From 3dc81b4b5a89f4e37af45ec9954723c79c3017cf Mon Sep 17 00:00:00 2001
From: Paul Cristian Sarbu <paul.cristian.sarbu@huawei.com>
Date: Mon, 29 Jan 2024 16:27:40 +0100
Subject: serve source tree: Increase server-side granularity in response
 statuses

For archives and Git repositories we should ensure that not finding
the witnessing entity (archive content blob or Git commit,
respectively) results in a distinct status in the response to a
request that sets up roots on the serve endpoint. This will allow
just-mr to better handle its interaction with the serve endpoint.
---
 src/buildtool/file_system/git_repo.cpp | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

(limited to 'src/buildtool/file_system/git_repo.cpp')

diff --git a/src/buildtool/file_system/git_repo.cpp b/src/buildtool/file_system/git_repo.cpp
index f679647e..72f85f6a 100644
--- a/src/buildtool/file_system/git_repo.cpp
+++ b/src/buildtool/file_system/git_repo.cpp
@@ -932,9 +932,9 @@ auto GitRepo::FetchFromPath(std::shared_ptr<git_config> cfg,
 auto GitRepo::GetSubtreeFromCommit(std::string const& commit,
                                    std::string const& subdir,
                                    anon_logger_ptr const& logger) noexcept
-    -> std::optional<std::string> {
+    -> std::variant<bool, std::string> {
 #ifdef BOOTSTRAP_BUILD_TOOL
-    return std::nullopt;
+    return true;
 #else
     try {
         // preferably with a "fake" repository!
@@ -955,7 +955,7 @@ auto GitRepo::GetSubtreeFromCommit(std::string const& commit,
                             GetGitCAS()->git_path_.string(),
                             GitLastError()),
                 true /*fatal*/);
-            return std::nullopt;
+            return true;  // fatal failure
         }
 
         git_commit* commit_ptr{nullptr};
@@ -968,7 +968,7 @@ auto GitRepo::GetSubtreeFromCommit(std::string const& commit,
                       true /*fatal*/);
             // cleanup resources
             git_commit_free(commit_ptr);
-            return std::nullopt;
+            return false;  // non-fatal failure
         }
         auto commit_obj = std::unique_ptr<git_commit, decltype(&commit_closer)>(
             commit_ptr, commit_closer);
@@ -985,7 +985,7 @@ auto GitRepo::GetSubtreeFromCommit(std::string const& commit,
                       true /*fatal*/);
             // cleanup resources
             git_tree_free(tree_ptr);
-            return std::nullopt;
+            return true;  // fatal failure
         }
         auto tree = std::unique_ptr<git_tree, decltype(&tree_closer)>(
             tree_ptr, tree_closer);
@@ -1004,7 +1004,7 @@ auto GitRepo::GetSubtreeFromCommit(std::string const& commit,
                     true /*fatal*/);
                 // cleanup resources
                 git_tree_entry_free(subtree_entry_ptr);
-                return std::nullopt;
+                return true;  // fatal failure
             }
             auto subtree_entry =
                 std::unique_ptr<git_tree_entry, decltype(&tree_entry_closer)>(
@@ -1012,16 +1012,16 @@ auto GitRepo::GetSubtreeFromCommit(std::string const& commit,
 
             std::string subtree_hash{
                 git_oid_tostr_s(git_tree_entry_id(subtree_entry.get()))};
-            return subtree_hash;
+            return subtree_hash;  // success
         }
         // if no subdir, get hash from tree
         std::string tree_hash{git_oid_tostr_s(git_tree_id(tree.get()))};
-        return tree_hash;
+        return tree_hash;  // success
     } catch (std::exception const& ex) {
         Logger::Log(LogLevel::Error,
                     "get subtree from commit failed with:\n{}",
                     ex.what());
-        return std::nullopt;
+        return true;  // fatal failure
     }
 #endif  // BOOTSTRAP_BUILD_TOOL
 }
@@ -1145,7 +1145,11 @@ auto GitRepo::GetSubtreeFromPath(std::filesystem::path const& fpath,
         // find relative path from root to given path
         auto subdir = std::filesystem::relative(fpath, *root).string();
         // get subtree from head commit and subdir
-        return GetSubtreeFromCommit(head_commit, subdir, wrapped_logger);
+        auto res = GetSubtreeFromCommit(head_commit, subdir, wrapped_logger);
+        if (std::holds_alternative<bool>(res)) {
+            return std::nullopt;
+        }
+        return std::get<std::string>(res);
     } catch (std::exception const& ex) {
         Logger::Log(LogLevel::Error,
                     "get subtree from path failed with:\n{}",
-- 
cgit v1.2.3