send.h

   1 /*
   2  * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file send.h Sender-related defines and structures. */
   8
   9 /** The sender subcommands. */
  10 enum {SENDER_ADD, SENDER_DELETE, SENDER_ALLOW, SENDER_DENY, SENDER_ON, SENDER_OFF, NUM_SENDER_CMDS};
  11
  12 /**
  13  * Describes one supported sender of para_server.
  14  *
  15  * \sa http_send.c ortp_send.c, dccp_send.c.
  16  */
  17 struct sender {
  18         /** The name of the sender. */
  19         const char *name;
  20         /**
  21          * The init function of this sender.
  22          *
  23          * It must fill in all function pointers of \a s as well as the \a
  24          * client_cmds array, see below. It should also do all necessary
  25          * preparations to init this sending facility, for example it could
  26          * open a tcp port.
  27          */
  28         void (*init)(struct sender *s);
  29         /**
  30          * Return the help text of this sender.
  31          *
  32          * The result must be dynamically allocated and is freed by the caller.
  33          */
  34         char* (*help)(void);
  35         /**
  36          * Return current status info about this sender.
  37          *
  38          * The result must be dynamically allocated and is freed by the caller.
  39          */
  40         char* (*info)(void);
  41         /**
  42          * The send-hook.
  43          *
  44          * It gets called whenever para_server is playing and the current
  45          * audio format handler indicates that another chunk of data should
  46          * be sent now. The two parameters \a current_chunk and \a chunks_sent
  47          * only differ if the stream was repositioned by the \a ff or \a jmp
  48          * command. Of course, \a buf is a pointer to the chunk of data which
  49          * should be sent, and \a len is the length of this buffer.
  50         */
  51         void (*send)(long unsigned current_chunk, long unsigned chunks_sent,
  52                 const char *buf, size_t len);
  53         /**
  54          * Add file descriptors to fd_sets.
  55          *
  56          * The pre_select function of each supported sender is called just before
  57          * para_server enters its main select loop. Each sender may add its own
  58          * file descriptors to the \a rfds or the \a wfds set.
  59          *
  60          * If a file descriptor was added, \a max_fileno must be increased by
  61          * this function, if necessary.
  62          *
  63          * \sa select(2).
  64          */
  65         void (*pre_select)(int *max_fileno, fd_set *rfds, fd_set *wfds);
  66         /**
  67          * Handle the file descriptors which are ready for I/O.
  68          *
  69          * If the pre_select hook added one ore more file descriptors to the
  70          * read or write set, this is the hook to check the result and do any
  71          * I/O on those descriptors which are ready for reading/writing.
  72          */
  73         void (*post_select)(fd_set *rfds, fd_set *wfds);
  74         /**
  75          * Terminate all connected clients.
  76          *
  77          * This is called e.g. if the stop command was executed. It should make
  78          * the clients aware of the end-of-file condition.
  79          */
  80         void (*shutdown_clients)(void);
  81         /**
  82          * Array of function pointers for the sender subcommands.
  83          *
  84          * Each sender may implement any subset of the sender commands by
  85          * filling in the appropriate function pointer in the array. A \p NULL
  86          * pointer means this command is not implemented by this sender.
  87          */
  88         int (*client_cmds[NUM_SENDER_CMDS])(struct sender_command_data*);
  89 };