pitrou commented on a change in pull request #8187: URL: https://github.com/apache/arrow/pull/8187#discussion_r494324838
########## File path: cpp/src/arrow/filesystem/filesystem.cc ########## @@ -457,18 +458,52 @@ Status CopyFiles(const std::vector<FileLocator>& sources, ARROW_ASSIGN_OR_RAISE(auto source, sources[i].filesystem->OpenInputStream(sources[i].path)); - auto dest_dir = internal::GetAbstractPathParent(destinations[i].path).first; - if (!dest_dir.empty()) { - RETURN_NOT_OK(destinations[i].filesystem->CreateDir(dest_dir)); - } - ARROW_ASSIGN_OR_RAISE( auto destination, destinations[i].filesystem->OpenOutputStream(destinations[i].path)); return internal::CopyStream(source, destination, chunk_size); }); } +Status CopyFiles(const std::shared_ptr<FileSystem>& source_fs, + const FileSelector& source_sel, + const std::shared_ptr<FileSystem>& destination_fs, + const std::string& destination_base_dir, int64_t chunk_size, + bool use_threads) { + ARROW_ASSIGN_OR_RAISE(auto source_infos, source_fs->GetFileInfo(source_sel)); + std::vector<FileLocator> sources, destinations; + + std::unordered_set<std::string> destination_dirs; + destination_dirs.insert(destination_base_dir); + + for (const FileInfo& source_info : source_infos) { + auto relative = internal::RemoveAncestor(source_sel.base_dir, source_info.path()); + if (!relative.has_value()) { + return Status::Invalid("GetFileInfo() yielded path '", source_info.path(), + "', which is outside base dir '", source_sel.base_dir, "'"); + } + + auto destination_path = + internal::ConcatAbstractPath(destination_base_dir, relative->to_string()); + + if (source_info.IsDirectory()) { + destination_dirs.insert(destination_path); + } else if (source_info.IsFile()) { + sources.push_back({source_fs, source_info.path()}); + destinations.push_back({destination_fs, destination_path}); + } + } + + std::vector<std::string> dirs(destination_dirs.size()); + std::move(destination_dirs.begin(), destination_dirs.end(), dirs.begin()); + RETURN_NOT_OK(::arrow::internal::OptionalParallelFor( + use_threads, static_cast<int>(dirs.size()), [&](int i) { + return dirs[i].empty() ? Status::OK() : destination_fs->CreateDir(dirs[i]); Review comment: This will call `CreateDir` separately for intermediate directories, even though `recursive = true` is passed. This seems a bit wasteful, though I'm not sure it matters much in practice (it could be annoying on remote filesystems such as S3). ########## File path: cpp/src/arrow/filesystem/filesystem.cc ########## @@ -457,18 +458,52 @@ Status CopyFiles(const std::vector<FileLocator>& sources, ARROW_ASSIGN_OR_RAISE(auto source, sources[i].filesystem->OpenInputStream(sources[i].path)); - auto dest_dir = internal::GetAbstractPathParent(destinations[i].path).first; - if (!dest_dir.empty()) { - RETURN_NOT_OK(destinations[i].filesystem->CreateDir(dest_dir)); - } - ARROW_ASSIGN_OR_RAISE( auto destination, destinations[i].filesystem->OpenOutputStream(destinations[i].path)); return internal::CopyStream(source, destination, chunk_size); }); } +Status CopyFiles(const std::shared_ptr<FileSystem>& source_fs, + const FileSelector& source_sel, + const std::shared_ptr<FileSystem>& destination_fs, + const std::string& destination_base_dir, int64_t chunk_size, + bool use_threads) { + ARROW_ASSIGN_OR_RAISE(auto source_infos, source_fs->GetFileInfo(source_sel)); + std::vector<FileLocator> sources, destinations; + + std::unordered_set<std::string> destination_dirs; + destination_dirs.insert(destination_base_dir); + + for (const FileInfo& source_info : source_infos) { + auto relative = internal::RemoveAncestor(source_sel.base_dir, source_info.path()); + if (!relative.has_value()) { + return Status::Invalid("GetFileInfo() yielded path '", source_info.path(), + "', which is outside base dir '", source_sel.base_dir, "'"); + } + + auto destination_path = + internal::ConcatAbstractPath(destination_base_dir, relative->to_string()); + + if (source_info.IsDirectory()) { + destination_dirs.insert(destination_path); + } else if (source_info.IsFile()) { + sources.push_back({source_fs, source_info.path()}); + destinations.push_back({destination_fs, destination_path}); + } + } + + std::vector<std::string> dirs(destination_dirs.size()); + std::move(destination_dirs.begin(), destination_dirs.end(), dirs.begin()); Review comment: Interesting, I didn't know this `std::move` override! ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org