use cbor for maps

abstutil/Cargo.toml

@@ -5,4 +5,5 @@ authors = ["Dustin Carlino <dabreegster@gmail.com>"]
 
 [dependencies]
 serde = "1.0"
+serde_cbor = "0.8.2"
 serde_json = "1.0"

abstutil/src/lib.rs

@@ -1,10 +1,11 @@
 extern crate serde;
+extern crate serde_cbor;
 extern crate serde_json;
 
 use serde::Serialize;
 use serde::de::DeserializeOwned;
 use std::fs::File;
-use std::io::{Error, Read, Write};
+use std::io::{Error, ErrorKind, Read, Write};
 
 pub fn write_json<T: Serialize>(path: &str, obj: &T) -> Result<(), Error> {
     let mut file = File::create(path)?;
@@ -19,3 +20,14 @@ pub fn read_json<T: DeserializeOwned>(path: &str) -> Result<T, Error> {
     let obj: T = serde_json::from_str(&contents).unwrap();
     Ok(obj)
 }
+
+pub fn write_binary<T: Serialize>(path: &str, obj: &T) -> Result<(), Error> {
+    let mut file = File::create(path)?;
+    serde_cbor::to_writer(&mut file, obj).map_err(|err| Error::new(ErrorKind::Other, err))
+}
+
+pub fn read_binary<T: DeserializeOwned>(path: &str) -> Result<T, Error> {
+    let file = File::open(path)?;
+    let obj: T = serde_cbor::from_reader(file).map_err(|err| Error::new(ErrorKind::Other, err))?;
+    Ok(obj)
+}

convert_osm/src/main.rs

@@ -50,7 +50,7 @@ fn main() {
     let (map, bounds) = osm::osm_to_raw_roads(&flags.osm);
     let mut map = osm::split_up_roads(&map, &elevation);
     let parcels_map: raw_data::Map =
-        abstutil::read_json(&flags.parcels).expect("loading parcels failed");
+        abstutil::read_binary(&flags.parcels).expect("loading parcels failed");
     println!(
         "Finding matching parcels from {} candidates",
         parcels_map.parcels.len()
@@ -94,5 +94,5 @@ fn main() {
     }
 
     println!("writing to {}", flags.output);
-    abstutil::write_json(&flags.output, &map).expect("serializing map failed");
+    abstutil::write_binary(&flags.output, &map).expect("serializing map failed");
 }

docs/lanes.md

@@ -107,7 +107,6 @@ wait slow down even more -- before any of this change, lanes on adjacent roads s
 	- debug impossibly long derived roads, like the horizontal E McGraw. try to detect by comparing length of original points with length of derived center pts.
 	- big maps start centered over emptiness
 	- some bldg paths are quite long.
-	- more compact output
 	- draw sidewalk and parking markings
 	- make final Map serializable too
 		- useful to precompute sidewalk paths

kml/src/main.rs

@@ -31,5 +31,5 @@ fn main() {
 
     let out_path = &args[2];
     println!("writing to {}", out_path);
-    abstutil::write_json(out_path, &map).expect("serializing map failed");
+    abstutil::write_binary(out_path, &map).expect("serializing map failed");
 }

map_model/src/map.rs

@@ -29,7 +29,7 @@ pub struct Map {
 
 impl Map {
     pub fn new(path: &str) -> Result<Map, Error> {
-        let data: raw_data::Map = abstutil::read_json(path)?;
+        let data: raw_data::Map = abstutil::read_binary(path)?;
 
         let bounds = data.get_gps_bounds();
         let mut m = Map {