Add Rust benchmarks (#349)

* format, benchmark, README.md
* move rand into dev dependency

Author: drinckes

.travis.yml

@@ -119,8 +119,11 @@ matrix:
     # Rust implementation. Lives in rust/
     - language: rust
       env: OLC_PATH=rust
+      before_script:
+        - rustup component add rustfmt
       # Adding caching of .cargo doesn't improve the build/test times.
       script:
         - cd rust/
-        - cargo build --verbose --all
-        - cargo test --verbose --all
+        - cargo fmt --all -- --check
+        - cargo build
+        - cargo test -- --nocapture

rust/Cargo.toml

@@ -10,3 +10,6 @@ exclude = ["rust.iml"]
 
 [dependencies]
 geo = "^0.4.3"
+
+[dev-dependencies]
+rand = "^0.6.5"

rust/README.md

@@ -0,0 +1,16 @@
+This is the Rust implementation of the Open Location Code library.
+
+# Contributing
+
+## Code Formatting
+
+Code must be formatted with `rustfmt`. You can do this by running `cargo fmt`.
+
+The formatting will be checked in the TravisCI integration tests. If the files
+need formatting the tests will fail.
+
+## Testing
+
+Test code by running `cargo test -- --nocapture`. This will run the tests
+including the benchmark loops.
+

rust/src/codearea.rs

@@ -1,4 +1,4 @@
-use geo::{Point};
+use geo::Point;
 
 pub struct CodeArea {
     pub south: f64,
@@ -12,9 +12,12 @@ pub struct CodeArea {
 impl CodeArea {
     pub fn new(south: f64, west: f64, north: f64, east: f64, code_length: usize) -> CodeArea {
         CodeArea {
-            south: south, west: west, north: north, east: east,
+            south: south,
+            west: west,
+            north: north,
+            east: east,
             center: Point::new((west + east) / 2f64, (south + north) / 2f64),
-            code_length: code_length
+            code_length: code_length,
         }
     }
 
@@ -24,8 +27,7 @@ impl CodeArea {
             self.west + other.west,
             self.north + other.north,
             self.east + other.east,
-            self.code_length + other.code_length
+            self.code_length + other.code_length,
         )
     }
 }
-

rust/src/consts.rs

@@ -10,10 +10,8 @@ pub const PADDING_CHAR_STR: &'static str = "0";
 
 // The character set used to encode the values.
 pub const CODE_ALPHABET: [char; 20] = [
-'2', '3', '4', '5', '6',
-'7', '8', '9', 'C', 'F',
-'G', 'H', 'J', 'M', 'P',
-'Q', 'R', 'V', 'W', 'X',
+    '2', '3', '4', '5', '6', '7', '8', '9', 'C', 'F', 'G', 'H', 'J', 'M', 'P', 'Q', 'R', 'V', 'W',
+    'X',
 ];
 
 // The base to use to convert numbers to/from.
@@ -36,9 +34,7 @@ pub const MAX_CODE_LENGTH: usize = 15;
 // The resolution values in degrees for each position in the lat/lng pair
 // encoding. These give the place value of each position, and therefore the
 // dimensions of the resulting area.
-pub const PAIR_RESOLUTIONS: [f64; 5] = [
-    20.0f64, 1.0f64, 0.05f64, 0.0025f64, 0.000125f64
-];
+pub const PAIR_RESOLUTIONS: [f64; 5] = [20.0f64, 1.0f64, 0.05f64, 0.0025f64, 0.000125f64];
 
 // Number of columns in the grid refinement method.
 pub const GRID_COLUMNS: f64 = 4f64;

rust/src/interface.rs

@@ -3,14 +3,14 @@ use geo::Point;
 use codearea::CodeArea;
 
 use consts::{
-    SEPARATOR, SEPARATOR_POSITION, PADDING_CHAR, PADDING_CHAR_STR, CODE_ALPHABET, ENCODING_BASE,
-    LATITUDE_MAX, LONGITUDE_MAX, PAIR_CODE_LENGTH, MAX_CODE_LENGTH, PAIR_RESOLUTIONS, GRID_COLUMNS, GRID_ROWS,
-    MIN_TRIMMABLE_CODE_LEN,
+    CODE_ALPHABET, ENCODING_BASE, GRID_COLUMNS, GRID_ROWS, LATITUDE_MAX, LONGITUDE_MAX,
+    MAX_CODE_LENGTH, MIN_TRIMMABLE_CODE_LEN, PADDING_CHAR, PADDING_CHAR_STR, PAIR_CODE_LENGTH,
+    PAIR_RESOLUTIONS, SEPARATOR, SEPARATOR_POSITION,
 };
 
 use private::{
-    code_value, normalize_longitude, clip_latitude, compute_latitude_precision, prefix_by_reference,
-    narrow_region,
+    clip_latitude, code_value, compute_latitude_precision, narrow_region, normalize_longitude,
+    prefix_by_reference,
 };
 
 /// Determines if a code is a valid Open Location Code.
@@ -62,7 +62,7 @@ pub fn is_valid(_code: &str) -> bool {
             return false;
         }
         // Extract the padding from the code (mutates code)
-        let padding: String = code.drain(ppos..eppos+1).collect();
+        let padding: String = code.drain(ppos..eppos + 1).collect();
         if padding.chars().any(|c| c != PADDING_CHAR) {
             // Padding must be one, contiguous block of padding chars
             return false;
@@ -80,8 +80,7 @@ pub fn is_valid(_code: &str) -> bool {
 /// A short Open Location Code is a sequence created by removing four or more
 /// digits from an Open Location Code. It must include a separator character.
 pub fn is_short(_code: &str) -> bool {
-    is_valid(_code) &&
-        _code.find(SEPARATOR).unwrap() < SEPARATOR_POSITION
+    is_valid(_code) && _code.find(SEPARATOR).unwrap() < SEPARATOR_POSITION
 }
 
 /// Determines if a code is a valid full Open Location Code.
@@ -143,9 +142,7 @@ pub fn encode(pt: Point<f64>, code_length: usize) -> String {
         }
     }
     if digit < SEPARATOR_POSITION {
-        code.push_str(
-            PADDING_CHAR_STR.repeat(SEPARATOR_POSITION - digit).as_str()
-        );
+        code.push_str(PADDING_CHAR_STR.repeat(SEPARATOR_POSITION - digit).as_str());
         code.push(SEPARATOR);
     }
     code
@@ -159,7 +156,8 @@ pub fn decode(_code: &str) -> Result<CodeArea, String> {
     if !is_full(_code) {
         return Err(format!("Code must be a valid full code: {}", _code));
     }
-    let mut code = _code.to_string()
+    let mut code = _code
+        .to_string()
         .replace(SEPARATOR, "")
         .replace(PADDING_CHAR_STR, "")
         .to_uppercase();
@@ -189,7 +187,13 @@ pub fn decode(_code: &str) -> Result<CodeArea, String> {
             lng += lng_res * (code_value(chr) as f64 % GRID_COLUMNS);
         }
     }
-    Ok(CodeArea::new(lat, lng, lat + lat_res, lng + lng_res, code.len()))
+    Ok(CodeArea::new(
+        lat,
+        lng,
+        lat + lat_res,
+        lng + lng_res,
+        code.len(),
+    ))
 }
 
 /// Remove characters from the start of an OLC code.
@@ -218,13 +222,16 @@ pub fn shorten(_code: &str, ref_pt: Point<f64>) -> Result<String, String> {
 
     let codearea: CodeArea = decode(_code).unwrap();
     if codearea.code_length < MIN_TRIMMABLE_CODE_LEN {
-        return Err(format!("Code length must be at least {}", MIN_TRIMMABLE_CODE_LEN));
+        return Err(format!(
+            "Code length must be at least {}",
+            MIN_TRIMMABLE_CODE_LEN
+        ));
     }
 
     // How close are the latitude and longitude to the code center.
-    let range = (codearea.center.lat() - clip_latitude(ref_pt.lat())).abs().max(
-        (codearea.center.lng() - normalize_longitude(ref_pt.lng())).abs()
-    );
+    let range = (codearea.center.lat() - clip_latitude(ref_pt.lat()))
+        .abs()
+        .max((codearea.center.lng() - normalize_longitude(ref_pt.lng())).abs());
 
     for i in 0..PAIR_RESOLUTIONS.len() - 2 {
         // Check if we're close enough to shorten. The range must be less than 1/2
@@ -299,6 +306,8 @@ pub fn recover_nearest(_code: &str, ref_pt: Point<f64>) -> Result<String, String
     } else if ref_lng - half_res > longitude {
         longitude += resolution;
     }
-    Ok(encode(Point::new(longitude, latitude), code_area.code_length))
+    Ok(encode(
+        Point::new(longitude, latitude),
+        code_area.code_length,
+    ))
 }
-

rust/src/lib.rs

@@ -7,5 +7,4 @@ mod codearea;
 pub use codearea::CodeArea;
 
 mod interface;
-pub use interface::{is_valid, is_short, is_full, encode, decode, shorten, recover_nearest};
-
+pub use interface::{decode, encode, is_full, is_short, is_valid, recover_nearest, shorten};

rust/src/private.rs

@@ -1,6 +1,6 @@
 use consts::{
-    CODE_ALPHABET, ENCODING_BASE, LATITUDE_MAX, LONGITUDE_MAX, PAIR_CODE_LENGTH, GRID_ROWS,
-    GRID_COLUMNS, NARROW_REGION_PRECISION,
+    CODE_ALPHABET, ENCODING_BASE, GRID_COLUMNS, GRID_ROWS, LATITUDE_MAX, LONGITUDE_MAX,
+    NARROW_REGION_PRECISION, PAIR_CODE_LENGTH,
 };
 
 use interface::encode;
@@ -19,7 +19,7 @@ pub fn normalize_longitude(value: f64) -> f64 {
     while result >= LONGITUDE_MAX {
         result -= LONGITUDE_MAX * 2f64;
     }
-    while result < -LONGITUDE_MAX{
+    while result < -LONGITUDE_MAX {
         result += LONGITUDE_MAX * 2f64;
     }
     result
@@ -31,7 +31,7 @@ pub fn clip_latitude(latitude_degrees: f64) -> f64 {
 
 pub fn compute_latitude_precision(code_length: usize) -> f64 {
     if code_length <= PAIR_CODE_LENGTH {
-        return ENCODING_BASE.powf((code_length as f64 / -2f64 + 2f64).floor())
+        return ENCODING_BASE.powf((code_length as f64 / -2f64 + 2f64).floor());
     }
     ENCODING_BASE.powi(-3i32) / GRID_ROWS.powf(code_length as f64 - PAIR_CODE_LENGTH as f64)
 }
@@ -41,9 +41,9 @@ pub fn prefix_by_reference(pt: Point<f64>, code_length: usize) -> String {
     let mut code = encode(
         Point::new(
             (pt.lng() / precision).floor() * precision,
-            (pt.lat() / precision).floor() * precision
+            (pt.lat() / precision).floor() * precision,
         ),
-        PAIR_CODE_LENGTH
+        PAIR_CODE_LENGTH,
     );
     code.drain(code_length..);
     code

rust/tests/all_test.rs

@@ -1,11 +1,14 @@
-extern crate open_location_code;
 extern crate geo;
+extern crate open_location_code;
+extern crate rand;
 
+use rand::Rng;
+use std::time::Instant;
 use std::vec::Vec;
 
-use open_location_code::{is_valid, is_short, is_full};
-use open_location_code::{encode, decode};
-use open_location_code::{shorten, recover_nearest};
+use open_location_code::{decode, encode};
+use open_location_code::{is_full, is_short, is_valid};
+use open_location_code::{recover_nearest, shorten};
 
 use geo::Point;
 
@@ -77,9 +80,12 @@ fn encode_test() {
         let code = cols[3];
 
         assert_eq!(
-            encode(Point::new(lng, lat), len), code,
+            encode(Point::new(lng, lat), len),
+            code,
             "encoding lat={},lng={},len={}",
-            lat, lng, len
+            lat,
+            lng,
+            len
         );
 
         tested += 1;
@@ -99,7 +105,11 @@ fn shorten_recovery_test() {
         let test_type = cols[4];
 
         if test_type == "B" || test_type == "S" {
-            assert_eq!(shorten(full_code, Point::new(lng, lat)).unwrap(), short_code, "shorten");
+            assert_eq!(
+                shorten(full_code, Point::new(lng, lat)).unwrap(),
+                short_code,
+                "shorten"
+            );
         }
         if test_type == "B" || test_type == "R" {
             assert_eq!(
@@ -111,7 +121,63 @@ fn shorten_recovery_test() {
 
         tested += 1;
     }
-
     assert!(tested > 0);
 }
 
+#[test]
+fn benchmark_test() {
+    struct BenchmarkData {
+        lat: f64,
+        lng: f64,
+        len: usize,
+    }
+    let mut rng = rand::thread_rng();
+    // Create the benchmark data - coordinates and lengths for encoding, codes for decoding.
+    let loops = 100000;
+    let mut bd: Vec<BenchmarkData> = Vec::new();
+    for _i in 0..loops {
+        let lat = rng.gen_range(-90.0, 90.0);
+        let lng = rng.gen_range(-180.0, 180.0);
+        let mut len = rng.gen_range(2, 15);
+        // Make sure the length is even if it's less than 10.
+        if len < 10 && len % 2 == 1 {
+            len += 1;
+        }
+        let b = BenchmarkData {
+            lat: lat,
+            lng: lng,
+            len: len,
+        };
+        bd.push(b);
+    }
+
+    // Do the encode benchmark.
+    // Get the current time, loop through the benchmark data, print the time.
+    let mut codes: Vec<String> = Vec::new();
+    let mut now = Instant::now();
+    for b in &bd {
+        codes.push(encode(Point::new(b.lng, b.lat), b.len));
+    }
+    let enc_duration = now.elapsed().as_secs() * 1000000 + now.elapsed().subsec_micros() as u64;
+
+    // Do the encode benchmark.
+    // Get the current time, loop through the benchmark data, print the time.
+    now = Instant::now();
+    for c in codes {
+        let _c = decode(&c);
+    }
+    let dec_duration = now.elapsed().as_secs() * 1000000 + now.elapsed().subsec_micros() as u64;
+    // Output.
+    println!(
+        "Encoding benchmark: {} loops, total time {} usec, {} usec per encode",
+        loops,
+        enc_duration,
+        enc_duration as f64 / loops as f64
+    );
+    println!(
+        "Decoding benchmark: {} loops, total time {} usec, {} usec per decode",
+        loops,
+        dec_duration,
+        dec_duration as f64 / loops as f64
+    );
+}

rust/tests/csv_reader.rs

@@ -3,7 +3,7 @@ use std::fs::File;
 use std::io::{BufRead, BufReader, Lines};
 
 pub struct CSVReader {
-    iter: Lines<BufReader<File>>
+    iter: Lines<BufReader<File>>,
 }
 
 impl CSVReader {
@@ -32,4 +32,3 @@ impl Iterator for CSVReader {
         None
     }
 }
-