2 files changed, 8 insertions, 0 deletions
diff --git a/src/buildtool/file_system/git_tree.cpp b/src/buildtool/file_system/git_tree.cpp
index 8d220e30..30c98261 100644
--- a/src/buildtool/file_system/git_tree.cpp
+++ b/src/buildtool/file_system/git_tree.cpp
@@ -78,6 +78,13 @@ auto GitTree::LookupEntryByPath(
     return LookupEntryPyPath(*this, resolved.begin(), resolved.end());
 }
 
+auto GitTree::Size() const noexcept -> std::optional<std::size_t> {
+    if (auto header = cas_->ReadHeader(raw_id_)) {
+        return header->first;
+    }
+    return std::nullopt;
+}
+
 auto GitTreeEntry::Blob() const noexcept -> std::optional<std::string> {
     if (not IsBlob()) {
         return std::nullopt;
diff --git a/src/buildtool/file_system/git_tree.hpp b/src/buildtool/file_system/git_tree.hpp
index eb1c2147..25218634 100644
--- a/src/buildtool/file_system/git_tree.hpp
+++ b/src/buildtool/file_system/git_tree.hpp
@@ -47,6 +47,7 @@ class GitTree {
     [[nodiscard]] auto end() const noexcept { return entries_.end(); }
     [[nodiscard]] auto Hash() const noexcept { return ToHexString(raw_id_); }
     [[nodiscard]] auto RawHash() const noexcept { return raw_id_; }
+    [[nodiscard]] auto Size() const noexcept -> std::optional<std::size_t>;
 
   private:
     gsl::not_null<GitCASPtr> cas_;