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wlan-cloud-lib-cppkafka/include/cppkafka/message_builder.h
2018-12-05 20:04:10 -05:00

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/*
* Copyright (c) 2017, Matias Fontanini
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef CPPKAFKA_MESSAGE_BUILDER_H
#define CPPKAFKA_MESSAGE_BUILDER_H
#include <chrono>
#include "buffer.h"
#include "topic.h"
#include "macros.h"
#include "message.h"
#include "header_list.h"
namespace cppkafka {
/**
* \brief Base template class for message construction
*/
template <typename BufferType, typename Concrete>
class BasicMessageBuilder {
public:
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
using HeaderType = Header<BufferType>;
using HeaderListType = HeaderList<HeaderType>;
#endif
/**
* Construct a BasicMessageBuilder
*
* \param topic The topic into which this message would be produced
*/
BasicMessageBuilder(std::string topic);
/**
* Construct a BasicMessageBuilder from a Message object
*/
BasicMessageBuilder(const Message& message);
/**
* \brief Construct a message builder from another one that uses a different buffer type
*
* Note that this can only be used if BufferType can be constructed from an OtherBufferType
*
* \param rhs The message builder to be constructed from
*/
template <typename OtherBufferType, typename OtherConcrete>
BasicMessageBuilder(const BasicMessageBuilder<OtherBufferType, OtherConcrete>& rhs);
template <typename OtherBufferType, typename OtherConcrete>
BasicMessageBuilder(BasicMessageBuilder<OtherBufferType, OtherConcrete>&& rhs);
/**
* Default copy and move constructors and assignment operators
*/
BasicMessageBuilder(BasicMessageBuilder&&) = default;
BasicMessageBuilder(const BasicMessageBuilder&) = default;
BasicMessageBuilder& operator=(BasicMessageBuilder&&) = default;
BasicMessageBuilder& operator=(const BasicMessageBuilder&) = default;
/**
* Sets the topic in which this message will be produced
*
* \param value The topic to be used
*/
Concrete& topic(std::string value);
/**
* Sets the partition into which this message will be produced
*
* \param value The partition to be used
*/
Concrete& partition(int value);
/**
* Sets the message's key
*
* \param value The key to be used
*/
Concrete& key(const BufferType& value);
/**
* Sets the message's key
*
* \param value The key to be used
*/
Concrete& key(BufferType&& value);
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
/**
* Add a header(s) to the message
*
* \param header The header to be used
*/
Concrete& header(const HeaderType& header);
Concrete& headers(const HeaderListType& headers);
Concrete& headers(HeaderListType&& headers);
#endif
/**
* Sets the message's payload
*
* \param value The payload to be used
*/
Concrete& payload(const BufferType& value);
/**
* Sets the message's payload
*
* \param value The payload to be used
*/
Concrete& payload(BufferType&& value);
/**
* Sets the message's timestamp with a 'duration'
*
* \param value The timestamp to be used
*/
Concrete& timestamp(std::chrono::milliseconds value);
/**
* Sets the message's timestamp with a 'time_point'.
*
* \param value The timestamp to be used
*/
template <typename Clock, typename Duration = typename Clock::duration>
Concrete& timestamp(std::chrono::time_point<Clock, Duration> value);
/**
* Sets the message's user data pointer
*
* \param value Pointer to the user data to be used on the produce call
*/
Concrete& user_data(void* value);
/**
* Gets the topic this message will be produced into
*/
const std::string& topic() const;
/**
* Gets the partition this message will be produced into
*/
int partition() const;
/**
* Gets the message's key
*/
const BufferType& key() const;
/**
* Gets the message's key
*/
BufferType& key();
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
/**
* Gets the list of headers
*/
const HeaderListType& header_list() const;
/**
* Gets the list of headers
*/
HeaderListType& header_list();
#endif
/**
* Gets the message's payload
*/
const BufferType& payload() const;
/**
* Gets the message's payload
*/
BufferType& payload();
/**
* Gets the message's timestamp as a duration. If the timestamp was created with a 'time_point',
* the duration represents the number of milliseconds since epoch.
*/
std::chrono::milliseconds timestamp() const;
/**
* Gets the message's user data pointer
*/
void* user_data() const;
/**
* Private data accessor (internal use only)
*/
Message::InternalPtr internal() const;
Concrete& internal(Message::InternalPtr internal);
protected:
void construct_buffer(BufferType& lhs, const BufferType& rhs);
private:
Concrete& get_concrete();
std::string topic_;
int partition_{-1};
BufferType key_;
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
HeaderListType header_list_;
#endif
BufferType payload_;
std::chrono::milliseconds timestamp_{0};
void* user_data_;
Message::InternalPtr internal_;
};
template <typename T, typename C>
BasicMessageBuilder<T, C>::BasicMessageBuilder(std::string topic)
: topic_(std::move(topic)),
user_data_(nullptr) {
}
template <typename T, typename C>
BasicMessageBuilder<T, C>::BasicMessageBuilder(const Message& message)
: topic_(message.get_topic()),
key_(Buffer(message.get_key().get_data(), message.get_key().get_size())),
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
//Here we must copy explicitly the Message headers since they are non-owning and this class
//assumes full ownership. Otherwise we will be holding an invalid handle when Message goes
//out of scope and rdkafka frees its resource.
header_list_(message.get_header_list() ?
HeaderListType(rd_kafka_headers_copy(message.get_header_list().get_handle())) : HeaderListType()), //copy headers
#endif
payload_(Buffer(message.get_payload().get_data(), message.get_payload().get_size())),
timestamp_(message.get_timestamp() ? message.get_timestamp().get().get_timestamp() :
std::chrono::milliseconds(0)),
user_data_(message.get_user_data()),
internal_(message.internal()) {
}
template <typename T, typename C>
template <typename U, typename V>
BasicMessageBuilder<T, C>::BasicMessageBuilder(const BasicMessageBuilder<U, V>& rhs)
: topic_(rhs.topic()),
partition_(rhs.partition()),
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
header_list_(rhs.header_list()), //copy headers
#endif
timestamp_(rhs.timestamp()),
user_data_(rhs.user_data()),
internal_(rhs.internal()) {
get_concrete().construct_buffer(key_, rhs.key());
get_concrete().construct_buffer(payload_, rhs.payload());
}
template <typename T, typename C>
template <typename U, typename V>
BasicMessageBuilder<T, C>::BasicMessageBuilder(BasicMessageBuilder<U, V>&& rhs)
: topic_(rhs.topic()),
partition_(rhs.partition()),
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
header_list_(std::move(header_list())), //assume header ownership
#endif
timestamp_(rhs.timestamp()),
user_data_(rhs.user_data()),
internal_(rhs.internal()) {
get_concrete().construct_buffer(key_, std::move(rhs.key()));
get_concrete().construct_buffer(payload_, std::move(rhs.payload()));
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::topic(std::string value) {
topic_ = std::move(value);
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::partition(int value) {
partition_ = value;
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::key(const T& value) {
get_concrete().construct_buffer(key_, value);
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::key(T&& value) {
key_ = std::move(value);
return get_concrete();
}
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::header(const HeaderType& header) {
if (!header_list_) {
header_list_ = HeaderListType(5);
}
header_list_.add(header);
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::headers(const HeaderListType& headers) {
header_list_ = headers;
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::headers(HeaderListType&& headers) {
header_list_ = std::move(headers);
return get_concrete();
}
#endif
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::payload(const T& value) {
get_concrete().construct_buffer(payload_, value);
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::payload(T&& value) {
payload_ = std::move(value);
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::timestamp(std::chrono::milliseconds value) {
timestamp_ = value;
return get_concrete();
}
template <typename T, typename C>
template <typename Clock, typename Duration>
C& BasicMessageBuilder<T, C>::timestamp(std::chrono::time_point<Clock, Duration> value)
{
timestamp_ = std::chrono::duration_cast<std::chrono::milliseconds>(value.time_since_epoch());
return get_concrete();
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::user_data(void* value) {
user_data_ = value;
return get_concrete();
}
template <typename T, typename C>
const std::string& BasicMessageBuilder<T, C>::topic() const {
return topic_;
}
template <typename T, typename C>
int BasicMessageBuilder<T, C>::partition() const {
return partition_;
}
template <typename T, typename C>
const T& BasicMessageBuilder<T, C>::key() const {
return key_;
}
template <typename T, typename C>
T& BasicMessageBuilder<T, C>::key() {
return key_;
}
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
template <typename T, typename C>
const typename BasicMessageBuilder<T, C>::HeaderListType&
BasicMessageBuilder<T, C>::header_list() const {
return header_list_;
}
template <typename T, typename C>
typename BasicMessageBuilder<T, C>::HeaderListType&
BasicMessageBuilder<T, C>::header_list() {
return header_list_;
}
#endif
template <typename T, typename C>
const T& BasicMessageBuilder<T, C>::payload() const {
return payload_;
}
template <typename T, typename C>
T& BasicMessageBuilder<T, C>::payload() {
return payload_;
}
template <typename T, typename C>
std::chrono::milliseconds BasicMessageBuilder<T, C>::timestamp() const {
return timestamp_;
}
template <typename T, typename C>
void* BasicMessageBuilder<T, C>::user_data() const {
return user_data_;
}
template <typename T, typename C>
Message::InternalPtr BasicMessageBuilder<T, C>::internal() const {
return internal_;
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::internal(Message::InternalPtr internal) {
internal_ = internal;
return get_concrete();
}
template <typename T, typename C>
void BasicMessageBuilder<T, C>::construct_buffer(T& lhs, const T& rhs) {
lhs = rhs;
}
template <typename T, typename C>
C& BasicMessageBuilder<T, C>::get_concrete() {
return static_cast<C&>(*this);
}
/**
* \brief Message builder class
*
* Allows building a message including topic, partition, key, payload, etc.
*
* Example:
*
* \code
* Producer producer(...);
*
* string payload = "hello world";
* producer.produce(MessageBuilder("test").partition(5).payload(payload));
* \endcode
*/
class MessageBuilder : public BasicMessageBuilder<Buffer, MessageBuilder> {
public:
using Base = BasicMessageBuilder<Buffer, MessageBuilder>;
using BasicMessageBuilder<Buffer, MessageBuilder>::BasicMessageBuilder;
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
using HeaderType = Base::HeaderType;
using HeaderListType = Base::HeaderListType;
#endif
void construct_buffer(Buffer& lhs, const Buffer& rhs) {
lhs = Buffer(rhs.get_data(), rhs.get_size());
}
template <typename T>
void construct_buffer(Buffer& lhs, T&& rhs) {
lhs = Buffer(std::forward<T>(rhs));
}
MessageBuilder clone() const {
MessageBuilder builder(topic());
builder.key(Buffer(key().get_data(), key().get_size())).
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
headers(header_list()).
#endif
payload(Buffer(payload().get_data(), payload().get_size())).
timestamp(timestamp()).
user_data(user_data()).
internal(internal());
return builder;
}
};
/**
* \brief Message builder class for a specific data type
*/
template <typename T>
class ConcreteMessageBuilder : public BasicMessageBuilder<T, ConcreteMessageBuilder<T>> {
public:
using Base = BasicMessageBuilder<T, ConcreteMessageBuilder<T>>;
using BasicMessageBuilder<T, ConcreteMessageBuilder<T>>::BasicMessageBuilder;
#if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
using HeaderType = typename Base::HeaderType;
using HeaderListType = typename Base::HeaderListType;
#endif
};
} // cppkafka
#endif // CPPKAFKA_MESSAGE_BUILDER_H