AMQP-CPP/include/deferredcancel.h

104 lines
2.5 KiB
C++

/**
* DeferredCancel.h
*
* Deferred callback for instructions that cancel a running consumer. This
* deferred object allows one to register a callback that also gets the
* consumer tag as one of its parameters.
*
* @copyright 2014 Copernica BV
*/
/**
* Include guard
*/
#pragma once
/**
* Set up namespace
*/
namespace AMQP {
/**
* We extend from the default deferred and add extra functionality
*/
class DeferredCancel : public Deferred
{
private:
/**
* Pointer to the channel
* @var ChannelImpl
*/
ChannelImpl *_channel;
/**
* Callback to execute when the instruction is completed
* @var CancelCallback
*/
CancelCallback _cancelCallback;
/**
* Report success for frames that report cancel operations
* @param name Consumer tag that is cancelled
* @return Deferred
*/
virtual const std::shared_ptr<Deferred> &reportSuccess(const std::string &name) override;
/**
* The channel implementation may call our
* private members and construct us
*/
friend class ChannelImpl;
friend class ConsumedMessage;
public:
/**
* Protected constructor that can only be called
* from within the channel implementation
*
* Note: this constructor _should_ be protected, but because make_shared
* will then not work, we have decided to make it public after all,
* because the work-around would result in not-so-easy-to-read code.
*
* @param channel Pointer to the channel
* @param failed Are we already failed?
*/
DeferredCancel(ChannelImpl *channel, bool failed = false) :
Deferred(failed), _channel(channel) {}
public:
/**
* Register a function to be called when the cancel operation succeeded
*
* Only one callback can be registered. Successive calls
* to this function will clear callbacks registered before.
*
* @param callback the callback to execute
*/
DeferredCancel &onSuccess(const CancelCallback &callback)
{
// store callback
_cancelCallback = callback;
// allow chaining
return *this;
}
/**
* Register the function that is called when the cancel operation succeeded
* @param callback
*/
DeferredCancel &onSuccess(const SuccessCallback &callback)
{
// call base
Deferred::onSuccess(callback);
// allow chaining
return *this;
}
};
/**
* End namespace
*/
}