ObjectCAS: Move the method for calculating file digests to the public space.

This is needed for LocalCAS's splice routines.

1 files changed, 15 insertions, 12 deletions

diff --git a/src/buildtool/file_system/object_cas.hpp b/src/buildtool/file_system/object_cas.hpp
index 93b2055b..6dd1ae9f 100644
--- a/src/buildtool/file_system/object_cas.hpp
+++ b/src/buildtool/file_system/object_cas.hpp
@@ -97,6 +97,21 @@ class ObjectCAS {
         return blob_path;
     }
 
+    /// \brief Calculate the digest for a file.
+    /// \param file_path    File for which the digest needs to be calculated.
+    /// \return             File digest.
+    [[nodiscard]] static auto CreateDigest(
+        std::filesystem::path const& file_path) noexcept
+        -> std::optional<bazel_re::Digest> {
+        bool is_tree = kType == ObjectType::Tree;
+        auto hash = HashFunction::ComputeHashFile(file_path, is_tree);
+        if (hash) {
+            return ArtifactDigest(
+                hash->first.HexString(), hash->second, is_tree);
+        }
+        return std::nullopt;
+    }
+
   private:
     // For `Tree` the underlying storage type is non-executable file.
     static constexpr auto kStorageType =
@@ -113,18 +128,6 @@ class ObjectCAS {
         return ArtifactDigest::Create<kType>(bytes);
     }
 
-    [[nodiscard]] static auto CreateDigest(
-        std::filesystem::path const& file_path) noexcept
-        -> std::optional<bazel_re::Digest> {
-        bool is_tree = kType == ObjectType::Tree;
-        auto hash = HashFunction::ComputeHashFile(file_path, is_tree);
-        if (hash) {
-            return ArtifactDigest(
-                hash->first.HexString(), hash->second, is_tree);
-        }
-        return std::nullopt;
-    }
-
     [[nodiscard]] auto IsAvailable(
         bazel_re::Digest const& digest,
         std::filesystem::path const& path) const noexcept -> bool {