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diff --git a/src/buildtool/storage/uplinker.hpp b/src/buildtool/storage/uplinker.hpp
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+// 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.
+
+#ifndef INCLUDED_SRC_BUILDTOOL_STORAGE_UPLINKER_HPP
+#define INCLUDED_SRC_BUILDTOOL_STORAGE_UPLINKER_HPP
+
+#include <optional>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include "gsl/gsl"
+#include "src/buildtool/storage/config.hpp"
+
+template <bool>
+class LocalStorage;
+class TargetCacheKey;
+
+namespace build::bazel::remote::execution::v2 {
+class Digest;
+}
+namespace bazel_re = build::bazel::remote::execution::v2;
+
+/// \brief Global uplinker implementation.
+/// Responsible for uplinking objects across all generations to latest
+/// generation.
+class GlobalUplinker final {
+  public:
+    explicit GlobalUplinker(
+        gsl::not_null<StorageConfig const*> const& storage_config) noexcept;
+
+    /// \brief Uplink blob across LocalCASes from all generations to latest.
+    /// Note that blobs will NOT be synced between file/executable CAS.
+    /// \param digest         Digest of the blob to uplink.
+    /// \param is_executable  Indicate that blob is an executable.
+    /// \returns true if blob was found and successfully uplinked.
+    [[nodiscard]] auto UplinkBlob(bazel_re::Digest const& digest,
+                                  bool is_executable) const noexcept -> bool;
+
+    /// \brief Uplink tree across LocalCASes from all generations to latest.
+    /// Note that the tree will be deeply uplinked, i.e., all entries referenced
+    /// by this tree will be uplinked before (including sub-trees).
+    /// \param digest         Digest of the tree to uplink.
+    /// \returns true if tree was found and successfully uplinked (deep).
+    [[nodiscard]] auto UplinkTree(bazel_re::Digest const& digest) const noexcept
+        -> bool;
+
+    /// \brief Uplink large blob entry across LocalCASes from all generations to
+    /// latest. This method does not splice the large object.
+    /// \param digest         Digest of the large blob entry to uplink.
+    /// \returns true if large entry was found and successfully uplinked.
+    [[nodiscard]] auto UplinkLargeBlob(
+        bazel_re::Digest const& digest) const noexcept -> bool;
+
+    /// \brief Uplink entry from action cache across all generations to latest.
+    /// Note that the entry will be uplinked including all referenced items.
+    /// \param action_id    Id of the action to uplink entry for.
+    /// \returns true if cache entry was found and successfully uplinked.
+    [[nodiscard]] auto UplinkActionCacheEntry(
+        bazel_re::Digest const& action_id) const noexcept -> bool;
+
+    /// \brief Uplink entry from target cache across all generations to latest.
+    /// Note that the entry will be uplinked including all referenced items.
+    /// \param key  Target cache key to uplink entry for.
+    /// \param shard Optional explicit shard, if the default is not intended.
+    /// \returns true if cache entry was found and successfully uplinked.
+    [[nodiscard]] auto UplinkTargetCacheEntry(
+        TargetCacheKey const& key,
+        std::optional<std::string> const& shard = std::nullopt) const noexcept
+        -> bool;
+
+  private:
+    StorageConfig const& storage_config_;
+    std::vector<LocalStorage<false>> const generations_;
+};
+
+/// \brief An empty constructable Uplinker. Although it doesn't have any
+/// interface, it allows objects employing uplinking store the uplinker by
+/// reference instead of unobvious 'optional' raw pointers.
+class StubUplinker final {
+  public:
+    explicit StubUplinker(
+        gsl::not_null<StorageConfig const*> const& /*unused*/) noexcept {}
+};
+
+template <bool kDoGlobalUplink>
+using Uplinker =
+    std::conditional_t<kDoGlobalUplink, GlobalUplinker, StubUplinker>;
+
+#endif  // INCLUDED_SRC_BUILDTOOL_STORAGE_UPLINKER_HPP