From 8d4f583d63c657397583f778096b8bcb6d96c12f Mon Sep 17 00:00:00 2001
From: Paul Cristian Sarbu <paul.cristian.sarbu@huawei.com>
Date: Mon, 26 May 2025 10:41:15 +0200
Subject: Add utility methods for caching valid trees

...through marker files kept in storage under generation regime.

These can be used to allow valid source trees, i.e., those free of
upwards symlinks, to be cached in a persistent manner over multiple
builds.
---
 src/buildtool/file_system/git_tree_utils.hpp | 55 ++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 src/buildtool/file_system/git_tree_utils.hpp

(limited to 'src/buildtool/file_system/git_tree_utils.hpp')

diff --git a/src/buildtool/file_system/git_tree_utils.hpp b/src/buildtool/file_system/git_tree_utils.hpp
new file mode 100644
index 00000000..a20481bb
--- /dev/null
+++ b/src/buildtool/file_system/git_tree_utils.hpp
@@ -0,0 +1,55 @@
+// Copyright 2025 Huawei Cloud Computing Technology Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef INCLUDED_SRC_BUILDTOOL_FILE_SYSTEM_GIT_TREE_UTILS_HPP
+#define INCLUDED_SRC_BUILDTOOL_FILE_SYSTEM_GIT_TREE_UTILS_HPP
+
+#include <optional>
+#include <string>
+
+#include "src/buildtool/file_system/git_cas.hpp"
+#include "src/buildtool/file_system/git_tree.hpp"
+#include "src/buildtool/storage/config.hpp"
+
+/// \brief Utility methods for validating GitTree instances
+namespace GitTreeUtils {
+
+/// \brief Read a GitTree from a Git repository and ensure (recursively) that it
+/// is free of upwards symlinks. Performs storage-based caching of all found
+/// valid tree hashes.
+/// \param storage_config   Storage instance for caching valid tree hashes.
+/// \param tree_id  Git identifier of the tree to read and validate.
+/// \param git_cas  Git repository providing the tree.
+/// \returns GitTree instance free of upwards symlinks, recursively, on success
+/// or nullopt on failure.
+[[nodiscard]] auto ReadValidGitCASTree(StorageConfig const& storage_config,
+                                       std::string const& tree_id,
+                                       GitCASPtr const& git_cas) noexcept
+    -> std::optional<GitTree>;
+
+/// \brief Validate a known GitTreeEntry pointing to a Git tree, by checking
+/// recursively that it is free of upwards symlinks. Performs storage-based
+/// caching of all found valid tree hashes.
+/// \param storage_config   Storage instance for caching valid tree hashes.
+/// \param GitTreeEntryPtr  Pointer to an existing GitTreeEntry.
+/// \returns Flag stating if tree is (recursively) free of upwards symlinks.
+/// \note This method is useful when one has fast (and preferably cached) access
+/// to a GitTree instance and direct reading from a repository is not desired.
+[[nodiscard]] auto IsGitTreeValid(StorageConfig const& storage_config,
+                                  GitTreeEntryPtr const& entry) noexcept
+    -> bool;
+
+}  // namespace GitTreeUtils
+
+#endif  // INCLUDED_SRC_BUILDTOOL_FILE_SYSTEM_GIT_TREE_UTILS_HPP
-- 
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