enum_map::EnumMap;
 use tracing::{error, warn, info};
@@ -51,7 +52,7 @@ impl RtSim {
                                         loop {
                                             let mut backup_path = file_path.clone();
                                             backup_path.set_extension(if i == 0 {
-                                                format!("ron_backup_{}", i)
+                                                format!("backup_{}", i)
                                             } else {
                                                 "ron_backup".to_string()
                                             });
@@ -88,7 +89,7 @@ impl RtSim {
                 data_dir.push("rtsim");
                 data_dir
             });
-        path.push("state.ron");
+        path.push("state.dat");
         path
     }
 
@@ -112,7 +113,7 @@ impl RtSim {
         // TODO: Use slow job
         // slowjob_pool.spawn("RTSIM_SAVE", move || {
         std::thread::spawn(move || {
-            let tmp_file_name = "state_tmp.ron";
+            let tmp_file_name = "state_tmp.dat";
             if let Err(e) = file_path
                 .parent()
                 .map(|dir| {
@@ -124,7 +125,7 @@ impl RtSim {
                 .and_then(|tmp_file_path| {
                     Ok((File::create(&tmp_file_path)?, tmp_file_path))
                 })
-                .map_err(|e: io::Error| ron::Error::from(e))
+                .map_err(|e: io::Error| Box::new(e) as Box::<dyn Error>)
                 .and_then(|(mut file, tmp_file_path)| {
                     info!("Writing rtsim state to file...");
                     data.write_to(io::BufWriter::new(&mut file))?;