Add unique stream-end marker (7 zeros and one 1)

src/consts.rs

@@ -20,7 +20,9 @@ pub const QOI_MASK_3: u8 = 0xe0; // (111)00000
 pub const QOI_MASK_4: u8 = 0xf0; // (1111)0000
 
 pub const QOI_HEADER_SIZE: usize = 14;
-pub const QOI_PADDING: usize = 4;
+
+pub const QOI_PADDING: [u8; 8] = [0, 0, 0, 0, 0, 0, 0, 0x01]; // 7 zeros and one 0x01 marker
+pub const QOI_PADDING_SIZE: usize = 8;
 
 pub const QOI_MAGIC: u32 =
     (b'q' as u32) << 24 | (b'o' as u32) << 16 | (b'i' as u32) << 8 | (b'f' as u32);

src/decode.rs

@@ -1,6 +1,6 @@
 use std::mem;
 
-use crate::consts::{QOI_HEADER_SIZE, QOI_INDEX, QOI_PADDING};
+use crate::consts::{QOI_HEADER_SIZE, QOI_INDEX, QOI_PADDING, QOI_PADDING_SIZE};
 use crate::error::{Error, Result};
 use crate::header::Header;
 use crate::pixel::{Pixel, SupportedChannels};
@@ -35,10 +35,10 @@ pub fn qoi_decode_impl<const N: usize>(data: &[u8], n_pixels: usize) -> Result<V
 where
     Pixel<N>: SupportedChannels,
 {
-    if unlikely(data.len() < QOI_HEADER_SIZE + QOI_PADDING) {
+    if unlikely(data.len() < QOI_HEADER_SIZE + QOI_PADDING_SIZE) {
         return Err(Error::InputBufferTooSmall {
             size: data.len(),
-            required: QOI_HEADER_SIZE + QOI_PADDING,
+            required: QOI_HEADER_SIZE + QOI_PADDING_SIZE,
         });
     }
 
@@ -47,7 +47,7 @@ where
         // Safety: we have just allocated enough memory to set the length without problems
         pixels.set_len(n_pixels);
     }
-    let encoded_data_size = data.len() - QOI_HEADER_SIZE - QOI_PADDING;
+    let encoded_data_size = data.len() - QOI_HEADER_SIZE - QOI_PADDING_SIZE;
     let mut buf = unsafe {
         // Safety: we will check within the loop that there are no reads outside the slice
         ReadBuf::new(data.as_ptr().add(QOI_HEADER_SIZE), encoded_data_size)

src/encode.rs

@@ -3,7 +3,7 @@ use std::slice;
 use crate::colorspace::ColorSpace;
 use crate::consts::{
     QOI_COLOR, QOI_DIFF_16, QOI_DIFF_24, QOI_DIFF_8, QOI_HEADER_SIZE, QOI_INDEX, QOI_PADDING,
-    QOI_PIXELS_MAX, QOI_RUN_16, QOI_RUN_8,
+    QOI_PADDING_SIZE, QOI_PIXELS_MAX, QOI_RUN_16, QOI_RUN_8,
 };
 use crate::error::{Error, Result};
 use crate::header::Header;
@@ -220,7 +220,7 @@ where
         }
     }
 
-    buf.write([0; QOI_PADDING]);
+    buf.write(QOI_PADDING);
     Ok(buf.len())
 }
 
@@ -253,7 +253,7 @@ pub fn encode_to_vec_impl<const CANONICAL: bool>(
 pub fn encode_size_required(width: u32, height: u32, channels: u8) -> usize {
     let (width, height) = (width as usize, height as usize);
     let n_pixels = width.saturating_mul(height);
-    QOI_HEADER_SIZE + n_pixels.saturating_mul(usize::from(channels)) + n_pixels + QOI_PADDING
+    QOI_HEADER_SIZE + n_pixels.saturating_mul(usize::from(channels)) + n_pixels + QOI_PADDING_SIZE
 }
 
 #[inline]