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use lsp_types::{Position, Range, TextDocumentContentChangeEvent, Url};
#[derive(Clone)]
pub struct FullTextDocument {
pub uri: Url,
pub language_id: String,
pub version: i64,
pub text: String,
line_offset: Option<Vec<usize>>,
}
impl FullTextDocument {
pub fn new(uri: Url, language_id: String, version: i64, text: String) -> FullTextDocument {
FullTextDocument {
uri,
language_id,
version,
text,
line_offset: None,
}
}
pub fn update(&mut self, changes: Vec<TextDocumentContentChangeEvent>, version: i64) {
for change in changes {
if Self::is_incremental(&change) {
let range = get_wellformed_range(change.range.unwrap());
let start_offset = self.offset_at(range.start);
let end_offset = self.offset_at(range.end);
let (start_byte, end_byte) = self.transform_offset_to_byte_offset(start_offset, end_offset);
self.text = self.text[0..start_byte].to_string()
+ &change.text
+ &self.text[end_byte..];
let start_line = range.start.line as usize;
let end_line = range.end.line as usize;
let line_offsets = self.get_line_offsets();
let mut add_line_offsets =
compute_line_offsets(&change.text, false, Some(start_offset));
let add_line_offsets_len = add_line_offsets.len();
if end_line - start_line == add_line_offsets.len() {
for (i, offset) in add_line_offsets.into_iter().enumerate() {
line_offsets[i + start_line + 1] = offset;
}
} else {
*line_offsets = {
let mut res =
line_offsets[0..=start_line.min(line_offsets.len() - 1)].to_vec();
res.append(&mut add_line_offsets);
res.extend_from_slice(
&line_offsets[end_line.min(line_offsets.len() - 1) + 1..],
);
res
};
}
let diff: i32 = change.text.len() as i32 - (end_offset - start_offset) as i32;
if diff != 0 {
for i in start_line + 1 + add_line_offsets_len..line_offsets.len() {
line_offsets[i] = (line_offsets[i] as i32 + diff) as usize;
}
}
} else if Self::is_full(&change) {
self.text = change.text;
self.line_offset = None;
}
self.version = version;
}
}
pub fn transform_offset_to_byte_offset(&self, start_offset: usize, end_offset: usize) -> (usize, usize) {
let start_byte = self.text
.chars()
.take(start_offset)
.fold(0, |acc, cur| acc + cur.len_utf8());
let end_byte = (&self.text[start_offset..end_offset])
.chars()
.take(end_offset)
.fold(0, |acc, cur| acc + cur.len_utf8())
+ start_byte;
(start_byte, end_byte)
}
pub fn position_at(&mut self, mut offset: u32) -> Position {
offset = offset.min(self.text.len() as u32).max(0);
let line_offsets = self.get_line_offsets();
let mut low = 0usize;
let mut high = line_offsets.len();
if high == 0 {
return Position {
line: 0,
character: offset,
};
}
while low < high {
let mid = low + (high - low) / 2;
if line_offsets[mid] as u32 > offset {
high = mid;
} else {
low = mid + 1;
}
}
let line = low as u32 - 1;
return Position {
line,
character: offset - line_offsets[line as usize] as u32,
};
}
pub fn line_count(&mut self) -> usize {
self.get_line_offsets().len()
}
pub fn is_incremental(event: &TextDocumentContentChangeEvent) -> bool {
event.range.is_some()
}
pub fn is_full(event: &TextDocumentContentChangeEvent) -> bool {
!event.range_length.is_some() && !event.range.is_some()
}
pub fn get_line_offsets(&mut self) -> &mut Vec<usize> {
if self.line_offset.is_none() {
self.line_offset = Some(compute_line_offsets(&self.text, true, None));
}
self.line_offset.as_mut().unwrap()
}
pub fn offset_at(&mut self, position: Position) -> usize {
let line_offsets = self.get_line_offsets();
if position.line >= line_offsets.len() as u32 {
return self.text.len();
}
let line_offset = line_offsets[position.line as usize];
let next_line_offset = if position.line + 1 < line_offsets.len() as u32 {
line_offsets[position.line as usize + 1]
} else {
self.text.len()
};
(line_offset + position.character as usize)
.min(next_line_offset)
.max(line_offset)
}
}
pub fn compute_line_offsets(
text: &String,
is_at_line_start: bool,
text_offset: Option<usize>,
) -> Vec<usize> {
let text_offset = if let Some(offset) = text_offset {
offset
} else {
0
};
let mut result = if is_at_line_start {
vec![text_offset]
} else {
vec![]
};
let char_array: Vec<char> = text.chars().collect();
let mut i = 0;
while i < char_array.len() {
let &ch = unsafe { char_array.get_unchecked(i) };
if ch == '\r' || ch == '\n' {
if ch == '\r'
&& i + 1 < char_array.len()
&& unsafe { char_array.get_unchecked(i + 1) == &'\n' }
{
i += 1;
}
result.push(text_offset + i + 1);
}
i += 1;
}
result
}
fn get_wellformed_range(range: Range) -> Range {
let start = range.start;
let end = range.end;
if start.line > end.line || (start.line == end.line && start.character > end.character) {
Range::new(end, start)
} else {
range
}
}