1 files changed, 128 insertions, 0 deletions
diff --git a/vendor/jpeg-decoder/src/worker/mod.rs b/vendor/jpeg-decoder/src/worker/mod.rs
new file mode 100644
index 0000000..d6c2b10
--- /dev/null
+++ b/vendor/jpeg-decoder/src/worker/mod.rs
@@ -0,0 +1,128 @@
+mod immediate;
+mod multithreaded;
+#[cfg(all(
+    not(any(target_arch = "asmjs", target_arch = "wasm32")),
+    feature = "rayon"
+))]
+mod rayon;
+
+use crate::decoder::{choose_color_convert_func, ColorTransform};
+use crate::error::Result;
+use crate::parser::{Component, Dimensions};
+use crate::upsampler::Upsampler;
+
+use alloc::sync::Arc;
+use alloc::vec::Vec;
+use core::cell::RefCell;
+
+pub struct RowData {
+    pub index: usize,
+    pub component: Component,
+    pub quantization_table: Arc<[u16; 64]>,
+}
+
+pub trait Worker {
+    fn start(&mut self, row_data: RowData) -> Result<()>;
+    fn append_row(&mut self, row: (usize, Vec<i16>)) -> Result<()>;
+    fn get_result(&mut self, index: usize) -> Result<Vec<u8>>;
+    /// Default implementation for spawning multiple tasks.
+    fn append_rows(&mut self, row: &mut dyn Iterator<Item = (usize, Vec<i16>)>) -> Result<()> {
+        for item in row {
+            self.append_row(item)?;
+        }
+        Ok(())
+    }
+}
+
+#[allow(dead_code)]
+pub enum PreferWorkerKind {
+    Immediate,
+    Multithreaded,
+}
+
+#[derive(Default)]
+pub struct WorkerScope {
+    inner: core::cell::RefCell<Option<WorkerScopeInner>>,
+}
+
+enum WorkerScopeInner {
+    #[cfg(all(
+        not(any(target_arch = "asmjs", target_arch = "wasm32")),
+        feature = "rayon"
+    ))]
+    Rayon(rayon::Scoped),
+    #[cfg(not(any(target_arch = "asmjs", target_arch = "wasm32")))]
+    Multithreaded(multithreaded::MpscWorker),
+    Immediate(immediate::ImmediateWorker),
+}
+
+impl WorkerScope {
+    pub fn with<T>(with: impl FnOnce(&Self) -> T) -> T {
+        with(&WorkerScope {
+            inner: RefCell::default(),
+        })
+    }
+
+    pub fn get_or_init_worker<T>(
+        &self,
+        prefer: PreferWorkerKind,
+        f: impl FnOnce(&mut dyn Worker) -> T,
+    ) -> T {
+        let mut inner = self.inner.borrow_mut();
+        let inner = inner.get_or_insert_with(move || match prefer {
+            #[cfg(all(
+                not(any(target_arch = "asmjs", target_arch = "wasm32")),
+                feature = "rayon"
+            ))]
+            PreferWorkerKind::Multithreaded => WorkerScopeInner::Rayon(Default::default()),
+            #[allow(unreachable_patterns)]
+            #[cfg(not(any(target_arch = "asmjs", target_arch = "wasm32")))]
+            PreferWorkerKind::Multithreaded => WorkerScopeInner::Multithreaded(Default::default()),
+            _ => WorkerScopeInner::Immediate(Default::default()),
+        });
+
+        f(match &mut *inner {
+            #[cfg(all(
+                not(any(target_arch = "asmjs", target_arch = "wasm32")),
+                feature = "rayon"
+            ))]
+            WorkerScopeInner::Rayon(worker) => worker,
+            #[cfg(not(any(target_arch = "asmjs", target_arch = "wasm32")))]
+            WorkerScopeInner::Multithreaded(worker) => worker,
+            WorkerScopeInner::Immediate(worker) => worker,
+        })
+    }
+}
+
+pub fn compute_image_parallel(
+    components: &[Component],
+    data: Vec<Vec<u8>>,
+    output_size: Dimensions,
+    color_transform: ColorTransform,
+) -> Result<Vec<u8>> {
+    #[cfg(all(
+        not(any(target_arch = "asmjs", target_arch = "wasm32")),
+        feature = "rayon"
+    ))]
+    return rayon::compute_image_parallel(components, data, output_size, color_transform);
+
+    #[allow(unreachable_code)]
+    {
+        let color_convert_func = choose_color_convert_func(components.len(), color_transform)?;
+        let upsampler = Upsampler::new(components, output_size.width, output_size.height)?;
+        let line_size = output_size.width as usize * components.len();
+        let mut image = vec![0u8; line_size * output_size.height as usize];
+
+        for (row, line) in image.chunks_mut(line_size).enumerate() {
+            upsampler.upsample_and_interleave_row(
+                &data,
+                row,
+                output_size.width as usize,
+                line,
+                color_convert_func,
+            );
+        }
+
+        Ok(image)
+    }
+}