From 5e9234326754cc83140ecaae798c31fe3ec5c165 Mon Sep 17 00:00:00 2001
From: Oliver Reiche <oliver.reiche@huawei.com>
Date: Mon, 5 May 2025 18:23:51 +0200
Subject: BazelNetwork: Read supported remote RBE version

---
 src/buildtool/execution_api/remote/TARGETS            |  1 +
 .../remote/bazel/bazel_capabilities_client.cpp        | 19 ++++++++++++++++++-
 .../remote/bazel/bazel_capabilities_client.hpp        | 18 ++++++++++++++++++
 .../execution_api/remote/bazel/bazel_network.hpp      |  4 ++++
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/buildtool/execution_api/remote/TARGETS b/src/buildtool/execution_api/remote/TARGETS
index 7fccc2c6..fc46db70 100644
--- a/src/buildtool/execution_api/remote/TARGETS
+++ b/src/buildtool/execution_api/remote/TARGETS
@@ -42,6 +42,7 @@
     ]
   , "proto":
     [ ["@", "bazel_remote_apis", "", "remote_execution_proto"]
+    , ["@", "bazel_remote_apis", "", "semver_proto"]
     , ["@", "googleapis", "", "google_bytestream_proto"]
     , ["@", "googleapis", "", "google_longrunning_operations_proto"]
     , ["@", "googleapis", "", "google_rpc_status_proto"]
diff --git a/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.cpp b/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.cpp
index 20a1dce1..00d113d8 100644
--- a/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.cpp
+++ b/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.cpp
@@ -21,6 +21,7 @@
 
 #include <grpcpp/grpcpp.h>
 
+#include "build/bazel/semver/semver.pb.h"
 #include "fmt/core.h"
 #include "src/buildtool/common/bazel_types.hpp"
 #include "src/buildtool/common/remote/client_common.hpp"
@@ -28,6 +29,14 @@
 #include "src/buildtool/logging/log_level.hpp"
 
 namespace {
+
+[[nodiscard]] auto ParseSemVer(build::bazel::semver::SemVer const&
+                                   version) noexcept -> Capabilities::Version {
+    return Capabilities::Version{.major = version.major(),
+                                 .minor = version.minor(),
+                                 .patch = version.patch()};
+}
+
 [[nodiscard]] auto Parse(std::optional<bazel_re::ServerCapabilities>
                              response) noexcept -> Capabilities {
     if (not response.has_value()) {
@@ -50,8 +59,16 @@ namespace {
     }
     return Capabilities{
         .MaxBatchTransferSize = max_batch,
-    };
+        .low_api_version = response->has_deprecated_api_version()
+                               ? ParseSemVer(response->deprecated_api_version())
+                               : (response->has_low_api_version()  // NOLINT
+                                      ? ParseSemVer(response->low_api_version())
+                                      : Capabilities::kMinVersion),
+        .high_api_version = response->has_high_api_version()
+                                ? ParseSemVer(response->high_api_version())
+                                : Capabilities::kMaxVersion};
 }
+
 }  // namespace
 
 BazelCapabilitiesClient::BazelCapabilitiesClient(
diff --git a/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.hpp b/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.hpp
index b33bb2de..ddff0ef0 100644
--- a/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.hpp
+++ b/src/buildtool/execution_api/remote/bazel/bazel_capabilities_client.hpp
@@ -16,7 +16,9 @@
 #define INCLUDED_SRC_BUILDTOOL_EXECUTION_API_REMOTE_BAZEL_BAZEL_CAPABILITIES_CLIENT_HPP
 
 #include <cstddef>
+#include <cstdint>
 #include <functional>
+#include <limits>
 #include <memory>
 #include <shared_mutex>
 #include <string>
@@ -34,8 +36,24 @@ namespace bazel_re = build::bazel::remote::execution::v2;
 
 struct Capabilities final {
     using Ptr = gsl::not_null<std::shared_ptr<Capabilities>>;
+    struct Version {
+        std::int32_t major{};
+        std::int32_t minor{};
+        std::int32_t patch{};
+
+        [[nodiscard]] auto operator<=>(Version const& other) const noexcept =
+            default;
+    };
+
+    static constexpr Version kMinVersion{.major = 0, .minor = 0, .patch = 0};
+    static constexpr Version kMaxVersion{
+        .major = std::numeric_limits<std::int32_t>::max(),
+        .minor = std::numeric_limits<std::int32_t>::max(),
+        .patch = std::numeric_limits<std::int32_t>::max()};
 
     std::size_t const MaxBatchTransferSize = MessageLimits::kMaxGrpcLength;
+    Version const low_api_version = kMinVersion;
+    Version const high_api_version = kMaxVersion;
 };
 
 class BazelCapabilitiesClient final {
diff --git a/src/buildtool/execution_api/remote/bazel/bazel_network.hpp b/src/buildtool/execution_api/remote/bazel/bazel_network.hpp
index 4dbf1467..403e0f05 100644
--- a/src/buildtool/execution_api/remote/bazel/bazel_network.hpp
+++ b/src/buildtool/execution_api/remote/bazel/bazel_network.hpp
@@ -97,6 +97,10 @@ class BazelNetwork {
         std::vector<std::string> const& output_files) const noexcept
         -> std::optional<bazel_re::ActionResult>;
 
+    [[nodiscard]] auto GetCapabilities() const noexcept -> Capabilities::Ptr {
+        return capabilities_->GetCapabilities(instance_name_);
+    }
+
   private:
     std::string const instance_name_;
     std::unique_ptr<BazelCapabilitiesClient> capabilities_;
-- 
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