#include <CRingBufferTransport.h>
class CRingBufferTransport : public CRingItemTransport
{
public:
CRingBufferTransport(CRingBuffer& writer);
CRingBufferTransport(CRingBufferChunkAccess& reader);
virtual void recv(void** ppData, size_t& size);
virtual void send(iovec* parts, size_t numParts);
};
Provides a transport for data to and from a ring buffer. Often these are at endpoints of a computation, but need not be.
Note that there is a constructor for writing and a different
one for reading. This represents the fundamental
difference between producers and consumers of ring
data. Attempting to receive data from
a ring transport that's been set up to as a producer
or attempting to send data to a ring buffer
that's been setup as a consumer results in a
std::logic_error exception.
CRingBufferTransport(CRingBuffer& writer);
Use this constructor for producers into
ring buffers. Objects constructed with this
version of the constructor only support
send
CRingBufferTransport(CRingBufferChunkAccess& reader);
This version of the constructor is used
for consumers. Objects constructed
in this manner are only capable of
recv calls.
The reader parameter
is a reference to a
CRingBufferChunkAccess
class. See the
CRingBufferChunkAccess(3daq)
class for more information about it, and
specifically, how to construct it.
virtual void recv(void** ppData, size_t& size);
Receives the next ring item from the ring buffer. Receives from this transport are always receiving a full ring item.
virtual void send(iovec* parts, size_t numParts);
Puts data into the ring buffer. Note that each iovec element does a put into the ring buffer. Thus, if a ring item is spread across several iovec elements, the put is not atomic. In many cases, because of the way data are gotten from the ring buffer, this fact is not important.