| Alphare |
| hg-reviewers |
| Automatic diff as part of commit; lint not applicable. |
| Automatic diff as part of commit; unit tests not applicable. |
| data: &'a [u8], | data: &'a [u8], | ||||
| } | } | ||||
| impl Chunk<'_> { | impl Chunk<'_> { | ||||
| /// Adjusted start of the chunk to replace. | /// Adjusted start of the chunk to replace. | ||||
| /// | /// | ||||
| /// The offset, taking into account the growth/shrinkage of data | /// The offset, taking into account the growth/shrinkage of data | ||||
| /// induced by previously applied chunks. | /// induced by previously applied chunks. | ||||
| fn start_offseted_by(&self, offset: i32) -> u32 { | fn start_offset_by(&self, offset: i32) -> u32 { | ||||
| let start = self.start as i32 + offset; | let start = self.start as i32 + offset; | ||||
| assert!(start >= 0, "negative chunk start should never happen"); | assert!(start >= 0, "negative chunk start should never happen"); | ||||
| start as u32 | start as u32 | ||||
| } | } | ||||
| /// Adjusted end of the chunk to replace. | /// Adjusted end of the chunk to replace. | ||||
| /// | /// | ||||
| /// The offset, taking into account the growth/shrinkage of data | /// The offset, taking into account the growth/shrinkage of data | ||||
| /// induced by previously applied chunks. | /// induced by previously applied chunks. | ||||
| fn end_offseted_by(&self, offset: i32) -> u32 { | fn end_offset_by(&self, offset: i32) -> u32 { | ||||
| self.start_offseted_by(offset) + self.data.len() as u32 | self.start_offset_by(offset) + self.data.len() as u32 | ||||
| } | } | ||||
| /// Length of the replaced chunk. | /// Length of the replaced chunk. | ||||
| fn replaced_len(&self) -> u32 { | fn replaced_len(&self) -> u32 { | ||||
| self.end - self.start | self.end - self.start | ||||
| } | } | ||||
| /// Length difference between the replacing data and the replaced data. | /// Length difference between the replacing data and the replaced data. | ||||
| let mut pos = 0; | let mut pos = 0; | ||||
| // For each chunk of `other`, chunks of `self` are processed | // For each chunk of `other`, chunks of `self` are processed | ||||
| // until they start after the end of the current chunk. | // until they start after the end of the current chunk. | ||||
| for Chunk { start, end, data } in other.chunks.iter() { | for Chunk { start, end, data } in other.chunks.iter() { | ||||
| // Add chunks of `self` that start before this chunk of `other` | // Add chunks of `self` that start before this chunk of `other` | ||||
| // without overlap. | // without overlap. | ||||
| while pos < self.chunks.len() | while pos < self.chunks.len() | ||||
| && self.chunks[pos].end_offseted_by(offset) <= *start | && self.chunks[pos].end_offset_by(offset) <= *start | ||||
| { | { | ||||
| let first = self.chunks[pos].clone(); | let first = self.chunks[pos].clone(); | ||||
| offset += first.len_diff(); | offset += first.len_diff(); | ||||
| chunks.push(first); | chunks.push(first); | ||||
| pos += 1; | pos += 1; | ||||
| } | } | ||||
| // The current chunk of `self` starts before this chunk of `other` | // The current chunk of `self` starts before this chunk of `other` | ||||
| // with overlap. | // with overlap. | ||||
| // The left-most part of data is added as an insertion chunk. | // The left-most part of data is added as an insertion chunk. | ||||
| // The right-most part data is kept in the chunk. | // The right-most part data is kept in the chunk. | ||||
| if pos < self.chunks.len() | if pos < self.chunks.len() | ||||
| && self.chunks[pos].start_offseted_by(offset) < *start | && self.chunks[pos].start_offset_by(offset) < *start | ||||
| { | { | ||||
| let first = &mut self.chunks[pos]; | let first = &mut self.chunks[pos]; | ||||
| let (data_left, data_right) = first.data.split_at( | let (data_left, data_right) = first.data.split_at( | ||||
| (*start - first.start_offseted_by(offset)) as usize, | (*start - first.start_offset_by(offset)) as usize, | ||||
| ); | ); | ||||
| let left = Chunk { | let left = Chunk { | ||||
| start: first.start, | start: first.start, | ||||
| end: first.start, | end: first.start, | ||||
| data: data_left, | data: data_left, | ||||
| }; | }; | ||||
| first.data = data_right; | first.data = data_right; | ||||
| // chunk of `other`. | // chunk of `other`. | ||||
| // Offset tracking continues with `end_offset` to adjust the end | // Offset tracking continues with `end_offset` to adjust the end | ||||
| // of the current chunk of `other`. | // of the current chunk of `other`. | ||||
| let mut next_offset = offset; | let mut next_offset = offset; | ||||
| // Discard the chunks of `self` that are totally overridden | // Discard the chunks of `self` that are totally overridden | ||||
| // by the current chunk of `other` | // by the current chunk of `other` | ||||
| while pos < self.chunks.len() | while pos < self.chunks.len() | ||||
| && self.chunks[pos].end_offseted_by(next_offset) <= *end | && self.chunks[pos].end_offset_by(next_offset) <= *end | ||||
| { | { | ||||
| let first = &self.chunks[pos]; | let first = &self.chunks[pos]; | ||||
| next_offset += first.len_diff(); | next_offset += first.len_diff(); | ||||
| pos += 1; | pos += 1; | ||||
| } | } | ||||
| // Truncate the left-most part of chunk of `self` that overlaps | // Truncate the left-most part of chunk of `self` that overlaps | ||||
| // the current chunk of `other`. | // the current chunk of `other`. | ||||
| if pos < self.chunks.len() | if pos < self.chunks.len() | ||||
| && self.chunks[pos].start_offseted_by(next_offset) < *end | && self.chunks[pos].start_offset_by(next_offset) < *end | ||||
| { | { | ||||
| let first = &mut self.chunks[pos]; | let first = &mut self.chunks[pos]; | ||||
| let how_much_to_discard = | let how_much_to_discard = | ||||
| *end - first.start_offseted_by(next_offset); | *end - first.start_offset_by(next_offset); | ||||
| first.data = &first.data[(how_much_to_discard as usize)..]; | first.data = &first.data[(how_much_to_discard as usize)..]; | ||||
| next_offset += how_much_to_discard as i32; | next_offset += how_much_to_discard as i32; | ||||
| } | } | ||||
| // Add the chunk of `other` with adjusted position. | // Add the chunk of `other` with adjusted position. | ||||
| chunks.push(Chunk { | chunks.push(Chunk { | ||||