Merge pull request #122 from lovasoa/benchmarks

Add three benchmarks to the crate

Author: fintelia

.travis.yml

@@ -12,4 +12,7 @@ env:
   - FEATURES="rayon"
 script:
   - cargo build --verbose --no-default-features --features "$FEATURES"
-  - cargo test --verbose --no-default-features --features "$FEATURES"
+  - cargo test --tests --benches --no-default-features --features "$FEATURES"
+  - cargo bench --bench decoding_benchmark --no-default-features --features "$FEATURES" -- --warm-up-time 1 --measurement-time 1 --sample-size 25
+
+cache: cargo

Cargo.toml

@@ -17,6 +17,11 @@ rayon = { version = "1.0", optional = true }
 [dev-dependencies]
 png = "0.14"
 walkdir = "2.0"
+criterion = "0.3"
+
+[[bench]]
+name = "decoding_benchmark"
+harness = false
 
 [features]
 default = ["rayon"]

appveyor.yml

@@ -16,4 +16,5 @@ build: false
 
 test_script:
   - cargo build --verbose
-  - cargo test --verbose
+  - cargo test --tests --benches
+  - cargo bench --bench decoding_benchmark --no-default-features --features "$FEATURES" -- --warm-up-time 1 --measurement-time 1 --sample-size 25

benches/decoding_benchmark.rs

@@ -0,0 +1,33 @@
+extern crate criterion;
+extern crate jpeg_decoder;
+
+use criterion::{black_box, Criterion};
+
+use jpeg_decoder as jpeg;
+use jpeg_decoder::ImageInfo;
+
+fn read_image(image: &[u8]) -> Vec<u8> {
+    jpeg::Decoder::new(black_box(image)).decode().unwrap()
+}
+
+fn read_metadata(image: &[u8]) -> ImageInfo {
+    let mut decoder = jpeg::Decoder::new(black_box(image));
+    decoder.read_info().unwrap();
+    decoder.info().unwrap()
+}
+
+fn main() {
+    let mut c = Criterion::default().configure_from_args();
+    c.bench_function("decode a 512x512 JPEG", |b| b.iter(|| {
+        read_image(include_bytes!("tower.jpg"))
+    }));
+
+    c.bench_function("decode a 512x512 progressive JPEG", |b| b.iter(|| {
+        read_image(include_bytes!("tower_progressive.jpg"))
+    }));
+
+    c.bench_function("extract metadata from an image", |b| b.iter(|| {
+        read_metadata(include_bytes!("tower.jpg"))
+    }));
+    c.final_summary();
+}