modules/platforms/cpp/ignite/protocol/reader.h - ignite-3 - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements. See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You 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.
  */

 #pragma once

 #include <ignite/common/bytes_view.h>
 #include <ignite/common/ignite_error.h>
 #include <ignite/common/uuid.h>
 #include <ignite/protocol/utils.h>

 #include <msgpack.h>

 #include <cstdint>
 #include <functional>

 namespace ignite::protocol {

 /**
  * Reader.
  */
 class reader {
 public:
     // Deleted
     reader() = delete;
     reader(reader &&) = delete;
     reader(const reader &) = delete;
     reader &operator=(reader &&) = delete;
     reader &operator=(const reader &) = delete;

     /**
      * Constructor.
      *
      * @param buffer Buffer.
      */
     explicit reader(bytes_view buffer);

     /**
      * Destructor.
      */
     ~reader() { msgpack_unpacked_destroy(&m_current_val); }

     /**
      * Read object of type T from msgpack stream.
      *
      * @tparam T Type of the object to read.
      * @return Object of type T.
      * @throw ignite_error if there is no object of specified type in the stream.
      */
     template<typename T>
     [[nodiscard]] T read_object() {
         check_data_in_stream();

         auto res = unpack_object<T>(m_current_val.data);
         next();

         return res;
     }

     /**
      * Read object of type T from msgpack stream.
      *
      * @tparam T Type of the object to read.
      * @return Object of type T or @c nullopt if there is object of other type in the stream.
      * @throw ignite_error if there is no data left in the stream.
      */
     template<typename T>
     [[nodiscard]] std::optional<T> try_read_object() {
         check_data_in_stream();

         auto res = try_unpack_object<T>(m_current_val.data);
         if (res)
             next();

         return res;
     }

     /**
      * Read object of type T from msgpack stream or nil.
      *
      * @tparam T Type of the object to read.
      * @return Object of type T or std::nullopt if there is nil in the stream.
      * @throw ignite_error if there is no object of specified type in the stream.
      */
     template<typename T>
     [[nodiscard]] std::optional<T> read_object_nullable() {
         if (try_read_nil())
             return std::nullopt;

         return read_object<T>();
     }

     /**
      * Read object of type T from msgpack stream or returns default value if the value in stream is nil.
      *
      * @tparam T Type of the object to read.
      * @param on_nil Object to be returned on nil.
      * @return Object of type T or @c on_nil if there is nil in stream.
      * @throw ignite_error if there is no object of specified type in the stream.
      */
     template<typename T>
     [[nodiscard]] T read_object_or_default(T &&on_nil) {
         if (try_read_nil())
             return std::forward<T>(on_nil);

         return read_object<T>();
     }

     /**
      * Read int8.
      *
      * @return Value.
      */
     [[nodiscard]] std::int8_t read_int8() { return read_object<std::int8_t>(); }

     /**
      * Read uint8.
      *
      * @return Value.
      */
     [[nodiscard]] std::uint8_t read_uint8() { return read_object<std::uint8_t>(); }

     /**
      * Read int16.
      *
      * @return Value.
      */
     [[nodiscard]] std::int16_t read_int16() { return read_object<std::int16_t>(); }

     /**
      * Read uint16.
      *
      * @return Value.
      */
     [[nodiscard]] std::uint16_t read_uint16() { return read_object<std::uint16_t>(); }

     /**
      * Read int32.
      *
      * @return Value.
      */
     [[nodiscard]] std::int32_t read_int32() { return read_object<std::int32_t>(); }

     /**
      * Read timestamp.
      *
      * @return Timestamp.
      */
     [[nodiscard]] ignite_timestamp read_timestamp() {
         auto seconds = read_int64();
         auto nanos = read_int32();
         return {seconds, nanos};
     }

     /**
      * Read timestamp or null.
      *
      * @return Timestamp or std::nullopt.
      */
     [[nodiscard]] std::optional<ignite_timestamp> read_timestamp_opt() {
         if (try_read_nil())
             return std::nullopt;

         return {read_timestamp()};
     }

     /**
      * Read array of int32.
      *
      * @return Value.
      */
     [[nodiscard]] std::vector<std::int32_t> read_int32_array() {
         auto length = read_int32();
         std::vector<std::int32_t> values(length);

         for (auto i = 0; i < length; i++) {
             values[i] = read_int32();
         }

         return values;
     }

     /**
      * Read array of int32.
      *
      * @return Value or nullopt.
      */
     [[nodiscard]] std::optional<std::vector<std::int32_t>> read_int32_array_nullable() {
         if (try_read_nil()) {
             return std::nullopt;
         }

         return read_int32_array();
     }

     /**
      * Read array of int64.
      *
      * @return Value or nullopt.
      */
     [[nodiscard]] std::vector<std::int64_t> read_int64_array() {
         auto length = read_int32();
         std::vector<std::int64_t> values(length);

         for (auto i = 0; i < length; i++) {
             values[i] = read_int64();
         }

         return values;
     }

     /**
      * Read array of int64.
      *
      * @return Value or nullopt.
      */
     [[nodiscard]] std::optional<std::vector<std::int64_t>> read_int64_array_nullable() {
         if (try_read_nil()) {
             return std::nullopt;
         }

         return read_int64_array();
     }

     /**
      * Read int32 or nullopt.
      *
      * @return Value or nullopt if the next value in stream is not integer.
      */
     [[nodiscard]] std::optional<std::int32_t> try_read_int32() { return try_read_object<std::int32_t>(); }

     /**
      * Read int32 or nullopt.
      *
      * @return Value or nullopt if the next value in stream is nil.
      */
     [[nodiscard]] std::optional<std::int32_t> read_int32_nullable() { return read_object_nullable<std::int32_t>(); }

     /**
      * Read uint8 or nullopt.
      *
      * @return Value or nullopt if the next value in stream is nil.
      */
     [[nodiscard]] std::optional<std::uint8_t> read_uint8_nullable() { return read_object_nullable<std::uint8_t>(); }

     /**
      * Read int16 or nullopt.
      *
      * @return Value or nullopt if the next value in stream is nil.
      */
     [[nodiscard]] std::optional<std::int16_t> read_int16_nullable() { return read_object_nullable<std::int16_t>(); }

     /**
      * Read int64 number.
      *
      * @return Value.
      */
     [[nodiscard]] std::int64_t read_int64() { return read_object<int64_t>(); }

     /**
      * Read bool.
      *
      * @return Value.
      */
     [[nodiscard]] bool read_bool() { return read_object<bool>(); }

     /**
      * Read string.
      *
      * @return String value.
      */
     [[nodiscard]] std::string read_string() { return read_object<std::string>(); }

     /**
      * Read string.
      *
      * @return String value or nullopt.
      */
     [[nodiscard]] std::optional<std::string> read_string_nullable() { return read_object_nullable<std::string>(); }

     /**
      * Read UUID.
      *
      * @return UUID value.
      */
     [[nodiscard]] uuid read_uuid() { return read_object<uuid>(); }

     /**
      * Read array.
      *
      * @return Binary data view.
      */
     [[nodiscard]] bytes_view read_binary() {
         auto res = unpack_binary(m_current_val.data);
         next();
         return res;
     }

     /**
      * If the next value is Nil, read it and move reader to the next position.
      *
      * @return @c true if the value was nil.
      */
     bool try_read_nil();

     /**
      * Skip next value.
      */
     void skip() { next(); }

     /**
      * Skip next value.
      */
     void skip(int count) {
         for (int i = 0; i < count; i++) {
             skip();
         }
     }

     /**
      * Position.
      *
      * @return Current position in memory.
      */
     [[nodiscard]] size_t position() const { return m_offset; }

 private:
     /**
      * Move to the next value.
      */
     void next();

     /**
      * Check whether there is a data in stream and throw ignite_error if there is none.
      */
     void check_data_in_stream() const {
         if (m_move_res < 0)
             throw ignite_error("No more data in stream");
     }

     /** Buffer. */
     bytes_view m_buffer;

     /** Current value. */
     msgpack_unpacked m_current_val;

     /** Result of the last move operation. */
     msgpack_unpack_return m_move_res;

     /** Offset to next value. */
     std::size_t m_offset_next{0};

     /** Offset. */
     std::size_t m_offset{0};
 };

 } // namespace ignite::protocol
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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.
	*/

	#pragma once

	#include <ignite/common/bytes_view.h>
	#include <ignite/common/ignite_error.h>
	#include <ignite/common/uuid.h>
	#include <ignite/protocol/utils.h>

	#include <msgpack.h>

	#include <cstdint>
	#include <functional>

	namespace ignite::protocol {

	/**
	* Reader.
	*/
	class reader {
	public:
	// Deleted
	reader() = delete;
	reader(reader &&) = delete;
	reader(const reader &) = delete;
	reader &operator=(reader &&) = delete;
	reader &operator=(const reader &) = delete;

	/**
	* Constructor.
	*
	* @param buffer Buffer.
	*/
	explicit reader(bytes_view buffer);

	/**
	* Destructor.
	*/
	~reader() { msgpack_unpacked_destroy(&m_current_val); }

	/**
	* Read object of type T from msgpack stream.
	*
	* @tparam T Type of the object to read.
	* @return Object of type T.
	* @throw ignite_error if there is no object of specified type in the stream.
	*/
	template<typename T>
	[[nodiscard]] T read_object() {
	check_data_in_stream();

	auto res = unpack_object<T>(m_current_val.data);
	next();

	return res;
	}

	/**
	* Read object of type T from msgpack stream.
	*
	* @tparam T Type of the object to read.
	* @return Object of type T or @c nullopt if there is object of other type in the stream.
	* @throw ignite_error if there is no data left in the stream.
	*/
	template<typename T>
	[[nodiscard]] std::optional<T> try_read_object() {
	check_data_in_stream();

	auto res = try_unpack_object<T>(m_current_val.data);
	if (res)
	next();

	return res;
	}

	/**
	* Read object of type T from msgpack stream or nil.
	*
	* @tparam T Type of the object to read.
	* @return Object of type T or std::nullopt if there is nil in the stream.
	* @throw ignite_error if there is no object of specified type in the stream.
	*/
	template<typename T>
	[[nodiscard]] std::optional<T> read_object_nullable() {
	if (try_read_nil())
	return std::nullopt;

	return read_object<T>();
	}

	/**
	* Read object of type T from msgpack stream or returns default value if the value in stream is nil.
	*
	* @tparam T Type of the object to read.
	* @param on_nil Object to be returned on nil.
	* @return Object of type T or @c on_nil if there is nil in stream.
	* @throw ignite_error if there is no object of specified type in the stream.
	*/
	template<typename T>
	[[nodiscard]] T read_object_or_default(T &&on_nil) {
	if (try_read_nil())
	return std::forward<T>(on_nil);

	return read_object<T>();
	}

	/**
	* Read int8.
	*
	* @return Value.
	*/
	[[nodiscard]] std::int8_t read_int8() { return read_object<std::int8_t>(); }

	/**
	* Read uint8.
	*
	* @return Value.
	*/
	[[nodiscard]] std::uint8_t read_uint8() { return read_object<std::uint8_t>(); }

	/**
	* Read int16.
	*
	* @return Value.
	*/
	[[nodiscard]] std::int16_t read_int16() { return read_object<std::int16_t>(); }

	/**
	* Read uint16.
	*
	* @return Value.
	*/
	[[nodiscard]] std::uint16_t read_uint16() { return read_object<std::uint16_t>(); }

	/**
	* Read int32.
	*
	* @return Value.
	*/
	[[nodiscard]] std::int32_t read_int32() { return read_object<std::int32_t>(); }

	/**
	* Read timestamp.
	*
	* @return Timestamp.
	*/
	[[nodiscard]] ignite_timestamp read_timestamp() {
	auto seconds = read_int64();
	auto nanos = read_int32();
	return {seconds, nanos};
	}

	/**
	* Read timestamp or null.
	*
	* @return Timestamp or std::nullopt.
	*/
	[[nodiscard]] std::optional<ignite_timestamp> read_timestamp_opt() {
	if (try_read_nil())
	return std::nullopt;

	return {read_timestamp()};
	}

	/**
	* Read array of int32.
	*
	* @return Value.
	*/
	[[nodiscard]] std::vector<std::int32_t> read_int32_array() {
	auto length = read_int32();
	std::vector<std::int32_t> values(length);

	for (auto i = 0; i < length; i++) {
	values[i] = read_int32();
	}

	return values;
	}

	/**
	* Read array of int32.
	*
	* @return Value or nullopt.
	*/
	[[nodiscard]] std::optional<std::vector<std::int32_t>> read_int32_array_nullable() {
	if (try_read_nil()) {
	return std::nullopt;
	}

	return read_int32_array();
	}

	/**
	* Read array of int64.
	*
	* @return Value or nullopt.
	*/
	[[nodiscard]] std::vector<std::int64_t> read_int64_array() {
	auto length = read_int32();
	std::vector<std::int64_t> values(length);

	for (auto i = 0; i < length; i++) {
	values[i] = read_int64();
	}

	return values;
	}

	/**
	* Read array of int64.
	*
	* @return Value or nullopt.
	*/
	[[nodiscard]] std::optional<std::vector<std::int64_t>> read_int64_array_nullable() {
	if (try_read_nil()) {
	return std::nullopt;
	}

	return read_int64_array();
	}

	/**
	* Read int32 or nullopt.
	*
	* @return Value or nullopt if the next value in stream is not integer.
	*/
	[[nodiscard]] std::optional<std::int32_t> try_read_int32() { return try_read_object<std::int32_t>(); }

	/**
	* Read int32 or nullopt.
	*
	* @return Value or nullopt if the next value in stream is nil.
	*/
	[[nodiscard]] std::optional<std::int32_t> read_int32_nullable() { return read_object_nullable<std::int32_t>(); }

	/**
	* Read uint8 or nullopt.
	*
	* @return Value or nullopt if the next value in stream is nil.
	*/
	[[nodiscard]] std::optional<std::uint8_t> read_uint8_nullable() { return read_object_nullable<std::uint8_t>(); }

	/**
	* Read int16 or nullopt.
	*
	* @return Value or nullopt if the next value in stream is nil.
	*/
	[[nodiscard]] std::optional<std::int16_t> read_int16_nullable() { return read_object_nullable<std::int16_t>(); }

	/**
	* Read int64 number.
	*
	* @return Value.
	*/
	[[nodiscard]] std::int64_t read_int64() { return read_object<int64_t>(); }

	/**
	* Read bool.
	*
	* @return Value.
	*/
	[[nodiscard]] bool read_bool() { return read_object<bool>(); }

	/**
	* Read string.
	*
	* @return String value.
	*/
	[[nodiscard]] std::string read_string() { return read_object<std::string>(); }

	/**
	* Read string.
	*
	* @return String value or nullopt.
	*/
	[[nodiscard]] std::optional<std::string> read_string_nullable() { return read_object_nullable<std::string>(); }

	/**
	* Read UUID.
	*
	* @return UUID value.
	*/
	[[nodiscard]] uuid read_uuid() { return read_object<uuid>(); }

	/**
	* Read array.
	*
	* @return Binary data view.
	*/
	[[nodiscard]] bytes_view read_binary() {
	auto res = unpack_binary(m_current_val.data);
	next();
	return res;
	}

	/**
	* If the next value is Nil, read it and move reader to the next position.
	*
	* @return @c true if the value was nil.
	*/
	bool try_read_nil();

	/**
	* Skip next value.
	*/
	void skip() { next(); }

	/**
	* Skip next value.
	*/
	void skip(int count) {
	for (int i = 0; i < count; i++) {
	skip();
	}
	}

	/**
	* Position.
	*
	* @return Current position in memory.
	*/
	[[nodiscard]] size_t position() const { return m_offset; }

	private:
	/**
	* Move to the next value.
	*/
	void next();

	/**
	* Check whether there is a data in stream and throw ignite_error if there is none.
	*/
	void check_data_in_stream() const {
	if (m_move_res < 0)
	throw ignite_error("No more data in stream");
	}

	/** Buffer. */
	bytes_view m_buffer;

	/** Current value. */
	msgpack_unpacked m_current_val;

	/** Result of the last move operation. */
	msgpack_unpack_return m_move_res;

	/** Offset to next value. */
	std::size_t m_offset_next{0};

	/** Offset. */
	std::size_t m_offset{0};
	};

	} // namespace ignite::protocol