handlers: update location-to-hash endpoint with count parameter

Summary:
To reduce the size over the wire on cases where we would be traversing the
changelog on the client, we want to allow the endpoint to return a whole parent
chain with their hashes.

Reviewed By: kulshrax

Differential Revision: D23456216

fbshipit-source-id: d048462fa8415d0466dd8e814144347df7a3452a

eden/mononoke/edenapi_server/src/errors.rs

@@ -60,8 +60,6 @@ pub enum ErrorKind {
     CompleteTreeRequestFailed,
     #[error("Dag location to hash request failed")]
     CommitLocationToHashRequestFailed,
-    #[error("Functionality not implemented")]
-    NotImplemented,
     #[error("Commit data request failed")]
     CommitRevlogDataRequestFailed,
     #[error("HgId not found: {0}")]

eden/mononoke/edenapi_server/src/handlers/commit.rs

@@ -5,7 +5,7 @@
  * GNU General Public License version 2.
  */
 
-use anyhow::{format_err, Context, Error};
+use anyhow::{Context, Error};
 use futures::{stream, StreamExt};
 use gotham::state::{FromState, State};
 use gotham_derive::{StateData, StaticResponseExtender};
@@ -73,19 +73,18 @@ async fn translate_location(
     hg_repo_ctx: HgRepoContext,
     location: CommitLocation,
 ) -> Result<CommitLocationToHash, Error> {
-    if location.count != 1 {
-        return Err(
-            format_err!("location to hash with count different that 1 is unimplemented")
-                .context(ErrorKind::NotImplemented),
-        );
-    }
     let known_descendant = HgChangesetId::new(HgNodeHash::from(location.known_descendant));
 
-    let ancestor: HgChangesetId = hg_repo_ctx
-        .location_to_hg_changeset_id(known_descendant, location.distance_to_descendant)
+    let ancestors: Vec<HgChangesetId> = hg_repo_ctx
+        .location_to_hg_changeset_id(
+            known_descendant,
+            location.distance_to_descendant,
+            location.count,
+        )
         .await
         .with_context(|| ErrorKind::CommitLocationToHashRequestFailed)?;
-    let answer = CommitLocationToHash::new(location, ancestor.into_nodehash().into());
+    let converted = ancestors.iter().map(|a| a.into_nodehash().into()).collect();
+    let answer = CommitLocationToHash::new(location, converted);
 
     Ok(answer)
 }

eden/mononoke/mononoke_api/src/hg/repo.rs

@@ -9,10 +9,9 @@ use blobrepo::BlobRepo;
 use blobrepo_hg::BlobRepoHg;
 use bytes::Bytes;
 use context::CoreContext;
-use futures::{
-    compat::{Future01CompatExt, Stream01CompatExt},
-    TryStream, TryStreamExt,
-};
+use futures::compat::{Future01CompatExt, Stream01CompatExt};
+use futures::future;
+use futures::{TryStream, TryStreamExt};
 use hgproto::GettreepackArgs;
 use mercurial_types::blobs::RevlogChangeset;
 use mercurial_types::{HgChangesetId, HgFileNodeId, HgManifestId};
@@ -127,7 +126,8 @@ impl HgRepoContext {
         &self,
         known_descendant: HgChangesetId,
         distance_to_descendant: u64,
-    ) -> Result<HgChangesetId, MononokeError> {
+        count: u64,
+    ) -> Result<Vec<HgChangesetId>, MononokeError> {
         let known_descendent_csid = self
             .blob_repo()
             .get_bonsai_from_hg(self.ctx().clone(), known_descendant)
@@ -139,16 +139,18 @@ impl HgRepoContext {
                     known_descendant
                 ))
             })?;
-        let result_csid = self
+        let result_csids = self
             .repo()
-            .location_to_changeset_id(known_descendent_csid, distance_to_descendant)
+            .location_to_changeset_id(known_descendent_csid, distance_to_descendant, count)
             .await?;
-        let result = self
-            .blob_repo()
-            .get_hg_from_bonsai_changeset(self.ctx().clone(), result_csid)
-            .compat()
-            .await?;
-        Ok(result)
+        let hg_id_futures = result_csids.iter().map(|result_csid| {
+            self.blob_repo()
+                .get_hg_from_bonsai_changeset(self.ctx().clone(), *result_csid)
+                .compat()
+        });
+        future::try_join_all(hg_id_futures)
+            .await
+            .map_err(MononokeError::from)
     }
 
     pub async fn revlog_commit_data(

eden/mononoke/mononoke_api/src/repo.rs

@@ -1172,7 +1172,8 @@ impl RepoContext {
         &self,
         known_descendant: ChangesetId,
         distance_to_descendant: u64,
-    ) -> Result<ChangesetId, MononokeError> {
+        count: u64,
+    ) -> Result<Vec<ChangesetId>, MononokeError> {
         let blob_repo = self.blob_repo();
         let segmented_changelog =
             blob_repo
@@ -1183,7 +1184,12 @@ impl RepoContext {
                     ))
                 })?;
         let ancestor = segmented_changelog
-            .location_to_changeset_id(&self.ctx, known_descendant, distance_to_descendant)
+            .location_to_many_changeset_ids(
+                &self.ctx,
+                known_descendant,
+                distance_to_descendant,
+                count,
+            )
             .await
             .map_err(MononokeError::from)?;
         Ok(ancestor)

eden/scm/lib/edenapi/types/src/commit.rs

@@ -50,7 +50,7 @@ pub struct CommitLocationToHashRequest {
 #[derive(Serialize, Deserialize)]
 pub struct CommitLocationToHash {
     pub location: CommitLocation,
-    pub hgid: HgId,
+    pub hgids: Vec<HgId>,
 }
 
 impl CommitLocation {
@@ -64,8 +64,8 @@ impl CommitLocation {
 }
 
 impl CommitLocationToHash {
-    pub fn new(location: CommitLocation, hgid: HgId) -> Self {
-        Self { location, hgid }
+    pub fn new(location: CommitLocation, hgids: Vec<HgId>) -> Self {
+        Self { location, hgids }
     }
 }