stat RPC now uses Hermes instead of Margo (3a17e07a) · Commits · David Auer / gekkofs

include/client/rpc/hg_rpcs.hpp

+109 −0

Original line number	Diff line number	Diff line
		@@ -331,6 +331,115 @@ struct create {
		};
		};

		//==============================================================================
		// definitions for stat
		struct stat {

		// forward declarations of public input/output types for this RPC
		class input;
		class output;

		// traits used so that the engine knows what to do with the RPC
		using self_type = stat;
		using handle_type = hermes::rpc_handle<self_type>;
		using input_type = input;
		using output_type = output;
		using mercury_input_type = rpc_path_only_in_t;
		using mercury_output_type = rpc_stat_out_t;

		// RPC public identifier
		constexpr static const uint64_t public_id = 1396244480;

		// RPC internal Mercury identifier
		constexpr static const hg_id_t mercury_id = public_id;

		// RPC name
		constexpr static const auto name = hg_tag::stat;

		// requires response?
		constexpr static const auto requires_response = true;

		// Mercury callback to serialize input arguments
		constexpr static const auto mercury_in_proc_cb =
		HG_GEN_PROC_NAME(rpc_path_only_in_t);

		// Mercury callback to serialize output arguments
		constexpr static const auto mercury_out_proc_cb =
		HG_GEN_PROC_NAME(rpc_stat_out_t);

		class input {

		template <typename ExecutionContext>
		friend hg_return_t hermes::detail::post_to_mercury(ExecutionContext*);

		public:
		input(const std::string& path ) :
		m_path(path) { }

		input(input&& rhs) = default;
		input(const input& other) = default;
		input& operator=(input&& rhs) = default;
		input& operator=(const input& other) = default;

		std::string
		path() const {
		return m_path;
		}

		explicit
		input(const rpc_path_only_in_t& other) :
		m_path(other.path) { }

		explicit
		operator rpc_path_only_in_t() {
		return {m_path.c_str()};
		}

		private:
		std::string m_path;
		};

		class output {

		template <typename ExecutionContext>
		friend hg_return_t hermes::detail::post_to_mercury(ExecutionContext*);

		public:
		output() :
		m_err(),
		m_db_val() {}

		output(int32_t err, const std::string& db_val) :
		m_err(err),
		m_db_val(db_val) {}

		output(output&& rhs) = default;
		output(const output& other) = default;
		output& operator=(output&& rhs) = default;
		output& operator=(const output& other) = default;

		explicit
		output(const rpc_stat_out_t& out) {
		m_err = out.err;
		m_db_val = out.db_val;
		}

		int32_t
		err() const {
		return m_err;
		}

		std::string
		db_val() const {
		return m_db_val;
		}

		private:
		int32_t m_err;
		std::string m_db_val;
		};
		};

		} // namespace rpc
		} // namespace gkfs

src/client/preload.cpp

+1 −0

Original line number	Diff line number	Diff line
		@@ -192,6 +192,7 @@ bool init_hermes_client(const std::string& transport_prefix) {

		rpc_config_id = gkfs::rpc::fs_config::public_id;
		rpc_mk_node_id = gkfs::rpc::create::public_id;
		rpc_stat_id = gkfs::rpc::stat::public_id;

		return true;
		}

src/client/rpc/hg_rpcs.cpp

+1 −0

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@ void
		register_user_request_types() {
		(void) registered_requests().add<gkfs::rpc::fs_config>();
		(void) registered_requests().add<gkfs::rpc::create>();
		(void) registered_requests().add<gkfs::rpc::stat>();
		}

		}} // namespace hermes::detail

src/client/rpc/ld_rpc_metadentry.cpp

+22 −38

Original line number	Diff line number	Diff line
		@@ -58,50 +58,34 @@ int mk_node(const std::string& path, const mode_t mode) {
		}

		int stat(const std::string& path, string& attr) {
		hg_handle_t handle;
		rpc_path_only_in_t in{};
		rpc_stat_out_t out{};
		int err = 0;
		// fill in
		in.path = path.c_str();
		CTX->log()->debug("{}() Creating Mercury handle ...", __func__);
		auto ret = margo_create_wrap(rpc_stat_id, path, handle);
		if (ret != HG_SUCCESS) {
		errno = EBUSY;
		return -1;
		}
		// Send rpc
		ret = margo_forward_timed_wrap(handle, &in);
		// Get response
		if (ret != HG_SUCCESS) {
		errno = EBUSY;
		CTX->log()->error("{}() timed out", __func__);
		margo_destroy(handle);

		auto endp = CTX->hosts2().at(
		CTX->distributor()->locate_file_metadata(path));

		try {
		CTX->log()->debug("{}() Sending RPC ...", __func__);
		// TODO(amiranda): add a post() with RPC_TIMEOUT to hermes so that we can
		// retry for RPC_TRIES (see old commits with margo)
		// TODO(amiranda): hermes will eventually provide a post(endpoint)
		// returning one result and a broadcast(endpoint_set) returning a
		// result_set. When that happens we can remove the .at(0) :/
		auto out =
		ld_network_service->post<gkfs::rpc::stat>(endp, path).get().at(0);
		CTX->log()->debug("{}() Got response success: {}", __func__, out.err());

		if(out.err() != 0) {
		errno = out.err();
		return -1;
		} else {
		attr = out.db_val();
		}

		ret = margo_get_output(handle, &out);
		if (ret != HG_SUCCESS) {
		} catch(const std::exception& ex) {
		CTX->log()->error("{}() while getting rpc output", __func__);
		errno = EBUSY;
		margo_free_output(handle, &out);
		margo_destroy(handle);
		return -1;
		}

		CTX->log()->debug("{}() Got response success: {}", __func__, out.err);

		if(out.err != 0) {
		err = -1;
		errno = out.err;
		} else {
		attr = out.db_val;
		}

		/* clean up resources consumed by this rpc */
		margo_free_output(handle, &out);
		margo_destroy(handle);
		return err;
		return 0;
		}

		int decr_size(const std::string& path, size_t length) {