just-mr: rework progress reporting and statistics

To avoid unnecessary work, just-mr uses on-disk caches, including
for the mapping of a distdir to the corresponding git tree. This,
however, implies that the number of repositories that are actually
considered varies: in order to fetch a distdir repository, all
involved archives have to be fetched, but if we have a cache hit
none of them is even looked at.

So, in order to have a consistent reporting only count top-level
targets (i.e., the reachable repositories) in the statistics,
not the archives implicitly contained in a distdir, nor low-level
sub tasks. The actual fetch acitvity is shown separately by the
task tracker.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/other_tools/root_maps/commit_git_map.hpp b/src/other_tools/root_maps/commit_git_map.hpp
index 992f876c..413d83ac 100644
--- a/src/other_tools/root_maps/commit_git_map.hpp
+++ b/src/other_tools/root_maps/commit_git_map.hpp
@@ -16,6 +16,7 @@
 #define INCLUDED_SRC_OTHER_TOOLS_ROOT_MAPS_COMMIT_GIT_MAP_HPP
 
 #include <string>
+#include <utility>
 
 #include "nlohmann/json.hpp"
 #include "src/other_tools/just_mr/utils.hpp"
@@ -49,8 +50,10 @@ struct hash<GitRepoInfo> {
 };
 }  // namespace std
 
-/// \brief Maps a Git repository commit hash to its tree workspace root.
-using CommitGitMap = AsyncMapConsumer<GitRepoInfo, nlohmann::json>;
+/// \brief Maps a Git repository commit hash to its tree workspace root,
+/// together with the information whether it was a cache hit.
+using CommitGitMap =
+    AsyncMapConsumer<GitRepoInfo, std::pair<nlohmann::json, bool>>;
 
 [[nodiscard]] auto CreateCommitGitMap(
     gsl::not_null<CriticalGitOpMap*> const& critical_git_op_map,