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// Copyright 2018-2019 Mozilla // 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 // // http://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. use std::{ borrow::Cow, cmp::Ordering, collections::{HashMap, HashSet}, convert::{TryFrom, TryInto}, fmt, mem, ops::Deref, ptr, }; use smallbitvec::SmallBitVec; use crate::error::{Error, ErrorKind, Result}; use crate::guid::Guid; /// The type for entry indices in the tree. type Index = usize; /// A complete, rooted bookmark tree with tombstones. /// /// The tree stores bookmark items in a vector, and uses indices in the vector /// to identify parents and children. This makes traversal and lookup very /// efficient. Retrieving a node's parent takes one indexing operation, /// retrieving children takes one indexing operation per child, and retrieving /// a node by random GUID takes one hash map lookup and one indexing operation. #[derive(Debug)] pub struct Tree { entry_index_by_guid: HashMap<Guid, Index>, entries: Vec<TreeEntry>, deleted_guids: HashSet<Guid>, problems: Problems, } impl Tree { /// Returns a builder for a rooted tree. pub fn with_root(root: Item) -> Builder { let mut entry_index_by_guid = HashMap::new(); entry_index_by_guid.insert(root.guid.clone(), 0); Builder { entries: vec![BuilderEntry { item: root, content: None, parent: BuilderEntryParent::Root, children: Vec::new(), }], deleted_guids: HashSet::new(), entry_index_by_guid, reparent_orphans_to: None, } } /// Returns the number of nodes in the tree. #[inline] pub fn size(&self) -> usize { self.entries.len() } /// Returns the root node. #[inline] pub fn root(&self) -> Node<'_> { Node(self, &self.entries[0]) } /// Returns an iterator for all tombstoned GUIDs. #[inline] pub fn deletions(&self) -> impl Iterator<Item = &Guid> { self.deleted_guids.iter() } /// Indicates if the GUID is known to be deleted. If `Tree::node_for_guid` /// returns `None` and `Tree::is_deleted` returns `false`, the item doesn't /// exist in the tree at all. #[inline] pub fn is_deleted(&self, guid: &Guid) -> bool { self.deleted_guids.contains(guid) } /// Indicates if the GUID is mentioned in the tree, either as a node or /// a deletion. #[inline] pub fn mentions(&self, guid: &Guid) -> bool { self.entry_index_by_guid.contains_key(guid) || self.deleted_guids.contains(guid) } /// Returns an iterator for all node and tombstone GUIDs. pub fn guids(&self) -> impl Iterator<Item = &Guid> { self.entries .iter() .map(|entry| &entry.item.guid) .chain(self.deleted_guids.iter()) } /// Returns the node for a given `guid`, or `None` if a node with the `guid` /// doesn't exist in the tree, or was deleted. pub fn node_for_guid(&self, guid: &Guid) -> Option<Node<'_>> { self.entry_index_by_guid .get(guid) .map(|&index| Node(self, &self.entries[index])) } /// Returns the structure divergences found when building the tree. #[inline] pub fn problems(&self) -> &Problems { &self.problems } } impl fmt::Display for Tree { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let root = self.root(); f.write_str(&root.to_ascii_string())?; if !self.deleted_guids.is_empty() { f.write_str("\nDeleted: [")?; for (i, guid) in self.deleted_guids.iter().enumerate() { if i != 0 { f.write_str(", ")?; } f.write_str(guid.as_ref())?; } } if !self.problems.is_empty() { f.write_str("\nProblems:\n")?; for (i, summary) in self.problems.summarize().enumerate() { if i != 0 { f.write_str("\n")?; } write!(f, "❗️ {}", summary)?; } } Ok(()) } } /// A tree builder builds a bookmark tree structure from a flat list of items /// and parent-child associations. /// /// # Tree structure /// /// In a well-formed tree: /// /// - Each item exists in exactly one folder. Two different folder's /// `children` should never reference the same item. /// - Each folder contains existing children. A folder's `children` should /// never reference tombstones, or items that don't exist in the tree at all. /// - Each item has a `parentid` that agrees with its parent's `children`. In /// other words, if item B's `parentid` is A, then A's `children` should /// contain B. /// /// Because of Reasons, things are (a lot) messier in practice. /// /// # Structure inconsistencies /// /// Sync stores structure in two places: a `parentid` property on each item, /// which points to its parent's GUID, and a list of ordered `children` on the /// item's parent. They're duplicated because, historically, Sync clients didn't /// stage incoming records. Instead, they applied records one at a time, /// directly to the live local tree. This meant that, if a client saw a child /// before its parent, it would first use the `parentid` to decide where to keep /// the child, then fix up parents and positions using the parent's `children`. /// /// This is also why moving an item into a different folder uploads records for /// the item, old folder, and new folder. The item has a new `parentid`, and the /// folders have new `children`. Similarly, deleting an item uploads a tombstone /// for the item, and a record for the item's old parent. /// /// Unfortunately, bugs (bug 1258127) and missing features (bug 1253051) in /// older clients sometimes caused them to upload invalid or incomplete changes. /// For example, a client might have: /// /// - Uploaded a moved child, but not its parents. This means the child now /// appears in multiple parents. In the most extreme case, an item might be /// referenced in two different sets of `children`, _and_ have a third, /// completely unrelated `parentid`. /// - Deleted a child, and tracked the deletion, but didn't flag the parent for /// reupload. The parent folder now has a tombstone child. /// - Tracked and uploaded items that shouldn't exist on the server at all, /// like the left pane or reading list roots (bug 1309255). /// - Missed new folders created during a sync, creating holes in the tree. /// /// Newer clients shouldn't do this, but we might still have inconsistent /// records on the server that will confuse older clients. Additionally, Firefox /// for iOS includes a much stricter bookmarks engine that refuses to sync if /// it detects inconsistencies. /// /// # Divergences /// /// To work around this, the builder lets the structure _diverge_. This allows: /// /// - Items with multiple parents. /// - Items with missing `parentid`s. /// - Folders with `children` whose `parentid`s don't match the folder. /// - Items whose `parentid`s don't mention the item in their `children`. /// - Items with `parentid`s that point to nonexistent or deleted folders. /// - Folders with nonexistent `children`. /// - Non-syncable items, like custom roots. /// - Any combination of these. /// /// # Resolving divergences /// /// Building a tree using `std::convert::TryInto<Tree>::try_into` resolves /// divergences using these rules: /// /// 1. User content roots should always be children of the Places root. If /// they appear in other parents, we move them. /// 2. Items that appear in multiple `children`, and items with mismatched /// `parentid`s, use the chronologically newer parent, based on the parent's /// last modified time. We always prefer parents by `children` over /// `parentid,` because `children` also gives us the item's position. /// 3. Items that aren't mentioned in any parent's `children`, but have a /// `parentid` that references an existing folder in the tree, are reparented /// to the end of that folder, after the folder's `children`. /// 4. Items that reference a nonexistent or non-folder `parentid`, or don't /// have a `parentid` at all, are reparented to the default folder. /// 5. If the default folder isn't set, or doesn't exist, items from rule 4 are /// reparented to the root instead. /// /// The result is a well-formed tree structure that can be merged. The merger /// detects if the structure diverged, and flags affected items for reupload. #[derive(Debug)] pub struct Builder { entry_index_by_guid: HashMap<Guid, Index>, entries: Vec<BuilderEntry>, deleted_guids: HashSet<Guid>, reparent_orphans_to: Option<Guid>, } impl Builder { /// Sets the default folder for reparented orphans. If not set, doesn't /// exist, or not a folder, orphans will be reparented to the root. #[inline] pub fn reparent_orphans_to(&mut self, guid: &Guid) -> &mut Builder { self.reparent_orphans_to = Some(guid.clone()); self } /// Inserts an `item` into the tree. Returns an error if the item already /// exists. pub fn item(&mut self, item: Item) -> Result<ItemBuilder<'_>> { assert_eq!(self.entries.len(), self.entry_index_by_guid.len()); if self.entry_index_by_guid.contains_key(&item.guid) { return Err(ErrorKind::DuplicateItem(item.guid.clone()).into()); } let entry_index = self.entries.len(); self.entry_index_by_guid .insert(item.guid.clone(), entry_index); self.entries.push(BuilderEntry { item, content: None, parent: BuilderEntryParent::None, children: Vec::new(), }); Ok(ItemBuilder(self, entry_index)) } /// Sets parents for a `child_guid`. Depending on where the parent comes /// from, `child_guid` may not need to exist in the tree. pub fn parent_for(&mut self, child_guid: &Guid) -> ParentBuilder<'_> { assert_eq!(self.entries.len(), self.entry_index_by_guid.len()); let entry_child = match self.entry_index_by_guid.get(child_guid) { Some(&child_index) => BuilderEntryChild::Exists(child_index), None => BuilderEntryChild::Missing(child_guid.clone()), }; ParentBuilder(self, entry_child) } /// Notes a tombstone for a deleted item, marking it as deleted in the /// tree. #[inline] pub fn deletion(&mut self, guid: Guid) -> &mut Builder { self.deleted_guids.insert(guid); self } /// Equivalent to using our implementation of`TryInto<Tree>::try_into`, but /// provided both for convenience when updating from previous versions of /// `dogear`, and for cases where a type hint would otherwise be needed to /// clarify the target type of the conversion. pub fn into_tree(self) -> Result<Tree> { self.try_into() } /// Mutates content and structure for an existing item. This is only /// exposed to tests. #[cfg(test)] pub fn mutate(&mut self, child_guid: &Guid) -> ItemBuilder<'_> { assert_eq!(self.entries.len(), self.entry_index_by_guid.len()); match self.entry_index_by_guid.get(child_guid) { Some(&child_index) => ItemBuilder(self, child_index), None => panic!("Can't mutate nonexistent item {}", child_guid), } } } impl TryFrom<Builder> for Tree { type Error = Error; /// Builds a tree from all stored items and parent-child associations, /// resolving inconsistencies like orphans, multiple parents, and /// parent-child disagreements. fn try_from(mut builder: Builder) -> Result<Tree> { let mut problems = Problems::default(); // The indices in this bit vector point to zombie entries, which exist // in the tree, but are also flagged as deleted. We'll remove these // zombies from the set of deleted GUIDs, and mark them as diverged for // reupload. let mut zombies = SmallBitVec::from_elem(builder.entries.len(), false); // First, resolve parents for all entries, and build a lookup table for // items without a position. let mut parents = Vec::with_capacity(builder.entries.len()); let mut reparented_child_indices_by_parent: HashMap<Index, Vec<Index>> = HashMap::new(); for (entry_index, entry) in builder.entries.iter().enumerate() { let r = ResolveParent::new(&builder, entry, &mut problems); let resolved_parent = r.resolve(); if let ResolvedParent::ByParentGuid(parent_index) = resolved_parent { // Reparented items are special: since they aren't mentioned in // that parent's `children`, we don't know their positions. Note // them for when we resolve children. We also clone the GUID, // since we use it for sorting, but can't access it by // reference once we call `builder.entries.into_iter()` below. let reparented_child_indices = reparented_child_indices_by_parent .entry(parent_index) .or_default(); reparented_child_indices.push(entry_index); } if builder.deleted_guids.remove(&entry.item.guid) { zombies.set(entry_index, true); } parents.push(resolved_parent); } // If any parents form cycles, abort. We haven't seen cyclic trees in // the wild, and breaking cycles would add complexity. if let Some(index) = detect_cycles(&parents) { return Err(ErrorKind::Cycle(builder.entries[index].item.guid.clone()).into()); } // Then, resolve children, and build a slab of entries for the tree. let mut entries = Vec::with_capacity(builder.entries.len()); for (entry_index, entry) in builder.entries.into_iter().enumerate() { // Each entry is consistent, until proven otherwise! let mut divergence = Divergence::Consistent; let parent_index = match &parents[entry_index] { ResolvedParent::Root => { // The Places root doesn't have a parent, and should always // be the first entry. assert_eq!(entry_index, 0); None } ResolvedParent::ByStructure(index) => { // The entry has a valid parent by structure, yay! Some(*index) } ResolvedParent::ByChildren(index) | ResolvedParent::ByParentGuid(index) => { // The entry has multiple parents, and we resolved one, // so it's diverged. divergence = Divergence::Diverged; Some(*index) } }; // If the entry is a zombie, mark it as diverged, so that the merger // can remove the tombstone and reupload the item. if zombies[entry_index] { divergence = Divergence::Diverged; } // Check if the entry's children exist and agree that this entry is // their parent. let mut child_indices = Vec::with_capacity(entry.children.len()); for child in entry.children { match child { BuilderEntryChild::Exists(child_index) => { if zombies[entry_index] { // If the entry has a zombie child, mark it as // diverged. divergence = Divergence::Diverged; } match &parents[child_index] { ResolvedParent::Root => { // The Places root can't be a child of another entry. unreachable!("A child can't be a top-level root"); } ResolvedParent::ByStructure(parent_index) => { // If the child has a valid parent by structure, it // must be the entry. If it's not, there's a bug // in `ResolveParent` or `BuilderEntry`. assert_eq!(*parent_index, entry_index); child_indices.push(child_index); } ResolvedParent::ByChildren(parent_index) => { // If the child has multiple parents, we may have // resolved a different one, so check if we decided // to keep the child in this entry. divergence = Divergence::Diverged; if *parent_index == entry_index { child_indices.push(child_index); } } ResolvedParent::ByParentGuid(parent_index) => { // We should only ever prefer parents // `by_parent_guid` over parents `by_children` for // misparented user content roots. Otherwise, // there's a bug in `ResolveParent`. assert_eq!(*parent_index, 0); divergence = Divergence::Diverged; } } } BuilderEntryChild::Missing(child_guid) => { // If the entry's `children` mention a deleted or // nonexistent GUID, note it as a problem, and ignore // the child. divergence = Divergence::Diverged; let problem = if builder.deleted_guids.remove(&child_guid) { Problem::DeletedChild { child_guid: child_guid.clone(), } } else { Problem::MissingChild { child_guid: child_guid.clone(), } }; problems.note(&entry.item.guid, problem); } } } // Reparented items don't appear in our `children`, so we move them // to the end, after existing children (rules 3-4). if let Some(reparented_child_indices) = reparented_child_indices_by_parent.get(&entry_index) { divergence = Divergence::Diverged; child_indices.extend_from_slice(reparented_child_indices); } entries.push(TreeEntry { item: entry.item, content: entry.content, parent_index, child_indices, divergence, }); } // Now we have a consistent tree. Ok(Tree { entry_index_by_guid: builder.entry_index_by_guid, entries, deleted_guids: builder.deleted_guids, problems, }) } } /// Adds an item with content and structure to a tree builder. pub struct ItemBuilder<'b>(&'b mut Builder, Index); impl<'b> ItemBuilder<'b> { /// Sets content info for an item that hasn't been uploaded or merged yet. /// We'll try to dedupe local items with content info to remotely changed /// items with similar contents and different GUIDs. #[inline] pub fn content<'c>(&'c mut self, content: Content) -> &'c mut ItemBuilder<'b> { mem::replace(&mut self.0.entries[self.1].content, Some(content)); self } /// Records a `parent_guid` from the item's parent's `children`. See /// `ParentBuilder::by_children`. #[inline] pub fn by_children(self, parent_guid: &Guid) -> Result<&'b mut Builder> { let b = ParentBuilder(self.0, BuilderEntryChild::Exists(self.1)); b.by_children(parent_guid) } /// Records a `parent_guid` from the item's `parentid`. See /// `ParentBuilder::by_parent_guid`. #[inline] pub fn by_parent_guid(self, parent_guid: Guid) -> Result<&'b mut Builder> { let b = ParentBuilder(self.0, BuilderEntryChild::Exists(self.1)); b.by_parent_guid(parent_guid) } /// Records a `parent_guid` from a valid tree structure. This is for /// callers who already know their structure is consistent, like /// `Store::fetch_local_tree()` on Desktop, and /// `std::convert::TryInto<Tree>` in the tests. /// /// Both the item and `parent_guid` must exist, and the `parent_guid` must /// refer to a folder. /// /// `by_structure(parent_guid)` is logically the same as: /// /// ```no_run /// # use dogear::{Item, Kind, Result, ROOT_GUID, Tree}; /// # fn main() -> Result<()> { /// # let mut builder = Tree::with_root(Item::new(ROOT_GUID, Kind::Folder)); /// # let child_guid = "bookmarkAAAA".into(); /// # let parent_guid = "folderAAAAAA".into(); /// builder.parent_for(&child_guid) /// .by_children(&parent_guid)? /// .parent_for(&child_guid) /// .by_parent_guid(parent_guid)?; /// # Ok(()) /// # } /// ``` /// /// ...But more convenient. It's also more efficient, because it avoids /// multiple lookups for the item and parent, as well as an extra heap /// allocation to store the parents. pub fn by_structure(self, parent_guid: &Guid) -> Result<&'b mut Builder> { let parent_index = match self.0.entry_index_by_guid.get(parent_guid) { Some(&parent_index) if self.0.entries[parent_index].item.is_folder() => parent_index, _ => { return Err(ErrorKind::InvalidParent( self.0.entries[self.1].item.guid.clone(), parent_guid.clone(), ) .into()); } }; self.0.entries[self.1].parents_by(&[ BuilderParentBy::Children(parent_index), BuilderParentBy::KnownItem(parent_index), ])?; self.0.entries[parent_index] .children .push(BuilderEntryChild::Exists(self.1)); Ok(self.0) } } /// Adds structure for an existing item to a tree builder. pub struct ParentBuilder<'b>(&'b mut Builder, BuilderEntryChild); impl<'b> ParentBuilder<'b> { /// Records a `parent_guid` from the item's parent's `children`. The /// `parent_guid` must refer to an existing folder in the tree, but /// the item itself doesn't need to exist. This handles folders with /// missing children. pub fn by_children(self, parent_guid: &Guid) -> Result<&'b mut Builder> { let parent_index = match self.0.entry_index_by_guid.get(parent_guid) { Some(&parent_index) if self.0.entries[parent_index].item.is_folder() => parent_index, _ => { let child_guid = match &self.1 { BuilderEntryChild::Exists(index) => &self.0.entries[*index].item.guid, BuilderEntryChild::Missing(guid) => guid, }; return Err( ErrorKind::InvalidParent(child_guid.clone(), parent_guid.clone()).into(), ); } }; if let BuilderEntryChild::Exists(child_index) = &self.1 { self.0.entries[*child_index].parents_by(&[BuilderParentBy::Children(parent_index)])?; } self.0.entries[parent_index].children.push(self.1); Ok(self.0) } /// Records a `parent_guid` from the item's `parentid`. The item must /// exist in the tree, but the `parent_guid` doesn't need to exist, /// or even refer to a folder. The builder will reparent items with /// missing and non-folder `parentid`s to the default folder when it /// builds the tree. pub fn by_parent_guid(self, parent_guid: Guid) -> Result<&'b mut Builder> { match &self.1 { BuilderEntryChild::Exists(child_index) => { self.0.entries[*child_index] .parents_by(&[BuilderParentBy::UnknownItem(parent_guid)])?; } BuilderEntryChild::Missing(child_guid) => { return Err(ErrorKind::MissingItem(child_guid.clone()).into()); } } Ok(self.0) } } /// An entry wraps a tree item with references to its parents and children, /// which index into the tree's `entries` vector. This indirection exists /// because Rust is more strict about ownership of parents and children. /// /// For example, we can't have entries own their children without sacrificing /// fast random lookup: we'd need to store references to the entries in the /// lookup map, but a struct can't hold references into itself. /// /// Similarly, we can't have entries hold `Weak` pointers to `Rc` entries for /// the parent and children, because we need to update the parent when we insert /// a new node, but `Rc` won't hand us a mutable reference to the entry as long /// as it has outstanding `Weak` pointers. /// /// We *could* use GUIDs instead of indices, and store the entries in a /// `HashMap<String, Entry>`, but that's inefficient: we'd need to store N /// copies of the GUID for parent and child lookups, and retrieving children /// would take one hash map lookup *per child*. /// /// Note that we always compare references to entries, instead of deriving /// `PartialEq`, because two entries with the same fields but in different /// trees should never compare equal. #[derive(Debug)] struct TreeEntry { item: Item, content: Option<Content>, divergence: Divergence, parent_index: Option<Index>, child_indices: Vec<Index>, } /// A builder entry holds an item and its structure. It's the builder's analog /// of a `TreeEntry`. #[derive(Debug)] struct BuilderEntry { item: Item, content: Option<Content>, parent: BuilderEntryParent, children: Vec<BuilderEntryChild>, } impl BuilderEntry { /// Adds `new_parents` for the entry. fn parents_by(&mut self, new_parents: &[BuilderParentBy]) -> Result<()> { let old_parent = mem::replace(&mut self.parent, BuilderEntryParent::None); let new_parent = match old_parent { BuilderEntryParent::Root => { mem::replace(&mut self.parent, BuilderEntryParent::Root); return Err(ErrorKind::DuplicateItem(self.item.guid.clone()).into()); } BuilderEntryParent::None => match new_parents { [BuilderParentBy::Children(from_children), BuilderParentBy::KnownItem(from_item)] | [BuilderParentBy::KnownItem(from_item), BuilderParentBy::Children(from_children)] if from_children == from_item => { // If the parent's `children` and item's `parentid` match, // we have a complete structure, so we can avoid an extra // allocation for the partial structure. BuilderEntryParent::Complete(*from_children) } new_parents => BuilderEntryParent::Partial(new_parents.to_vec()), }, BuilderEntryParent::Complete(index) => { let mut parents = vec![ BuilderParentBy::Children(index), BuilderParentBy::KnownItem(index), ]; parents.extend_from_slice(new_parents); BuilderEntryParent::Partial(parents) } BuilderEntryParent::Partial(mut parents) => { parents.extend_from_slice(new_parents); BuilderEntryParent::Partial(parents) } }; mem::replace(&mut self.parent, new_parent); Ok(()) } } /// Holds an existing child index, or missing child GUID, for a builder entry. #[derive(Debug)] enum BuilderEntryChild { Exists(Index), Missing(Guid), } /// Holds one or more parents for a builder entry. #[derive(Clone, Debug)] enum BuilderEntryParent { /// The entry is an orphan. None, /// The entry is a top-level root, from which all other entries descend. /// A tree can only have one root. Root, /// The entry has two matching parents from its structure. This is the fast /// path for local trees, which are always valid. Complete(Index), /// The entry has an incomplete or divergent structure. This is the path for /// all remote trees, valid and invalid, since we add structure from /// `parentid`s and `children` separately. This is also the path for /// mismatched and multiple parents. Partial(Vec<BuilderParentBy>), } /// Describes where a builder entry's parent comes from. #[derive(Clone, Debug)] enum BuilderParentBy { /// The entry's parent references the entry in its `children`. Children(Index), /// The entry's parent comes from its `parentid`, and will be resolved /// when we build the tree. UnknownItem(Guid), /// The entry's parent comes from its `parentid` and has been /// resolved. KnownItem(Index), } /// Resolves the parent for a builder entry. struct ResolveParent<'a> { builder: &'a Builder, entry: &'a BuilderEntry, problems: &'a mut Problems, } impl<'a> ResolveParent<'a> { fn new( builder: &'a Builder, entry: &'a BuilderEntry, problems: &'a mut Problems, ) -> ResolveParent<'a> { ResolveParent { builder, entry, problems, } } fn resolve(self) -> ResolvedParent { if self.entry.item.guid.is_built_in_root() { self.user_content_root() } else { self.item() } } /// Returns the parent for this builder entry. This unifies parents /// `by_structure`, which are known to be consistent, and parents /// `by_children` and `by_parent_guid`, which are consistent if they match. fn parent(&self) -> Cow<'a, BuilderEntryParent> { let parents = match &self.entry.parent { // Roots and orphans pass through as-is. BuilderEntryParent::Root => return Cow::Owned(BuilderEntryParent::Root), BuilderEntryParent::None => return Cow::Owned(BuilderEntryParent::None), BuilderEntryParent::Complete(index) => { // The entry is known to have a valid parent by structure. This // is the fast path, used for local trees in Desktop. return Cow::Owned(BuilderEntryParent::Complete(*index)); } BuilderEntryParent::Partial(parents) => parents, }; // The entry has zero, one, or many parents, recorded separately. Check // if it has exactly two: one `by_parent_guid`, and one `by_children`. let (index_by_guid, index_by_children) = match parents.as_slice() { [BuilderParentBy::UnknownItem(guid), BuilderParentBy::Children(index_by_children)] | [BuilderParentBy::Children(index_by_children), BuilderParentBy::UnknownItem(guid)] => { match self.builder.entry_index_by_guid.get(guid) { Some(&index_by_guid) => (index_by_guid, *index_by_children), None => return Cow::Borrowed(&self.entry.parent), } } [BuilderParentBy::KnownItem(index_by_guid), BuilderParentBy::Children(index_by_children)] | [BuilderParentBy::Children(index_by_children), BuilderParentBy::KnownItem(index_by_guid)] => { (*index_by_guid, *index_by_children) } // In all other cases (missing `parentid`, missing from `children`, // multiple parents), return all possible parents. We'll pick one // when we resolve the parent. _ => return Cow::Borrowed(&self.entry.parent), }; // If the entry has matching parents `by_children` and `by_parent_guid`, // it has a valid parent by structure. This is the "fast slow path", // used for remote trees in Desktop, because their structure is built in // two passes. In all other cases, we have a parent-child disagreement, // so return all possible parents. if index_by_guid == index_by_children { Cow::Owned(BuilderEntryParent::Complete(index_by_children)) } else { Cow::Borrowed(&self.entry.parent) } } /// Resolves the parent for a user content root: menu, mobile, toolbar, and /// unfiled. These are simpler to resolve than non-roots because they must /// be children of the Places root (rule 1), which is always the first /// entry. fn user_content_root(self) -> ResolvedParent { match self.parent().as_ref() { BuilderEntryParent::None => { // Orphaned content root. This should only happen if the content // root doesn't have a parent `by_parent_guid`. self.problems.note(&self.entry.item.guid, Problem::Orphan); ResolvedParent::ByParentGuid(0) } BuilderEntryParent::Root => { unreachable!("A user content root can't be a top-level root") } BuilderEntryParent::Complete(index) => { if *index == 0 { ResolvedParent::ByStructure(*index) } else { // Move misparented content roots to the Places root. let parent_guid = self.builder.entries[*index].item.guid.clone(); self.problems.note( &self.entry.item.guid, Problem::MisparentedRoot(vec![ DivergedParent::ByChildren(parent_guid.clone()), DivergedParentGuid::Folder(parent_guid).into(), ]), ); ResolvedParent::ByParentGuid(0) } } BuilderEntryParent::Partial(parents_by) => { // Ditto for content roots with multiple parents or parent-child // disagreements. self.problems.note( &self.entry.item.guid, Problem::MisparentedRoot( parents_by .iter() .map(|parent_by| { PossibleParent::new(self.builder, parent_by).summarize() }) .collect(), ), ); ResolvedParent::ByParentGuid(0) } } } /// Resolves the parent for a top-level Places root or other item, using /// rules 2-5. fn item(self) -> ResolvedParent { match self.parent().as_ref() { BuilderEntryParent::Root => ResolvedParent::Root, BuilderEntryParent::None => { // The item doesn't have a `parentid`, and isn't mentioned in // any `children`. Reparent to the default folder (rule 4) or // Places root (rule 5). let parent_index = self.reparent_orphans_to_default_index(); self.problems.note(&self.entry.item.guid, Problem::Orphan); ResolvedParent::ByParentGuid(parent_index) } BuilderEntryParent::Complete(index) => { // The item's `parentid` and parent's `children` match, so keep // it in its current parent. ResolvedParent::ByStructure(*index) } BuilderEntryParent::Partial(parents) => { // For items with one or more than two parents, pick the // youngest (minimum age). let possible_parents = parents .iter() .map(|parent_by| PossibleParent::new(self.builder, parent_by)) .collect::<Vec<_>>(); self.problems.note( &self.entry.item.guid, Problem::DivergedParents( possible_parents .iter() .map(PossibleParent::summarize) .collect(), ), ); possible_parents .into_iter() .min() .and_then(|p| match p.parent_by { BuilderParentBy::Children(index) => { Some(ResolvedParent::ByChildren(*index)) } BuilderParentBy::KnownItem(index) => { Some(ResolvedParent::ByParentGuid(*index)) } BuilderParentBy::UnknownItem(guid) => self .builder .entry_index_by_guid .get(guid) .filter(|&&index| self.builder.entries[index].item.is_folder()) .map(|&index| ResolvedParent::ByParentGuid(index)), }) .unwrap_or_else(|| { // Fall back to the default folder (rule 4) or root // (rule 5) if we didn't find a parent. let parent_index = self.reparent_orphans_to_default_index(); ResolvedParent::ByParentGuid(parent_index) }) } } } /// Returns the index of the default parent entry for reparented orphans. /// This is either the default folder (rule 4), or the root, if the /// default folder isn't set, doesn't exist, or isn't a folder (rule 5). fn reparent_orphans_to_default_index(&self) -> Index { self.builder .reparent_orphans_to .as_ref() .and_then(|guid| self.builder.entry_index_by_guid.get(guid)) .cloned() .filter(|&parent_index| { let parent_entry = &self.builder.entries[parent_index]; parent_entry.item.is_folder() }) .unwrap_or(0) } } // A possible parent for an item with conflicting parents. We use this wrapper's // `Ord` implementation to decide which parent is youngest. #[derive(Clone, Copy, Debug)] struct PossibleParent<'a> { builder: &'a Builder, parent_by: &'a BuilderParentBy, } impl<'a> PossibleParent<'a> { fn new(builder: &'a Builder, parent_by: &'a BuilderParentBy) -> PossibleParent<'a> { PossibleParent { builder, parent_by } } /// Returns the problem with this conflicting parent. fn summarize(&self) -> DivergedParent { let entry = match self.parent_by { BuilderParentBy::Children(index) => { return DivergedParent::ByChildren(self.builder.entries[*index].item.guid.clone()); } BuilderParentBy::KnownItem(index) => &self.builder.entries[*index], BuilderParentBy::UnknownItem(guid) => { match self.builder.entry_index_by_guid.get(guid) { Some(index) => &self.builder.entries[*index], None => { if self.builder.deleted_guids.contains(guid) { return DivergedParentGuid::Deleted(guid.clone()).into(); } return DivergedParentGuid::Missing(guid.clone()).into(); } } } }; if entry.item.is_folder() { DivergedParentGuid::Folder(entry.item.guid.clone()).into() } else { DivergedParentGuid::NonFolder(entry.item.guid.clone()).into() } } } impl<'a> Ord for PossibleParent<'a> { /// Compares two possible parents to determine which is younger /// (`Ordering::Less`). Prefers parents from `children` over `parentid` /// (rule 2), and `parentid`s that reference folders over non-folders /// (rule 4). fn cmp(&self, other: &PossibleParent<'_>) -> Ordering { let (index, other_index) = match (&self.parent_by, &other.parent_by) { (BuilderParentBy::Children(index), BuilderParentBy::Children(other_index)) => { // Both `self` and `other` mention the item in their `children`. (*index, *other_index) } (BuilderParentBy::Children(_), BuilderParentBy::KnownItem(_)) => { // `self` mentions the item in its `children`, and the item's // `parentid` is `other`, so prefer `self`. return Ordering::Less; } (BuilderParentBy::Children(_), BuilderParentBy::UnknownItem(_)) => { // As above, except we don't know if `other` exists. We don't // need to look it up, though, because we can unconditionally // prefer `self`. return Ordering::Less; } (BuilderParentBy::KnownItem(_), BuilderParentBy::Children(_)) => { // The item's `parentid` is `self`, and `other` mentions the // item in its `children`, so prefer `other`. return Ordering::Greater; } (BuilderParentBy::UnknownItem(_), BuilderParentBy::Children(_)) => { // As above. We don't know if `self` exists, but we // unconditionally prefer `other`. return Ordering::Greater; } // Cases where `self` and `other` are `parentid`s, existing or not, // are academic, since it doesn't make sense for an item to have // multiple `parentid`s. _ => return Ordering::Equal, }; // If both `self` and `other` are folders, compare timestamps. If one is // a folder, but the other isn't, we prefer the folder. If neither is a // folder, it doesn't matter. let entry = &self.builder.entries[index]; let other_entry = &self.builder.entries[other_index]; match (entry.item.is_folder(), other_entry.item.is_folder()) { (true, true) => entry.item.age.cmp(&other_entry.item.age), (false, true) => Ordering::Greater, (true, false) => Ordering::Less, (false, false) => Ordering::Equal, } } } impl<'a> PartialOrd for PossibleParent<'a> { fn partial_cmp(&self, other: &PossibleParent<'_>) -> Option<Ordering> { Some(self.cmp(other)) } } impl<'a> PartialEq for PossibleParent<'a> { fn eq(&self, other: &PossibleParent<'_>) -> bool { self.cmp(other) == Ordering::Equal } } impl<'a> Eq for PossibleParent<'a> {} /// Describes a resolved parent for an item. #[derive(Debug)] enum ResolvedParent { /// The item is a top-level root, and has no parent. Root, /// The item has a valid, consistent structure. ByStructure(Index), /// The item has multiple parents; this is the one we picked. ByChildren(Index), /// The item has a parent-child disagreement: the folder referenced by the /// item's `parentid` doesn't mention the item in its `children`, the /// `parentid` doesn't exist at all, or the item is a misparented content /// root. ByParentGuid(Index), } impl ResolvedParent { fn index(&self) -> Option<Index> { match self { ResolvedParent::Root => None, ResolvedParent::ByStructure(index) | ResolvedParent::ByChildren(index) | ResolvedParent::ByParentGuid(index) => Some(*index), } } } /// Detects cycles in resolved parents, using Floyd's tortoise and the hare /// algorithm. Returns the index of the entry where the cycle was detected, /// or `None` if there aren't any cycles. fn detect_cycles(parents: &[ResolvedParent]) -> Option<Index> { let mut seen = SmallBitVec::from_elem(parents.len(), false); for (entry_index, parent) in parents.iter().enumerate() { if seen[entry_index] { continue; } let mut parent_index = parent.index(); let mut grandparent_index = parent.index().and_then(|index| parents[index].index()); while let (Some(i), Some(j)) = (parent_index, grandparent_index) { if i == j { return Some(i); } if seen[i] || seen[j] { break; } parent_index = parent_index.and_then(|index| parents[index].index()); grandparent_index = grandparent_index .and_then(|index| parents[index].index()) .and_then(|index| parents[index].index()); } seen.set(entry_index, true); } None } /// Indicates if a tree entry's structure diverged. #[derive(Debug)] enum Divergence { /// The structure is already correct, and doesn't need to be reuploaded. Consistent, /// The node has structure problems, and should be flagged for reupload /// when merging. Diverged, } /// Describes a structure divergence for an item in a bookmark tree. These are /// used for logging and validation telemetry. #[derive(Clone, Debug, Eq, Hash, PartialEq)] pub enum Problem { /// The item doesn't have a `parentid`, and isn't mentioned in any folders. Orphan, /// The item is a user content root (menu, mobile, toolbar, or unfiled), /// but `parent_guid` isn't the Places root. MisparentedRoot(Vec<DivergedParent>), /// The item has diverging parents. If the vector contains more than one /// `DivergedParent::ByChildren`, the item has multiple parents. If the /// vector contains a `DivergedParent::ByParentGuid`, with or without a /// `DivergedParent::ByChildren`, the item has a parent-child disagreement. DivergedParents(Vec<DivergedParent>), /// The item is mentioned in a folder's `children`, but doesn't exist. MissingChild { child_guid: Guid }, /// The item is mentioned in a folder's `children`, but is deleted. DeletedChild { child_guid: Guid }, } impl Problem { /// Returns count deltas for this problem. fn counts(&self) -> ProblemCounts { let (parents, deltas) = match self { Problem::Orphan => { return ProblemCounts { orphans: 1, ..ProblemCounts::default() } } Problem::DeletedChild { .. } => { return ProblemCounts { deleted_children: 1, ..ProblemCounts::default() } } Problem::MissingChild { .. } => { return ProblemCounts { missing_children: 1, ..ProblemCounts::default() } } // For misparented roots, or items with diverged parents, we need to // do a bit more work to determine all the problems. For example, a // toolbar root with a `parentid` pointing to a nonexistent folder, // and mentioned in the `children` of unfiled and menu has three // problems: it's a misparented root, with multiple parents, and a // missing `parentid`. Problem::MisparentedRoot(parents) => ( parents, ProblemCounts { misparented_roots: 1, ..ProblemCounts::default() }, ), Problem::DivergedParents(parents) => (parents, ProblemCounts::default()), }; let deltas = match parents.as_slice() { // For items with different parents `by_parent_guid` and // `by_children`, report a parent-child disagreement. [DivergedParent::ByChildren(_)] | [DivergedParent::ByParentGuid(_)] | [DivergedParent::ByChildren(_), DivergedParent::ByParentGuid(_)] | [DivergedParent::ByParentGuid(_), DivergedParent::ByChildren(_)] => ProblemCounts { parent_child_disagreements: 1, ..deltas }, // For items with multiple parents `by_children`, and possibly by // `by_parent_guid`, report a disagreement _and_ multiple parents. _ => ProblemCounts { multiple_parents_by_children: 1, parent_child_disagreements: 1, ..deltas }, }; // Count invalid or missing parents, but only once, since we're counting // the number of _items with the problem_, not the _occurrences of the // problem_. This is specifically for roots; it doesn't make sense for // other items to have multiple `parentid`s. parents.iter().fold(deltas, |deltas, parent| match parent { DivergedParent::ByChildren(_) => deltas, DivergedParent::ByParentGuid(p) => match p { DivergedParentGuid::Folder(_) => deltas, DivergedParentGuid::NonFolder(_) => { if deltas.non_folder_parent_guids > 0 { deltas } else { ProblemCounts { non_folder_parent_guids: 1, ..deltas } } } DivergedParentGuid::Deleted(_) => { if deltas.deleted_parent_guids > 0 { deltas } else { ProblemCounts { deleted_parent_guids: 1, ..deltas } } } DivergedParentGuid::Missing(_) => { if deltas.missing_parent_guids > 0 { deltas } else { ProblemCounts { missing_parent_guids: 1, ..deltas } } } }, }) } } /// Describes where an invalid parent comes from. #[derive(Clone, Debug, Eq, Hash, PartialEq)] pub enum DivergedParent { /// The item appears in this folder's `children`. ByChildren(Guid), /// The `parentid` references this folder. ByParentGuid(DivergedParentGuid), } impl From<DivergedParentGuid> for DivergedParent { fn from(d: DivergedParentGuid) -> DivergedParent { DivergedParent::ByParentGuid(d) } } impl fmt::Display for DivergedParent { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match self { DivergedParent::ByChildren(parent_guid) => { write!(f, "is in children of {}", parent_guid) } DivergedParent::ByParentGuid(p) => match p { DivergedParentGuid::Folder(parent_guid) => write!(f, "has parent {}", parent_guid), DivergedParentGuid::NonFolder(parent_guid) => { write!(f, "has non-folder parent {}", parent_guid) } DivergedParentGuid::Deleted(parent_guid) => { write!(f, "has deleted parent {}", parent_guid) } DivergedParentGuid::Missing(parent_guid) => { write!(f, "has nonexistent parent {}", parent_guid) } }, } } } /// Describes an invalid `parentid`. #[derive(Clone, Debug, Eq, Hash, PartialEq)] pub enum DivergedParentGuid { /// Exists and is a folder. Folder(Guid), /// Exists, but isn't a folder. NonFolder(Guid), /// Is explicitly deleted. Deleted(Guid), /// Doesn't exist at all. Missing(Guid), } /// Records problems for all items in a tree. #[derive(Debug, Default)] pub struct Problems(HashMap<Guid, Vec<Problem>>); impl Problems { /// Notes a problem for an item. #[inline] pub fn note(&mut self, guid: &Guid, problem: Problem) -> &mut Problems { self.0.entry(guid.clone()).or_default().push(problem); self } /// Returns `true` if there are no problems. #[inline] pub fn is_empty(&self) -> bool { self.0.is_empty() } /// Returns an iterator for all problems. pub fn summarize(&self) -> impl Iterator<Item = ProblemSummary<'_>> { self.0.iter().flat_map(|(guid, problems)| { problems .iter() .map(move |problem| ProblemSummary(guid, problem)) }) } /// Returns total counts for each problem. If any counts are not 0, the /// tree structure diverged. pub fn counts(&self) -> ProblemCounts { self.0 .values() .flatten() .fold(ProblemCounts::default(), |totals, problem| { totals.add(problem.counts()) }) } } /// A printable summary of a problem for an item. #[derive(Clone, Copy, Debug)] pub struct ProblemSummary<'a>(&'a Guid, &'a Problem); impl<'a> ProblemSummary<'a> { #[inline] pub fn guid(&self) -> &Guid { &self.0 } #[inline] pub fn problem(&self) -> &Problem { &self.1 } } impl<'a> fmt::Display for ProblemSummary<'a> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let parents = match self.problem() { Problem::Orphan => return write!(f, "{} is an orphan", self.guid()), Problem::MisparentedRoot(parents) => { write!(f, "{} is a user content root", self.guid())?; if parents.is_empty() { return Ok(()); } f.write_str(", but ")?; parents } Problem::DivergedParents(parents) => { if parents.is_empty() { return write!(f, "{} has diverged parents", self.guid()); } write!(f, "{} ", self.guid())?; parents } Problem::MissingChild { child_guid } => { return write!(f, "{} has nonexistent child {}", self.guid(), child_guid); } Problem::DeletedChild { child_guid } => { return write!(f, "{} has deleted child {}", self.guid(), child_guid); } }; match parents.as_slice() { [a] => write!(f, "{}", a)?, [a, b] => write!(f, "{} and {}", a, b)?, _ => { for (i, parent) in parents.iter().enumerate() { if i != 0 { f.write_str(", ")?; } if i == parents.len() - 1 { f.write_str("and ")?; } write!(f, "{}", parent)?; } } } Ok(()) } } /// Records total problem counts for telemetry. An item can have multiple /// problems, but each problem is only counted once per item. #[derive(Clone, Copy, Default, Debug, Eq, Hash, PartialEq)] pub struct ProblemCounts { /// Number of items that aren't mentioned in any parent's `children` and /// don't have a `parentid`. These are very rare; it's likely that a /// problem child has at least a `parentid`. pub orphans: usize, /// Number of roots that aren't children of the Places root. pub misparented_roots: usize, /// Number of items with multiple, conflicting parents `by_children`. pub multiple_parents_by_children: usize, /// Number of items whose `parentid` is deleted. pub deleted_parent_guids: usize, /// Number of items whose `parentid` doesn't exist. pub missing_parent_guids: usize, /// Number of items whose `parentid` isn't a folder. pub non_folder_parent_guids: usize, /// Number of items whose `parentid`s disagree with their parents' /// `children`. pub parent_child_disagreements: usize, /// Number of deleted items mentioned in all parents' `children`. pub deleted_children: usize, /// Number of nonexistent items mentioned in all parents' `children`. pub missing_children: usize, } impl ProblemCounts { /// Adds two sets of counts together. pub fn add(&self, other: ProblemCounts) -> ProblemCounts { ProblemCounts { orphans: self.orphans + other.orphans, misparented_roots: self.misparented_roots + other.misparented_roots, multiple_parents_by_children: self.multiple_parents_by_children + other.multiple_parents_by_children, deleted_parent_guids: self.deleted_parent_guids + other.deleted_parent_guids, missing_parent_guids: self.missing_parent_guids + other.missing_parent_guids, non_folder_parent_guids: self.non_folder_parent_guids + other.non_folder_parent_guids, parent_child_disagreements: self.parent_child_disagreements + other.parent_child_disagreements, deleted_children: self.deleted_children + other.deleted_children, missing_children: self.missing_children + other.missing_children, } } } /// A node in a bookmark tree that knows its parent and children, and /// dereferences to its item. #[derive(Clone, Copy, Debug)] pub struct Node<'t>(&'t Tree, &'t TreeEntry); impl<'t> Node<'t> { /// Returns content info for deduping this item, if available. pub fn content(&self) -> Option<&'t Content> { self.1.content.as_ref() } /// Returns an iterator for all children of this node. pub fn children<'n>(&'n self) -> impl Iterator<Item = Node<'t>> + 'n { self.1 .child_indices .iter() .map(move |&child_index| Node(self.0, &self.0.entries[child_index])) } /// Returns the child at the given index, or `None` if the index is out of /// bounds. pub fn child(&self, index: usize) -> Option<Node<'_>> { self.1 .child_indices .get(index) .map(|&child_index| Node(self.0, &self.0.entries[child_index])) } /// Returns `true` if this and `other` have the same child GUIDs. pub fn has_matching_children<'u>(&self, other: Node<'u>) -> bool { if self.1.child_indices.len() != other.1.child_indices.len() { return false; } for (index, &child_index) in self.1.child_indices.iter().enumerate() { let guid = &self.0.entries[child_index].item.guid; let other_guid = &other.0.entries[other.1.child_indices[index]].item.guid; if guid != other_guid { return false; } } true } /// Returns the resolved parent of this node, or `None` if this is the /// root node. pub fn parent(&self) -> Option<Node<'_>> { self.1 .parent_index .as_ref() .map(|&parent_index| Node(self.0, &self.0.entries[parent_index])) } /// Returns the level of this node in the tree. pub fn level(&self) -> i64 { if self.is_root() { return 0; } self.parent().map_or(-1, |parent| parent.level() + 1) } /// Indicates if this node is for a syncable item. /// /// Syncable items descend from the four user content roots. For historical /// reasons, the Desktop tags root and its descendants are also marked as /// syncable, even though they are not part of the synced tree structure. /// Any other roots and their descendants, like the left pane root, /// left pane queries, and custom roots, are non-syncable. /// /// Newer Desktops should never reupload non-syncable items /// (bug 1274496), and should have removed them in Places /// migrations (bug 1310295). However, these items may be /// reparented locally to unfiled, in which case they're seen as /// syncable. If the remote tree has the missing parents /// and roots, we'll determine that the items are non-syncable /// when merging, remove them locally, and mark them for deletion /// remotely. pub fn is_syncable(&self) -> bool { if self.is_root() { return false; } if self.is_built_in_root() { return true; } match self.kind { // Exclude livemarks (bug 1477671). Kind::Livemark => false, // Exclude orphaned Places queries (bug 1433182). Kind::Query if self.diverged() => false, _ => self.parent().map_or(false, |parent| parent.is_syncable()), } } /// Indicates if this node's structure diverged because it /// existed in multiple parents, or was reparented. #[inline] pub fn diverged(&self) -> bool { match &self.1.divergence { Divergence::Diverged => true, Divergence::Consistent => false, } } /// Returns an ASCII art (with emoji!) representation of this node and all /// its descendants. Handy for logging. pub fn to_ascii_string(&self) -> String { self.to_ascii_fragment("") } fn to_ascii_fragment(&self, prefix: &str) -> String { match self.1.item.kind { Kind::Folder => { let children_prefix = format!("{}| ", prefix); let children = self .children() .map(|n| n.to_ascii_fragment(&children_prefix)) .collect::<Vec<String>>(); let kind = if self.diverged() { "❗️📂" } else { "📂" }; if children.is_empty() { format!("{}{} {}", prefix, kind, self.1.item) } else { format!( "{}{} {}\n{}", prefix, kind, self.1.item, children.join("\n") ) } } _ => { let kind = if self.diverged() { "❗️🔖" } else { "🔖" }; format!("{}{} {}", prefix, kind, self.1.item) } } } /// Indicates if this node is the root node. #[inline] pub fn is_root(&self) -> bool { ptr::eq(self.1, &self.0.entries[0]) } /// Indicates if this node is a Places built-in root. Any other roots except /// these are non-syncable. #[inline] pub fn is_built_in_root(&self) -> bool { self.1.item.guid.is_built_in_root() } } impl<'t> Deref for Node<'t> { type Target = Item; fn deref(&self) -> &Item { &self.1.item } } impl<'t> fmt::Display for Node<'t> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { self.1.item.fmt(f) } } /// An item in a local or remote bookmark tree. #[derive(Debug, Eq, PartialEq)] pub struct Item { pub guid: Guid, pub kind: Kind, pub age: i64, pub needs_merge: bool, pub validity: Validity, } impl Item { /// Creates an item with the given kind. #[inline] pub fn new(guid: Guid, kind: Kind) -> Item { Item { guid, kind, age: 0, needs_merge: false, validity: Validity::Valid, } } /// Indicates if the item is a folder. Only folders are allowed to have /// children. #[inline] pub fn is_folder(&self) -> bool { self.kind == Kind::Folder } /// Indicates if the item can be merged with another item. Only items with /// compatible kinds can be merged. #[inline] pub fn has_compatible_kind(&self, remote_node: &Item) -> bool { match (&self.kind, &remote_node.kind) { // Bookmarks and queries are interchangeable, as simply changing the URL // can cause it to flip kinds. (Kind::Bookmark, Kind::Query) => true, (Kind::Query, Kind::Bookmark) => true, (local_kind, remote_kind) => local_kind == remote_kind, } } } impl fmt::Display for Item { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let kind = match self.validity { Validity::Valid => format!("{}", self.kind), Validity::Reupload | Validity::Replace => format!("{} ({})", self.kind, self.validity), }; let info = if self.needs_merge { format!("{}; Age = {}ms; Unmerged", kind, self.age) } else { format!("{}; Age = {}ms", kind, self.age) }; write!(f, "{} ({})", self.guid, info) } } /// Synced item kinds. Each corresponds to a Sync record type. #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] pub enum Kind { Bookmark, Query, Folder, Livemark, Separator, } impl fmt::Display for Kind { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::Debug::fmt(self, f) } } /// Synced item validity. #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] pub enum Validity { /// The item is valid, and can be applied as-is. Valid, /// The item can be applied, but should also be flagged for reupload. Places /// uses this to rewrite legacy tag queries. Reupload, /// The item isn't valid at all, and should either be replaced with a valid /// local copy, or deleted if a valid local copy doesn't exist. Places uses /// this to flag bookmarks and queries without valid URLs. Replace, } impl fmt::Display for Validity { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::Debug::fmt(self, f) } } /// A merged bookmark node that indicates which side to prefer, and holds merged /// child nodes. #[derive(Debug)] pub struct MergedNode<'t> { pub guid: Guid, pub merge_state: MergeState<'t>, pub merged_children: Vec<MergedNode<'t>>, } impl<'t> MergedNode<'t> { /// Creates a merged node from the given merge state. pub fn new(guid: Guid, merge_state: MergeState<'t>) -> MergedNode<'t> { MergedNode { guid, merge_state, merged_children: Vec::new(), } } /// Indicates if the merged node exists locally and has a new GUID. /// The merger uses this to flag deduped items and items with invalid /// GUIDs with new local structure. pub fn local_guid_changed(&self) -> bool { self.merge_state .local_node() .map_or(false, |local_node| local_node.guid != self.guid) } /// Indicates if the merged node exists remotely and has a new GUID. The /// merger uses this to flag parents and children of remote nodes with /// invalid GUIDs for reupload. pub fn remote_guid_changed(&self) -> bool { self.merge_state .remote_node() .map_or(false, |remote_node| remote_node.guid != self.guid) } /// Returns an ASCII art representation of the root and its descendants, /// similar to `Node::to_ascii_string`. #[inline] pub fn to_ascii_string(&self) -> String { self.to_ascii_fragment("") } fn to_ascii_fragment(&self, prefix: &str) -> String { match self.merge_state.node().kind { Kind::Folder => { let children_prefix = format!("{}| ", prefix); let children = self .merged_children .iter() .map(|n| n.to_ascii_fragment(&children_prefix)) .collect::<Vec<String>>(); if children.is_empty() { format!("{}📂 {}", prefix, &self) } else { format!("{}📂 {}\n{}", prefix, &self, children.join("\n")) } } _ => format!("{}🔖 {}", prefix, &self), } } } impl<'t> fmt::Display for MergedNode<'t> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "{} {}", self.guid, self.merge_state) } } /// The merge state indicates which side we should prefer, local or remote, when /// resolving conflicts. #[derive(Clone, Copy, Debug)] pub enum MergeState<'t> { /// A local-only merge state means the item only exists locally, and should /// be uploaded. LocalOnly(Node<'t>), /// Local-only with a new local structure means the item should be uploaded, /// _and_ has new children (reparented or repositioned) locally. LocalOnlyWithNewLocalStructure(Node<'t>), /// A remote-only merge state means the item only exists remotely, and /// should be applied. RemoteOnly(Node<'t>), /// Remote-only with a new remote structure means the item should be /// applied, _and_ has a new child list that should be uploaded. RemoteOnlyWithNewRemoteStructure(Node<'t>), /// A local merge state means the item exists on both sides, and has newer /// local changes that should be uploaded. Local { local_node: Node<'t>, remote_node: Node<'t>, }, /// Local with a new local structure means the item has newer local changes /// that should be uploaded, and new children locally. LocalWithNewLocalStructure { local_node: Node<'t>, remote_node: Node<'t>, }, /// A remote merge state means the item exists on both sides, and has newer /// remote changes that should be applied. Remote { local_node: Node<'t>, remote_node: Node<'t>, }, /// Remote with a new remote structure means the item has newer remote /// changes that should be applied, and a new child list that should be /// uploaded. RemoteWithNewRemoteStructure { local_node: Node<'t>, remote_node: Node<'t>, }, /// An unchanged merge state means the item and its children are the /// same on both sides, and don't need to be uploaded or applied. Unchanged { local_node: Node<'t>, remote_node: Node<'t>, }, /// Unchanged with a new local structure means the item hasn't changed, but /// its children have. The new children should be applied locally, but not /// uploaded. UnchangedWithNewLocalStructure { local_node: Node<'t>, remote_node: Node<'t>, }, } impl<'t> MergeState<'t> { /// Returns the local node for the item, or `None` if the item only exists /// remotely. The inverse of `remote_node()`. pub fn local_node(&self) -> Option<&Node<'t>> { match self { MergeState::LocalOnly(local_node) | MergeState::LocalOnlyWithNewLocalStructure(local_node) | MergeState::Local { local_node, .. } | MergeState::LocalWithNewLocalStructure { local_node, .. } | MergeState::Remote { local_node, .. } | MergeState::RemoteWithNewRemoteStructure { local_node, .. } | MergeState::Unchanged { local_node, .. } | MergeState::UnchangedWithNewLocalStructure { local_node, .. } => Some(local_node), MergeState::RemoteOnly(_) | MergeState::RemoteOnlyWithNewRemoteStructure(_) => None, } } /// Returns the remote node for the item, or `None` if the node only exists /// locally. The inverse of `local_node()`. pub fn remote_node(&self) -> Option<&Node<'t>> { match self { MergeState::Local { remote_node, .. } | MergeState::LocalWithNewLocalStructure { remote_node, .. } | MergeState::RemoteOnly(remote_node) | MergeState::RemoteOnlyWithNewRemoteStructure(remote_node) | MergeState::Remote { remote_node, .. } | MergeState::RemoteWithNewRemoteStructure { remote_node, .. } | MergeState::Unchanged { remote_node, .. } | MergeState::UnchangedWithNewLocalStructure { remote_node, .. } => Some(remote_node), MergeState::LocalOnly(_) | MergeState::LocalOnlyWithNewLocalStructure(_) => None, } } /// Returns `true` if the remote item should be inserted into or updated /// in the local tree. This is not necessarily the inverse of /// `should_upload()`, as remote items with new structure should be both /// applied and reuploaded, and unchanged items should be neither. pub fn should_apply_item(&self) -> bool { match self { MergeState::RemoteOnly(_) | MergeState::RemoteOnlyWithNewRemoteStructure(_) | MergeState::Remote { .. } | MergeState::RemoteWithNewRemoteStructure { .. } => true, MergeState::LocalOnly(_) | MergeState::LocalOnlyWithNewLocalStructure(_) | MergeState::Local { .. } | MergeState::LocalWithNewLocalStructure { .. } | MergeState::Unchanged { .. } | MergeState::UnchangedWithNewLocalStructure { .. } => false, } } /// Returns `true` if the item has a new structure (parent or children) /// that should be updated in the local tree. pub fn should_apply_structure(&self) -> bool { match self { MergeState::LocalOnlyWithNewLocalStructure(_) | MergeState::LocalWithNewLocalStructure { .. } | MergeState::RemoteOnly(_) | MergeState::RemoteOnlyWithNewRemoteStructure(_) | MergeState::Remote { .. } | MergeState::RemoteWithNewRemoteStructure { .. } | MergeState::UnchangedWithNewLocalStructure { .. } => true, MergeState::LocalOnly(_) | MergeState::Local { .. } | MergeState::Unchanged { .. } => { false } } } /// Returns `true` if the item should be flagged for (re)upload. pub fn should_upload(&self) -> bool { match self { MergeState::LocalOnly(_) | MergeState::LocalOnlyWithNewLocalStructure(_) | MergeState::Local { .. } | MergeState::LocalWithNewLocalStructure { .. } | MergeState::RemoteOnlyWithNewRemoteStructure(_) | MergeState::RemoteWithNewRemoteStructure { .. } => true, MergeState::RemoteOnly(_) | MergeState::Remote { .. } | MergeState::Unchanged { .. } | MergeState::UnchangedWithNewLocalStructure { .. } => false, } } /// Returns a new merge state, indicating that the item has a new merged /// structure that should be applied locally. pub fn with_new_local_structure(self) -> MergeState<'t> { match self { MergeState::LocalOnly(local_node) => { MergeState::LocalOnlyWithNewLocalStructure(local_node) } MergeState::LocalOnlyWithNewLocalStructure(local_node) => { MergeState::LocalOnlyWithNewLocalStructure(local_node) } MergeState::Local { local_node, remote_node, } => MergeState::LocalWithNewLocalStructure { local_node, remote_node, }, MergeState::LocalWithNewLocalStructure { local_node, remote_node, } => MergeState::LocalWithNewLocalStructure { local_node, remote_node, }, MergeState::RemoteOnly(remote_node) => MergeState::RemoteOnly(remote_node), MergeState::RemoteOnlyWithNewRemoteStructure(local_node) => { MergeState::RemoteOnlyWithNewRemoteStructure(local_node) } MergeState::Remote { local_node, remote_node, } => MergeState::Remote { local_node, remote_node, }, MergeState::RemoteWithNewRemoteStructure { local_node, remote_node, } => MergeState::RemoteWithNewRemoteStructure { local_node, remote_node, }, MergeState::Unchanged { local_node, remote_node, } => { // Once the structure changes, it doesn't matter which side we // pick; we'll need to reupload the item to the server, anyway. MergeState::UnchangedWithNewLocalStructure { local_node, remote_node, } } MergeState::UnchangedWithNewLocalStructure { local_node, remote_node, } => MergeState::UnchangedWithNewLocalStructure { local_node, remote_node, }, } } /// Returns a new merge state, indicating that the item has a new merged /// structure that should be reuploaded to the server. pub fn with_new_remote_structure(self) -> MergeState<'t> { match self { MergeState::LocalOnly(local_node) => MergeState::LocalOnly(local_node), MergeState::LocalOnlyWithNewLocalStructure(local_node) => { MergeState::LocalOnlyWithNewLocalStructure(local_node) } MergeState::Local { local_node, remote_node, } => MergeState::Local { local_node, remote_node, }, MergeState::LocalWithNewLocalStructure { local_node, remote_node, } => MergeState::LocalWithNewLocalStructure { local_node, remote_node, }, MergeState::RemoteOnly(remote_node) => { MergeState::RemoteOnlyWithNewRemoteStructure(remote_node) } MergeState::RemoteOnlyWithNewRemoteStructure(remote_node) => { MergeState::RemoteOnlyWithNewRemoteStructure(remote_node) } MergeState::Remote { local_node, remote_node, } => MergeState::RemoteWithNewRemoteStructure { local_node, remote_node, }, MergeState::RemoteWithNewRemoteStructure { local_node, remote_node, } => MergeState::RemoteWithNewRemoteStructure { local_node, remote_node, }, MergeState::Unchanged { local_node, remote_node, } => { // Once the structure changes, it doesn't matter which side we // pick; we'll need to reupload the item to the server, anyway. MergeState::Local { local_node, remote_node, } } MergeState::UnchangedWithNewLocalStructure { local_node, remote_node, } => MergeState::LocalWithNewLocalStructure { local_node, remote_node, }, } } /// Returns the node from the preferred side. Unlike `local_node()` and /// `remote_node()`, this doesn't indicate which side, so it's only used /// for logging and `try_from()`. fn node(&self) -> &Node<'t> { match self { MergeState::LocalOnly(local_node) | MergeState::LocalOnlyWithNewLocalStructure(local_node) | MergeState::Local { local_node, .. } | MergeState::LocalWithNewLocalStructure { local_node, .. } | MergeState::Unchanged { local_node, .. } | MergeState::UnchangedWithNewLocalStructure { local_node, .. } => local_node, MergeState::RemoteOnly(remote_node) | MergeState::RemoteOnlyWithNewRemoteStructure(remote_node) | MergeState::Remote { remote_node, .. } | MergeState::RemoteWithNewRemoteStructure { remote_node, .. } => remote_node, } } } impl<'t> fmt::Display for MergeState<'t> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_str(match self { MergeState::LocalOnly(_) | MergeState::Local { .. } => "(Local, Local)", MergeState::LocalOnlyWithNewLocalStructure(_) | MergeState::LocalWithNewLocalStructure { .. } => "(Local, New)", MergeState::RemoteOnly(_) | MergeState::Remote { .. } => "(Remote, Remote)", MergeState::RemoteOnlyWithNewRemoteStructure(_) | MergeState::RemoteWithNewRemoteStructure { .. } => "(Remote, New)", MergeState::Unchanged { .. } => "(Unchanged, Unchanged)", MergeState::UnchangedWithNewLocalStructure { .. } => "(Unchanged, New)", }) } } /// Content info for an item in the local or remote tree. This is used to dedupe /// new local items to remote items that don't exist locally, with different /// GUIDs and similar content. /// /// - Bookmarks must have the same title and URL. /// - Queries must have the same title and query URL. /// - Folders and livemarks must have the same title. /// - Separators must have the same position within their parents. #[derive(Debug, Eq, Hash, PartialEq)] pub enum Content { Bookmark { title: String, url_href: String }, Folder { title: String }, Separator, }