From aa5d38b0fb8f5178ca7b887da45b84bd1d017ccd Mon Sep 17 00:00:00 2001
From: Colin <colin@uninsane.org>
Date: Mon, 14 Jun 2021 21:04:08 -0700
Subject: [PATCH] Add ability to save/resume a simulation to a state file

---
 src/driver.rs | 18 ++++++++++++++++--
 src/render.rs |  7 ++++++-
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/driver.rs b/src/driver.rs
index fbf7cd6..9b1e717 100644
--- a/src/driver.rs
+++ b/src/driver.rs
@@ -7,7 +7,7 @@ use crate::sim::{GenericSim, SimState};
 use crate::stim::AbstractStimulus;
 
 use log::{info, trace};
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 use std::sync::{Arc, Mutex};
 use std::sync::mpsc::{sync_channel, SyncSender, Receiver};
@@ -106,7 +106,21 @@ impl<R: Real, M: Material<R> + Send + Sync + 'static> Driver<R, M> {
 impl<R: Real + Send + Sync + Serialize, M: Material<R> + Serialize + Send + Sync + 'static> Driver<R, M> {
     pub fn add_serializer_renderer(&mut self, out_base: &str, step_frequency: u64) {
         let fmt_str = format!("{out_base}{{step_no}}.bc", out_base=out_base);
-        self.add_renderer(render::SerializerRenderer::new_static(&*fmt_str), out_base, step_frequency);
+        self.add_renderer(render::SerializerRenderer::new_static(&*fmt_str), &*fmt_str, step_frequency);
+    }
+}
+
+impl<R, M> Driver<R, M>
+where
+    R: Real + Send + Sync + Serialize + for<'a> Deserialize<'a>,
+    M: Material<R> + Serialize + for<'a> Deserialize<'a> + Send + Sync + 'static,
+{
+    pub fn add_state_file(&mut self, state_file: &str, snapshot_frequency: u64) {
+        let ser = render::SerializerRenderer::new(state_file);
+        if let Some(state) = ser.try_load() {
+            self.state = state.state;
+        }
+        self.add_renderer(ser, state_file, snapshot_frequency);
     }
 }
 
diff --git a/src/render.rs b/src/render.rs
index 796b20d..353c453 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -13,7 +13,7 @@ use imageproc::{pixelops, drawing};
 use rayon::prelude::*;
 use serde::{Serialize, Deserialize};
 use std::fs::File;
-use std::io::{BufWriter, Write as _};
+use std::io::{BufReader, BufWriter, Write as _};
 use std::path::PathBuf;
 use std::sync::{Mutex, RwLock};
 use y4m;
@@ -699,6 +699,11 @@ impl SerializerRenderer {
         //serde_cbor::to_writer(out, &snap).unwrap();
         bincode::serialize_into(out, &frame).unwrap();
     }
+
+    pub fn try_load<S: GenericSim + for <'a> Deserialize<'a>>(&self) -> Option<SerializedFrame<S>> {
+        let mut reader = BufReader::new(File::open(&*self.fmt_str).ok()?);
+        bincode::deserialize_from(&mut reader).ok()
+    }
 }
 
 impl<S: GenericSim + Serialize> Renderer<S> for SerializerRenderer {