refactoring json saving/loading

Cargo.toml

@@ -1,3 +1,3 @@
 [workspace]
 
-members = ["control", "convert_osm", "editor", "ezgui", "geom", "headless", "kml", "map_model", "sim"]
+members = ["abstutil", "control", "convert_osm", "editor", "ezgui", "geom", "headless", "kml", "map_model", "sim"]

POLISH.md

@@ -3,7 +3,8 @@
 Overlapping with TODO.md and docs/backlog.md, we have... a new list of visible
 things needing polish!
 
-- sometimes UI zooms in at once, then unzooms slowly
+## Just appearance
+
 - sidewalk paths start in building centers and end in sidewalk centers
 	- this is probably fine to show agents moving, but at least draw
 	  building layer before sidewalk layer
@@ -13,3 +14,7 @@ things needing polish!
 	- parking with... circled P's and maybe partial horizontal lines to
 	  show spots?
 	- copy the green Seattle color scheme for bike lanes
+
+## Interaction
+
+- sometimes UI zooms in at once, then unzooms slowly

abstutil/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "abstutil"
+version = "0.1.0"
+authors = ["Dustin Carlino <dabreegster@gmail.com>"]
+
+[dependencies]
+serde = "1.0"
+serde_json = "1.0"

abstutil/src/lib.rs

@@ -0,0 +1,21 @@
+extern crate serde;
+extern crate serde_json;
+
+use serde::Serialize;
+use serde::de::DeserializeOwned;
+use std::fs::File;
+use std::io::{Error, Read, Write};
+
+pub fn write_json<T: Serialize>(path: &str, obj: &T) -> Result<(), Error> {
+    let mut file = File::create(path)?;
+    file.write_all(serde_json::to_string_pretty(obj).unwrap().as_bytes())?;
+    Ok(())
+}
+
+pub fn read_json<T: DeserializeOwned>(path: &str) -> Result<T, Error> {
+    let mut file = File::open(path)?;
+    let mut contents = String::new();
+    file.read_to_string(&mut contents)?;
+    let obj: T = serde_json::from_str(&contents).unwrap();
+    Ok(obj)
+}

editor/Cargo.toml

@@ -5,6 +5,7 @@ authors = ["Dustin Carlino <dabreegster@gmail.com>"]
 
 [dependencies]
 aabb-quadtree = "0.1.0"
+abstutil = { path = "../abstutil" }
 control = { path = "../control" }
 geo = "0.9.1"
 geom = { path = "../geom" }
@@ -19,7 +20,6 @@ pistoncore-glutin_window = "*"
 rand = "0.5.1"
 serde = "1.0"
 serde_derive = "1.0"
-serde_json = "1.0"
 sim = { path = "../sim" }
 structopt = "0.2"
 strum = "0.9.0"

editor/src/colors.rs

@@ -1,12 +1,10 @@
 // Copyright 2018 Google LLC, licensed under http://www.apache.org/licenses/LICENSE-2.0
 
-extern crate serde_json;
-
+use abstutil;
 use graphics::types::Color;
 use rand;
 use std::collections::BTreeMap;
-use std::fs::File;
-use std::io::{Error, Read, Write};
+use std::io::Error;
 use strum::IntoEnumIterator;
 
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize, EnumIter, EnumString, ToString,
@@ -57,17 +55,8 @@ pub struct ColorScheme {
 }
 
 impl ColorScheme {
-    pub fn write(&self, path: &str) -> Result<(), Error> {
-        let mut file = File::create(path)?;
-        file.write_all(serde_json::to_string_pretty(self).unwrap().as_bytes())?;
-        Ok(())
-    }
-
     pub fn load(path: &str) -> Result<ColorScheme, Error> {
-        let mut file = File::open(path)?;
-        let mut contents = String::new();
-        file.read_to_string(&mut contents)?;
-        let mut scheme: ColorScheme = serde_json::from_str(&contents).unwrap();
+        let mut scheme: ColorScheme = abstutil::read_json(path)?;
 
         for color in Colors::iter() {
             if !scheme.map.contains_key(&color) {

editor/src/main.rs

@@ -1,6 +1,7 @@
 // Copyright 2018 Google LLC, licensed under http://www.apache.org/licenses/LICENSE-2.0
 
 extern crate aabb_quadtree;
+extern crate abstutil;
 extern crate control;
 extern crate ezgui;
 extern crate geo;
@@ -35,7 +36,6 @@ mod animation;
 mod colors;
 mod plugins;
 mod render;
-mod savestate;
 mod ui;
 
 #[derive(StructOpt, Debug)]

editor/src/plugins/sim_controls.rs

@@ -1,5 +1,6 @@
 // Copyright 2018 Google LLC, licensed under http://www.apache.org/licenses/LICENSE-2.0
 
+use abstutil;
 use control::ControlMap;
 use ezgui::input::UserInput;
 use geom::GeomMap;
@@ -47,14 +48,11 @@ impl SimController {
             self.desired_speed += ADJUST_SPEED;
         }
         if input.unimportant_key_pressed(Key::O, "Press O to save sim state") {
-            self.sim
-                .write_savestate("sim_state")
-                .expect("Writing sim state failed");
+            abstutil::write_json("sim_state", &self.sim).expect("Writing sim state failed");
             println!("Wrote sim_state");
         }
         if input.unimportant_key_pressed(Key::P, "Press P to load sim state") {
-            self.sim =
-                straw_model::Sim::load_savestate("sim_state").expect("Loading sim state failed");
+            self.sim = abstutil::read_json("sim_state").expect("sim state failed");
         }
         if self.last_step.is_some() {
             if input.unimportant_key_pressed(Key::Space, "Press space to pause sim") {

editor/src/savestate.rs

@@ -1,34 +0,0 @@
-// Copyright 2018 Google LLC, licensed under http://www.apache.org/licenses/LICENSE-2.0
-
-extern crate serde;
-extern crate serde_json;
-
-use control::{ModifiedStopSign, ModifiedTrafficSignal};
-use map_model::IntersectionID;
-use std::collections::HashMap;
-use std::fs::File;
-use std::io::{Error, Read, Write};
-
-#[derive(Serialize, Deserialize, Debug)]
-pub struct EditorState {
-    pub cam_x: f64,
-    pub cam_y: f64,
-    pub cam_zoom: f64,
-
-    pub traffic_signals: HashMap<IntersectionID, ModifiedTrafficSignal>,
-    pub stop_signs: HashMap<IntersectionID, ModifiedStopSign>,
-}
-
-pub fn write(path: &str, state: EditorState) -> Result<(), Error> {
-    let mut file = File::create(path)?;
-    file.write_all(serde_json::to_string_pretty(&state).unwrap().as_bytes())?;
-    Ok(())
-}
-
-pub fn load(path: &str) -> Result<EditorState, Error> {
-    let mut file = File::open(path)?;
-    let mut contents = String::new();
-    file.read_to_string(&mut contents)?;
-    let state: EditorState = serde_json::from_str(&contents).unwrap();
-    Ok(state)
-}

editor/src/ui.rs

@@ -3,15 +3,19 @@
 // TODO this should just be a way to handle interactions between plugins
 
 extern crate map_model;
+extern crate serde;
 
+use abstutil;
 use animation;
 use colors::{ColorScheme, Colors};
 use control::ControlMap;
+use control::{ModifiedStopSign, ModifiedTrafficSignal};
 use ezgui::ToggleableLayer;
 use ezgui::canvas::{Canvas, GfxCtx};
 use ezgui::input::UserInput;
 use geom;
 use graphics::types::Color;
+use map_model::IntersectionID;
 use piston::input::{Key, MouseCursorEvent};
 use piston::window::Size;
 use plugins::classification::OsmClassifier;
@@ -25,8 +29,8 @@ use plugins::stop_sign_editor::StopSignEditor;
 use plugins::traffic_signal_editor::TrafficSignalEditor;
 use plugins::turn_colors::TurnColors;
 use render;
-use savestate;
 use sim::CarID;
+use std::collections::HashMap;
 use std::process;
 
 // TODO ideally these would be tuned kind of dynamically based on rendering speed
@@ -115,7 +119,7 @@ impl UI {
             cs: ColorScheme::load("color_scheme").unwrap(),
         };
 
-        match savestate::load("editor_state") {
+        match abstutil::read_json::<EditorState>("editor_state") {
             Ok(state) => {
                 println!("Loaded previous editor_state");
                 ui.canvas.cam_x = state.cam_x;
@@ -281,7 +285,7 @@ impl UI {
         }
 
         if input.unimportant_key_pressed(Key::Escape, "Press escape to quit") {
-            let state = savestate::EditorState {
+            let state = EditorState {
                 cam_x: self.canvas.cam_x,
                 cam_y: self.canvas.cam_y,
                 cam_zoom: self.canvas.cam_zoom,
@@ -289,10 +293,8 @@ impl UI {
                 stop_signs: self.control_map.get_stop_signs_savestate(),
             };
             // TODO maybe make state line up with the map, so loading from a new map doesn't break
-            savestate::write("editor_state", state).expect("Saving editor_state failed");
-            self.cs
-                .write("color_scheme")
-                .expect("Saving color_scheme failed");
+            abstutil::write_json("editor_state", &state).expect("Saving editor_state failed");
+            abstutil::write_json("color_scheme", &self.cs).expect("Saving color_scheme failed");
             println!("Saved editor_state and color_scheme");
             process::exit(0);
         }
@@ -571,3 +573,13 @@ impl UI {
         }
     }
 }
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct EditorState {
+    pub cam_x: f64,
+    pub cam_y: f64,
+    pub cam_zoom: f64,
+
+    pub traffic_signals: HashMap<IntersectionID, ModifiedTrafficSignal>,
+    pub stop_signs: HashMap<IntersectionID, ModifiedStopSign>,
+}

sim/Cargo.toml

@@ -15,5 +15,4 @@ piston2d-graphics = "*"
 rand = { version = "0.5.1", features = ["serde1"] }
 serde = "1.0"
 serde_derive = "1.0"
-serde_json = "1.0"
 vecmath = "0.3.1"

sim/src/straw_model.rs

@@ -1,7 +1,5 @@
 // Copyright 2018 Google LLC, licensed under http://www.apache.org/licenses/LICENSE-2.0
 
-extern crate serde_json;
-
 use common::{CarID, Tick, SPEED_LIMIT};
 use control::ControlMap;
 use dimensioned::si;
@@ -14,8 +12,6 @@ use multimap::MultiMap;
 use rand::{FromEntropy, Rng, SeedableRng, XorShiftRng};
 use std::collections::{BTreeMap, HashSet};
 use std::f64;
-use std::fs::File;
-use std::io::{Error, Read, Write};
 use std::time::{Duration, Instant};
 use straw_intersections::{IntersectionPolicy, StopSign, TrafficSignal};
 
@@ -556,20 +552,6 @@ impl Sim {
         b.last_sim_time = self.time;
         speed.value_unsafe
     }
-
-    pub fn write_savestate(&self, path: &str) -> Result<(), Error> {
-        let mut file = File::create(path)?;
-        file.write_all(serde_json::to_string_pretty(self).unwrap().as_bytes())?;
-        Ok(())
-    }
-
-    pub fn load_savestate(path: &str) -> Result<Sim, Error> {
-        let mut file = File::open(path)?;
-        let mut contents = String::new();
-        file.read_to_string(&mut contents)?;
-        let sim: Sim = serde_json::from_str(&contents).unwrap();
-        Ok(sim)
-    }
 }
 
 pub struct Benchmark {