This commit is contained in:
Ed Guloien
2026-05-28 16:10:26 -04:00
parent b21662247d
commit 11da9ba05d
+37 -23
View File
@@ -1,4 +1,3 @@
#[derive(PartialEq, Debug, Clone, Copy)]
struct Range {
// todo: consider just using a map instead
@@ -12,7 +11,7 @@ enum RangeLocation {
LeftEnd,
RightEnd,
Middle,
No
No,
}
impl Range {
@@ -25,7 +24,7 @@ impl Range {
return RangeLocation::LeftEnd;
}
if index >= self.end {
return RangeLocation::No
return RangeLocation::No;
}
if index == self.end - 1 {
return RangeLocation::RightEnd;
@@ -44,14 +43,24 @@ pub struct Blob {
}
impl Blob {
pub fn new() -> Self { Self {bytes: Vec::new(), valid_ranges: Vec::new()} }
pub fn new() -> Self {
Self {
bytes: Vec::new(),
valid_ranges: Vec::new(),
}
}
pub fn append(&mut self, input: &[u8]) {
let new_range = Range {start: self.bytes.len(), end: self.bytes.len() + input.len()};
let new_range = Range {
start: self.bytes.len(),
end: self.bytes.len() + input.len(),
};
// we are appending so only have to check the last range
match self.valid_ranges.last_mut() {
Some(range) if range.where_in_range(new_range.start) != RangeLocation::No => range.end = new_range.end,
Some(range) if range.where_in_range(new_range.start) != RangeLocation::No => {
range.end = new_range.end
}
_ => self.valid_ranges.push(new_range),
}
self.bytes.extend_from_slice(input);
@@ -60,21 +69,24 @@ impl Blob {
// todo: better way to do the return type?
pub fn read(&mut self, start: usize, len: usize, output: &mut [u8]) {
assert!(len == output.len()); // todo: add error handling
let slice = &mut self.bytes[start..start+len];
let slice = &mut self.bytes[start..start + len];
slice.swap_with_slice(output);
// we copy existing entries into a new list to avoid iterator invalidation
// of inserting while iterating
// todo: might be a better way
let clear_range = Range{ start, end: start + len };
let clear_range = Range {
start,
end: start + len,
};
let mut new_ranges = Vec::new();
let mut i = 0;
while i < self.valid_ranges.len() {
let mut extra_range : Option<Range> = None;
let mut extra_range: Option<Range> = None;
let mut range = self.valid_ranges[i];
if range.where_in_range(clear_range.start) == RangeLocation::LeftEnd {
range.start = clear_range.end;
} else if range.where_in_range(clear_range.end-1) == RangeLocation::RightEnd {
} else if range.where_in_range(clear_range.end - 1) == RangeLocation::RightEnd {
range.end = clear_range.end
} else if range.where_in_range(clear_range.start) == RangeLocation::Middle {
let end = range.end;
@@ -86,10 +98,12 @@ impl Blob {
new_ranges.push(range);
}
if let Some(er) = extra_range && !er.is_empty() {
if let Some(er) = extra_range
&& !er.is_empty()
{
new_ranges.push(er);
}
i+=1;
i += 1;
}
self.valid_ranges = new_ranges;
}
@@ -105,10 +119,10 @@ mod tests {
#[test]
fn test_range() {
let range = Range{start:0, end:3};
let range = Range { start: 0, end: 3 };
assert_eq!(range, range); // identity
let range2 = Range{start:0, end:3};
let range2 = Range { start: 0, end: 3 };
assert_eq!(range, range2); // similar
assert_eq!(range.where_in_range(0), RangeLocation::LeftEnd);
@@ -121,25 +135,25 @@ mod tests {
fn test_blob() {
let mut b = Blob::new();
b.append(&[b'a', b'b', b'c']);
assert_eq!(b.valid_ranges, &[Range{start:0, end:3}]);
assert_eq!(b.valid_ranges, &[Range { start: 0, end: 3 }]);
let mut read = vec![0; 1];
b.read(0,1, &mut read); // left read
assert_eq!(b.valid_ranges, &[Range{start:1, end:3}]);
b.read(0, 1, &mut read); // left read
assert_eq!(b.valid_ranges, &[Range { start: 1, end: 3 }]);
let mut read = vec![0; 1];
b.read(0,1, &mut read); // dupe read // todo: should error or fail
assert_eq!(b.valid_ranges, &[Range{start:1, end:3}]);
b.read(0, 1, &mut read); // dupe read // todo: should error or fail
assert_eq!(b.valid_ranges, &[Range { start: 1, end: 3 }]);
let mut read = vec![0; 2];
b.read(1,2, &mut read); // right read
b.read(1, 2, &mut read); // right read
assert_eq!(b.valid_ranges, &[]);
b.append(&[b'a', b'b', b'c']);
assert_eq!(b.valid_ranges, &[Range{start:3, end:6}]);
assert_eq!(b.valid_ranges, &[Range { start: 3, end: 6 }]);
let mut read = vec![0; 1];
b.read(4,1, &mut read); // middle read
assert_eq!(b.valid_ranges, &[Range::new(3,4), Range::new(5,6)]);
b.read(4, 1, &mut read); // middle read
assert_eq!(b.valid_ranges, &[Range::new(3, 4), Range::new(5, 6)]);
println!("blob: {:?}", b.bytes);
}
}