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Diffstat (limited to 'c')
| -rw-r--r-- | c/zmq.h | 206 |
1 files changed, 206 insertions, 0 deletions
@@ -0,0 +1,206 @@ +/* + Copyright (c) 2007-2009 FastMQ Inc. + + This file is part of 0MQ. + + 0MQ is free software; you can redistribute it and/or modify it under + the terms of the Lesser GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + 0MQ is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + Lesser GNU General Public License for more details. + + You should have received a copy of the Lesser GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#ifndef __ZMQ_H_INCLUDED__ +#define __ZMQ_H_INCLUDED__ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <stddef.h> + +#if defined MSC_VER && defined ZMQ_BUILDING_LIBZMQ +#define ZMQ_EXPORT __declspec(dllexport) +#else +#define ZMQ_EXPORT +#endif + +// Maximal size of "Very Small Message". VSMs are passed by value +// to avoid excessive memory allocation/deallocation. +// If VMSs larger than 255 bytes are required, type of 'vsm_size' +// field in zmq_msg_t structure should be modified accordingly. +#define ZMQ_MAX_VSM_SIZE 30 + +// Message & notification types. +#define ZMQ_GAP 1 +#define ZMQ_DELIMITER 31 +#define ZMQ_VSM 32 + +// Socket options. +#define ZMQ_HWM 1 +#define ZMQ_LWM 2 +#define ZMQ_SWAP 3 +#define ZMQ_MASK 4 +#define ZMQ_AFFINITY 5 +#define ZMQ_IDENTITY 6 + +// The operation should be performed in non-blocking mode. I.e. if it cannot +// be processed immediately, error should be returned with errno set to EAGAIN. +#define ZMQ_NOBLOCK 1 + +// zmq_send should not flush the message downstream immediately. Instead, it +// should batch ZMQ_NOFLUSH messages and send them downstream only if zmq_flush +// is invoked. This is an optimisation for cases where several messages are +// sent in a single business transaction. However, the effect is measurable +// only in extremely high-perf scenarios (million messages a second or so). +// If that's not your case, use standard flushing send instead. See exchange +// example for illustration of ZMQ_NOFLUSH functionality. +#define ZMQ_NOFLUSH 2 + +// Socket to communicate with a single peer. Allows for a singe connect or a +// single accept. There's no message routing or message filtering involved. +#define ZMQ_P2P 0 + +// Socket to distribute data. Recv fuction is not implemented for this socket +// type. Messages are distributed in fanout fashion to all peers. +#define ZMQ_PUB 1 + +// Socket to subscribe to distributed data. Send function is not implemented +// for this socket type. However, subscribe function can be used to modify the +// message filter. +#define ZMQ_SUB 2 + +// Socket to send requests on and receive replies from. Requests are +// load-balanced among all the peers. This socket type doesn't allow for more +// recv's that there were send's. +#define ZMQ_REQ 3 + +// Socket to receive requests from and send replies to. This socket type allows +// only an alternated sequence of recv's and send's. Each send is routed to +// the peer that the previous recv delivered message from. +#define ZMQ_REP 4 + +// Prototype for the message body deallocation functions. +// It is deliberately defined in the way to comply with standard C free. +typedef void (zmq_free_fn) (void *data); + +// A message. If 'shared' is true, message content pointed to by 'content' +// is shared, i.e. reference counting is used to manage its lifetime +// rather than straighforward malloc/free. struct zmq_msg_content is +// not declared in the API. +struct zmq_msg_t +{ + void *content; + unsigned char shared; + unsigned char vsm_size; + unsigned char vsm_data [ZMQ_MAX_VSM_SIZE]; +}; + +// Initialise an empty message (zero bytes long). +ZMQ_EXPORT int zmq_msg_init (struct zmq_msg_t *msg); + +// Initialise a message 'size' bytes long. +// +// Errors: ENOMEM - the size is too large to allocate. +ZMQ_EXPORT int zmq_msg_init_size (struct zmq_msg_t *msg, size_t size); + +// Initialise a message from an existing buffer. Message isn't copied, +// instead 0MQ infrastructure take ownership of the buffer and call +// deallocation functio (ffn) once it's not needed anymore. +ZMQ_EXPORT int zmq_msg_init_data (struct zmq_msg_t *msg, void *data, + size_t size, zmq_free_fn *ffn); + +// Deallocate the message. +ZMQ_EXPORT int zmq_msg_close (struct zmq_msg_t *msg); + +// Move the content of the message from 'src' to 'dest'. The content isn't +// copied, just moved. 'src' is an empty message after the call. Original +// content of 'dest' message is deallocated. +ZMQ_EXPORT int zmq_msg_move (struct zmq_msg_t *dest, struct zmq_msg_t *src); + +// Copy the 'src' message to 'dest'. The content isn't copied, instead +// reference count is increased. Don't modify the message data after the +// call as they are shared between two messages. Original content of 'dest' +// message is deallocated. +ZMQ_EXPORT int zmq_msg_copy (struct zmq_msg_t *dest, struct zmq_msg_t *src); + +// Returns pointer to message data. +ZMQ_EXPORT void *zmq_msg_data (struct zmq_msg_t *msg); + +// Return size of message data (in bytes). +ZMQ_EXPORT size_t zmq_msg_size (struct zmq_msg_t *msg); + +// Returns type of the message. +ZMQ_EXPORT int zmq_msg_type (struct zmq_msg_t *msg); + +// Initialise 0MQ context. 'app_threads' specifies maximal number +// of application threads that can have open sockets at the same time. +// 'io_threads' specifies the size of thread pool to handle I/O operations. +// +// Errors: EINVAL - one of the arguments is less than zero or there are no +// threads declared at all. +ZMQ_EXPORT void *zmq_init (int app_threads, int io_threads); + +// Deinitialise 0MQ context including all the open sockets. Closing +// sockets after zmq_term has been called will result in undefined behaviour. +ZMQ_EXPORT int zmq_term (void *context); + +// Open a socket. +// +// Errors: EINVAL - invalid socket type. +// EMFILE - the number of application threads entitled to hold open +// sockets at the same time was exceeded. +ZMQ_EXPORT void *zmq_socket (void *context, int type); + +// Close the socket. +ZMQ_EXPORT int zmq_close (void *s); + +// Sets an option on the socket. +// EINVAL - unknown option, a value with incorrect length or an invalid value. +ZMQ_EXPORT int zmq_setsockopt (void *s, int option_, const void *optval_, + size_t optvallen_); + +// Bind the socket to a particular address. +ZMQ_EXPORT int zmq_bind (void *s, const char *addr); + +// Connect the socket to a particular address. +ZMQ_EXPORT int zmq_connect (void *s, const char *addr); + +// Send the message 'msg' to the socket 's'. 'flags' argument can be +// combination of following values: +// ZMQ_NOBLOCK - if message cannot be sent, return immediately. +// ZMQ_NOFLUSH - message won't be sent immediately. It'll be sent with either +// subsequent flushing send or explicit call to zmq_flush +// function. +// +// Errors: EAGAIN - message cannot be sent at the moment (applies only to +// non-blocking send). +// ENOTSUP - function isn't supported by particular socket type. +ZMQ_EXPORT int zmq_send (void *s, struct zmq_msg_t *msg, int flags); + +// Flush the messages that were send using ZMQ_NOFLUSH flag down the stream. +// +// Errors: ENOTSUP - function isn't supported by particular socket type. +ZMQ_EXPORT int zmq_flush (void *s); + +// Send a message from the socket 's'. 'flags' argument can be combination +// of following values: +// ZMQ_NOBLOCK - if message cannot be received, return immediately. +// +// Errors: EAGAIN - message cannot be received at the moment (applies only to +// non-blocking receive). +// ENOTSUP - function isn't supported by particular socket type. +ZMQ_EXPORT int zmq_recv (void *s, struct zmq_msg_t *msg, int flags); + +#ifdef __cplusplus +} +#endif + +#endif |