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         void (*free_config)(void *conf);
  54         /**
  55          * Open one instance of the receiver.
  56          *
  57          * This should allocate the output buffer of \a rn. and may also
  58          * perform any other work necessary for retrieving the stream according
  59          * to the configuration stored in the \a conf member of \a rn which is
  60          * guaranteed to point to valid configuration data (as previously
  61          * obtained from the config parser).
  62          *
  63          * \sa receiver_node::conf, receiver_node::buf.
  64          */
  65         int (*open)(struct receiver_node *rn);
  66         /**
  67          * Close this instance of the receiver.
  68          *
  69          * It should free all resources associated with given receiver node
  70          * that were allocated during the corresponding open call.
  71          *
  72          * \sa receiver_node.
  73          */
  74         void (*close)(struct receiver_node *rn);
  75         /**
  76          * Add file descriptors to fd_sets and compute timeout for select(2).
  77          *
  78          * The pre_select function gets called from the driving application
  79          * before entering its select loop. The receiver may use this hook to
  80          * add any file descriptors to the sets of file descriptors given by \a
  81          * s.
  82          *
  83          * \sa select(2), time.c struct task, struct sched.
  84          */
  85         void (*pre_select)(struct sched *s, struct task *t);
  86         /**
  87          * Evaluate the result from select().
  88          *
  89          * This hook gets called after the call to select(). It should check
  90          * all file descriptors which were added to any of the the fd sets
  91          * during the previous call to pre_select. According to the result, it
  92          * may then use any non-blocking I/O to establish a connection or to
  93          * receive the audio data.
  94          *
  95          * \sa select(2), struct receiver.
  96          */
  97         void (*post_select)(struct sched *s, struct task *t);
  98
  99         /** The two help texts of this receiver. */
 100         struct ggo_help help;
 101 };
 102
 103 /** Define an array of all available receivers. */
 104 #define DEFINE_RECEIVER_ARRAY struct receiver receivers[] = { \
 105         HTTP_RECEIVER \
 106         DCCP_RECEIVER \
 107         UDP_RECEIVER \
 108         {.name = NULL}};
 109
 110 /** Iterate over all available receivers. */
 111 #define FOR_EACH_RECEIVER(i) for (i = 0; receivers[i].name; i++)
 112
 113 void recv_init(void);
 114 void *check_receiver_arg(char *ra, int *receiver_num);
 115 void print_receiver_helps(int detailed);
 116 int generic_recv_pre_select(struct sched *s, struct task *t);
 117
 118 /** \cond */
 119 extern void http_recv_init(struct receiver *r);
 120 #define HTTP_RECEIVER {.name = "http", .init = http_recv_init},
 121 extern void dccp_recv_init(struct receiver *r);
 122 #define DCCP_RECEIVER {.name = "dccp", .init = dccp_recv_init},
 123 extern void udp_recv_init(struct receiver *r);
 124 #define UDP_RECEIVER {.name = "udp", .init = udp_recv_init},
 125
 126 extern struct receiver receivers[];
 127 /** \endcond */
 128