use std::cmp::Ordering;
use std::fmt::{Debug, Error, Formatter};
use std::io::Read;
use std::iter::Peekable;
use std::pin::Pin;
use std::sync::Arc;
use itertools::Itertools;
use thiserror::Error;
use crate::backend::{
BackendError, Conflict, ConflictId, ConflictPart, FileId, TreeEntriesNonRecursiveIterator,
TreeEntry, TreeId, TreeValue,
};
use crate::files::MergeResult;
use crate::matchers::{EverythingMatcher, Matcher};
use crate::repo_path::{RepoPath, RepoPathComponent, RepoPathJoin};
use crate::store::Store;
use crate::{backend, files};
#[derive(Debug, Error)]
pub enum TreeMergeError {
#[error("Failed to read file with ID {} ", .file_id.hex())]
ReadError {
source: std::io::Error,
file_id: FileId,
},
#[error("Backend error: {0}")]
BackendError(#[from] BackendError),
}
#[derive(Clone)]
pub struct Tree {
store: Arc<Store>,
dir: RepoPath,
id: TreeId,
data: Arc<backend::Tree>,
}
impl Debug for Tree {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
f.debug_struct("Tree")
.field("dir", &self.dir)
.field("id", &self.id)
.finish()
}
}
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct DiffSummary {
pub modified: Vec<RepoPath>,
pub added: Vec<RepoPath>,
pub removed: Vec<RepoPath>,
}
impl DiffSummary {
pub fn is_empty(&self) -> bool {
self.modified.is_empty() && self.added.is_empty() && self.removed.is_empty()
}
}
impl Tree {
pub fn new(store: Arc<Store>, dir: RepoPath, id: TreeId, data: Arc<backend::Tree>) -> Self {
Tree {
store,
dir,
id,
data,
}
}
pub fn null(store: Arc<Store>, dir: RepoPath) -> Self {
Tree {
store,
dir,
id: TreeId::new(vec![]),
data: Arc::new(backend::Tree::default()),
}
}
pub fn store(&self) -> &Arc<Store> {
&self.store
}
pub fn dir(&self) -> &RepoPath {
&self.dir
}
pub fn id(&self) -> &TreeId {
&self.id
}
pub fn data(&self) -> &backend::Tree {
&self.data
}
pub fn entries_non_recursive(&self) -> TreeEntriesNonRecursiveIterator {
self.data.entries()
}
pub fn entries(&self) -> TreeEntriesIterator<'static> {
TreeEntriesIterator::new(self.clone(), &EverythingMatcher)
}
pub fn entries_matching<'matcher>(
&self,
matcher: &'matcher dyn Matcher,
) -> TreeEntriesIterator<'matcher> {
TreeEntriesIterator::new(self.clone(), matcher)
}
pub fn entry(&self, basename: &RepoPathComponent) -> Option<TreeEntry> {
self.data.entry(basename)
}
pub fn value(&self, basename: &RepoPathComponent) -> Option<&TreeValue> {
self.data.value(basename)
}
pub fn path_value(&self, path: &RepoPath) -> Option<TreeValue> {
assert_eq!(self.dir(), &RepoPath::root());
match path.split() {
Some((dir, basename)) => self
.sub_tree_recursive(dir.components())
.and_then(|tree| tree.data.value(basename).cloned()),
None => Some(TreeValue::Tree(self.id.clone())),
}
}
pub fn sub_tree(&self, name: &RepoPathComponent) -> Option<Tree> {
self.data.value(name).and_then(|sub_tree| match sub_tree {
TreeValue::Tree(sub_tree_id) => {
let subdir = self.dir.join(name);
Some(self.store.get_tree(&subdir, sub_tree_id).unwrap())
}
_ => None,
})
}
pub fn known_sub_tree(&self, name: &RepoPathComponent, id: &TreeId) -> Tree {
let subdir = self.dir.join(name);
self.store.get_tree(&subdir, id).unwrap()
}
fn sub_tree_recursive(&self, components: &[RepoPathComponent]) -> Option<Tree> {
if components.is_empty() {
Some(Tree {
store: self.store.clone(),
dir: self.dir.clone(),
id: self.id.clone(),
data: self.data.clone(),
})
} else {
match self.data.entry(&components[0]) {
None => None,
Some(entry) => match entry.value() {
TreeValue::Tree(sub_tree_id) => {
let sub_tree = self.known_sub_tree(entry.name(), sub_tree_id);
sub_tree.sub_tree_recursive(&components[1..])
}
_ => None,
},
}
}
}
pub fn diff<'matcher>(
&self,
other: &Tree,
matcher: &'matcher dyn Matcher,
) -> TreeDiffIterator<'matcher> {
recursive_tree_diff(self.clone(), other.clone(), matcher)
}
pub fn diff_summary(&self, other: &Tree, matcher: &dyn Matcher) -> DiffSummary {
let mut modified = vec![];
let mut added = vec![];
let mut removed = vec![];
for (file, diff) in self.diff(other, matcher) {
match diff {
Diff::Modified(_, _) => modified.push(file.clone()),
Diff::Added(_) => added.push(file.clone()),
Diff::Removed(_) => removed.push(file.clone()),
}
}
modified.sort();
added.sort();
removed.sort();
DiffSummary {
modified,
added,
removed,
}
}
pub fn conflicts_matching(&self, matcher: &dyn Matcher) -> Vec<(RepoPath, ConflictId)> {
let mut conflicts = vec![];
for (name, value) in self.entries_matching(matcher) {
if let TreeValue::Conflict(id) = value {
conflicts.push((name.clone(), id.clone()));
}
}
conflicts
}
pub fn conflicts(&self) -> Vec<(RepoPath, ConflictId)> {
self.conflicts_matching(&EverythingMatcher)
}
pub fn has_conflict(&self) -> bool {
!self.conflicts().is_empty()
}
}
pub struct TreeEntriesIterator<'matcher> {
tree: Pin<Box<Tree>>,
entry_iterator: TreeEntriesNonRecursiveIterator<'static>,
subdir_iterator: Option<Box<TreeEntriesIterator<'matcher>>>,
matcher: &'matcher dyn Matcher,
}
impl<'matcher> TreeEntriesIterator<'matcher> {
fn new(tree: Tree, matcher: &'matcher dyn Matcher) -> Self {
let tree = Box::pin(tree);
let entry_iterator = tree.entries_non_recursive();
let entry_iterator: TreeEntriesNonRecursiveIterator<'static> =
unsafe { std::mem::transmute(entry_iterator) };
Self {
tree,
entry_iterator,
subdir_iterator: None,
matcher,
}
}
}
impl Iterator for TreeEntriesIterator<'_> {
type Item = (RepoPath, TreeValue);
fn next(&mut self) -> Option<Self::Item> {
loop {
if let Some(subdir_iter) = &mut self.subdir_iterator {
if let Some(item) = subdir_iter.next() {
return Some(item);
}
self.subdir_iterator = None;
}
let entry = self.entry_iterator.next()?;
match entry.value() {
TreeValue::Tree(id) => {
let subtree = self.tree.known_sub_tree(entry.name(), id);
self.subdir_iterator =
Some(Box::new(TreeEntriesIterator::new(subtree, self.matcher)));
}
other => {
let path = self.tree.dir().join(entry.name());
if !self.matcher.matches(&path) {
continue;
}
return Some((path, other.clone()));
}
};
}
}
}
#[derive(Debug, PartialEq, Eq, Clone)]
pub enum Diff<T> {
Modified(T, T),
Added(T),
Removed(T),
}
impl<T> Diff<T> {
pub fn as_options(&self) -> (Option<&T>, Option<&T>) {
match self {
Diff::Modified(left, right) => (Some(left), Some(right)),
Diff::Added(right) => (None, Some(right)),
Diff::Removed(left) => (Some(left), None),
}
}
pub fn into_options(self) -> (Option<T>, Option<T>) {
match self {
Diff::Modified(left, right) => (Some(left), Some(right)),
Diff::Added(right) => (None, Some(right)),
Diff::Removed(left) => (Some(left), None),
}
}
}
struct TreeEntryDiffIterator<'trees, 'matcher> {
it1: Peekable<TreeEntriesNonRecursiveIterator<'trees>>,
it2: Peekable<TreeEntriesNonRecursiveIterator<'trees>>,
_matcher: &'matcher dyn Matcher,
}
impl<'trees, 'matcher> TreeEntryDiffIterator<'trees, 'matcher> {
fn new(tree1: &'trees Tree, tree2: &'trees Tree, matcher: &'matcher dyn Matcher) -> Self {
let it1 = tree1.entries_non_recursive().peekable();
let it2 = tree2.entries_non_recursive().peekable();
TreeEntryDiffIterator {
it1,
it2,
_matcher: matcher,
}
}
}
impl<'trees, 'matcher> Iterator for TreeEntryDiffIterator<'trees, 'matcher> {
type Item = (
RepoPathComponent,
Option<&'trees TreeValue>,
Option<&'trees TreeValue>,
);
fn next(&mut self) -> Option<Self::Item> {
loop {
let entry1 = self.it1.peek();
let entry2 = self.it2.peek();
match (&entry1, &entry2) {
(Some(before), Some(after)) => {
match before.name().cmp(after.name()) {
Ordering::Less => {
let before = self.it1.next().unwrap();
return Some((before.name().clone(), Some(before.value()), None));
}
Ordering::Greater => {
let after = self.it2.next().unwrap();
return Some((after.name().clone(), None, Some(after.value())));
}
Ordering::Equal => {
let before = self.it1.next().unwrap();
let after = self.it2.next().unwrap();
if before.value() != after.value() {
return Some((
before.name().clone(),
Some(before.value()),
Some(after.value()),
));
}
}
}
}
(Some(_), None) => {
let before = self.it1.next().unwrap();
return Some((before.name().clone(), Some(before.value()), None));
}
(None, Some(_)) => {
let after = self.it2.next().unwrap();
return Some((after.name().clone(), None, Some(after.value())));
}
(None, None) => {
return None;
}
}
}
}
}
fn diff_entries<'trees, 'matcher>(
tree1: &'trees Tree,
tree2: &'trees Tree,
matcher: &'matcher dyn Matcher,
) -> TreeEntryDiffIterator<'trees, 'matcher> {
TreeEntryDiffIterator::new(tree1, tree2, matcher)
}
pub fn recursive_tree_diff(root1: Tree, root2: Tree, matcher: &dyn Matcher) -> TreeDiffIterator {
TreeDiffIterator::new(RepoPath::root(), root1, root2, matcher)
}
pub struct TreeDiffIterator<'matcher> {
dir: RepoPath,
tree1: Pin<Box<Tree>>,
tree2: Pin<Box<Tree>>,
matcher: &'matcher dyn Matcher,
entry_iterator: TreeEntryDiffIterator<'static, 'matcher>,
added_file: Option<(RepoPath, TreeValue)>,
subdir_iterator: Option<Box<TreeDiffIterator<'matcher>>>,
}
impl<'matcher> TreeDiffIterator<'matcher> {
fn new(
dir: RepoPath,
tree1: Tree,
tree2: Tree,
matcher: &'matcher dyn Matcher,
) -> TreeDiffIterator {
let tree1 = Box::pin(tree1);
let tree2 = Box::pin(tree2);
let root_entry_iterator: TreeEntryDiffIterator = diff_entries(&tree1, &tree2, matcher);
let root_entry_iterator: TreeEntryDiffIterator<'static, 'matcher> =
unsafe { std::mem::transmute(root_entry_iterator) };
Self {
dir,
tree1,
tree2,
matcher,
entry_iterator: root_entry_iterator,
added_file: None,
subdir_iterator: None,
}
}
}
impl Iterator for TreeDiffIterator<'_> {
type Item = (RepoPath, Diff<TreeValue>);
fn next(&mut self) -> Option<Self::Item> {
loop {
if let Some(subdir_iterator) = &mut self.subdir_iterator {
if let Some(element) = subdir_iterator.next() {
return Some(element);
}
self.subdir_iterator = None;
}
if let Some((name, value)) = self.added_file.take() {
return Some((name, Diff::Added(value)));
}
let (name, before, after) = self.entry_iterator.next()?;
let tree_before = matches!(before, Some(TreeValue::Tree(_)));
let tree_after = matches!(after, Some(TreeValue::Tree(_)));
if tree_before || tree_after {
let subdir = &name;
let subdir_path = self.dir.join(subdir);
let before_tree = match before {
Some(TreeValue::Tree(id_before)) => {
self.tree1.known_sub_tree(subdir, id_before)
}
_ => Tree::null(self.tree1.store().clone(), subdir_path.clone()),
};
let after_tree = match after {
Some(TreeValue::Tree(id_after)) => self.tree2.known_sub_tree(subdir, id_after),
_ => Tree::null(self.tree2.store().clone(), subdir_path.clone()),
};
self.subdir_iterator = Some(Box::new(TreeDiffIterator::new(
subdir_path,
before_tree,
after_tree,
self.matcher,
)));
}
let file_path = self.dir.join(&name);
if self.matcher.matches(&file_path) {
if !tree_before && tree_after {
if let Some(file_before) = before {
return Some((file_path, Diff::Removed(file_before.clone())));
}
} else if tree_before && !tree_after {
if let Some(file_after) = after {
self.added_file = Some((file_path, file_after.clone()));
}
} else if !tree_before && !tree_after {
match (before, after) {
(Some(file_before), Some(file_after)) => {
return Some((
file_path,
Diff::Modified(file_before.clone(), file_after.clone()),
));
}
(None, Some(file_after)) => {
return Some((file_path, Diff::Added(file_after.clone())));
}
(Some(file_before), None) => {
return Some((file_path, Diff::Removed(file_before.clone())));
}
(None, None) => {
panic!("unexpected diff")
}
}
}
}
}
}
}
pub fn merge_trees(
side1_tree: &Tree,
base_tree: &Tree,
side2_tree: &Tree,
) -> Result<TreeId, TreeMergeError> {
let store = base_tree.store();
let dir = base_tree.dir();
assert_eq!(side1_tree.dir(), dir);
assert_eq!(side2_tree.dir(), dir);
if base_tree.id() == side1_tree.id() {
return Ok(side2_tree.id().clone());
}
if base_tree.id() == side2_tree.id() || side1_tree.id() == side2_tree.id() {
return Ok(side1_tree.id().clone());
}
let mut new_tree = side1_tree.data().clone();
for (basename, maybe_base, maybe_side2) in
diff_entries(base_tree, side2_tree, &EverythingMatcher)
{
let maybe_side1 = side1_tree.value(&basename);
if maybe_side1 == maybe_base {
match maybe_side2 {
None => new_tree.remove(&basename),
Some(side2) => new_tree.set(basename, side2.clone()),
};
} else if maybe_side1 == maybe_side2 {
} else {
let new_value =
merge_tree_value(store, dir, &basename, maybe_base, maybe_side1, maybe_side2)?;
match new_value {
None => new_tree.remove(&basename),
Some(value) => new_tree.set(basename, value),
}
}
}
Ok(store.write_tree(dir, &new_tree)?)
}
fn maybe_tree_id<'id>(
value: Option<&'id TreeValue>,
empty_tree_id: &'id TreeId,
) -> Option<&'id TreeId> {
match value {
Some(TreeValue::Tree(id)) => Some(id),
None => Some(empty_tree_id),
_ => None,
}
}
fn merge_tree_value(
store: &Arc<Store>,
dir: &RepoPath,
basename: &RepoPathComponent,
maybe_base: Option<&TreeValue>,
maybe_side1: Option<&TreeValue>,
maybe_side2: Option<&TreeValue>,
) -> Result<Option<TreeValue>, TreeMergeError> {
let empty_tree_id = store.empty_tree_id();
let base_tree_id = maybe_tree_id(maybe_base, empty_tree_id);
let side1_tree_id = maybe_tree_id(maybe_side1, empty_tree_id);
let side2_tree_id = maybe_tree_id(maybe_side2, empty_tree_id);
Ok(match (base_tree_id, side1_tree_id, side2_tree_id) {
(Some(base_id), Some(side1_id), Some(side2_id)) => {
let subdir = dir.join(basename);
let base_tree = store.get_tree(&subdir, base_id)?;
let side1_tree = store.get_tree(&subdir, side1_id)?;
let side2_tree = store.get_tree(&subdir, side2_id)?;
let merged_tree_id = merge_trees(&side1_tree, &base_tree, &side2_tree)?;
if merged_tree_id == *empty_tree_id {
None
} else {
Some(TreeValue::Tree(merged_tree_id))
}
}
_ => {
let mut conflict = Conflict::default();
if let Some(base) = maybe_base {
conflict.removes.push(ConflictPart {
value: base.clone(),
});
}
if let Some(side1) = maybe_side1 {
conflict.adds.push(ConflictPart {
value: side1.clone(),
});
}
if let Some(side2) = maybe_side2 {
conflict.adds.push(ConflictPart {
value: side2.clone(),
});
}
let filename = dir.join(basename);
let conflict = simplify_conflict(store, &filename, &conflict)?;
if conflict.adds.is_empty() {
return Ok(None);
}
if conflict.removes.is_empty() && conflict.adds.len() == 1 {
return Ok(Some(conflict.adds[0].value.clone()));
}
if let Some((merged_content, executable)) =
try_resolve_file_conflict(store, &filename, &conflict)?
{
let id = store.write_file(&filename, &mut merged_content.as_slice())?;
Some(TreeValue::File { id, executable })
} else {
let conflict_id = store.write_conflict(&filename, &conflict)?;
Some(TreeValue::Conflict(conflict_id))
}
}
})
}
fn try_resolve_file_conflict(
store: &Store,
filename: &RepoPath,
conflict: &Conflict,
) -> Result<Option<(Vec<u8>, bool)>, TreeMergeError> {
let mut exec_delta = 0;
let mut regular_delta = 0;
let mut removed_file_ids = vec![];
let mut added_file_ids = vec![];
for part in &conflict.removes {
match &part.value {
TreeValue::File { id, executable } => {
if *executable {
exec_delta -= 1;
} else {
regular_delta -= 1;
}
removed_file_ids.push(id.clone());
}
_ => {
return Ok(None);
}
}
}
for part in &conflict.adds {
match &part.value {
TreeValue::File { id, executable } => {
if *executable {
exec_delta += 1;
} else {
regular_delta += 1;
}
added_file_ids.push(id.clone());
}
_ => {
return Ok(None);
}
}
}
let executable = if exec_delta > 0 && regular_delta <= 0 {
true
} else if regular_delta > 0 && exec_delta <= 0 {
false
} else {
return Ok(None);
};
let mut removed_contents = vec![];
let mut added_contents = vec![];
for file_id in removed_file_ids {
let mut content = vec![];
store
.read_file(filename, &file_id)?
.read_to_end(&mut content)
.map_err(|err| TreeMergeError::ReadError {
source: err,
file_id,
})?;
removed_contents.push(content);
}
for file_id in added_file_ids {
let mut content = vec![];
store
.read_file(filename, &file_id)?
.read_to_end(&mut content)
.map_err(|err| TreeMergeError::ReadError {
source: err,
file_id,
})?;
added_contents.push(content);
}
let merge_result = files::merge(
&removed_contents.iter().map(Vec::as_slice).collect_vec(),
&added_contents.iter().map(Vec::as_slice).collect_vec(),
);
match merge_result {
MergeResult::Resolved(merged_content) => Ok(Some((merged_content, executable))),
MergeResult::Conflict(_) => Ok(None),
}
}
fn conflict_part_to_conflict(
store: &Store,
path: &RepoPath,
part: &ConflictPart,
) -> Result<Conflict, BackendError> {
match &part.value {
TreeValue::Conflict(id) => {
let conflict = store.read_conflict(path, id)?;
Ok(conflict)
}
other => Ok(Conflict {
removes: vec![],
adds: vec![ConflictPart {
value: other.clone(),
}],
}),
}
}
fn simplify_conflict(
store: &Store,
path: &RepoPath,
conflict: &Conflict,
) -> Result<Conflict, BackendError> {
let mut new_removes = vec![];
let mut new_adds = vec![];
for part in &conflict.adds {
match part.value {
TreeValue::Conflict(_) => {
let conflict = conflict_part_to_conflict(store, path, part)?;
new_removes.extend_from_slice(&conflict.removes);
new_adds.extend_from_slice(&conflict.adds);
}
_ => {
new_adds.push(part.clone());
}
}
}
for part in &conflict.removes {
match part.value {
TreeValue::Conflict(_) => {
let conflict = conflict_part_to_conflict(store, path, part)?;
new_removes.extend_from_slice(&conflict.adds);
new_adds.extend_from_slice(&conflict.removes);
}
_ => {
new_removes.push(part.clone());
}
}
}
let mut add_index = 0;
while add_index < new_adds.len() {
let add = &new_adds[add_index];
add_index += 1;
for (remove_index, remove) in new_removes.iter().enumerate() {
if remove.value == add.value {
new_removes.remove(remove_index);
add_index -= 1;
new_adds.remove(add_index);
break;
}
}
}
Ok(Conflict {
adds: new_adds,
removes: new_removes,
})
}