Removed ChunkInfo and added additional functions on decoder

src/decoder/ifd.rs

@@ -451,8 +451,8 @@ impl Entry {
         // Case 3: There is more than one value, but it fits in the offset field.
         if value_bytes <= 4 || bigtiff && value_bytes <= 8 {
             match self.type_ {
-                Type::BYTE => return Ok(offset_to_bytes(self.count as usize, self)?),
-                Type::SBYTE => return Ok(offset_to_sbytes(self.count as usize, self)?),
+                Type::BYTE => return offset_to_bytes(self.count as usize, self),
+                Type::SBYTE => return offset_to_sbytes(self.count as usize, self),
                 Type::ASCII => {
                     let mut buf = vec![0; self.count as usize];
                     self.r(bo).read_exact(&mut buf)?;

src/decoder/image.rs

@@ -61,39 +61,6 @@ impl TileAttributes {
     }
 }
 
-#[derive(Debug)]
-#[non_exhaustive]
-/// ChunkInfo describes the properties of a chunk (either tile or strip).
-pub struct ChunkInfo {
-    /// Width of the chunk as specified (includes potential padding). This has the same
-    /// value for all chunks in the image.
-    pub chunk_width: u32,
-    /// Height/Length of the chunk as specified (includes potential padding). This has
-    /// the same value for all chunks in the image.
-    pub chunk_height: u32,
-
-    /// Width of the data (excluding potential padding). This can take different values
-    /// on the right column of the image due to padding.
-    pub data_width: u32,
-    /// Height/Length of the data (excluding potential padding). This can take different values
-    /// on the bottom row of the image due to padding.
-    pub data_height: u32,
-}
-
-impl ChunkInfo {
-    #[inline]
-    /// Returns the amount of padding (pixles) on the right-side of the chunk.
-    pub fn padding_right(&self) -> u32 {
-        self.chunk_width - self.data_width
-    }
-
-    #[inline]
-    /// Returns the amount of padding (pixles) on the bottom-side of the chunk.
-    pub fn padding_down(&self) -> u32 {
-        self.chunk_height - self.data_height
-    }
-}
-
 #[derive(Debug)]
 pub(crate) struct Image {
     pub ifd: Option<Directory>,
@@ -408,39 +375,38 @@ impl Image {
         Ok((*file_offset, *compressed_bytes))
     }
 
-    pub(crate) fn chunk_dimensions(&self) -> TiffResult<(usize, usize)> {
+    pub(crate) fn chunk_dimensions(&self) -> TiffResult<(u32, u32)> {
         match self.chunk_type {
             ChunkType::Strip => {
-                let width = usize::try_from(self.width)?;
                 let strip_attrs = self.strip_decoder.as_ref().unwrap();
-                Ok((width, usize::try_from(strip_attrs.rows_per_strip)?))
+                Ok((self.width, strip_attrs.rows_per_strip))
             }
             ChunkType::Tile => {
                 let tile_attrs = self.tile_attributes.as_ref().unwrap();
-                Ok((tile_attrs.tile_width, tile_attrs.tile_length))
+                Ok((
+                    u32::try_from(tile_attrs.tile_width)?,
+                    u32::try_from(tile_attrs.tile_length)?,
+                ))
             }
         }
     }
 
-    pub(crate) fn chunk_info(&self, chunk_index: u32) -> Option<ChunkInfo> {
-        match &self.chunk_type {
-            ChunkType::Strip => {
-                let rows_per_strip = self.strip_decoder.as_ref().unwrap().rows_per_strip;
+    pub(crate) fn chunk_data_dimensions(&self, chunk_index: u32) -> TiffResult<(u32, u32)> {
+        let dims = self.chunk_dimensions()?;
 
+        match self.chunk_type {
+            ChunkType::Strip => {
                 let strip_height_without_padding = chunk_index
-                    .checked_mul(rows_per_strip)
-                    .and_then(|x| self.height.checked_sub(x))?;
+                    .checked_mul(dims.1)
+                    .and_then(|x| self.height.checked_sub(x))
+                    .ok_or(TiffError::UsageError(UsageError::InvalidChunkIndex(
+                        chunk_index,
+                    )))?;
 
                 // Ignore potential vertical padding on the bottommost strip
-                let strip_height = rows_per_strip.min(strip_height_without_padding);
+                let strip_height = dims.1.min(strip_height_without_padding);
 
-                Some(ChunkInfo {
-                    chunk_width: self.width,
-                    chunk_height: rows_per_strip,
-
-                    data_width: self.width,
-                    data_height: strip_height,
-                })
+                Ok((dims.0, strip_height))
             }
             ChunkType::Tile => {
                 let tile_attrs = self.tile_attributes.as_ref().unwrap();
@@ -449,13 +415,7 @@ impl Image {
                 let tile_width = tile_attrs.tile_width - padding_right;
                 let tile_length = tile_attrs.tile_length - padding_down;
 
-                Some(ChunkInfo {
-                    chunk_width: tile_attrs.tile_width as u32,
-                    chunk_height: tile_attrs.tile_length as u32,
-
-                    data_width: tile_width as u32,
-                    data_height: tile_length as u32,
-                })
+                Ok((u32::try_from(tile_width)?, u32::try_from(tile_length)?))
             }
         }
     }
@@ -528,21 +488,21 @@ impl Image {
         let predictor = self.predictor;
         let samples = self.bits_per_sample.len();
 
-        let chunk_info = self.chunk_info(chunk_index).ok_or(TiffError::UsageError(
-            UsageError::InvalidChunkIndex(chunk_index),
-        ))?;
+        let chunk_dims = self.chunk_dimensions()?;
+        let data_dims = self.chunk_data_dimensions(chunk_index)?;
+
+        let padding_right = chunk_dims.0 - data_dims.0;
 
         let jpeg_tables = self.jpeg_tables.clone();
         let mut reader =
             Self::create_reader(reader, compression_method, *compressed_bytes, jpeg_tables)?;
 
-        if output_width == chunk_info.data_width as usize && chunk_info.padding_right() == 0 {
-            let total_samples =
-                chunk_info.data_width as usize * chunk_info.data_height as usize * samples;
+        if output_width == data_dims.0 as usize && padding_right == 0 {
+            let total_samples = data_dims.0 as usize * data_dims.1 as usize * samples;
             let tile = &mut buffer.as_bytes_mut()[..total_samples * byte_len];
             reader.read_exact(tile)?;
 
-            for row in 0..chunk_info.data_height as usize {
+            for row in 0..data_dims.1 as usize {
                 let row_start = row as usize * output_width as usize * samples;
                 let row_end = (row + 1) * output_width as usize * samples;
                 let row = buffer.subrange(row_start..row_end);
@@ -551,13 +511,14 @@ impl Image {
             if photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
                 super::invert_colors(&mut buffer.subrange(0..total_samples), color_type);
             }
-        } else if chunk_info.padding_right() > 0 && self.predictor == Predictor::FloatingPoint {
+        } else if padding_right > 0 && self.predictor == Predictor::FloatingPoint {
             // The floating point predictor shuffles the padding bytes into the encoded output, so
             // this case is handled specially when needed.
-            let mut encoded = vec![0u8; chunk_info.chunk_width as usize * samples * byte_len];
-            for row in 0..chunk_info.data_height as usize {
+            let mut encoded = vec![0u8; chunk_dims.0 as usize * samples * byte_len];
+
+            for row in 0..data_dims.1 as usize {
                 let row_start = row * output_width as usize * samples;
-                let row_end = row_start + chunk_info.data_width as usize * samples;
+                let row_end = row_start + data_dims.0 as usize * samples;
 
                 reader.read_exact(&mut encoded)?;
                 match buffer.subrange(row_start..row_end) {
@@ -570,17 +531,16 @@ impl Image {
                 }
             }
         } else {
-            for row in 0..chunk_info.data_height as usize {
+            for row in 0..data_dims.1 as usize {
                 let row_start = row * output_width as usize * samples;
-                let row_end = row_start + chunk_info.data_width as usize * samples;
+                let row_end = row_start + data_dims.0 as usize * samples;
 
                 let row = &mut buffer.as_bytes_mut()[(row_start * byte_len)..(row_end * byte_len)];
                 reader.read_exact(row)?;
 
                 // Skip horizontal padding
-                if chunk_info.padding_right() > 0 {
-                    let len =
-                        u64::try_from(chunk_info.padding_right() as usize * samples * byte_len)?;
+                if padding_right > 0 {
+                    let len = u64::try_from(padding_right as usize * samples * byte_len)?;
                     io::copy(&mut reader.by_ref().take(len), &mut io::sink())?;
                 }
 

src/decoder/mod.rs

@@ -8,7 +8,7 @@ use crate::{
 };
 
 use self::ifd::Directory;
-use self::image::{ChunkInfo, Image};
+use self::image::Image;
 use crate::tags::{
     CompressionMethod, PhotometricInterpretation, Predictor, SampleFormat, Tag, Type,
 };
@@ -1147,7 +1147,7 @@ impl<R: Read + Seek> Decoder<R> {
     pub fn read_strip(&mut self) -> TiffResult<DecodingResult> {
         let result = self.read_chunk(self.current_chunk)?;
 
-        Ok(result.0)
+        Ok(result)
     }
 
     /// Read a single tile from the image and return it as a Vector. This method does not return
@@ -1160,36 +1160,37 @@ impl<R: Read + Seek> Decoder<R> {
 
         self.current_chunk += 1;
 
-        Ok(result.0)
+        Ok(result)
     }
 
-    /// Read the specified chunk (at index `chunk_index`) and return the binary data as a Vector and
-    /// `ChunkInfo` describing the size of the chunk.
-    pub fn read_chunk(&mut self, chunk_index: u32) -> TiffResult<(DecodingResult, ChunkInfo)> {
-        let chunk_info = self
-            .image()
-            .chunk_info(chunk_index)
-            .ok_or(UsageError::InvalidChunkIndex(chunk_index))?;
+    /// Read the specified chunk (at index `chunk_index`) and return the binary data as a Vector.
+    pub fn read_chunk(&mut self, chunk_index: u32) -> TiffResult<DecodingResult> {
+        let data_dims = self.image().chunk_data_dimensions(chunk_index)?;
 
-        let mut result = self.result_buffer(
-            chunk_info.data_width as usize,
-            chunk_info.data_height as usize,
-        )?;
+        let mut result = self.result_buffer(data_dims.0 as usize, data_dims.1 as usize)?;
 
-        self.read_chunk_to_buffer(
-            result.as_buffer(0),
-            chunk_index,
-            chunk_info.data_width as usize,
-        )?;
+        self.read_chunk_to_buffer(result.as_buffer(0), chunk_index, data_dims.0 as usize)?;
 
-        Ok((result, chunk_info))
+        Ok(result)
+    }
+
+    /// Returns the default chunk size for the current image. Any given chunk in the image is at most as large as
+    /// the value returned here. For the size of the data (chunk minus padding), use `chunk_data_dimensions`.
+    pub fn chunk_dimensions(&self) -> TiffResult<(u32, u32)> {
+        self.image().chunk_dimensions()
+    }
+
+    /// Returns the size of the data in the chunk with the specified index. This is the default size of the chunk,
+    /// minus any padding.
+    pub fn chunk_data_dimensions(&self, chunk_index: u32) -> TiffResult<(u32, u32)> {
+        self.image().chunk_data_dimensions(chunk_index)
     }
 
     /// Decodes the entire image and return it as a Vector
     pub fn read_image(&mut self) -> TiffResult<DecodingResult> {
-        let width = usize::try_from(self.image().width)?;
-        let height = usize::try_from(self.image().height)?;
-        let mut result = self.result_buffer(width, height)?;
+        let width = self.image().width;
+        let height = self.image().height;
+        let mut result = self.result_buffer(width as usize, height as usize)?;
         if width == 0 || height == 0 {
             return Ok(result);
         }
@@ -1212,20 +1213,20 @@ impl<R: Read + Seek> Decoder<R> {
             ));
         }
 
-        let chunks_across = (width - 1) / chunk_dimensions.0 + 1;
-        let strip_samples = width * chunk_dimensions.1 * samples;
+        let chunks_across = ((width - 1) / chunk_dimensions.0 + 1) as usize;
+        let strip_samples = width as usize * chunk_dimensions.1 as usize * samples;
 
         for chunk in 0..self.image().chunk_offsets.len() {
             self.goto_offset_u64(self.image().chunk_offsets[chunk])?;
 
             let x = chunk % chunks_across;
             let y = chunk / chunks_across;
-            let buffer_offset = y * strip_samples + x * chunk_dimensions.0 * samples;
+            let buffer_offset = y * strip_samples + x * chunk_dimensions.0 as usize * samples;
             let byte_order = self.reader.byte_order;
             self.image.expand_chunk(
                 &mut self.reader,
                 result.as_buffer(buffer_offset).copy(),
-                width,
+                width as usize,
                 byte_order,
                 chunk as u32,
             )?;

src/encoder/compression/deflate.rs

@@ -53,7 +53,7 @@ impl Compression for Deflate {
 impl CompressionAlgorithm for Deflate {
     fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
         let mut encoder = ZlibEncoder::new(writer, self.level);
-        encoder.write_all(&bytes)?;
+        encoder.write_all(bytes)?;
         encoder.try_finish()?;
         Ok(encoder.total_out())
     }

src/encoder/compression/packbits.rs

@@ -157,7 +157,7 @@ mod tests {
         let mut compressed_data = Vec::<u8>::new();
         let mut writer = Cursor::new(&mut compressed_data);
         Packbits::default()
-            .write_to(&mut writer, &UNCOMPRESSED_DATA)
+            .write_to(&mut writer, UNCOMPRESSED_DATA)
             .unwrap();
         assert_eq!(compressed_data, EXPECTED_COMPRESSED_DATA);
     }
@@ -207,7 +207,7 @@ mod tests {
         let mut compressed_data = Vec::<u8>::new();
         let mut writer = Cursor::new(&mut compressed_data);
         Packbits::default()
-            .write_to(&mut writer, &TEST_DATA)
+            .write_to(&mut writer, TEST_DATA)
             .unwrap();
         assert_eq!(compressed_data, EXPECTED_COMPRESSED_DATA);
     }

tests/decode_images.rs

@@ -276,7 +276,7 @@ fn test_tiled_incremental() {
 
     for tile in 0..tiles {
         match decoder.read_chunk(tile).unwrap() {
-            (DecodingResult::U8(res), _) => {
+            DecodingResult::U8(res) => {
                 let sum: u64 = res.into_iter().map(<u64>::from).sum();
                 assert_eq!(sum, sums[tile as usize]);
             }

tests/encode_images.rs

@@ -513,7 +513,7 @@ fn test_rows_per_strip() {
         for i in 0..50 {
             let img2 = [i; 2 * 100];
             match decoder.read_chunk(i as u32).unwrap() {
-                (DecodingResult::U8(data), _) => assert_eq!(&img2[..], &data[..]),
+                DecodingResult::U8(data) => assert_eq!(&img2[..], &data[..]),
                 other => panic!("Incorrect strip type {:?}", other),
             }
         }