Validate bazel_re::Digests in BazelDigestFactory

1 files changed, 49 insertions, 0 deletions

diff --git a/src/buildtool/common/bazel_digest_factory.cpp b/src/buildtool/common/bazel_digest_factory.cpp
new file mode 100644
index 00000000..4ff885aa
--- /dev/null
+++ b/src/buildtool/common/bazel_digest_factory.cpp
@@ -0,0 +1,49 @@
+// Copyright 2024 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.
+
+#include "src/buildtool/common/bazel_digest_factory.hpp"
+
+#include <utility>
+
+#include "src/buildtool/crypto/hasher.hpp"
+
+auto BazelDigestFactory::Create(HashInfo const& hash_info,
+                                std::int64_t size) noexcept
+    -> bazel_re::Digest {
+    auto hash = hash_info.HashType() == HashFunction::Type::GitSHA1
+                    ? Prefix(hash_info.Hash(), hash_info.IsTree())
+                    : hash_info.Hash();
+
+    bazel_re::Digest digest{};
+    digest.set_hash(std::move(hash));
+    digest.set_size_bytes(size);
+    return digest;
+}
+
+auto BazelDigestFactory::ToHashInfo(HashFunction::Type hash_type,
+                                    bazel_re::Digest const& digest) noexcept
+    -> expected<HashInfo, std::string> {
+    bool const is_prefixed = IsPrefixed(hash_type, digest.hash());
+
+    auto hash = is_prefixed ? Unprefix(digest.hash()) : digest.hash();
+    auto const is_tree = is_prefixed and digest.hash().starts_with(kTreeTag);
+    return HashInfo::Create(hash_type, std::move(hash), is_tree);
+}
+
+auto BazelDigestFactory::IsPrefixed(HashFunction::Type hash_type,
+                                    std::string const& hash) noexcept -> bool {
+    auto const tagged_length =
+        HashFunction{hash_type}.MakeHasher().GetHashLength() + kTagLength;
+    return hash.size() == tagged_length;
+}