LargeObjectCAS: Implement auxiliary class for storing error information.

2 files changed, 31 insertions, 1 deletions

diff --git a/src/buildtool/storage/large_object_cas.hpp b/src/buildtool/storage/large_object_cas.hpp
index a1a93606..881acc15 100644
--- a/src/buildtool/storage/large_object_cas.hpp
+++ b/src/buildtool/storage/large_object_cas.hpp
@@ -17,12 +17,43 @@
 
 #include <filesystem>
 #include <optional>
+#include <string>
+#include <utility>
 #include <vector>
 
 #include "src/buildtool/common/bazel_types.hpp"
 #include "src/buildtool/file_system/file_storage.hpp"
 #include "src/buildtool/file_system/object_type.hpp"
 
+enum class LargeObjectErrorCode {
+    /// \brief An internal error occured.
+    Internal = 0,
+
+    /// \brief The digest is not in the CAS.
+    FileNotFound,
+};
+
+/// \brief Describes an error that occurred during split-splice.
+class LargeObjectError final {
+  public:
+    LargeObjectError(LargeObjectErrorCode code, std::string message)
+        : code_(code), message_(std::move(message)) {}
+
+    /// \brief Obtain the error code.
+    [[nodiscard]] auto Code() const noexcept -> LargeObjectErrorCode {
+        return code_;
+    }
+
+    /// \brief Obtain the error message.
+    [[nodiscard]] auto Message() && noexcept -> std::string {
+        return std::move(message_);
+    }
+
+  private:
+    LargeObjectErrorCode const code_;
+    std::string message_;
+};
+
 /// \brief Stores auxiliary information for reconstructing large objects.
 /// The entries are keyed by the hash of the spliced result and the value of an
 /// entry is the concatenation of the hashes of chunks the large object is
diff --git a/src/buildtool/storage/large_object_cas.tpp b/src/buildtool/storage/large_object_cas.tpp
index 12894992..d5228c72 100644
--- a/src/buildtool/storage/large_object_cas.tpp
+++ b/src/buildtool/storage/large_object_cas.tpp
@@ -18,7 +18,6 @@
 #include <cstdint>
 #include <cstdlib>
 #include <fstream>
-#include <string>
 
 #include "nlohmann/json.hpp"
 #include "src/buildtool/compatibility/native_support.hpp"