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/**
* mds — A micro-display server
* Copyright © 2014, 2015, 2016, 2017 Mattias Andrée (maandree@kth.se)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MDS_MDS_SERVER_MULTICAST_H
#define MDS_MDS_SERVER_MULTICAST_H
#include "queued-interception.h"
#define MULTICAST_T_VERSION 0
/**
* Message multicast state
*/
typedef struct multicast {
/**
* Queue of clients that is listening this message
*/
struct queued_interception *interceptions;
/**
* The number of clients in `interceptions`
*/
size_t interceptions_count;
/**
* The index of the current/next client in `interceptions` to whom to send the message
*/
size_t interceptions_ptr;
/**
* The message to send
*/
char *message;
/**
* The length of `message`
*/
size_t message_length;
/**
* How much of the message that has already been sent to the current recipient
*/
size_t message_ptr;
/**
* How much of the message to skip if the recipient is not a modifier
*/
size_t message_prefix;
} multicast_t;
/**
* Initialise a message multicast state
*
* @param this The message multicast state
*/
__attribute__((nonnull))
void multicast_initialise(multicast_t *restrict this);
/**
* Destroy a message multicast state
*
* @param this The message multicast state
*/
__attribute__((nonnull))
void multicast_destroy(multicast_t *restrict this);
/**
* Calculate the buffer size need to marshal a message multicast state
*
* @param this The client information
* @return The number of bytes to allocate to the output buffer
*/
__attribute__((pure, nonnull))
size_t multicast_marshal_size(const multicast_t *restrict this);
/**
* Marshals a message multicast state
*
* @param this The message multicast state
* @param data Output buffer for the marshalled data
* @return The number of bytes that have been written (everything will be written)
*/
__attribute__((nonnull))
size_t multicast_marshal(const multicast_t *restrict this, char *restrict data);
/**
* Unmarshals a message multicast state
*
* @param this Memory slot in which to store the new message multicast state
* @param data In buffer with the marshalled data
* @return Zero on error, `errno` will be set accordingly, otherwise the
* number of read bytes. Destroy the message multicast state on error.
*/
__attribute__((nonnull))
size_t multicast_unmarshal(multicast_t *restrict this, char *restrict data);
/**
* Pretend to unmarshal a message multicast state
*
* @param data In buffer with the marshalled data
* @return The number of read bytes
*/
__attribute__((pure, nonnull))
size_t multicast_unmarshal_skip(char *restrict data);
#endif
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