Fix Rust PNG benchmark
The Rust PNG benchmark no longer compiles. This is similar to the issue
that was fixed in pull request #68 for the Rust GIF benchmark. A new
version of the png crate was published that broke clean builds. I've
pinned the version to 0.17, which is the newest, and changed the code to
use the new API.
NOTE: Parts of the png crate documentation hasn't been updated to
correctly list the new transformation defaults. The documentation for
the `normalize_to_color8` method does say that the defaults changed from
version 0.16 to 0.17.
diff --git a/script/bench-rust-png/Cargo.toml b/script/bench-rust-png/Cargo.toml
index 3664f3e..e3983b3 100644
--- a/script/bench-rust-png/Cargo.toml
+++ b/script/bench-rust-png/Cargo.toml
@@ -4,5 +4,5 @@
authors = ["Nigel Tao <nigeltao@golang.org>"]
[dependencies]
-png = "*"
+png = "0.17"
rustc_version_runtime = "*"
diff --git a/script/bench-rust-png/src/main.rs b/script/bench-rust-png/src/main.rs
index ca7be26..95a4c67 100644
--- a/script/bench-rust-png/src/main.rs
+++ b/script/bench-rust-png/src/main.rs
@@ -145,19 +145,20 @@
// decode returns the number of bytes processed.
fn decode(dst0: &mut [u8], dst1: &mut [u8], src: &[u8]) -> u64 {
- let decoder = png::Decoder::new(src);
- let (info, mut reader) = decoder.read_info().unwrap();
+ let mut decoder = png::Decoder::new(src);
+ decoder.set_transformations(png::Transformations::normalize_to_color8());
+ let mut reader = decoder.read_info().unwrap();
+ let info = reader.next_frame(dst0).unwrap();
let num_bytes = info.buffer_size() as u64;
- reader.next_frame(dst0).unwrap();
if info.color_type == png::ColorType::Grayscale {
// No conversion necessary.
return num_bytes;
- } else if info.color_type == png::ColorType::RGB {
+ } else if info.color_type == png::ColorType::Rgb {
// Convert RGB => BGRA.
let new_size = ((num_bytes / 3) * 4) as usize;
rgb_to_bgra(&dst0[..num_bytes as usize], &mut dst1[..new_size]);
return new_size as u64;
- } else if info.color_type == png::ColorType::RGBA {
+ } else if info.color_type == png::ColorType::Rgba {
// Convert RGBA => BGRA.
for i in 0..((num_bytes / 4) as usize) {
let d = dst0[(4 * i) + 0];
