recv.h

   1 /*
   2  * Copyright (C) 2005-2011 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file recv.h Receiver-related structures and exported symbols of recv_common.c. */
   8
   9 /**
  10  * Describes one instance of a receiver.
  11  */
  12 struct receiver_node {
  13         /** Points to the corresponding receiver. */
  14         struct receiver *receiver;
  15         /** Receiver-specific data. */
  16         void *private_data;
  17         /** Pointer to the configuration data for this instance. */
  18         void *conf;
  19         /** The task associated with this instance. */
  20         struct task task;
  21         /** The receiver node is always the root of the buffer tree. */
  22         struct btr_node *btrn;
  23 };
  24
  25 /**
  26  * Describes one supported paraslash receiver.
  27  *
  28  * \sa http_recv.c, udp_recv.c
  29  */
  30 struct receiver {
  31         /**
  32          * The name of the receiver.
  33          */
  34         const char *name;
  35         /**
  36          * The receiver init function.
  37          *
  38          * It must fill in all other function pointers and is assumed to succeed.
  39          *
  40          * \sa http_recv_init udp_recv_init.
  41          */
  42         void (*init)(struct receiver *r);
  43         /**
  44          * The command line parser of the receiver.
  45          *
  46          * It should check whether the command line options given by \a argc and \a
  47          * argv are valid.  On success, it should return a pointer to the
  48          * receiver-specific configuration data determined by \a argc and \a argv.
  49          * Note that this might be called more than once with different values of
  50          * \a argc and \a argv.
  51          */
  52         void *(*parse_config)(int argc, char **argv);
  53         /**
  54          * Deallocate the configuration structure of a receiver node.
  55          *
  56          * This calls the receiver-specific cleanup function generated by
  57          * gengetopt.
  58          */
  59         void (*free_config)(void *conf);
  60         /**
  61          * Open one instance of the receiver.
  62          *
  63          * This should allocate the output buffer of \a rn. and may also
  64          * perform any other work necessary for retrieving the stream according
  65          * to the configuration stored in the \a conf member of \a rn which is
  66          * guaranteed to point to valid configuration data (as previously
  67          * obtained from the config parser).
  68          *
  69          * \sa receiver_node::conf, receiver_node::buf.
  70          */
  71         int (*open)(struct receiver_node *rn);
  72         /**
  73          * Close this instance of the receiver.
  74          *
  75          * It should free all resources associated with given receiver node
  76          * that were allocated during the corresponding open call.
  77          *
  78          * \sa receiver_node.
  79          */
  80         void (*close)(struct receiver_node *rn);
  81         /**
  82          * Add file descriptors to fd_sets and compute timeout for select(2).
  83          *
  84          * The pre_select function gets called from the driving application
  85          * before entering its select loop. The receiver may use this hook to
  86          * add any file descriptors to the sets of file descriptors given by \a
  87          * s.
  88          *
  89          * \sa select(2), time.c struct task, struct sched.
  90          */
  91         void (*pre_select)(struct sched *s, struct task *t);
  92         /**
  93          * Evaluate the result from select().
  94          *
  95          * This hook gets called after the call to select(). It should check
  96          * all file descriptors which were added to any of the the fd sets
  97          * during the previous call to pre_select. According to the result, it
  98          * may then use any non-blocking I/O to establish a connection or to
  99          * receive the audio data.
 100          *
 101          * \sa select(2), struct receiver.
 102          */
 103         void (*post_select)(struct sched *s, struct task *t);
 104
 105         /** The two help texts of this receiver. */
 106         struct ggo_help help;
 107 };
 108
 109 /** Define an array of all available receivers. */
 110 #define DEFINE_RECEIVER_ARRAY struct receiver receivers[] = { \
 111         HTTP_RECEIVER \
 112         DCCP_RECEIVER \
 113         UDP_RECEIVER \
 114         {.name = NULL}};
 115
 116 /** Iterate over all available receivers. */
 117 #define FOR_EACH_RECEIVER(i) for (i = 0; receivers[i].name; i++)
 118
 119 void recv_init(void);
 120 void *check_receiver_arg(char *ra, int *receiver_num);
 121 void print_receiver_helps(int detailed);
 122 int generic_recv_pre_select(struct sched *s, struct task *t);
 123
 124 /** \cond */
 125 extern void http_recv_init(struct receiver *r);
 126 #define HTTP_RECEIVER {.name = "http", .init = http_recv_init},
 127 extern void dccp_recv_init(struct receiver *r);
 128 #define DCCP_RECEIVER {.name = "dccp", .init = dccp_recv_init},
 129 extern void udp_recv_init(struct receiver *r);
 130 #define UDP_RECEIVER {.name = "udp", .init = udp_recv_init},
 131
 132 extern struct receiver receivers[];
 133 /** \endcond */
 134