From 35af0aa84f76daddbb6d6959f9746bd09e306278 Mon Sep 17 00:00:00 2001
From: Héctor Ramón Jiménez <hector@hecrj.dev>
Date: Sat, 30 Mar 2024 13:50:40 +0100
Subject: Fix batched writes logic in `iced_wgpu::buffer`
---
wgpu/src/buffer.rs | 59 +++++++++++++++++++++++++++++-------------------------
1 file changed, 32 insertions(+), 27 deletions(-)
diff --git a/wgpu/src/buffer.rs b/wgpu/src/buffer.rs
index c9d6b828..463ea24a 100644
--- a/wgpu/src/buffer.rs
+++ b/wgpu/src/buffer.rs
@@ -1,7 +1,12 @@
use std::marker::PhantomData;
+use std::num::NonZeroU64;
use std::ops::RangeBounds;
-pub const MAX_WRITE_SIZE: usize = 1024 * 100;
+pub const MAX_WRITE_SIZE: usize = 100 * 1024;
+
+#[allow(unsafe_code)]
+const MAX_WRITE_SIZE_U64: NonZeroU64 =
+ unsafe { NonZeroU64::new_unchecked(MAX_WRITE_SIZE as u64) };
#[derive(Debug)]
pub struct Buffer<T> {
@@ -70,40 +75,40 @@ impl<T: bytemuck::Pod> Buffer<T> {
contents: &[T],
) -> usize {
let bytes: &[u8] = bytemuck::cast_slice(contents);
+ let mut bytes_written = 0;
- if bytes.len() <= MAX_WRITE_SIZE {
+ // Split write into multiple chunks if necessary
+ while bytes_written + MAX_WRITE_SIZE < bytes.len() {
belt.write_buffer(
encoder,
&self.raw,
- offset as u64,
- (bytes.len() as u64).try_into().expect("Non-empty write"),
+ (offset + bytes_written) as u64,
+ MAX_WRITE_SIZE_U64,
device,
)
- .copy_from_slice(bytes);
- } else {
- let mut bytes_written = 0;
-
- let bytes_per_chunk = (bytes.len().min(MAX_WRITE_SIZE) as u64)
- .try_into()
- .expect("Non-empty write");
-
- while bytes_written < bytes.len() {
- belt.write_buffer(
- encoder,
- &self.raw,
- (offset + bytes_written) as u64,
- bytes_per_chunk,
- device,
- )
- .copy_from_slice(
- &bytes[bytes_written
- ..bytes_written + bytes_per_chunk.get() as usize],
- );
-
- bytes_written += bytes_per_chunk.get() as usize;
- }
+ .copy_from_slice(
+ &bytes[bytes_written..bytes_written + MAX_WRITE_SIZE],
+ );
+
+ bytes_written += MAX_WRITE_SIZE;
}
+ // There will always be some bytes left, since the previous
+ // loop guarantees `bytes_written < bytes.len()`
+ let bytes_left = ((bytes.len() - bytes_written) as u64)
+ .try_into()
+ .expect("non-empty write");
+
+ // Write them
+ belt.write_buffer(
+ encoder,
+ &self.raw,
+ (offset + bytes_written) as u64,
+ bytes_left,
+ device,
+ )
+ .copy_from_slice(&bytes[bytes_written..]);
+
self.offsets.push(offset as u64);
bytes.len()
--
cgit