refactor(dag): Remove legacy functions

See https://github.com/arxanas/git-branchless/pull/619/files/08134fa4127c808ef1457b1a36a418ab258b8c10#r1014902301

git-branchless-lib/src/core/dag.rs

@@ -296,28 +296,6 @@ impl Dag {
         Ok(dag)
     }
 
-    /// Get one of the merge-base OIDs for the given pair of OIDs. If there are
-    /// multiple possible merge-bases, one is arbitrarily returned.
-    #[instrument]
-    pub fn get_one_merge_base_oid(
-        &self,
-        effects: &Effects,
-        repo: &Repo,
-        lhs_oid: NonZeroOid,
-        rhs_oid: NonZeroOid,
-    ) -> eyre::Result<Option<NonZeroOid>> {
-        let set = vec![CommitVertex::from(lhs_oid), CommitVertex::from(rhs_oid)];
-        let set = self
-            .inner
-            .sort(&CommitSet::from_static_names(set))
-            .wrap_err("Sorting DAG vertex set")?;
-        let vertex = self.inner.gca_one(set).wrap_err("Computing merge-base")?;
-        match vertex {
-            None => Ok(None),
-            Some(vertex) => Ok(Some(vertex.to_hex().parse()?)),
-        }
-    }
-
     /// Get the parent OID for the given OID. Returns an error if the given OID
     /// does not have exactly 1 parent.
     #[instrument]
@@ -429,32 +407,6 @@ impl Dag {
         })
     }
 
-    /// Find a path from the provided head to its merge-base with the main
-    /// branch.
-    #[instrument]
-    pub fn find_path_to_main_branch(
-        &self,
-        effects: &Effects,
-        head: CommitSet,
-    ) -> eyre::Result<Option<CommitSet>> {
-        // FIXME: this assumes that there is only one merge-base with the main branch.
-        let merge_base = {
-            let (_effects, _progress) = effects.start_operation(OperationType::GetMergeBase);
-            self.query().gca_one(self.main_branch_commit.union(&head))?
-        };
-        let merge_base = match merge_base {
-            Some(merge_base) => merge_base,
-            None => return Ok(None),
-        };
-
-        // FIXME: this assumes that there is only one path to the merge-base.
-        let path = {
-            let (_effects, _progress) = effects.start_operation(OperationType::FindPathToMergeBase);
-            self.query().range(CommitSet::from(merge_base), head)?
-        };
-        Ok(Some(path))
-    }
-
     /// Given a CommitSet, return a list of CommitSets, each representing a
     /// connected component of the set.
     ///

git-branchless/src/commands/move.rs

@@ -8,7 +8,7 @@ use std::convert::TryFrom;
 use std::fmt::Write;
 use std::time::SystemTime;
 
-use eden_dag::DagAlgorithm;
+use eden_dag::{DagAlgorithm, VertexName};
 use lib::core::repo_ext::RepoExt;
 use lib::util::ExitCode;
 use rayon::ThreadPoolBuilder;
@@ -32,7 +32,7 @@ use lib::git::{GitRunInfo, NonZeroOid, Repo};
 #[instrument]
 fn resolve_base_commit(
     dag: &Dag,
-    merge_base_oid: Option<NonZeroOid>,
+    merge_base_oid: Option<VertexName>,
     oid: NonZeroOid,
 ) -> eyre::Result<NonZeroOid> {
     let bases = match merge_base_oid {
@@ -207,7 +207,9 @@ pub fn r#move(
     let base_oids = {
         let mut result = Vec::new();
         for base_oid in commit_set_to_vec(&base_oids)? {
-            let merge_base_oid = dag.get_one_merge_base_oid(effects, &repo, base_oid, dest_oid)?;
+            let merge_base_oid = dag
+                .query()
+                .gca_one(vec![base_oid, dest_oid].into_iter().collect::<CommitSet>())?;
             let base_commit_oid = resolve_base_commit(&dag, merge_base_oid, base_oid)?;
             result.push(CommitSet::from(base_commit_oid))
         }

git-branchless/src/commands/smartlog.rs

@@ -231,14 +231,20 @@ mod graph {
                         // Find the nearest ancestor that is included in the graph and
                         // also on the same branch.
 
-                        let nearest_branch_ancestor = match dag
-                            .find_path_to_main_branch(effects, CommitSet::from(parent_oid))?
-                        {
-                            Some(path_to_main_branch) => dag.query().heads_ancestors(
-                                path_to_main_branch.intersection(&graph_vertices),
-                            )?,
+                        let parent_set = CommitSet::from(parent_oid);
+                        let merge_base = dag
+                            .query()
+                            .gca_one(dag.main_branch_commit.union(&parent_set))?;
+
+                        let path_to_main_branch = match merge_base {
+                            Some(merge_base) => {
+                                dag.query().range(CommitSet::from(merge_base), parent_set)?
+                            }
                             None => CommitSet::empty(),
                         };
+                        let nearest_branch_ancestor = dag
+                            .query()
+                            .heads_ancestors(path_to_main_branch.intersection(&graph_vertices))?;
 
                         let ancestor_oids = commit_set_to_vec(&nearest_branch_ancestor)?;
                         for ancestor_oid in ancestor_oids.iter() {
@@ -414,6 +420,7 @@ mod graph {
 mod render {
     use std::cmp::Ordering;
     use std::collections::HashSet;
+    use std::convert::TryFrom;
 
     use cursive::theme::Effect;
     use cursive::utils::markup::StyledString;
@@ -440,7 +447,6 @@ mod render {
     /// Returns the list such that the topologically-earlier subgraphs are first in
     /// the list (i.e. those that would be rendered at the bottom of the smartlog).
     fn split_commit_graph_by_roots(
-        effects: &Effects,
         repo: &Repo,
         dag: &Dag,
         graph: &SmartlogGraph,
@@ -465,10 +471,13 @@ mod render {
                 _ => return lhs_oid.cmp(rhs_oid),
             };
 
-            let merge_base_oid = dag.get_one_merge_base_oid(effects, repo, *lhs_oid, *rhs_oid);
+            let merge_base_oid = dag
+                .query()
+                .gca_one(vec![*lhs_oid, *rhs_oid].into_iter().collect::<CommitSet>());
             let merge_base_oid = match merge_base_oid {
                 Err(_) => return lhs_oid.cmp(rhs_oid),
-                Ok(merge_base_oid) => merge_base_oid,
+                Ok(None) => None,
+                Ok(Some(merge_base_oid)) => NonZeroOid::try_from(merge_base_oid).ok(),
             };
 
             match merge_base_oid {
@@ -698,7 +707,7 @@ mod render {
         head_oid: Option<NonZeroOid>,
         commit_descriptors: &mut [&mut dyn NodeDescriptor],
     ) -> eyre::Result<Vec<StyledString>> {
-        let root_oids = split_commit_graph_by_roots(effects, repo, dag, graph);
+        let root_oids = split_commit_graph_by_roots(repo, dag, graph);
         let lines = get_output(
             effects.get_glyphs(),
             dag,