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// Copyright 2018-2019 Joe Neeman. // // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your // option. This file may not be copied, modified, or distributed // except according to those terms. // // See the LICENSE-APACHE or LICENSE-MIT files at the top-level directory // of this distribution. use ojo_graph::Graph; use ojo_multimap::MMap; use ojo_partition::Partition; use std::collections::BTreeSet as Set; use std::collections::HashSet; use crate::{NodeId, PatchId}; /// The different kinds of edges. #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)] pub enum EdgeKind { /// This edge points to a live node. Live, /// This edge was not present in the original graggle. It was added as an optimization, to skip /// over deleted nodes. (TODO: reference some more detailed docs on pseudo-edges) Pseudo, // The order here is important: by putting deleted edges last, we can efficiently ignore them: // if we iterate through the neighbors of node but stop at the first deleted one, then we've // ignored all of the deleted neighbors. /// This edges points to a deleted node. Deleted, } impl EdgeKind { fn from_deleted(deleted: bool) -> EdgeKind { if deleted { EdgeKind::Deleted } else { EdgeKind::Live } } } /// This struct represents a directed edge in a graggle graph. /// /// Note that we don't actually store the source node, only the destination. However, the main way /// of getting access to an `Edge` is via the `Graggle::out_edges` or `Graggle::in_edges` functions, so /// usually you will only encounter an `Edge` if you already know what the source node is. /// /// Note that edges are ordered, and that live edges will always come before deleted edges. This /// helps ensure quick access to live edges. #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)] pub struct Edge { /// What kind of edge is it? pub kind: EdgeKind, /// The destination of this (directed) edge. pub dest: NodeId, /// Which patch introduced this edge? /// /// If this is a pseudo-edge, then this field will be "blank", meaning that it will be set to /// `PatchId::cur`. /// /// This field is necessary because of the possiblity that two different patches will add the /// same edge. If this happens and then one of the patches is unapplied, we'd better make sure /// to still have an edge present afterwards. pub patch: PatchId, } impl Edge { fn not_deleted(&self) -> bool { self.kind != EdgeKind::Deleted } fn new_pseudo(dest: NodeId) -> Edge { Edge { dest: dest, kind: EdgeKind::Pseudo, patch: PatchId::cur(), } } fn new_live(dest: NodeId, patch: PatchId) -> Edge { Edge { dest, kind: EdgeKind::Live, patch, } } fn new_deleted(dest: NodeId, patch: PatchId) -> Edge { Edge { dest, kind: EdgeKind::Deleted, patch, } } // "Real" means either live or deleted, but not pseudo fn new_real(dest: NodeId, deleted: bool, patch: PatchId) -> Edge { Edge { dest, kind: EdgeKind::from_deleted(deleted), patch, } } } impl ojo_graph::Edge<NodeId> for Edge { fn target(&self) -> NodeId { self.dest } } #[derive(Clone, Debug, Default, Deserialize, Serialize)] #[serde(rename = "Graggle")] pub(crate) struct GraggleData { nodes: Set<NodeId>, deleted_nodes: Set<NodeId>, edges: MMap<NodeId, Edge>, back_edges: MMap<NodeId, Edge>, // A partition of all the deleted nodes into weakly connected components. deleted_partition: Partition<NodeId>, // A map from pseudo-edges (the forward-pointing ones only) to the set of parts (identified by // their representative) that are responsible for the pseudo-edge. pseudo_edge_reasons: MMap<(NodeId, NodeId), NodeId>, // A map from "reasons" (i.e. representatives of a partition) to edges that are there because // of that reason. reason_pseudo_edges: MMap<NodeId, (NodeId, NodeId)>, // These are the component representatives whose components are dirty (i.e. we need to // recalculate the connectedness relation that they induce). dirty_reps: Set<NodeId>, } // Two Graggles compare as equal if they have the same nodes and edges (including pseudo-edges). We // don't check the rest of the fields, as they are only there for optimization. impl PartialEq<GraggleData> for GraggleData { fn eq(&self, other: &GraggleData) -> bool { self.nodes.eq(&other.nodes) && self.deleted_nodes.eq(&other.deleted_nodes) && self.edges.eq(&other.edges) && self.back_edges.eq(&other.back_edges) } } impl GraggleData { pub fn new() -> GraggleData { Default::default() } pub fn as_graggle(&'_ self) -> Graggle<'_> { Graggle { data: self } } pub fn all_out_edges<'b>(&'b self, node: &NodeId) -> impl Iterator<Item = &'b Edge> + 'b { self.edges.get(node) } pub fn all_in_edges<'b>(&'b self, node: &NodeId) -> impl Iterator<Item = &'b Edge> + 'b { self.back_edges.get(node) } pub fn add_node(&mut self, id: NodeId) { self.nodes.insert(id); } fn has_live_edge(&self, src: &NodeId, dest: &NodeId) -> bool { // Construct the smallest (in the sense of Edge's order) edge that could possibly go from // src to dest. let e = Edge::new_live(*dest, PatchId::cur()); if let Some(actual_e) = self.edges.get_from(src, &e).next() { // actual_e is an edge going from src to something greater than or equal to dest. // There's an edge from src to dest if and only if actual_e goes to dest. actual_e.dest == *dest && actual_e.kind == EdgeKind::Live } else { false } } // We just deleted the pseudo-edge from src to dest. Clean up the corresponding entries in // pseudo_edge_reasons and reason_pseudo_edges. fn remove_pseudo_edge_reasons(&mut self, src: &NodeId, dest: &NodeId) { let reasons = self .pseudo_edge_reasons .get(&(*src, *dest)) .cloned() .collect::<Vec<_>>(); self.pseudo_edge_reasons.remove_all(&(*src, *dest)); for r in reasons { self.reason_pseudo_edges.remove(&r, &(*src, *dest)); } } // Deletes an edge (both forward and back), but does nothing else to ensure consistency and // maintain invariants. fn internal_delete_edge(&mut self, src: &NodeId, edge: &Edge) { self.edges.remove(src, edge); let back_edge = Edge { dest: *src, // NOTE: This is not really correct: to get the right kind, we should really check // whether src is live. However, it still works because (assuming we resolve patch // dependencies correctly) every edge we delete either has two live endpoints or it is // a pseudo-edge (in which case it is a pseudo-edge in both directions). kind: edge.kind, patch: edge.patch, }; self.back_edges.remove(&edge.dest, &back_edge); } fn internal_delete_back_edge(&mut self, dest: &NodeId, back_edge: &Edge) { self.back_edges.remove(dest, back_edge); let edge = Edge { dest: *dest, kind: back_edge.kind, patch: back_edge.patch, }; self.edges.remove(&back_edge.dest, &edge); } pub fn unadd_node(&mut self, id: &NodeId) { // If we are unadding a node, it means we are unapplying the patch in which the node was // introduced. Since we must have already unapplied any reverse-dependencies of the patch, // the node must be live (it can't have been marked as deleted). assert!(self.nodes.contains(id)); self.nodes.remove(id); // Remove all the edges that had anything to do with this node. (When unapplying a patch, // most of the edges would probably have already been deleted, but there might be lingering // pseudo-edges.) let out_edges = self.all_out_edges(id).cloned().collect::<Vec<_>>(); let in_edges = self.all_in_edges(id).cloned().collect::<Vec<_>>(); for e in out_edges { self.internal_delete_edge(id, &e); if e.kind == EdgeKind::Pseudo { self.remove_pseudo_edge_reasons(id, &e.dest); } } for e in in_edges { self.internal_delete_back_edge(id, &e); if e.kind == EdgeKind::Pseudo { self.remove_pseudo_edge_reasons(&e.dest, id); } } // Because we just unadded a node that was live, it can't have any effect on pseudo-edges, // so no need to update them. } /// Given a live node, marks it as deleted. That is, the node doesn't vanish; it turns into a /// tombstone. /// /// # Panics /// Panics if the node doesn't exist, or if exists but is not live. pub fn delete_node(&mut self, id: &NodeId) { assert!(self.nodes.contains(id)); self.nodes.remove(id); self.deleted_nodes.insert(id.clone()); // It's possible that deleted_partition already contains this node (if pseudo-edges weren't // resolved recently). if !self.deleted_partition.contains(id.clone()) { self.deleted_partition.insert(id.clone()); } // All the edges (both forward and backwards) pointing towards the newly deleted node need // to be marked as deleted. let out_neighbors = self.all_out_edges(id).cloned().collect::<Vec<_>>(); let in_neighbors = self.all_in_edges(id).cloned().collect::<Vec<_>>(); for e in out_neighbors { self.delete_opposite_edge(id, &e, true); } for e in in_neighbors { self.delete_opposite_edge(id, &e, false); } self.mark_dirty(id); } pub fn undelete_node(&mut self, id: &NodeId) { assert!(self.deleted_nodes.contains(id)); self.deleted_nodes.remove(id); self.nodes.insert(id.clone()); // All the edges (both forward and backwards) pointing towards the newly deleted node need // to be marked as live. let out_neighbors = self.all_out_edges(id).cloned().collect::<Vec<_>>(); let in_neighbors = self.all_in_edges(id).cloned().collect::<Vec<_>>(); for e in out_neighbors { self.undelete_opposite_edge(id, &e, true); } for e in in_neighbors { self.undelete_opposite_edge(id, &e, false); } // Mark the entire connected component containing `id` as dirty. Note that we don't // actually remove `id` from the component, because it might take too long to compute how // the component splits up. When it comes time to compute the new connectivity relation, we // will figure out how the component splits. self.mark_dirty(id); } // The node `src` has just been deleted, and `edge` is an edge pointing out from it (either // forwards or backwards). We want to delete the edge pointing from edge.dest to src. fn delete_opposite_edge(&mut self, src: &NodeId, edge: &Edge, edge_points_forwards: bool) { // This is the edge_map that points in the opposite direction as `edge`. let opposite_edges = if edge_points_forwards { &mut self.back_edges } else { &mut self.edges }; if edge.kind == EdgeKind::Pseudo { // Pseudo-edges don't get marked as deleted, they just get removed. let opposite_edge = Edge::new_pseudo(*src); opposite_edges.remove(&edge.dest, &opposite_edge); } else { // To mark the edge as deleted, we actually remove it and then add it back in again // (because deleted edges appear in a different position in the map). let mut opposite_edge = Edge::new_live(*src, edge.patch); opposite_edges.remove(&edge.dest, &opposite_edge); opposite_edge.kind = EdgeKind::Deleted; opposite_edges.insert(edge.dest, opposite_edge); } // The node `src` was just deleted. If `edge.dest` is also deleted, it means that they now // belong to the same connected component of deleted edges. if edge.kind == EdgeKind::Deleted { self.merge_components(src, &edge.dest); } } // The node `src` was just undeleted, and `edge` points out from `src`. fn undelete_opposite_edge(&mut self, src: &NodeId, edge: &Edge, edge_points_forwards: bool) { // This is the edge_map that points in the opposite direction as `edge`. let opposite_edges = if edge_points_forwards { &mut self.back_edges } else { &mut self.edges }; // Unlike `delete_opposite_edge`, there's no change of encountering a pseudo-edge pointing // from `edge.dest` to `src` (because `src` was just undeleted, and while it was deleted no // pseudo-edges pointed at it). let mut opposite_edge = Edge::new_deleted(*src, edge.patch); opposite_edges.remove(&edge.dest, &opposite_edge); opposite_edge.kind = EdgeKind::Live; opposite_edges.insert(edge.dest, opposite_edge); // Unlike in `delete_opposite_edge`, there's no need here to do anything about pseudo-edges // and partition-merging. That's because the entire partition that `src` used to belong to // has already been marked as dirty. } // `id` and `other` are two deleted nodes that have just been connected by an edge. We need to // mark them as being in the same connected component of deleted nodes. This also entails // marking the merged component as dirty, and removing any obsolete pseudo-edges. fn merge_components(&mut self, id1: &NodeId, id2: &NodeId) { let rep1 = self.deleted_partition.representative(*id1); let rep2 = self.deleted_partition.representative(*id2); self.deleted_partition.merge(rep1, rep2); let new_rep = self.deleted_partition.representative(rep1); self.delete_obsolete_reason(&rep1); self.delete_obsolete_reason(&rep2); self.dirty_reps.remove(&rep1); self.dirty_reps.remove(&rep2); self.dirty_reps.insert(new_rep); } // `reason` was (and possibly still is) the representative of a component that got modified. We // can't trust any pseudo-edges coming from that component, so delete them all. fn delete_obsolete_reason(&mut self, reason: &NodeId) { let obsolete_pairs = self .reason_pseudo_edges .get(reason) .cloned() .collect::<Vec<_>>(); for (src, dest) in obsolete_pairs { let e = Edge::new_pseudo(dest); self.pseudo_edge_reasons.remove(&(src, dest), reason); // If that was the last reason for the pseudo-edge, delete it. if self.pseudo_edge_reasons.get(&(src, dest)).next().is_none() { self.internal_delete_edge(&src, &e); } } self.reason_pseudo_edges.remove_all(reason); } // Marks the component containing `id` as dirty. fn mark_dirty(&mut self, id: &NodeId) { let rep = self.deleted_partition.representative(*id); self.delete_obsolete_reason(&rep); self.dirty_reps.insert(rep); } pub fn add_edge(&mut self, from: NodeId, to: NodeId, patch: PatchId) { let from_deleted = !self.nodes.contains(&from); let to_deleted = !self.nodes.contains(&to); assert!(!from_deleted || self.deleted_nodes.contains(&from)); assert!(!to_deleted || self.deleted_nodes.contains(&to)); self.edges .insert(from, Edge::new_real(to, to_deleted, patch)); self.back_edges .insert(to, Edge::new_real(from, from_deleted, patch)); if from_deleted && to_deleted { self.merge_components(&from, &to); } else if from_deleted { self.mark_dirty(&from); } else if to_deleted { self.mark_dirty(&to); } } pub fn resolve_pseudo_edges(&mut self) { let mut dirty_reps = Set::new(); std::mem::swap(&mut dirty_reps, &mut self.dirty_reps); // Each partition represented by a dirty rep needs to be rechecked, because it's possible // that it actually encompasses multiple connected components in the new graggle. let graggle = self.as_graggle(); let graph = graggle.as_full_graph(); let sub_graph = graph.node_filtered(|u| { !graggle.is_live(u) && dirty_reps.contains(&self.deleted_partition.representative(*u)) }); let components = sub_graph.weak_components().into_parts(); // Remove all the messed up parts from the partition, and replace them with the correct // ones. for rep in dirty_reps { self.deleted_partition.remove_part(rep); } for component in &components { // Add everything in the current component as a new component in deleted_partition. let mut iter = component.iter(); // Unwrap is ok because the components are guaranteed to be non-empty. let rep = iter.next().unwrap(); self.deleted_partition.insert(*rep); for u in iter { self.deleted_partition.insert(*u); self.deleted_partition.merge(*rep, *u); } } // Add in the required pseudo-edges and fix up the partition. for component in components { self.add_component_pseudo_edges(&component); } } /// # Panics /// /// Panics unless `from` and `to` are nodes in this graggle. In particular, if you're planning to /// remove some nodes and the edge between them, you need to remove the edge first. pub fn unadd_edge(&mut self, from: &NodeId, to: &NodeId, patch: PatchId) { let from_deleted = self.deleted_nodes.contains(&from); let to_deleted = self.deleted_nodes.contains(&to); assert!(from_deleted || self.nodes.contains(&from)); assert!(to_deleted || self.nodes.contains(&to)); let forward_edge = Edge::new_real(*to, to_deleted, patch); let back_edge = Edge::new_real(*from, from_deleted, patch); self.edges.remove(&from, &forward_edge); self.back_edges.remove(&to, &back_edge); if from_deleted { self.mark_dirty(from); } if to_deleted { self.mark_dirty(to); } } // Adds all the pseudo-edges that are induced by a single connected component of deleted nodes. // // `component` must be a non-empty connected component of the deleted nodes. fn add_component_pseudo_edges(&mut self, component: &HashSet<NodeId>) { let graggle = self.as_graggle(); let graph = graggle.as_full_graph(); let mut neighborhood = graph.neighbor_set(component.iter()); neighborhood.extend(component.iter().cloned()); // Find the representative of this connected component. The unwrap is ok because // `component` is non-empty. let rep = self .deleted_partition .representative(*component.iter().next().unwrap()); // This is the collection of all live nodes that are adjacent to a particular connected // component of deleted nodes. We will compute the complete connectivity relation that // the deleted nodes induce on these boundary nodes, and then we will add a pseudo-edge // for each connected pair. let boundary = neighborhood.iter().filter(|u| graggle.is_live(u)); let mut pairs = Vec::new(); for u in boundary { let sub_graph = graph.edge_filtered(|src, edge| { (src == u && component.contains(&edge.dest)) || component.contains(src) }); for visit in sub_graph.dfs_from(u) { if let ojo_graph::dfs::Visit::Edge { dst, status, .. } = visit { // Only take into account the first visit to a node. Besides being more // efficient, this means we'll avoid adding self-loops. if status == ojo_graph::dfs::Status::New && graggle.is_live(&dst) { pairs.push((*u, dst)); } } } } for (src, dest) in pairs { // Only add a pseudo-edge if there is not already an edge present. if !self.has_live_edge(&src, &dest) { self.edges.insert(src, Edge::new_pseudo(dest)); self.back_edges.insert(dest, Edge::new_pseudo(src)); self.pseudo_edge_reasons.insert((src, dest), rep); self.reason_pseudo_edges.insert(rep, (src, dest)); } } } fn is_live(&self, node: &NodeId) -> bool { self.nodes.contains(node) } // Brute-force compute the pseudo-edges that should start at node u. fn pseudo_edges(&self, u: &NodeId) -> HashSet<NodeId> { use ojo_graph::dfs::{Status, Visit}; let mut ret = HashSet::new(); // Pseudo-edges that should start at u are those that can be reached from u by ignoring // other pseudo-edges, and only going through deleted intermediate edges. This latter // property can be enforced by only traversing edges that either go from u to a deleted // node or else start at a deleted node. let graph = self.as_graggle().as_full_graph(); let u_graph = graph.edge_filtered(|src, edge| { edge.kind != EdgeKind::Pseudo && ((src == u && !self.is_live(&edge.dest)) || !self.is_live(src)) }); for visit in u_graph.dfs_from(u) { if let Visit::Edge { dst, status, .. } = visit { if status == Status::New && dst != *u && self.is_live(&dst) && !self.has_live_edge(u, &dst) { ret.insert(dst); } } } ret } pub fn assert_consistent(&self) { // The live and deleted nodes should be disjoint. assert!(self.nodes.is_disjoint(&self.deleted_nodes)); let node_exists = |id| self.nodes.contains(id) || self.deleted_nodes.contains(id); // The source and destination of every edge should exist somewhere, and they should not be // the same. // The destination should be deleted if and only if the edge kind is `Deleted`. // There should be a one-to-one correspondence between edges and back_edges. let mut seen_back_edges = HashSet::new(); for (src, edge) in self.edges.iter() { assert!(node_exists(src)); assert!(node_exists(&edge.dest)); assert!(src != &edge.dest); assert_eq!( self.deleted_nodes.contains(&edge.dest), edge.kind == EdgeKind::Deleted ); let back_edge = Edge { dest: *src, kind: if edge.kind == EdgeKind::Pseudo { EdgeKind::Pseudo } else { EdgeKind::from_deleted(self.deleted_nodes.contains(src)) }, patch: edge.patch, }; assert!(self.back_edges.contains(&edge.dest, &back_edge)); seen_back_edges.insert((edge.dest, back_edge)); } // We've checked that every forward edge corresponds to a backward edge; now check that // every backward edge was encountered in this way. for (src, back_edge) in self.back_edges.iter() { assert!(seen_back_edges.contains(&(*src, *back_edge))); } // The deleted partition should contain all of the deleted nodes (if the pseudo-edges // haven't been resolved yet, it may also contain nodes that have been undeleted). for u in &self.deleted_nodes { assert!(self.deleted_partition.contains(*u)); } // If the pseudo-edges are up-to-date, there are some additional checks we can do. if self.dirty_reps.is_empty() { // Everything in the deleted partition should be a deleted node. for u in self.deleted_partition.iter_parts().flat_map(|p| p) { assert!(self.deleted_nodes.contains(&u)); } // Every pseudo-edge should have at least one reason. for (src, edge) in self.edges.iter() { if edge.kind == EdgeKind::Pseudo { assert!(self .pseudo_edge_reasons .get(&(*src, edge.dest)) .next() .is_some()); } } // Every reason should correspond to a pseudo-edge. for (&(src, dest), _) in self.pseudo_edge_reasons.iter() { assert!(self.edges.contains(&src, &Edge::new_pseudo(dest))); } // Every reason should be a representative in the partition. for (reason, _) in self.reason_pseudo_edges.iter() { assert!(self.deleted_partition.is_rep(reason)); } // Check that the pseudo-edges are correct. for u in &self.nodes { let correct_pseudo_edges = self.pseudo_edges(u); let actual_pseudo_edges = self .all_out_edges(u) .filter(|e| e.kind == EdgeKind::Pseudo) .map(|e| e.dest) .collect::<HashSet<_>>(); assert_eq!(correct_pseudo_edges, actual_pseudo_edges); } } } } // This wrapping is a bit annoying. It would be simpler just to rename `GraggleData` to `Graggle` and // then pass around `&Graggle`s. The thing is that we want to implement `Graph` for `&Graggle`, and I // had some problems with that for some reason (can no longer remember why...). Certainly, the lack // of ATCs/GATs means we can't implement `Graph` for `Graggle`. /// A graggle is like a file, except that its lines are not necessarily in a linear order (rather, /// they form a directed graph). /// /// This is a read-only view into a graggle. It implements [`Graph`](graph::Graph), so you may /// apply graph-based algorithms on it. /// /// Note that lines in a graggle may be either live or deleted (nodes that are ``deleted'' are not /// actually removed, but they are simply marked as being deleted). Some of the methods on `Graggle` /// ignore the deleted lines, while others expose them. // // TODO: should explain back-edges and pseudo-edges here #[derive(Clone, Copy, Debug)] pub struct Graggle<'a> { data: &'a GraggleData, } impl<'a> Graggle<'a> { /// Returns an iterator over all live nodes of this graggle. pub fn nodes(self) -> impl Iterator<Item = NodeId> + 'a { self.data.nodes.iter().cloned() } /// Returns an iterator over all edges pointing from `node` to another live node. pub fn out_edges(self, node: &NodeId) -> impl Iterator<Item = &'a Edge> + 'a { self.data.edges.get(node).take_while(|e| e.not_deleted()) } /// Returns an iterator over all live out-neighbors of `node`. pub fn out_neighbors(self, node: &NodeId) -> impl Iterator<Item = &'a NodeId> + 'a { self.out_edges(node).map(|e| &e.dest) } /// Returns an iterator over all live in-neighbors of `node`. pub fn in_neighbors(self, node: &NodeId) -> impl Iterator<Item = &'a NodeId> + 'a { self.in_edges(node).map(|e| &e.dest) } /// Returns an iterator over all edges pointing out of `node`, including those that point to /// deleted edges. pub fn all_out_edges(self, node: &NodeId) -> impl Iterator<Item = &'a Edge> + 'a { self.data.edges.get(node) } /// Returns an iterator over all backwards edges pointing from `node` to another live node. pub fn in_edges(self, node: &NodeId) -> impl Iterator<Item = &'a Edge> + 'a { self.data .back_edges .get(node) .take_while(|e| e.not_deleted()) } /// Returns an iterator over all backwards edges pointing out of `node`, including those that /// point to deleted edges. pub fn all_in_edges(self, node: &NodeId) -> impl Iterator<Item = &'a Edge> + 'a { self.data.back_edges.get(node) } /// Returns `true` if `node` belongs to this graggle (whether it is live or deleted). pub fn has_node(self, node: &NodeId) -> bool { self.data.nodes.contains(node) || self.data.deleted_nodes.contains(node) } /// Returns `true` if `node` is live. /// /// # Panics /// /// Panics unless `node` belongs to this graggle. pub fn is_live(self, node: &NodeId) -> bool { assert!(self.has_node(node)); self.data.nodes.contains(node) } /// Wraps `self` in [`LiveGraph`], which implements [`graph::Graph`] over the live nodes of /// this graggle. pub fn as_live_graph(self) -> LiveGraph<'a> { LiveGraph(self) } /// Wraps `self` in [`FullGraph`], which implements [`graph::Graph`] over all (live and /// deleted) nodes of this graggle. pub fn as_full_graph(self) -> FullGraph<'a> { FullGraph(self) } } impl<'a> From<&'a GraggleData> for Graggle<'a> { fn from(d: &'a GraggleData) -> Graggle<'a> { Graggle { data: d } } } /// A wrapper around [`Graggle`] implementing the [`graph::Graph`] trait. /// /// This represents only the part of the graggle containing live nodes. To examine the entire graggle /// (i.e. including deleted nodes), use [`FullGraph`]. pub struct LiveGraph<'a>(Graggle<'a>); impl<'a> ojo_graph::Graph for LiveGraph<'a> { type Node = NodeId; type Edge = Edge; fn nodes<'b>(&'b self) -> Box<dyn Iterator<Item = Self::Node> + 'b> { Box::new(self.0.data.nodes.iter().cloned()) } fn out_edges<'b>(&'b self, u: &NodeId) -> Box<dyn Iterator<Item = Self::Edge> + 'b> { Box::new(self.0.out_edges(u).cloned()) } fn in_edges<'b>(&'b self, u: &NodeId) -> Box<dyn Iterator<Item = Self::Edge> + 'b> { Box::new(self.0.in_edges(u).cloned()) } } /// A wrapper around [`Graggle`] implementing the [`graph::Graph`] trait. /// /// This represents only the entire graggle, even the nodes that are deleted. To examine only the /// live parts of the graggle, use [`LiveGraph`]. pub struct FullGraph<'a>(Graggle<'a>); impl<'a> ojo_graph::Graph for FullGraph<'a> { type Node = NodeId; type Edge = Edge; fn nodes<'b>(&'b self) -> Box<dyn Iterator<Item = Self::Node> + 'b> { Box::new( self.0 .data .nodes .iter() .chain(self.0.data.deleted_nodes.iter()) .cloned(), ) } fn out_edges<'b>(&'b self, u: &NodeId) -> Box<dyn Iterator<Item = Self::Edge> + 'b> { Box::new(self.0.all_out_edges(u).cloned()) } fn in_edges<'b>(&'b self, u: &NodeId) -> Box<dyn Iterator<Item = Self::Edge> + 'b> { Box::new(self.0.all_in_edges(u).cloned()) } } #[cfg(test)] #[macro_use] pub mod tests;