ctdb/common/pkt_write.h

   1 /*
   2    API for writing a packet
   3
   4    Copyright (C) Amitay Isaacs 2015
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #ifndef __CTDB_PKT_WRITE_H__
  21 #define __CTDB_PKT_WRITE_H__
  22
  23 #include <talloc.h>
  24 #include <tevent.h>
  25
  26 /**
  27  * @file pkt_write.h
  28  *
  29  * @brief Write a packet.
  30  *
  31  * Write a complete packet with possibly multiple system calls.
  32  */
  33
  34 /**
  35  * @brief Start async computation to write a packet
  36  *
  37  * This returns a tevent request to write a packet to given fd.  The fd
  38  * should be nonblocking. Freeing this request will free all the memory
  39  * associated with the request.
  40  *
  41  * @param[in] mem_ctx Talloc memory context
  42  * @param[in] ev Tevent context
  43  * @param[in] fd The non-blocking file/socket descriptor to write to
  44  * @param[in] buf The data
  45  * @param[in] buflen The size of the data
  46  * @return new tevent request or NULL on failure
  47  */
  48 struct tevent_req *pkt_write_send(TALLOC_CTX *mem_ctx,
  49                                   struct tevent_context *ev,
  50                                   int fd, uint8_t *buf, size_t buflen);
  51
  52 /**
  53  * @brief Function to actually write data to the socket
  54  *
  55  * This function should be called, when tevent fd event is triggered
  56  * for TEVENT_FD_WRITE event.  This function has the syntax of
  57  * tevent_fd_handler_t.  The private_data for this function is the tevent
  58  * request created by pkt_write_send function.
  59  *
  60  * @param[in] ev Tevent context
  61  * @param[in] fde Tevent fd context
  62  * @param[in] flags Tevent fd flags
  63  * @param[in] req The active tevent request
  64  */
  65 void pkt_write_handler(struct tevent_context *ev, struct tevent_fd *fde,
  66                        uint16_t flags, struct tevent_req *req);
  67
  68 /**
  69  * @brief Packet is sent
  70  *
  71  * This function returns the number of bytes written.
  72  *
  73  * @param[in] req Tevent request
  74  * @param[out] perrno errno in case of failure
  75  * @return the number of bytes written, or -1 on failure
  76  */
  77 ssize_t pkt_write_recv(struct tevent_req *req, int *perrno);
  78
  79 #endif /* __CTDB_PKT_WRITE_H__ */