standardize on u32 for coordinates and lengths

src/enabled_features.rs

@@ -8,10 +8,10 @@ pub struct EnabledFeatures {
     pub reject_dqts_with_zeros: bool,
 
     /// maximum jpeg width
-    pub max_jpeg_width: i32,
+    pub max_jpeg_width: u32,
 
     // maximum jpeg height
-    pub max_jpeg_height: i32,
+    pub max_jpeg_height: u32,
 
     /// Sadly C++ version has a bug where it uses 16 bit math in the SIMD path and 32 bit math in the scalar path
     pub use_16bit_dc_estimate: bool,
@@ -53,8 +53,8 @@ impl EnabledFeatures {
         Self {
             progressive: true,
             reject_dqts_with_zeros: false,
-            max_jpeg_height: i32::MAX,
-            max_jpeg_width: i32::MAX,
+            max_jpeg_height: u32::MAX,
+            max_jpeg_width: u32::MAX,
             use_16bit_dc_estimate: false,
             use_16bit_adv_predict: false,
             accept_invalid_dht: true,
@@ -70,8 +70,8 @@ impl EnabledFeatures {
         Self {
             progressive: true,
             reject_dqts_with_zeros: false,
-            max_jpeg_height: i32::MAX,
-            max_jpeg_width: i32::MAX,
+            max_jpeg_height: u32::MAX,
+            max_jpeg_width: u32::MAX,
             use_16bit_dc_estimate: true,
             use_16bit_adv_predict: true,
             accept_invalid_dht: true,

src/main.rs

@@ -113,14 +113,14 @@ Options:
     override_if(
         &mut pargs,
         "--max-width",
-        parse_i32,
+        parse_u32,
         &mut enabled_features.max_jpeg_width,
     )?;
 
     override_if(
         &mut pargs,
         "--max-height",
-        parse_i32,
+        parse_u32,
         &mut enabled_features.max_jpeg_height,
     )?;
 

src/structs/bit_reader.rs

@@ -23,10 +23,10 @@ pub struct BitReader<R> {
 }
 
 impl<R: BufRead + Seek> BitReader<R> {
-    pub fn get_stream_position(&mut self) -> i32 {
+    pub fn get_stream_position(&mut self) -> u32 {
         self.undo_read_ahead();
 
-        let pos: i32 = (self.inner.stream_position().unwrap() - self.start_offset)
+        let pos: u32 = (self.inner.stream_position().unwrap() - self.start_offset)
             .try_into()
             .unwrap();
 

src/structs/block_based_image.rs

@@ -16,11 +16,11 @@ use crate::structs::jpeg_header::JPegHeader;
 /// the image may only hold a subset of the components (specified by dpos_offset),
 /// but they can be merged
 pub struct BlockBasedImage {
-    block_width: i32,
+    block_width: u32,
 
-    original_height: i32,
+    original_height: u32,
 
-    dpos_offset: i32,
+    dpos_offset: u32,
 
     image: Vec<AlignedBlock>,
 }
@@ -32,22 +32,22 @@ impl BlockBasedImage {
     pub fn new(
         jpeg_header: &JPegHeader,
         component: usize,
-        luma_y_start: i32,
-        luma_y_end: i32,
+        luma_y_start: u32,
+        luma_y_end: u32,
     ) -> Self {
         let block_width = jpeg_header.cmp_info[component].bch;
         let original_height = jpeg_header.cmp_info[component].bcv;
         let max_size = block_width * original_height;
 
         let image_capcity = usize::try_from(
-            (i64::from(max_size) * i64::from(luma_y_end - luma_y_start)
-                + i64::from(jpeg_header.cmp_info[0].bcv - 1 /* round up */))
-                / i64::from(jpeg_header.cmp_info[0].bcv),
+            (u64::from(max_size) * u64::from(luma_y_end - luma_y_start)
+                + u64::from(jpeg_header.cmp_info[0].bcv - 1 /* round up */))
+                / u64::from(jpeg_header.cmp_info[0].bcv),
         )
         .unwrap();
 
-        let dpos_offset = i32::try_from(
-            i64::from(max_size) * i64::from(luma_y_start) / i64::from(jpeg_header.cmp_info[0].bcv),
+        let dpos_offset = u32::try_from(
+            u64::from(max_size) * u64::from(luma_y_start) / u64::from(jpeg_header.cmp_info[0].bcv),
         )
         .unwrap();
 
@@ -70,7 +70,7 @@ impl BlockBasedImage {
 
         for v in images {
             assert!(
-                v[index].dpos_offset == contents.len() as i32,
+                v[index].dpos_offset == contents.len() as u32,
                 "previous content should match new content"
             );
 
@@ -111,20 +111,20 @@ impl BlockBasedImage {
     }
 
     // blocks above the first line are never dereferenced
-    pub fn off_y(&self, y: i32) -> BlockContext {
+    pub fn off_y(&self, y: u32) -> BlockContext {
         return BlockContext::new(
             self.block_width * y,
-            self.block_width * (y - 1),
+            if y > 0 { self.block_width * (y - 1) } else { 0 },
             if (y & 1) != 0 { self.block_width } else { 0 },
             if (y & 1) != 0 { 0 } else { self.block_width },
         );
     }
 
-    pub fn get_block_width(&self) -> i32 {
+    pub fn get_block_width(&self) -> u32 {
         self.block_width
     }
 
-    pub fn get_original_height(&self) -> i32 {
+    pub fn get_original_height(&self) -> u32 {
         self.original_height
     }
 
@@ -133,7 +133,7 @@ impl BlockBasedImage {
     #[inline(always)]
     pub fn fill_up_to_dpos(
         &mut self,
-        dpos: i32,
+        dpos: u32,
         block_to_write: Option<AlignedBlock>,
     ) -> &mut AlignedBlock {
         // ensure that dpos_offset got set to the right value when we start writing
@@ -169,11 +169,11 @@ impl BlockBasedImage {
         return &mut self.image[relative_offset as usize];
     }
 
-    pub fn set_block_data(&mut self, dpos: i32, block_data: AlignedBlock) {
+    pub fn set_block_data(&mut self, dpos: u32, block_data: AlignedBlock) {
         self.fill_up_to_dpos(dpos, Some(block_data));
     }
 
-    pub fn get_block(&self, dpos: i32) -> &AlignedBlock {
+    pub fn get_block(&self, dpos: u32) -> &AlignedBlock {
         if (dpos - self.dpos_offset) as usize >= self.image.len() {
             return &EMPTY;
         } else {
@@ -191,7 +191,7 @@ impl BlockBasedImage {
     }
 
     #[inline(always)]
-    pub fn get_block_mut(&mut self, dpos: i32) -> &mut AlignedBlock {
+    pub fn get_block_mut(&mut self, dpos: u32) -> &mut AlignedBlock {
         self.fill_up_to_dpos(dpos, None)
     }
 }

src/structs/block_context.rs

@@ -8,11 +8,11 @@ use crate::structs::block_based_image::{AlignedBlock, BlockBasedImage, EMPTY_BLO
 use crate::structs::neighbor_summary::{NeighborSummary, NEIGHBOR_DATA_EMPTY};
 use crate::structs::probability_tables::ProbabilityTables;
 pub struct BlockContext {
-    cur_block_index: i32,
-    above_block_index: i32,
+    cur_block_index: u32,
+    above_block_index: u32,
 
-    cur_neighbor_summary_index: i32,
-    above_neighbor_summary_index: i32,
+    cur_neighbor_summary_index: u32,
+    above_neighbor_summary_index: u32,
 }
 pub struct NeighborData<'a> {
     pub above: &'a AlignedBlock,
@@ -25,13 +25,13 @@ pub struct NeighborData<'a> {
 impl BlockContext {
     // for debugging
     #[allow(dead_code)]
-    pub fn get_here_index(&self) -> i32 {
+    pub fn get_here_index(&self) -> u32 {
         self.cur_block_index
     }
 
     // as each new line BlockContext is set by `off_y`, no edge cases with dereferencing
     // out of bounds indices is possilbe, therefore no special treatment is needed
-    pub fn next(&mut self) -> i32 {
+    pub fn next(&mut self) -> u32 {
         self.cur_block_index += 1;
         self.above_block_index += 1;
         self.cur_neighbor_summary_index += 1;
@@ -41,10 +41,10 @@ impl BlockContext {
     }
 
     pub fn new(
-        cur_block_index: i32,
-        above_block_index: i32,
-        cur_neighbor_summary_index: i32,
-        above_neighbor_summary_index: i32,
+        cur_block_index: u32,
+        above_block_index: u32,
+        cur_neighbor_summary_index: u32,
+        above_neighbor_summary_index: u32,
     ) -> Self {
         return BlockContext {
             cur_block_index,

src/structs/component_info.rs

@@ -16,34 +16,34 @@ pub struct ComponentInfo {
     pub huff_ac: u8,
 
     /// sample factor vertical
-    pub sfv: i32,
+    pub sfv: u32,
 
     /// sample factor horizontal
-    pub sfh: i32,
+    pub sfh: u32,
 
     /// blocks in mcu
-    pub mbs: i32,
+    pub mbs: u32,
 
     /// block count vertical (interleaved)
-    pub bcv: i32,
+    pub bcv: u32,
 
     /// block count horizontal (interleaved)
-    pub bch: i32,
+    pub bch: u32,
 
     /// block count (all) (interleaved)
-    pub bc: i32,
+    pub bc: u32,
 
     /// block count vertical (non interleaved)
-    pub ncv: i32,
+    pub ncv: u32,
 
     /// block count horizontal (non interleaved)
-    pub nch: i32,
+    pub nch: u32,
 
     /// block count (all) (non interleaved)
-    pub nc: i32,
+    pub nc: u32,
 
     /// statistical identity
-    pub sid: i32,
+    pub sid: u32,
 
     /// jpeg internal id
     pub jid: u8,
@@ -53,16 +53,16 @@ impl Default for ComponentInfo {
     fn default() -> ComponentInfo {
         return ComponentInfo {
             q_table_index: 0xff,
-            sfv: -1,
-            sfh: -1,
-            mbs: -1,
-            bcv: -1,
-            bch: -1,
-            bc: -1,
-            ncv: -1,
-            nch: -1,
-            nc: -1,
-            sid: -1,
+            sfv: u32::MAX,
+            sfh: u32::MAX,
+            mbs: u32::MAX,
+            bcv: u32::MAX,
+            bch: u32::MAX,
+            bc: u32::MAX,
+            ncv: u32::MAX,
+            nch: u32::MAX,
+            nc: u32::MAX,
+            sid: u32::MAX,
             jid: 0xff,
             huff_dc: 0xff,
             huff_ac: 0xff,