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#![cfg(feature = "inline")]
use std::borrow::Cow;
use std::fmt;
use crate::text::{DiffableStr, TextDiff};
use crate::types::{Algorithm, Change, ChangeTag, DiffOp, DiffTag};
use crate::{capture_diff_deadline, get_diff_ratio};
use std::ops::Index;
use std::time::{Duration, Instant};
use super::utils::upper_seq_ratio;
struct MultiLookup<'bufs, 's, T: DiffableStr + ?Sized> {
strings: &'bufs [&'s T],
seqs: Vec<(&'s T, usize, usize)>,
}
impl<'bufs, 's, T: DiffableStr + ?Sized> MultiLookup<'bufs, 's, T> {
fn new(strings: &'bufs [&'s T]) -> MultiLookup<'bufs, 's, T> {
let mut seqs = Vec::new();
for (string_idx, string) in strings.iter().enumerate() {
let mut offset = 0;
let iter = {
#[cfg(feature = "unicode")]
{
string.tokenize_unicode_words()
}
#[cfg(not(feature = "unicode"))]
{
string.tokenize_words()
}
};
for word in iter {
seqs.push((word, string_idx, offset));
offset += word.len();
}
}
MultiLookup { strings, seqs }
}
pub fn len(&self) -> usize {
self.seqs.len()
}
fn get_original_slices(&self, idx: usize, len: usize) -> Vec<(usize, &'s T)> {
let mut last = None;
let mut rv = Vec::new();
for offset in 0..len {
let (s, str_idx, char_idx) = self.seqs[idx + offset];
last = match last {
None => Some((str_idx, char_idx, s.len())),
Some((last_str_idx, start_char_idx, last_len)) => {
if last_str_idx == str_idx {
Some((str_idx, start_char_idx, last_len + s.len()))
} else {
rv.push((
last_str_idx,
self.strings[last_str_idx]
.slice(start_char_idx..start_char_idx + last_len),
));
Some((str_idx, char_idx, s.len()))
}
}
};
}
if let Some((str_idx, start_char_idx, len)) = last {
rv.push((
str_idx,
self.strings[str_idx].slice(start_char_idx..start_char_idx + len),
));
}
rv
}
}
impl<'bufs, 's, T: DiffableStr + ?Sized> Index<usize> for MultiLookup<'bufs, 's, T> {
type Output = T;
fn index(&self, index: usize) -> &Self::Output {
self.seqs[index].0
}
}
fn push_values<'s, T: DiffableStr + ?Sized>(
v: &mut Vec<Vec<(bool, &'s T)>>,
idx: usize,
emphasized: bool,
s: &'s T,
) {
v.resize_with(v.len().max(idx + 1), Vec::new);
// newlines cause all kinds of wacky stuff if they end up highlighted.
// because of this we want to unemphasize all newlines we encounter.
if emphasized {
for seg in s.tokenize_lines_and_newlines() {
v[idx].push((!seg.ends_with_newline(), seg));
}
} else {
v[idx].push((false, s));
}
}
/// Represents the expanded textual change with inline highlights.
///
/// This is like [`Change`] but with inline highlight info.
#[derive(Debug, PartialEq, Eq, Hash, Clone, Ord, PartialOrd)]
#[cfg_attr(feature = "serde", derive(serde::Serialize))]
pub struct InlineChange<'s, T: DiffableStr + ?Sized> {
tag: ChangeTag,
old_index: Option<usize>,
new_index: Option<usize>,
values: Vec<(bool, &'s T)>,
}
impl<'s, T: DiffableStr + ?Sized> InlineChange<'s, T> {
/// Returns the change tag.
pub fn tag(&self) -> ChangeTag {
self.tag
}
/// Returns the old index if available.
pub fn old_index(&self) -> Option<usize> {
self.old_index
}
/// Returns the new index if available.
pub fn new_index(&self) -> Option<usize> {
self.new_index
}
/// Returns the changed values.
///
/// Each item is a tuple in the form `(emphasized, value)` where `emphasized`
/// is true if it should be highlighted as an inline diff.
///
/// Depending on the type of the underlying [`DiffableStr`] this value is
/// more or less useful. If you always want to have a utf-8 string it's
/// better to use the [`InlineChange::iter_strings_lossy`] method.
pub fn values(&self) -> &[(bool, &'s T)] {
&self.values
}
/// Iterates over all (potentially lossy) utf-8 decoded values.
///
/// Each item is a tuple in the form `(emphasized, value)` where `emphasized`
/// is true if it should be highlighted as an inline diff.
pub fn iter_strings_lossy(&self) -> impl Iterator<Item = (bool, Cow<'_, str>)> {
self.values()
.iter()
.map(|(emphasized, raw_value)| (*emphasized, raw_value.to_string_lossy()))
}
/// Returns `true` if this change does not end in a newline and must be
/// followed up by one if line based diffs are used.
pub fn missing_newline(&self) -> bool {
!self.values.last().map_or(true, |x| x.1.ends_with_newline())
}
}
impl<'s, T: DiffableStr + ?Sized> From<Change<&'s T>> for InlineChange<'s, T> {
fn from(change: Change<&'s T>) -> InlineChange<'s, T> {
InlineChange {
tag: change.tag(),
old_index: change.old_index(),
new_index: change.new_index(),
values: vec![(false, change.value())],
}
}
}
impl<'s, T: DiffableStr + ?Sized> fmt::Display for InlineChange<'s, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
for (emphasized, value) in self.iter_strings_lossy() {
let marker = match (emphasized, self.tag) {
(false, _) | (true, ChangeTag::Equal) => "",
(true, ChangeTag::Delete) => "-",
(true, ChangeTag::Insert) => "+",
};
write!(f, "{}{}{}", marker, value, marker)?;
}
if self.missing_newline() {
writeln!(f)?;
}
Ok(())
}
}
const MIN_RATIO: f32 = 0.5;
const TIMEOUT_MS: u64 = 500;
pub(crate) fn iter_inline_changes<'x, 'diff, 'old, 'new, 'bufs, T>(
diff: &'diff TextDiff<'old, 'new, 'bufs, T>,
op: &DiffOp,
) -> impl Iterator<Item = InlineChange<'x, T>> + 'diff
where
T: DiffableStr + ?Sized,
'x: 'diff,
'old: 'x,
'new: 'x,
{
let (tag, old_range, new_range) = op.as_tag_tuple();
if let DiffTag::Equal | DiffTag::Insert | DiffTag::Delete = tag {
return Box::new(diff.iter_changes(op).map(|x| x.into())) as Box<dyn Iterator<Item = _>>;
}
let mut old_index = old_range.start;
let mut new_index = new_range.start;
let old_slices = &diff.old_slices()[old_range];
let new_slices = &diff.new_slices()[new_range];
if upper_seq_ratio(old_slices, new_slices) < MIN_RATIO {
return Box::new(diff.iter_changes(op).map(|x| x.into())) as Box<dyn Iterator<Item = _>>;
}
let old_lookup = MultiLookup::new(old_slices);
let new_lookup = MultiLookup::new(new_slices);
let ops = capture_diff_deadline(
Algorithm::Patience,
&old_lookup,
0..old_lookup.len(),
&new_lookup,
0..new_lookup.len(),
Some(Instant::now() + Duration::from_millis(TIMEOUT_MS)),
);
if get_diff_ratio(&ops, old_lookup.len(), new_lookup.len()) < MIN_RATIO {
return Box::new(diff.iter_changes(op).map(|x| x.into())) as Box<dyn Iterator<Item = _>>;
}
let mut old_values = Vec::<Vec<_>>::new();
let mut new_values = Vec::<Vec<_>>::new();
for op in ops {
match op {
DiffOp::Equal {
old_index,
len,
new_index,
} => {
for (idx, slice) in old_lookup.get_original_slices(old_index, len) {
push_values(&mut old_values, idx, false, slice);
}
for (idx, slice) in new_lookup.get_original_slices(new_index, len) {
push_values(&mut new_values, idx, false, slice);
}
}
DiffOp::Delete {
old_index, old_len, ..
} => {
for (idx, slice) in old_lookup.get_original_slices(old_index, old_len) {
push_values(&mut old_values, idx, true, slice);
}
}
DiffOp::Insert {
new_index, new_len, ..
} => {
for (idx, slice) in new_lookup.get_original_slices(new_index, new_len) {
push_values(&mut new_values, idx, true, slice);
}
}
DiffOp::Replace {
old_index,
old_len,
new_index,
new_len,
} => {
for (idx, slice) in old_lookup.get_original_slices(old_index, old_len) {
push_values(&mut old_values, idx, true, slice);
}
for (idx, slice) in new_lookup.get_original_slices(new_index, new_len) {
push_values(&mut new_values, idx, true, slice);
}
}
}
}
let mut rv = Vec::new();
for values in old_values {
rv.push(InlineChange {
tag: ChangeTag::Delete,
old_index: Some(old_index),
new_index: None,
values,
});
old_index += 1;
}
for values in new_values {
rv.push(InlineChange {
tag: ChangeTag::Insert,
old_index: None,
new_index: Some(new_index),
values,
});
new_index += 1;
}
Box::new(rv.into_iter()) as Box<dyn Iterator<Item = _>>
}
#[test]
fn test_line_ops_inline() {
let diff = TextDiff::from_lines(
"Hello World\nsome stuff here\nsome more stuff here\n\nAha stuff here\nand more stuff",
"Stuff\nHello World\nsome amazing stuff here\nsome more stuff here\n",
);
assert_eq!(diff.newline_terminated(), true);
let changes = diff
.ops()
.iter()
.flat_map(|op| diff.iter_inline_changes(op))
.collect::<Vec<_>>();
insta::assert_debug_snapshot!(&changes);
}
#[test]
#[cfg(feature = "serde")]
fn test_serde() {
let diff = TextDiff::from_lines(
"Hello World\nsome stuff here\nsome more stuff here\n\nAha stuff here\nand more stuff",
"Stuff\nHello World\nsome amazing stuff here\nsome more stuff here\n",
);
assert_eq!(diff.newline_terminated(), true);
let changes = diff
.ops()
.iter()
.flat_map(|op| diff.iter_inline_changes(op))
.collect::<Vec<_>>();
let json = serde_json::to_string_pretty(&changes).unwrap();
insta::assert_snapshot!(&json);
}
|