forked from mirrors/jj
b253a28788
The `RefTarget::as_normal()` function is not specific to `RefTarget`, and I plan to use it from `local_working_copy`.
975 lines
36 KiB
Rust
975 lines
36 KiB
Rust
// Copyright 2023 The Jujutsu Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
//! Generic algorithms for working with merged values, plus specializations for
|
|
//! some common types of merged values.
|
|
|
|
use std::borrow::Borrow;
|
|
use std::collections::HashMap;
|
|
use std::fmt::{Debug, Formatter};
|
|
use std::hash::Hash;
|
|
use std::io::Write;
|
|
use std::iter::zip;
|
|
use std::slice;
|
|
use std::sync::Arc;
|
|
|
|
use itertools::Itertools;
|
|
use smallvec::{smallvec_inline, SmallVec};
|
|
|
|
use crate::backend;
|
|
use crate::backend::{BackendError, FileId, TreeId, TreeValue};
|
|
use crate::content_hash::ContentHash;
|
|
use crate::object_id::ObjectId;
|
|
use crate::repo_path::RepoPath;
|
|
use crate::store::Store;
|
|
use crate::tree::Tree;
|
|
|
|
/// Attempt to resolve trivial conflicts between the inputs. There must be
|
|
/// exactly one more adds than removes.
|
|
pub fn trivial_merge<'a, T>(removes: &'a [T], adds: &'a [T]) -> Option<&'a T>
|
|
where
|
|
T: Eq + Hash,
|
|
{
|
|
assert_eq!(
|
|
adds.len(),
|
|
removes.len() + 1,
|
|
"trivial_merge() requires exactly one more adds than removes"
|
|
);
|
|
trivial_merge_inner(
|
|
itertools::interleave(adds, removes),
|
|
adds.len() + removes.len(),
|
|
)
|
|
}
|
|
|
|
fn trivial_merge_inner<T>(mut values: impl Iterator<Item = T>, values_len: usize) -> Option<T>
|
|
where
|
|
T: Eq + Hash,
|
|
{
|
|
// Optimize the common cases of 3-way merge and 1-way (non-)merge
|
|
if values_len == 1 {
|
|
let add = values.next().unwrap();
|
|
return Some(add);
|
|
} else if values_len == 3 {
|
|
let (add0, remove, add1) = values.next_tuple().unwrap();
|
|
return if add0 == add1 {
|
|
Some(add0)
|
|
} else if add0 == remove {
|
|
Some(add1)
|
|
} else if add1 == remove {
|
|
Some(add0)
|
|
} else {
|
|
None
|
|
};
|
|
}
|
|
|
|
// Number of occurrences of each value, with positive indexes counted as +1 and
|
|
// negative as -1, thereby letting positive and negative terms with the same
|
|
// value (i.e. key in the map) cancel each other.
|
|
let mut counts: HashMap<T, i32> = HashMap::new();
|
|
for (value, n) in zip(values, [1, -1].into_iter().cycle()) {
|
|
counts.entry(value).and_modify(|e| *e += n).or_insert(n);
|
|
}
|
|
|
|
// Collect non-zero value. Values with a count of 0 means that they have
|
|
// cancelled out.
|
|
counts.retain(|_, count| *count != 0);
|
|
if counts.len() == 1 {
|
|
// If there is a single value with a count of 1 left, then that is the result.
|
|
let (value, count) = counts.into_iter().next().unwrap();
|
|
assert_eq!(count, 1);
|
|
Some(value)
|
|
} else if counts.len() == 2 {
|
|
// All sides made the same change.
|
|
// This matches what Git and Mercurial do (in the 3-way case at least), but not
|
|
// what Darcs and Pijul do. It means that repeated 3-way merging of multiple
|
|
// trees may give different results depending on the order of merging.
|
|
// TODO: Consider removing this special case, making the algorithm more strict,
|
|
// and maybe add a more lenient version that is used when the user explicitly
|
|
// asks for conflict resolution.
|
|
let ((value1, count1), (value2, count2)) = counts.into_iter().next_tuple().unwrap();
|
|
assert_eq!(count1 + count2, 1);
|
|
if count1 > 0 {
|
|
Some(value1)
|
|
} else {
|
|
Some(value2)
|
|
}
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// A generic representation of merged values.
|
|
///
|
|
/// There is exactly one more `adds()` than `removes()`. When interpreted as a
|
|
/// series of diffs, the merge's (i+1)-st add is matched with the i-th
|
|
/// remove. The zeroth add is considered a diff from the non-existent state.
|
|
#[derive(PartialEq, Eq, Hash, Clone)]
|
|
pub struct Merge<T> {
|
|
/// Alternates between positive and negative terms, starting with positive.
|
|
values: SmallVec<[T; 1]>,
|
|
}
|
|
|
|
impl<T: Debug> Debug for Merge<T> {
|
|
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), std::fmt::Error> {
|
|
// Format like an enum with two variants to make it less verbose in the common
|
|
// case of a resolved state.
|
|
if let Some(value) = self.as_resolved() {
|
|
f.debug_tuple("Resolved").field(value).finish()
|
|
} else {
|
|
f.debug_tuple("Conflicted").field(&self.values).finish()
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T> Merge<T> {
|
|
/// Creates a `Merge` from the given values, in which positive and negative
|
|
/// terms alternate.
|
|
pub fn from_vec(values: impl Into<SmallVec<[T; 1]>>) -> Self {
|
|
let values = values.into();
|
|
assert!(
|
|
values.len() & 1 != 0,
|
|
"must have one more adds than removes"
|
|
);
|
|
Merge { values }
|
|
}
|
|
|
|
/// Creates a new merge object from the given removes and adds.
|
|
pub fn from_removes_adds(
|
|
removes: impl IntoIterator<Item = T>,
|
|
adds: impl IntoIterator<Item = T>,
|
|
) -> Self {
|
|
let removes = removes.into_iter();
|
|
let mut adds = adds.into_iter();
|
|
let mut values = SmallVec::with_capacity(removes.size_hint().0 * 2 + 1);
|
|
values.push(adds.next().expect("must have at least one add"));
|
|
for diff in removes.zip_longest(adds) {
|
|
let (remove, add) = diff.both().expect("must have one more adds than removes");
|
|
values.extend([remove, add]);
|
|
}
|
|
Merge { values }
|
|
}
|
|
|
|
/// Creates a `Merge` with a single resolved value.
|
|
pub fn resolved(value: T) -> Self {
|
|
Merge {
|
|
values: smallvec_inline![value],
|
|
}
|
|
}
|
|
|
|
/// Create a `Merge` from a `removes` and `adds`, padding with `None` to
|
|
/// make sure that there is exactly one more `adds` than `removes`.
|
|
pub fn from_legacy_form(
|
|
removes: impl IntoIterator<Item = T>,
|
|
adds: impl IntoIterator<Item = T>,
|
|
) -> Merge<Option<T>> {
|
|
let removes = removes.into_iter();
|
|
let mut adds = adds.into_iter().fuse();
|
|
let mut values = smallvec_inline![adds.next()];
|
|
for diff in removes.zip_longest(adds) {
|
|
let (remove, add) = diff.map_any(Some, Some).or_default();
|
|
values.extend([remove, add]);
|
|
}
|
|
Merge { values }
|
|
}
|
|
|
|
/// The removed values, also called negative terms.
|
|
pub fn removes(&self) -> impl ExactSizeIterator<Item = &T> {
|
|
self.values[1..].iter().step_by(2)
|
|
}
|
|
|
|
/// The added values, also called positive terms.
|
|
pub fn adds(&self) -> impl ExactSizeIterator<Item = &T> {
|
|
self.values.iter().step_by(2)
|
|
}
|
|
|
|
/// Returns the zeroth added value, which is guaranteed to exist.
|
|
pub fn first(&self) -> &T {
|
|
&self.values[0]
|
|
}
|
|
|
|
/// Returns the `index`-th removed value, which is considered belonging to
|
|
/// the `index`-th diff pair.
|
|
pub fn get_remove(&self, index: usize) -> Option<&T> {
|
|
self.values.get(index * 2 + 1)
|
|
}
|
|
|
|
/// Returns the `index`-th added value, which is considered belonging to the
|
|
/// `index-1`-th diff pair. The zeroth add is a diff from the non-existent
|
|
/// state.
|
|
pub fn get_add(&self, index: usize) -> Option<&T> {
|
|
self.values.get(index * 2)
|
|
}
|
|
|
|
/// Removes the specified "removed"/"added" values. The removed slots are
|
|
/// replaced by the last "removed"/"added" values.
|
|
pub fn swap_remove(&mut self, remove_index: usize, add_index: usize) -> (T, T) {
|
|
// Swap with the last "added" and "removed" values in order.
|
|
let add = self.values.swap_remove(add_index * 2);
|
|
let remove = self.values.swap_remove(remove_index * 2 + 1);
|
|
(remove, add)
|
|
}
|
|
|
|
/// The number of positive terms in the conflict.
|
|
pub fn num_sides(&self) -> usize {
|
|
self.values.len() / 2 + 1
|
|
}
|
|
|
|
/// Whether this merge is resolved. Does not resolve trivial merges.
|
|
pub fn is_resolved(&self) -> bool {
|
|
self.values.len() == 1
|
|
}
|
|
|
|
/// Returns the resolved value, if this merge is resolved. Does not
|
|
/// resolve trivial merges.
|
|
pub fn as_resolved(&self) -> Option<&T> {
|
|
if let [value] = &self.values[..] {
|
|
Some(value)
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Returns the resolved value, if this merge is resolved. Otherwise returns
|
|
/// the merge itself as an `Err`. Does not resolve trivial merges.
|
|
pub fn into_resolved(mut self) -> Result<T, Merge<T>> {
|
|
if self.values.len() == 1 {
|
|
Ok(self.values.pop().unwrap())
|
|
} else {
|
|
Err(self)
|
|
}
|
|
}
|
|
|
|
/// Simplify the merge by joining diffs like A->B and B->C into A->C.
|
|
/// Also drops trivial diffs like A->A.
|
|
pub fn simplify(mut self) -> Self
|
|
where
|
|
T: PartialEq,
|
|
{
|
|
let mut add_index = 0;
|
|
while add_index < self.values.len() {
|
|
let add = &self.values[add_index];
|
|
let mut removes = self.values.iter().enumerate().skip(1).step_by(2);
|
|
if let Some((remove_index, _)) = removes.find(|&(_, remove)| remove == add) {
|
|
// Align the current "add" value to the `remove_index/2`-th diff, then
|
|
// delete the diff pair.
|
|
self.values.swap(remove_index + 1, add_index);
|
|
self.values.drain(remove_index..remove_index + 2);
|
|
} else {
|
|
add_index += 2;
|
|
}
|
|
}
|
|
self
|
|
}
|
|
|
|
/// If this merge can be trivially resolved, returns the value it resolves
|
|
/// to.
|
|
pub fn resolve_trivial(&self) -> Option<&T>
|
|
where
|
|
T: Eq + Hash,
|
|
{
|
|
trivial_merge_inner(self.values.iter(), self.values.len())
|
|
}
|
|
|
|
/// Pads this merge with to the specified number of sides with the specified
|
|
/// value. No-op if the requested size is not larger than the current size.
|
|
pub fn pad_to(&mut self, num_sides: usize, value: &T)
|
|
where
|
|
T: Clone,
|
|
{
|
|
if num_sides <= self.num_sides() {
|
|
return;
|
|
}
|
|
self.values.resize(num_sides * 2 - 1, value.clone());
|
|
}
|
|
|
|
/// Returns an iterator over references to the terms. The items will
|
|
/// alternate between positive and negative terms, starting with
|
|
/// positive (since there's one more of those).
|
|
pub fn iter(&self) -> slice::Iter<'_, T> {
|
|
self.values.iter()
|
|
}
|
|
|
|
/// A version of `Merge::iter()` that iterates over mutable references.
|
|
pub fn iter_mut(&mut self) -> slice::IterMut<'_, T> {
|
|
self.values.iter_mut()
|
|
}
|
|
|
|
/// Creates a new merge by applying `f` to each remove and add.
|
|
pub fn map<'a, U>(&'a self, f: impl FnMut(&'a T) -> U) -> Merge<U> {
|
|
let values = self.values.iter().map(f).collect();
|
|
Merge { values }
|
|
}
|
|
|
|
/// Creates a new merge by applying `f` to each remove and add, returning
|
|
/// `None if `f` returns `None` for any of them.
|
|
pub fn maybe_map<'a, U>(&'a self, f: impl FnMut(&'a T) -> Option<U>) -> Option<Merge<U>> {
|
|
let values = self.values.iter().map(f).collect::<Option<_>>()?;
|
|
Some(Merge { values })
|
|
}
|
|
|
|
/// Creates a new merge by applying `f` to each remove and add, returning
|
|
/// `Err if `f` returns `Err` for any of them.
|
|
pub fn try_map<'a, U, E>(
|
|
&'a self,
|
|
f: impl FnMut(&'a T) -> Result<U, E>,
|
|
) -> Result<Merge<U>, E> {
|
|
let values = self.values.iter().map(f).try_collect()?;
|
|
Ok(Merge { values })
|
|
}
|
|
}
|
|
|
|
/// Helper for consuming items from an iterator and then creating a `Merge`.
|
|
///
|
|
/// By not collecting directly into `Merge`, we can avoid creating invalid
|
|
/// instances of it. If we had `Merge::from_iter()` we would need to allow it to
|
|
/// accept iterators of any length (including 0). We couldn't make it panic on
|
|
/// even lengths because we can get passed such iterators from e.g.
|
|
/// `Option::from_iter()`. By collecting into `MergeBuilder` instead, we move
|
|
/// the checking until after `from_iter()` (to `MergeBuilder::build()`).
|
|
#[derive(Clone, Debug, PartialEq, Eq)]
|
|
pub struct MergeBuilder<T> {
|
|
values: SmallVec<[T; 1]>,
|
|
}
|
|
|
|
impl<T> Default for MergeBuilder<T> {
|
|
fn default() -> Self {
|
|
Self {
|
|
values: Default::default(),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T> MergeBuilder<T> {
|
|
/// Requires that exactly one more "adds" than "removes" have been added to
|
|
/// this builder.
|
|
pub fn build(self) -> Merge<T> {
|
|
Merge::from_vec(self.values)
|
|
}
|
|
}
|
|
|
|
impl<T> IntoIterator for Merge<T> {
|
|
type Item = T;
|
|
type IntoIter = smallvec::IntoIter<[T; 1]>;
|
|
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self.values.into_iter()
|
|
}
|
|
}
|
|
|
|
impl<T> FromIterator<T> for MergeBuilder<T> {
|
|
fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
|
|
let mut builder = MergeBuilder::default();
|
|
builder.extend(iter);
|
|
builder
|
|
}
|
|
}
|
|
|
|
impl<T> Extend<T> for MergeBuilder<T> {
|
|
fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
|
|
self.values.extend(iter)
|
|
}
|
|
}
|
|
|
|
impl<T> Merge<Option<T>> {
|
|
/// Creates a resolved merge with a value of `None`.
|
|
pub fn absent() -> Self {
|
|
Self::resolved(None)
|
|
}
|
|
|
|
/// Creates a resolved merge with a value of `Some(value)`.
|
|
pub fn normal(value: T) -> Self {
|
|
Self::resolved(Some(value))
|
|
}
|
|
|
|
/// Whether this represents a resolved value of `None`.
|
|
pub fn is_absent(&self) -> bool {
|
|
matches!(self.as_resolved(), Some(None))
|
|
}
|
|
|
|
/// The opposite of `is_absent()`.
|
|
pub fn is_present(&self) -> bool {
|
|
!self.is_absent()
|
|
}
|
|
|
|
/// Returns the value if this is present and non-conflicting.
|
|
pub fn as_normal(&self) -> Option<&T> {
|
|
self.as_resolved()?.as_ref()
|
|
}
|
|
|
|
/// Creates lists of `removes` and `adds` from a `Merge` by dropping
|
|
/// `None` values. Note that the conversion is lossy: the order of `None`
|
|
/// values is not preserved when converting back to a `Merge`.
|
|
pub fn into_legacy_form(self) -> (Vec<T>, Vec<T>) {
|
|
// Allocate the maximum size assuming there would be few `None`s.
|
|
let mut removes = Vec::with_capacity(self.values.len() / 2);
|
|
let mut adds = Vec::with_capacity(self.values.len() / 2 + 1);
|
|
let mut values = self.values.into_iter();
|
|
adds.extend(values.next().unwrap());
|
|
while let Some(remove) = values.next() {
|
|
removes.extend(remove);
|
|
adds.extend(values.next().unwrap());
|
|
}
|
|
(removes, adds)
|
|
}
|
|
}
|
|
|
|
impl<T> Merge<Merge<T>> {
|
|
/// Flattens a nested merge into a regular merge.
|
|
///
|
|
/// Let's say we have a 3-way merge of 3-way merges like this:
|
|
///
|
|
/// 4 5 7 8
|
|
/// 3 6
|
|
/// 1 2
|
|
/// 0
|
|
///
|
|
/// Flattening that results in this 9-way merge:
|
|
///
|
|
/// 4 5 0 7 8
|
|
/// 3 2 1 6
|
|
pub fn flatten(self) -> Merge<T> {
|
|
let mut outer_values = self.values.into_iter();
|
|
let mut result = outer_values.next().unwrap();
|
|
while let Some(mut remove) = outer_values.next() {
|
|
// Add removes reversed, and with the first element moved last, so we preserve
|
|
// the diffs
|
|
remove.values.rotate_left(1);
|
|
for i in 0..remove.values.len() / 2 {
|
|
remove.values.swap(i * 2, i * 2 + 1);
|
|
}
|
|
result.values.extend(remove.values);
|
|
let add = outer_values.next().unwrap();
|
|
result.values.extend(add.values);
|
|
}
|
|
result
|
|
}
|
|
}
|
|
|
|
impl<T: ContentHash> ContentHash for Merge<T> {
|
|
fn hash(&self, state: &mut impl digest::Update) {
|
|
self.values.hash(state)
|
|
}
|
|
}
|
|
|
|
/// The value at a given path in a commit. It depends on the context whether it
|
|
/// can be absent (`Merge::is_absent()`). For example, when getting the value at
|
|
/// a specific path, it may be, but when iterating over entries in a tree, it
|
|
/// shouldn't be.
|
|
pub type MergedTreeValue = Merge<Option<TreeValue>>;
|
|
|
|
impl MergedTreeValue {
|
|
/// Create a `Merge` from a `backend::Conflict`, padding with `None` to
|
|
/// make sure that there is exactly one more `adds()` than `removes()`.
|
|
pub fn from_backend_conflict(conflict: backend::Conflict) -> Self {
|
|
let removes = conflict.removes.into_iter().map(|term| term.value);
|
|
let adds = conflict.adds.into_iter().map(|term| term.value);
|
|
Merge::from_legacy_form(removes, adds)
|
|
}
|
|
|
|
/// Creates a `backend::Conflict` from a `Merge` by dropping `None`
|
|
/// values. Note that the conversion is lossy: the order of `None` values is
|
|
/// not preserved when converting back to a `Merge`.
|
|
pub fn into_backend_conflict(self) -> backend::Conflict {
|
|
let (removes, adds) = self.into_legacy_form();
|
|
let removes = removes
|
|
.into_iter()
|
|
.map(|value| backend::ConflictTerm { value })
|
|
.collect();
|
|
let adds = adds
|
|
.into_iter()
|
|
.map(|value| backend::ConflictTerm { value })
|
|
.collect();
|
|
backend::Conflict { removes, adds }
|
|
}
|
|
|
|
/// Whether this merge should be recursed into when doing directory walks.
|
|
pub fn is_tree(&self) -> bool {
|
|
self.is_present()
|
|
&& self
|
|
.iter()
|
|
.all(|value| matches!(value, Some(TreeValue::Tree(_)) | None))
|
|
}
|
|
|
|
/// If this merge contains only files or absent entries, returns a merge of
|
|
/// the `FileId`s`. The executable bits will be ignored. Use
|
|
/// `Merge::with_new_file_ids()` to produce a new merge with the original
|
|
/// executable bits preserved.
|
|
pub fn to_file_merge(&self) -> Option<Merge<Option<FileId>>> {
|
|
self.maybe_map(|term| match term {
|
|
None => Some(None),
|
|
Some(TreeValue::File { id, executable: _ }) => Some(Some(id.clone())),
|
|
_ => None,
|
|
})
|
|
}
|
|
|
|
/// Creates a new merge with the file ids from the given merge. In other
|
|
/// words, only the executable bits from `self` will be preserved.
|
|
pub fn with_new_file_ids(&self, file_ids: &Merge<Option<FileId>>) -> Self {
|
|
assert_eq!(self.values.len(), file_ids.values.len());
|
|
let values = zip(self.iter(), file_ids.iter())
|
|
.map(|(tree_value, file_id)| {
|
|
if let Some(TreeValue::File { id: _, executable }) = tree_value {
|
|
Some(TreeValue::File {
|
|
id: file_id.as_ref().unwrap().clone(),
|
|
executable: *executable,
|
|
})
|
|
} else {
|
|
assert!(tree_value.is_none());
|
|
assert!(file_id.is_none());
|
|
None
|
|
}
|
|
})
|
|
.collect();
|
|
Merge { values }
|
|
}
|
|
|
|
/// Give a summary description of the conflict's "removes" and "adds"
|
|
pub fn describe(&self, file: &mut dyn Write) -> std::io::Result<()> {
|
|
file.write_all(b"Conflict:\n")?;
|
|
for term in self.removes().flatten() {
|
|
file.write_all(format!(" Removing {}\n", describe_conflict_term(term)).as_bytes())?;
|
|
}
|
|
for term in self.adds().flatten() {
|
|
file.write_all(format!(" Adding {}\n", describe_conflict_term(term)).as_bytes())?;
|
|
}
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
impl<T> Merge<Option<T>>
|
|
where
|
|
T: Borrow<TreeValue>,
|
|
{
|
|
/// If every non-`None` term of a `MergedTreeValue`
|
|
/// is a `TreeValue::Tree`, this converts it to
|
|
/// a `Merge<Tree>`, with empty trees instead of
|
|
/// any `None` terms. Otherwise, returns `None`.
|
|
pub fn to_tree_merge(
|
|
&self,
|
|
store: &Arc<Store>,
|
|
dir: &RepoPath,
|
|
) -> Result<Option<Merge<Tree>>, BackendError> {
|
|
let tree_id_merge = self.maybe_map(|term| match term {
|
|
None => Some(None),
|
|
Some(value) => {
|
|
if let TreeValue::Tree(id) = value.borrow() {
|
|
Some(Some(id))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
});
|
|
if let Some(tree_id_merge) = tree_id_merge {
|
|
let get_tree = |id: &Option<&TreeId>| -> Result<Tree, BackendError> {
|
|
if let Some(id) = id {
|
|
store.get_tree(dir, id)
|
|
} else {
|
|
Ok(Tree::null(store.clone(), dir.to_owned()))
|
|
}
|
|
};
|
|
Ok(Some(tree_id_merge.try_map(get_tree)?))
|
|
} else {
|
|
Ok(None)
|
|
}
|
|
}
|
|
}
|
|
|
|
fn describe_conflict_term(value: &TreeValue) -> String {
|
|
match value {
|
|
TreeValue::File {
|
|
id,
|
|
executable: false,
|
|
} => {
|
|
format!("file with id {}", id.hex())
|
|
}
|
|
TreeValue::File {
|
|
id,
|
|
executable: true,
|
|
} => {
|
|
format!("executable file with id {}", id.hex())
|
|
}
|
|
TreeValue::Symlink(id) => {
|
|
format!("symlink with id {}", id.hex())
|
|
}
|
|
TreeValue::Tree(id) => {
|
|
format!("tree with id {}", id.hex())
|
|
}
|
|
TreeValue::GitSubmodule(id) => {
|
|
format!("Git submodule with id {}", id.hex())
|
|
}
|
|
TreeValue::Conflict(id) => {
|
|
format!("Conflict with id {}", id.hex())
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
fn c<T: Clone>(removes: &[T], adds: &[T]) -> Merge<T> {
|
|
Merge::from_removes_adds(removes.to_vec(), adds.to_vec())
|
|
}
|
|
|
|
#[test]
|
|
fn test_trivial_merge() {
|
|
assert_eq!(trivial_merge(&[], &[0]), Some(&0));
|
|
assert_eq!(trivial_merge(&[0], &[0, 0]), Some(&0));
|
|
assert_eq!(trivial_merge(&[0], &[0, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0], &[1, 0]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0], &[1, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0], &[1, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 0], &[0, 0, 0]), Some(&0));
|
|
assert_eq!(trivial_merge(&[0, 0], &[0, 0, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 0], &[0, 1, 0]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 0], &[0, 1, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 0], &[0, 1, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 0, 0]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 0, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 0, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 1, 0]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 1, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 1, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 2, 0]), None);
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 2, 1]), None);
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 2, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 0], &[1, 2, 3]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 0, 0]), Some(&0));
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 0, 1]), Some(&0));
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 0, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 1, 0]), Some(&0));
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 1, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 1, 2]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 2, 0]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 2, 1]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 2, 2]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[0, 2, 3]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 0, 0]), Some(&0));
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 0, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 0, 2]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 1, 0]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 1, 1]), Some(&1));
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 1, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 2, 0]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 2, 1]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 2, 2]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[1, 2, 3]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 0, 0]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 0, 1]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 0, 2]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 0, 3]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 1, 0]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 1, 1]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 1, 2]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 1, 3]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 2, 0]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 2, 1]), Some(&2));
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 2, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 2, 3]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 3, 0]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 3, 1]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 3, 2]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 3, 3]), None);
|
|
assert_eq!(trivial_merge(&[0, 1], &[2, 3, 4]), None);
|
|
}
|
|
|
|
#[test]
|
|
fn test_legacy_form_conversion() {
|
|
fn test_equivalent<T>(legacy_form: (Vec<T>, Vec<T>), merge: Merge<Option<T>>)
|
|
where
|
|
T: Clone + PartialEq + std::fmt::Debug,
|
|
{
|
|
assert_eq!(merge.clone().into_legacy_form(), legacy_form);
|
|
assert_eq!(Merge::from_legacy_form(legacy_form.0, legacy_form.1), merge);
|
|
}
|
|
// Non-conflict
|
|
test_equivalent(
|
|
(vec![], vec![0]),
|
|
Merge::from_removes_adds(vec![], vec![Some(0)]),
|
|
);
|
|
// Regular 3-way conflict
|
|
test_equivalent(
|
|
(vec![0], vec![1, 2]),
|
|
Merge::from_removes_adds(vec![Some(0)], vec![Some(1), Some(2)]),
|
|
);
|
|
// Modify/delete conflict
|
|
test_equivalent(
|
|
(vec![0], vec![1]),
|
|
Merge::from_removes_adds(vec![Some(0)], vec![Some(1), None]),
|
|
);
|
|
// Add/add conflict
|
|
test_equivalent(
|
|
(vec![], vec![0, 1]),
|
|
Merge::from_removes_adds(vec![None], vec![Some(0), Some(1)]),
|
|
);
|
|
// 5-way conflict
|
|
test_equivalent(
|
|
(vec![0, 1], vec![2, 3, 4]),
|
|
Merge::from_removes_adds(vec![Some(0), Some(1)], vec![Some(2), Some(3), Some(4)]),
|
|
);
|
|
// 5-way delete/delete conflict
|
|
test_equivalent(
|
|
(vec![0, 1], vec![]),
|
|
Merge::from_removes_adds(vec![Some(0), Some(1)], vec![None, None, None]),
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_as_resolved() {
|
|
assert_eq!(
|
|
Merge::from_removes_adds(vec![], vec![0]).as_resolved(),
|
|
Some(&0)
|
|
);
|
|
// Even a trivially resolvable merge is not resolved
|
|
assert_eq!(
|
|
Merge::from_removes_adds(vec![0], vec![0, 1]).as_resolved(),
|
|
None
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_simplify() {
|
|
// 1-way merge
|
|
assert_eq!(c(&[], &[0]).simplify(), c(&[], &[0]));
|
|
// 3-way merge
|
|
assert_eq!(c(&[0], &[0, 0]).simplify(), c(&[], &[0]));
|
|
assert_eq!(c(&[0], &[0, 1]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0], &[1, 0]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0], &[1, 1]).simplify(), c(&[0], &[1, 1]));
|
|
assert_eq!(c(&[0], &[1, 2]).simplify(), c(&[0], &[1, 2]));
|
|
// 5-way merge
|
|
assert_eq!(c(&[0, 0], &[0, 0, 0]).simplify(), c(&[], &[0]));
|
|
assert_eq!(c(&[0, 0], &[0, 0, 1]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0, 0], &[0, 1, 0]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0, 0], &[0, 1, 1]).simplify(), c(&[0], &[1, 1]));
|
|
assert_eq!(c(&[0, 0], &[0, 1, 2]).simplify(), c(&[0], &[1, 2]));
|
|
assert_eq!(c(&[0, 0], &[1, 0, 0]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0, 0], &[1, 0, 1]).simplify(), c(&[0], &[1, 1]));
|
|
assert_eq!(c(&[0, 0], &[1, 0, 2]).simplify(), c(&[0], &[1, 2]));
|
|
assert_eq!(c(&[0, 0], &[1, 1, 0]).simplify(), c(&[0], &[1, 1]));
|
|
assert_eq!(c(&[0, 0], &[1, 1, 1]).simplify(), c(&[0, 0], &[1, 1, 1]));
|
|
assert_eq!(c(&[0, 0], &[1, 1, 2]).simplify(), c(&[0, 0], &[1, 1, 2]));
|
|
assert_eq!(c(&[0, 0], &[1, 2, 0]).simplify(), c(&[0], &[1, 2]));
|
|
assert_eq!(c(&[0, 0], &[1, 2, 1]).simplify(), c(&[0, 0], &[1, 2, 1]));
|
|
assert_eq!(c(&[0, 0], &[1, 2, 2]).simplify(), c(&[0, 0], &[1, 2, 2]));
|
|
assert_eq!(c(&[0, 0], &[1, 2, 3]).simplify(), c(&[0, 0], &[1, 2, 3]));
|
|
assert_eq!(c(&[0, 1], &[0, 0, 0]).simplify(), c(&[1], &[0, 0]));
|
|
assert_eq!(c(&[0, 1], &[0, 0, 1]).simplify(), c(&[], &[0]));
|
|
assert_eq!(c(&[0, 1], &[0, 0, 2]).simplify(), c(&[1], &[0, 2]));
|
|
assert_eq!(c(&[0, 1], &[0, 1, 0]).simplify(), c(&[], &[0]));
|
|
assert_eq!(c(&[0, 1], &[0, 1, 1]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0, 1], &[0, 1, 2]).simplify(), c(&[], &[2]));
|
|
assert_eq!(c(&[0, 1], &[0, 2, 0]).simplify(), c(&[1], &[2, 0]));
|
|
assert_eq!(c(&[0, 1], &[0, 2, 1]).simplify(), c(&[], &[2]));
|
|
assert_eq!(c(&[0, 1], &[0, 2, 2]).simplify(), c(&[1], &[2, 2]));
|
|
assert_eq!(c(&[0, 1], &[0, 2, 3]).simplify(), c(&[1], &[2, 3]));
|
|
assert_eq!(c(&[0, 1], &[1, 0, 0]).simplify(), c(&[], &[0]));
|
|
assert_eq!(c(&[0, 1], &[1, 0, 1]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0, 1], &[1, 0, 2]).simplify(), c(&[], &[2]));
|
|
assert_eq!(c(&[0, 1], &[1, 1, 0]).simplify(), c(&[], &[1]));
|
|
assert_eq!(c(&[0, 1], &[1, 1, 1]).simplify(), c(&[0], &[1, 1]));
|
|
assert_eq!(c(&[0, 1], &[1, 1, 2]).simplify(), c(&[0], &[2, 1]));
|
|
assert_eq!(c(&[0, 1], &[1, 2, 0]).simplify(), c(&[], &[2]));
|
|
assert_eq!(c(&[0, 1], &[1, 2, 1]).simplify(), c(&[0], &[1, 2]));
|
|
assert_eq!(c(&[0, 1], &[1, 2, 2]).simplify(), c(&[0], &[2, 2]));
|
|
assert_eq!(c(&[0, 1], &[1, 2, 3]).simplify(), c(&[0], &[3, 2]));
|
|
assert_eq!(c(&[0, 1], &[2, 0, 0]).simplify(), c(&[1], &[2, 0]));
|
|
assert_eq!(c(&[0, 1], &[2, 0, 1]).simplify(), c(&[], &[2]));
|
|
assert_eq!(c(&[0, 1], &[2, 0, 2]).simplify(), c(&[1], &[2, 2]));
|
|
assert_eq!(c(&[0, 1], &[2, 0, 3]).simplify(), c(&[1], &[2, 3]));
|
|
assert_eq!(c(&[0, 1], &[2, 1, 0]).simplify(), c(&[], &[2]));
|
|
assert_eq!(c(&[0, 1], &[2, 1, 1]).simplify(), c(&[0], &[2, 1]));
|
|
assert_eq!(c(&[0, 1], &[2, 1, 2]).simplify(), c(&[0], &[2, 2]));
|
|
assert_eq!(c(&[0, 1], &[2, 1, 3]).simplify(), c(&[0], &[2, 3]));
|
|
assert_eq!(c(&[0, 1], &[2, 2, 0]).simplify(), c(&[1], &[2, 2]));
|
|
assert_eq!(c(&[0, 1], &[2, 2, 1]).simplify(), c(&[0], &[2, 2]));
|
|
assert_eq!(c(&[0, 1], &[2, 2, 2]).simplify(), c(&[0, 1], &[2, 2, 2]));
|
|
assert_eq!(c(&[0, 1], &[2, 2, 3]).simplify(), c(&[0, 1], &[2, 2, 3]));
|
|
assert_eq!(c(&[0, 1], &[2, 3, 0]).simplify(), c(&[1], &[2, 3]));
|
|
assert_eq!(c(&[0, 1], &[2, 3, 1]).simplify(), c(&[0], &[2, 3]));
|
|
assert_eq!(c(&[0, 1], &[2, 3, 2]).simplify(), c(&[0, 1], &[2, 3, 2]));
|
|
assert_eq!(c(&[0, 1], &[2, 3, 3]).simplify(), c(&[0, 1], &[2, 3, 3]));
|
|
assert_eq!(c(&[0, 1], &[2, 3, 4]).simplify(), c(&[0, 1], &[2, 3, 4]));
|
|
assert_eq!(
|
|
c(&[0, 1, 2], &[3, 4, 5, 0]).simplify(),
|
|
c(&[1, 2], &[3, 5, 4])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_merge_invariants() {
|
|
fn check_invariants(removes: &[u32], adds: &[u32]) {
|
|
let merge = Merge::from_removes_adds(removes.to_vec(), adds.to_vec());
|
|
// `simplify()` is idempotent
|
|
assert_eq!(
|
|
merge.clone().simplify().simplify(),
|
|
merge.clone().simplify(),
|
|
"simplify() not idempotent for {merge:?}"
|
|
);
|
|
// `resolve_trivial()` is unaffected by `simplify()`
|
|
assert_eq!(
|
|
merge.clone().simplify().resolve_trivial(),
|
|
merge.resolve_trivial(),
|
|
"simplify() changed result of resolve_trivial() for {merge:?}"
|
|
);
|
|
}
|
|
// 1-way merge
|
|
check_invariants(&[], &[0]);
|
|
for i in 0..=1 {
|
|
for j in 0..=i + 1 {
|
|
// 3-way merge
|
|
check_invariants(&[0], &[i, j]);
|
|
for k in 0..=j + 1 {
|
|
for l in 0..=k + 1 {
|
|
// 5-way merge
|
|
check_invariants(&[0, i], &[j, k, l]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn test_swap_remove() {
|
|
let mut x = c(&[1, 3, 5], &[0, 2, 4, 6]);
|
|
assert_eq!(x.swap_remove(0, 1), (1, 2));
|
|
assert_eq!(x, c(&[5, 3], &[0, 6, 4]));
|
|
assert_eq!(x.swap_remove(1, 0), (3, 0));
|
|
assert_eq!(x, c(&[5], &[4, 6]));
|
|
assert_eq!(x.swap_remove(0, 1), (5, 6));
|
|
assert_eq!(x, c(&[], &[4]));
|
|
}
|
|
|
|
#[test]
|
|
fn test_pad_to() {
|
|
let mut x = c(&[], &[1]);
|
|
x.pad_to(3, &2);
|
|
assert_eq!(x, c(&[2, 2], &[1, 2, 2]));
|
|
// No change if the requested size is smaller
|
|
x.pad_to(1, &3);
|
|
assert_eq!(x, c(&[2, 2], &[1, 2, 2]));
|
|
}
|
|
|
|
#[test]
|
|
fn test_iter() {
|
|
// 1-way merge
|
|
assert_eq!(c(&[], &[1]).iter().collect_vec(), vec![&1]);
|
|
// 5-way merge
|
|
assert_eq!(
|
|
c(&[1, 2], &[3, 4, 5]).iter().collect_vec(),
|
|
vec![&3, &1, &4, &2, &5]
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_from_iter() {
|
|
// 1-way merge
|
|
assert_eq!(MergeBuilder::from_iter([1]).build(), c(&[], &[1]));
|
|
// 5-way merge
|
|
assert_eq!(
|
|
MergeBuilder::from_iter([1, 2, 3, 4, 5]).build(),
|
|
c(&[2, 4], &[1, 3, 5])
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
#[should_panic]
|
|
fn test_from_iter_empty() {
|
|
MergeBuilder::from_iter([1; 0]).build();
|
|
}
|
|
|
|
#[test]
|
|
#[should_panic]
|
|
fn test_from_iter_even() {
|
|
MergeBuilder::from_iter([1, 2]).build();
|
|
}
|
|
|
|
#[test]
|
|
fn test_extend() {
|
|
// 1-way merge
|
|
let mut builder: MergeBuilder<i32> = Default::default();
|
|
builder.extend([1]);
|
|
assert_eq!(builder.build(), c(&[], &[1]));
|
|
// 5-way merge
|
|
let mut builder: MergeBuilder<i32> = Default::default();
|
|
builder.extend([1, 2]);
|
|
builder.extend([3, 4, 5]);
|
|
assert_eq!(builder.build(), c(&[2, 4], &[1, 3, 5]));
|
|
}
|
|
|
|
#[test]
|
|
fn test_map() {
|
|
fn increment(i: &i32) -> i32 {
|
|
i + 1
|
|
}
|
|
// 1-way merge
|
|
assert_eq!(c(&[], &[1]).map(increment), c(&[], &[2]));
|
|
// 3-way merge
|
|
assert_eq!(c(&[1], &[3, 5]).map(increment), c(&[2], &[4, 6]));
|
|
}
|
|
|
|
#[test]
|
|
fn test_maybe_map() {
|
|
fn sqrt(i: &i32) -> Option<i32> {
|
|
if *i >= 0 {
|
|
Some((*i as f64).sqrt() as i32)
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
// 1-way merge
|
|
assert_eq!(c(&[], &[1]).maybe_map(sqrt), Some(c(&[], &[1])));
|
|
assert_eq!(c(&[], &[-1]).maybe_map(sqrt), None);
|
|
// 3-way merge
|
|
assert_eq!(c(&[1], &[4, 9]).maybe_map(sqrt), Some(c(&[1], &[2, 3])));
|
|
assert_eq!(c(&[-1], &[4, 9]).maybe_map(sqrt), None);
|
|
assert_eq!(c(&[1], &[-4, 9]).maybe_map(sqrt), None);
|
|
}
|
|
|
|
#[test]
|
|
fn test_try_map() {
|
|
fn sqrt(i: &i32) -> Result<i32, ()> {
|
|
if *i >= 0 {
|
|
Ok((*i as f64).sqrt() as i32)
|
|
} else {
|
|
Err(())
|
|
}
|
|
}
|
|
// 1-way merge
|
|
assert_eq!(c(&[], &[1]).try_map(sqrt), Ok(c(&[], &[1])));
|
|
assert_eq!(c(&[], &[-1]).try_map(sqrt), Err(()));
|
|
// 3-way merge
|
|
assert_eq!(c(&[1], &[4, 9]).try_map(sqrt), Ok(c(&[1], &[2, 3])));
|
|
assert_eq!(c(&[-1], &[4, 9]).try_map(sqrt), Err(()));
|
|
assert_eq!(c(&[1], &[-4, 9]).try_map(sqrt), Err(()));
|
|
}
|
|
|
|
#[test]
|
|
fn test_flatten() {
|
|
// 1-way merge of 1-way merge
|
|
assert_eq!(c(&[], &[c(&[], &[0])]).flatten(), c(&[], &[0]));
|
|
// 1-way merge of 3-way merge
|
|
assert_eq!(c(&[], &[c(&[0], &[1, 2])]).flatten(), c(&[0], &[1, 2]));
|
|
// 3-way merge of 1-way merges
|
|
assert_eq!(
|
|
c(&[c(&[], &[0])], &[c(&[], &[1]), c(&[], &[2])]).flatten(),
|
|
c(&[0], &[1, 2])
|
|
);
|
|
// 3-way merge of 3-way merges
|
|
assert_eq!(
|
|
c(&[c(&[0], &[1, 2])], &[c(&[3], &[4, 5]), c(&[6], &[7, 8])]).flatten(),
|
|
c(&[3, 2, 1, 6], &[4, 5, 0, 7, 8])
|
|
);
|
|
}
|
|
}
|