intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 94 insertions, 0 deletions

diff --git a/library/cpp/grpc/server/grpc_async_ctx_base.h b/library/cpp/grpc/server/grpc_async_ctx_base.h
new file mode 100644
index 0000000000..51356d4ce5
--- /dev/null
+++ b/library/cpp/grpc/server/grpc_async_ctx_base.h
@@ -0,0 +1,94 @@
+#pragma once
+
+#include "grpc_server.h"
+
+#include <util/generic/vector.h>
+#include <util/generic/string.h>
+#include <util/system/yassert.h>
+#include <util/generic/set.h>
+
+#include <grpc++/server.h>
+#include <grpc++/server_context.h>
+
+#include <chrono>
+
+namespace NGrpc {
+
+template<typename TService>
+class TBaseAsyncContext: public ICancelableContext {
+public:
+    TBaseAsyncContext(typename TService::TCurrentGRpcService::AsyncService* service, grpc::ServerCompletionQueue* cq)
+        : Service(service)
+        , CQ(cq)
+    {
+    }
+
+    TString GetPeerName() const {
+        return TString(Context.peer());
+    }
+
+    TInstant Deadline() const {
+        // The timeout transferred in "grpc-timeout" header [1] and calculated from the deadline
+        // right before the request is getting to be send.
+        // 1. https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md
+        //
+        // After this timeout calculated back to the deadline on the server side
+        // using server grpc GPR_CLOCK_MONOTONIC time (raw_deadline() method).
+        // deadline() method convert this to epoch related deadline GPR_CLOCK_REALTIME
+        //
+
+        std::chrono::system_clock::time_point t = Context.deadline();
+        if (t == std::chrono::system_clock::time_point::max()) {
+            return TInstant::Max();
+        }
+        auto us = std::chrono::time_point_cast<std::chrono::microseconds>(t);
+        return TInstant::MicroSeconds(us.time_since_epoch().count());
+    }
+
+    TSet<TStringBuf> GetPeerMetaKeys() const {
+        TSet<TStringBuf> keys;
+        for (const auto& [key, _]: Context.client_metadata()) {
+            keys.emplace(key.data(), key.size());
+        }
+        return keys;
+    }
+
+    TVector<TStringBuf> GetPeerMetaValues(TStringBuf key) const {
+        const auto& clientMetadata = Context.client_metadata();
+        const auto range = clientMetadata.equal_range(grpc::string_ref{key.data(), key.size()});
+        if (range.first == range.second) {
+            return {};
+        }
+
+        TVector<TStringBuf> values;
+        values.reserve(std::distance(range.first, range.second));
+
+        for (auto it = range.first; it != range.second; ++it) {
+            values.emplace_back(it->second.data(), it->second.size());
+        }
+        return values;
+    }
+
+    grpc_compression_level GetCompressionLevel() const {
+        return Context.compression_level();
+    }
+
+    void Shutdown() override {
+        // Shutdown may only be called after request has started successfully
+        if (Context.c_call())
+            Context.TryCancel();
+    }
+
+protected:
+    //! The means of communication with the gRPC runtime for an asynchronous
+    //! server.
+    typename TService::TCurrentGRpcService::AsyncService* const Service;
+    //! The producer-consumer queue where for asynchronous server notifications.
+    grpc::ServerCompletionQueue* const CQ;
+    //! Context for the rpc, allowing to tweak aspects of it such as the use
+    //! of compression, authentication, as well as to send metadata back to the
+    //! client.
+    grpc::ServerContext Context;
+};
+
+} // namespace NGrpc