1 files changed, 134 insertions, 0 deletions
diff --git a/vendor/image/benches/encode.rs b/vendor/image/benches/encode.rs
new file mode 100644
index 0000000..0ca4b2a
--- /dev/null
+++ b/vendor/image/benches/encode.rs
@@ -0,0 +1,134 @@
+extern crate criterion;
+
+use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
+use image::{codecs::bmp::BmpEncoder, codecs::jpeg::JpegEncoder, ColorType};
+
+use std::fs::File;
+use std::io::{BufWriter, Seek, SeekFrom, Write};
+
+trait Encoder {
+    fn encode_raw(&self, into: &mut Vec<u8>, im: &[u8], dims: u32, color: ColorType);
+    fn encode_bufvec(&self, into: &mut Vec<u8>, im: &[u8], dims: u32, color: ColorType);
+    fn encode_file(&self, file: &File, im: &[u8], dims: u32, color: ColorType);
+}
+
+#[derive(Clone, Copy)]
+struct BenchDef {
+    with: &'static dyn Encoder,
+    name: &'static str,
+    sizes: &'static [u32],
+    colors: &'static [ColorType],
+}
+
+fn encode_all(c: &mut Criterion) {
+    const BENCH_DEFS: &'static [BenchDef] = &[
+        BenchDef {
+            with: &Bmp,
+            name: "bmp",
+            sizes: &[100u32, 200, 400],
+            colors: &[ColorType::L8, ColorType::Rgb8, ColorType::Rgba8],
+        },
+        BenchDef {
+            with: &Jpeg,
+            name: "jpeg",
+            sizes: &[64u32, 128, 256],
+            colors: &[ColorType::L8, ColorType::Rgb8, ColorType::Rgba8],
+        },
+    ];
+
+    for definition in BENCH_DEFS {
+        encode_definition(c, definition)
+    }
+}
+
+criterion_group!(benches, encode_all);
+criterion_main!(benches);
+
+type BenchGroup<'a> = criterion::BenchmarkGroup<'a, criterion::measurement::WallTime>;
+
+/// Benchmarks encoding a zeroed image.
+///
+/// For compressed formats this is surely not representative of encoding a normal image but it's a
+/// start for benchmarking.
+fn encode_zeroed(group: &mut BenchGroup, with: &dyn Encoder, size: u32, color: ColorType) {
+    let bytes = size as usize * usize::from(color.bytes_per_pixel());
+    let im = vec![0; bytes * bytes];
+
+    group.bench_with_input(
+        BenchmarkId::new(format!("zero-{:?}-rawvec", color), size),
+        &im,
+        |b, image| {
+            let mut v = vec![];
+            with.encode_raw(&mut v, &im, size, color);
+            b.iter(|| with.encode_raw(&mut v, image, size, color));
+        },
+    );
+    group.bench_with_input(
+        BenchmarkId::new(format!("zero-{:?}-bufvec", color), size),
+        &im,
+        |b, image| {
+            let mut v = vec![];
+            with.encode_raw(&mut v, &im, size, color);
+            b.iter(|| with.encode_bufvec(&mut v, image, size, color));
+        },
+    );
+    group.bench_with_input(
+        BenchmarkId::new(format!("zero-{:?}-file", color), size),
+        &im,
+        |b, image| {
+            let file = File::create("temp.bmp").unwrap();
+            b.iter(|| with.encode_file(&file, image, size, color));
+        },
+    );
+}
+
+fn encode_definition(criterion: &mut Criterion, def: &BenchDef) {
+    let mut group = criterion.benchmark_group(format!("encode-{}", def.name));
+
+    for &color in def.colors {
+        for &size in def.sizes {
+            encode_zeroed(&mut group, def.with, size, color);
+        }
+    }
+}
+
+struct Bmp;
+
+struct Jpeg;
+
+trait EncoderBase {
+    fn encode(&self, into: impl Write, im: &[u8], dims: u32, color: ColorType);
+}
+
+impl<T: EncoderBase> Encoder for T {
+    fn encode_raw(&self, into: &mut Vec<u8>, im: &[u8], dims: u32, color: ColorType) {
+        into.clear();
+        self.encode(into, im, dims, color);
+    }
+
+    fn encode_bufvec(&self, into: &mut Vec<u8>, im: &[u8], dims: u32, color: ColorType) {
+        into.clear();
+        let buf = BufWriter::new(into);
+        self.encode(buf, im, dims, color);
+    }
+
+    fn encode_file(&self, mut file: &File, im: &[u8], dims: u32, color: ColorType) {
+        file.seek(SeekFrom::Start(0)).unwrap();
+        let buf = BufWriter::new(file);
+        self.encode(buf, im, dims, color);
+    }
+}
+
+impl EncoderBase for Bmp {
+    fn encode(&self, mut into: impl Write, im: &[u8], size: u32, color: ColorType) {
+        let mut x = BmpEncoder::new(&mut into);
+        x.encode(im, size, size, color).unwrap();
+    }
+}
+
+impl EncoderBase for Jpeg {
+    fn encode(&self, mut into: impl Write, im: &[u8], size: u32, color: ColorType) {
+        let mut x = JpegEncoder::new(&mut into);
+        x.encode(im, size, size, color).unwrap();
+    }
+}