pub fn merge_directories(store: Store, dir_digests: Vec<Digest>) -> BoxFuture<Digest, String> {
    if dir_digests.is_empty() {
      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.
        let file_nodes = Iterator::flatten(
          directories
            .iter_mut()
            .map(|directory| directory.take_files().into_iter()),
        )
        .sorted_by(|a, b| a.name.cmp(&b.name));

        out_dir.set_files(protobuf::RepeatedField::from_vec(
          file_nodes.into_iter().dedup().collect(),
        ));
        let unique_count = out_dir
          .get_files()
          .iter()
          .map(bazel_protos::remote_execution::FileNode::get_name)
          .dedup()
          .count();
        if unique_count != out_dir.get_files().len() {
          let groups = out_dir
            .get_files()
            .iter()
            .group_by(|f| f.get_name().to_owned());
          for (file_name, group) in &groups {
            if group.count() > 1 {
              return future::err(format!(
                "Can only merge Directories with no duplicates, but found duplicate files: {}",
                file_name
              ))
              .to_boxed();
            }
          }
        }

        // Group and recurse for DirectoryNodes.
        let sorted_child_directories = {
          let mut merged_directories = Iterator::flatten(
            directories
              .iter_mut()
              .map(|directory| directory.take_directories().into_iter()),
          )
          .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)| {
              let store2 = store2.clone();
              let digests_result = group
                .map(|d| d.get_digest().into())
                .collect::<Result<Vec<_>, String>>();
              future::done(digests_result)
                .and_then(move |digests| Self::merge_directories(store2.clone(), digests))
                .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()
      })
      .to_boxed()
  }
///
/// Given Digest(s) representing Directory instances, merge them recursively into a single
/// output Directory Digest.
///
/// If a file is present with the same name and contents multiple times, it will appear once.
/// If a file is present with the same name, but different contents, an error will be returned.
///
Given Digest(s) representing Directory instances, merge them recursively into a single
output Directory Digest.

If a file is present with the same name and contents multiple times, it will appear once.
If a file is present with the same name, but different contents, an error will be returned.
Given Digest ( s ) representing Directory instances merge them recursively into a single output Directory Digest . If a file is present with the same name and contents multiple times it will appear once . If a file is present with the same name but different contents an error will be returned .
pub fn merge_directories(store: Store, dir_digests: Vec<Digest>) -> BoxFuture<Digest, String> {
    if dir_digests.is_empty() {
      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.
        let file_nodes = Iterator::flatten(
          directories
            .iter_mut()
            .map(|directory| directory.take_files().into_iter()),
        )
        .sorted_by(|a, b| a.name.cmp(&b.name));
        out_dir.set_files(protobuf::RepeatedField::from_vec(
          file_nodes.into_iter().dedup().collect(),
        ));
        let unique_count = out_dir
          .get_files()
          .iter()
          .map(bazel_protos::remote_execution::FileNode::get_name)
          .dedup()
          .count();
        if unique_count != out_dir.get_files().len() {
          let groups = out_dir
            .get_files()
            .iter()
            .group_by(|f| f.get_name().to_owned());
          for (file_name, group) in &groups {
            if group.count() > 1 {
              return future::err(format!(
                "Can only merge Directories with no duplicates, but found duplicate files: {}",
                file_name
              ))
              .to_boxed();
            }
          }
        }
        // Group and recurse for DirectoryNodes.
        let sorted_child_directories = {
          let mut merged_directories = Iterator::flatten(
            directories
              .iter_mut()
              .map(|directory| directory.take_directories().into_iter()),
          )
          .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)| {
              let store2 = store2.clone();
              let digests_result = group
                .map(|d| d.get_digest().into())
                .collect::<Result<Vec<_>, String>>();
              future::done(digests_result)
                .and_then(move |digests| Self::merge_directories(store2.clone(), digests))
                .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()
      })
      .to_boxed()
  }
pub fn merge_directories ( store : Store , dir_digests : Vec < Digest > ) -> BoxFuture < Digest , String > { if dir_digests . is_empty ( ) { 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. let file_nodes = Iterator :: flatten ( directories . iter_mut ( ) . map ( | directory | directory . take_files ( ) . into_iter ( ) ) , ) . sorted_by ( | a , b | a . name . cmp ( & b . name ) ) ; out_dir . set_files ( protobuf :: RepeatedField :: from_vec ( file_nodes . into_iter ( ) . dedup ( ) . collect ( ) , ) ) ; let unique_count = out_dir . get_files ( ) . iter ( ) . map ( bazel_protos :: remote_execution :: FileNode :: get_name ) . dedup ( ) . count ( ) ; if unique_count != out_dir . get_files ( ) . len ( ) { let groups = out_dir . get_files ( ) . iter ( ) . group_by ( | f | f . get_name ( ) . to_owned ( ) ) ; for ( file_name , group ) in & groups { if group . count ( ) > 1 { return future :: err ( format ! ( " " file_name ) ) . to_boxed ( ) ; } } } // Group and recurse for DirectoryNodes. let sorted_child_directories = { let mut merged_directories = Iterator :: flatten ( directories . iter_mut ( ) . map ( | directory | directory . take_directories ( ) . into_iter ( ) ) , ) . 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 ) | { let store2 = store2 . clone ( ) ; let digests_result = group . map ( | d | d . get_digest ( ) . into ( ) ) . collect :: < Result < Vec < _ > , String > > ( ) ; future :: done ( digests_result ) . and_then ( move | digests | Self :: merge_directories ( store2 . clone ( ) , digests ) ) . 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 ( ) } ) . 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>