SimpleAmqpClient

SimpleAmqpClient is an easy-to-use C++ wrapper around the rabbitmq-c C library. It derives inspiration from the puka AMQP library in that it abstracts away the underlying AMQP wire concept of channels and uses them as an error/consumer scope. This should make writing simple single-threaded AMQP-enabled apps easy.

Installing

Known to work in the following environments:

• Windows 10 (MSVC 2019, Win64)
• Windows 7 (MSVC 10, Win64, Win32). Likely to work in others, but has not been tested
• Linux (RHEL 6.0, GCC-4.4.5, 32 and 64 bit). Likely to work on other configurations, but has not been tested
• Mac OS X (10.7, 10.6, gcc-4.2, 32 and 64-bit). Likely to work on older version, but has not been tested

Pre-requisites

• boost-1.47.0 or newer (uses chrono, system internally in addition to other header based libraries such as sharedptr and noncopyable)
• rabbitmq-c you'll need version 0.8.0 or better.
• cmake 3.5+ what is needed for the build system
• Doxygen OPTIONAL only necessary to generate API documentation

Build procedure

This is a typical cmake project, it should work like most typical cmake projects:

In a sibling directory to where you extracted the source code:

mkdir simpleamqpclient-build
cd simpleamqpclient-build
cmake ..

Then use your the appropriate build utility to build the library (make, msbuild)

Interesting targets

• test - will build and run the tests
• install - will install the library and headers to whatever CMAKE_INSTALL_PREFIX is defined to
• doc - will generate API documentation if you have doxygen setup

Notes:

• The test google-test based test suite can be enabled by passing -DENABLE_TESTING=ON to cmake

Build procedure for Windows

Boost libraries are needed, so you can install them using nuget:

nuget install boost_chrono-vc142 -Version 1.77.0
nuget install boost_system-vc142 -Version 1.77.0
nuget install boost -Version 1.77.0

To build and install succesfully, rabbitmq-c should be built as shared library.

Let boost_chrono and boost_system be in same directory C:\boost, rabbitmq-c be on C:\rabbitmq-c, SSL be OFF, and VS2019 is used, than CMake CLI is:

cd cmake -G "Visual Studio 16" -A x64 -DBoost_INCLUDE_DIR="C:/boost.XX.XX.X.X/lib/native/include" -DBOOST_ROOT="C:/boost.X.XX.X.X" -DBOOST_LIBRARYDIR="C:/boost" -DRabbitmqc_INCLUDE_DIR="C:/rabbitmq-c/include" -DRabbitmqc_LIBRARY="C:/rabbitmq-c/lib/rabbitmq.4.lib" -DBoost_USE_STATIC_LIBS=ON -DBUILD_STATIC_LIBS=ON -DENABLE_SSL_SUPPORT=OFF ..

Using the library

#include <SimpleAmqpClient/SimpleAmqpClient.h>

Will include all the headers necessary to use the library. The corresponding library is SimpleAmqpClient

The main interface to the library is the AmqpClient::Channel class. It represents a connection to an AMQP broker, the connection is established on construction of an instance of this class.

AmqpClient::Channel::ptr_t connection = AmqpClient::Channel::Create("localhost");

All classes have a typedef ptr_t which is equivalent to boost::shared_ptr<> of the containing class. All classes also have a Create() method does the job creating a new ptr_t using boost::make_shared<>(). It is recommended that you use these methods to construct objects in the library.

Commands dealing with declaring/binding/unbinding/deleting exchanges and queues are all done with the above AmqpClient::Channel object. If one of these commands fails to complete a AmqpClient::ChannelException will be thrown, which can be caught and the AmqpClient::Channel object is still useable. If a more severe error occurs a AmqpClient::ConnectionException or AmqpClient::AmqpResponseLibraryException maybe thrown, in which case the Channel object is no longer in a usable state and further use will only generate more exceptions.

Consuming messages is done by setting up a consumer using the BasicConsume method. This method returns a consumer tag that should be used with the BasicConsumeMessage BasicQos, BasicRecover, and BasicCancel.

std::string consumer_tag = channel->BasicConsume("my_queue", "");
Envelope::ptr_t envelope = channel->BasicConsumeMessage(consumer_tag);
// Alternatively:
Envelope::ptr_t envelope;
channel->BasicConsumeMessage(consumer_tag, envelope, 10); // 10 ms timeout
// To ack:
channel->BasicAck(envelope);
// To cancel:
channel->BasicCancel(consumer_tag);