fn merge_helper(store: Store, dir_digests: Vec<Digest>) -> BoxFuture<Digest, String> {
    if dir_digests.is_empty() {
      // TODO: This will not have been stored... we'll need to explicitly store it.
      return future::ok(EMPTY_DIGEST).to_boxed();
    } else if dir_digests.len() == 1 {
      let mut dir_digests = dir_digests;
      return future::ok(dir_digests.pop().unwrap()).to_boxed();
    }

    let directories = dir_digests
      .into_iter()
      .map(|digest| {
        store
          .load_directory(digest)
          .and_then(move |maybe_directory| {
            maybe_directory
              .ok_or_else(|| format!("Digest {:?} did not exist in the Store.", digest))
          })
      })
      .collect::<Vec<_>>();
    join_all(directories)
      .and_then(move |mut directories| {
        let mut out_dir = bazel_protos::remote_execution::Directory::new();

        // Merge FileNodes.
        out_dir.set_files(protobuf::RepeatedField::from_vec(
          directories
            .iter_mut()
            .map(|directory| directory.take_files().into_iter())
            .flatten()
            .collect(),
        ));
        out_dir.mut_files().sort_by(|a, b| a.name.cmp(&b.name));

        // Group and recurse for DirectoryNodes.
        let sorted_child_directories = {
          let mut merged_directories = directories
            .iter_mut()
            .map(|directory| directory.take_directories().into_iter())
            .flatten()
            .collect::<Vec<_>>();
          merged_directories.sort_by(|a, b| a.name.cmp(&b.name));
          merged_directories
        };
        let store2 = store.clone();
        join_all(
          sorted_child_directories
            .into_iter()
            .group_by(|d| d.name.clone())
            .into_iter()
            .map(move |(child_name, group)| {
              Self::merge_helper(
                store2.clone(),
                group.map(|d| d.get_digest().into()).collect(),
              ).map(move |merged_digest| {
                let mut child_dir = bazel_protos::remote_execution::DirectoryNode::new();
                child_dir.set_name(child_name);
                child_dir.set_digest((&merged_digest).into());
                child_dir
              })
            })
            .collect::<Vec<_>>(),
        ).and_then(move |child_directories| {
          out_dir.set_directories(protobuf::RepeatedField::from_vec(child_directories));
          store.record_directory(&out_dir, true)
        })
          .to_boxed() as BoxFuture<_, _>
      })
      .to_boxed()
  }
///
/// Given Digest(s) representing Directory instances, merge them recursively into a single
/// output Directory Digest. Fails for collisions.
///
Given Digest(s) representing Directory instances, merge them recursively into a single
output Directory Digest. Fails for collisions.
Given Digest ( s ) representing Directory instances merge them recursively into a single output Directory Digest . Fails for collisions .
fn merge_helper(store: Store, dir_digests: Vec<Digest>) -> BoxFuture<Digest, String> {
    if dir_digests.is_empty() {
      // TODO: This will not have been stored... we'll need to explicitly store it.
      return future::ok(EMPTY_DIGEST).to_boxed();
    } else if dir_digests.len() == 1 {
      let mut dir_digests = dir_digests;
      return future::ok(dir_digests.pop().unwrap()).to_boxed();
    }
    let directories = dir_digests
      .into_iter()
      .map(|digest| {
        store
          .load_directory(digest)
          .and_then(move |maybe_directory| {
            maybe_directory
              .ok_or_else(|| format!("Digest {:?} did not exist in the Store.", digest))
          })
      })
      .collect::<Vec<_>>();
    join_all(directories)
      .and_then(move |mut directories| {
        let mut out_dir = bazel_protos::remote_execution::Directory::new();
        // Merge FileNodes.
        out_dir.set_files(protobuf::RepeatedField::from_vec(
          directories
            .iter_mut()
            .map(|directory| directory.take_files().into_iter())
            .flatten()
            .collect(),
        ));
        out_dir.mut_files().sort_by(|a, b| a.name.cmp(&b.name));
        // Group and recurse for DirectoryNodes.
        let sorted_child_directories = {
          let mut merged_directories = directories
            .iter_mut()
            .map(|directory| directory.take_directories().into_iter())
            .flatten()
            .collect::<Vec<_>>();
          merged_directories.sort_by(|a, b| a.name.cmp(&b.name));
          merged_directories
        };
        let store2 = store.clone();
        join_all(
          sorted_child_directories
            .into_iter()
            .group_by(|d| d.name.clone())
            .into_iter()
            .map(move |(child_name, group)| {
              Self::merge_helper(
                store2.clone(),
                group.map(|d| d.get_digest().into()).collect(),
              ).map(move |merged_digest| {
                let mut child_dir = bazel_protos::remote_execution::DirectoryNode::new();
                child_dir.set_name(child_name);
                child_dir.set_digest((&merged_digest).into());
                child_dir
              })
            })
            .collect::<Vec<_>>(),
        ).and_then(move |child_directories| {
          out_dir.set_directories(protobuf::RepeatedField::from_vec(child_directories));
          store.record_directory(&out_dir, true)
        })
          .to_boxed() as BoxFuture<_, _>
      })
      .to_boxed()
  }
fn merge_helper ( store : Store , dir_digests : Vec < Digest > ) -> BoxFuture < Digest , String > { if dir_digests . is_empty ( ) { // TODO: This will not have been stored... we'll need to explicitly store it. return future :: ok ( EMPTY_DIGEST ) . to_boxed ( ) ; } else if dir_digests . len ( ) == 1 { let mut dir_digests = dir_digests ; return future :: ok ( dir_digests . pop ( ) . unwrap ( ) ) . to_boxed ( ) ; } let directories = dir_digests . into_iter ( ) . map ( | digest | { store . load_directory ( digest ) . and_then ( move | maybe_directory | { maybe_directory . ok_or_else ( | | format ! ( " " digest ) ) } ) } ) . collect :: < Vec < _ > > ( ) ; join_all ( directories ) . and_then ( move | mut directories | { let mut out_dir = bazel_protos :: remote_execution :: Directory :: new ( ) ; // Merge FileNodes. out_dir . set_files ( protobuf :: RepeatedField :: from_vec ( directories . iter_mut ( ) . map ( | directory | directory . take_files ( ) . into_iter ( ) ) . flatten ( ) . collect ( ) , ) ) ; out_dir . mut_files ( ) . sort_by ( | a , b | a . name . cmp ( & b . name ) ) ; // Group and recurse for DirectoryNodes. let sorted_child_directories = { let mut merged_directories = directories . iter_mut ( ) . map ( | directory | directory . take_directories ( ) . into_iter ( ) ) . flatten ( ) . collect :: < Vec < _ > > ( ) ; merged_directories . sort_by ( | a , b | a . name . cmp ( & b . name ) ) ; merged_directories } ; let store2 = store . clone ( ) ; join_all ( sorted_child_directories . into_iter ( ) . group_by ( | d | d . name . clone ( ) ) . into_iter ( ) . map ( move | ( child_name , group ) | { Self :: merge_helper ( store2 . clone ( ) , group . map ( | d | d . get_digest ( ) . into ( ) ) . collect ( ) , ) . map ( move | merged_digest | { let mut child_dir = bazel_protos :: remote_execution :: DirectoryNode :: new ( ) ; child_dir . set_name ( child_name ) ; child_dir . set_digest ( ( & merged_digest ) . into ( ) ) ; child_dir } ) } ) . collect :: < Vec < _ > > ( ) , ) . and_then ( move | child_directories | { out_dir . set_directories ( protobuf :: RepeatedField :: from_vec ( child_directories ) ) ; store . record_directory ( & out_dir , true ) } ) . to_boxed ( ) as BoxFuture < _ , _ > } ) . to_boxed ( ) }
Given Digest(s) representing Directory instances, merge them recursively into a single
output Directory Digest.
Given Digest ( s ) representing Directory instances merge them recursively into a single output Directory Digest .
store
Store
dir_digests
Vec<Digest>
store
Store
dir_digests
Vec<Digest>