2 * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file recv.h Receiver-related structures and exported symbols of recv_common.c. */
10 * Describes one instance of a receiver.
12 struct receiver_node {
13 /** Points to the corresponding receiver. */
14 const struct receiver *receiver;
15 /** Receiver-specific data. */
17 /** The parsed command line options for this instance. */
18 struct lls_parse_result *lpr;
19 /** The task associated with this instance. */
21 /** The receiver node is always the root of the buffer tree. */
22 struct btr_node *btrn;
23 /** Each receiver node maintains a buffer pool for the received data. */
24 struct btr_pool *btrp;
26 * The file descriptor to receive the stream.
28 * The pre_select function of the receiver adds this file descriptor to
29 * the set of file descriptors which are watched for readability or
30 * writability, depending on the state of the connection (if any).
32 * If \a fd is readable, the post_select function of the receiver reads
33 * data from this fd into the buffer pool area of \a btrp.
41 * Describes one supported paraslash receiver.
43 * \sa \ref http_recv.c, \ref udp_recv.c.
47 * The optional receiver init function.
49 * Performs any initialization needed before the receiver can be opened.
53 * Open one instance of the receiver.
55 * This should allocate the output buffer of \a rn. and may also
56 * perform any other work necessary for retrieving the stream according
57 * to the configuration stored in the \a conf member of \a rn which is
58 * guaranteed to point to valid configuration data (as previously
59 * obtained from the config parser).
61 * \sa struct \ref receiver_node.
63 int (*open)(struct receiver_node *rn);
65 * Close this instance of the receiver.
67 * It should free all resources associated with given receiver node
68 * that were allocated during the corresponding open call.
70 * \sa \ref receiver_node.
72 void (*close)(struct receiver_node *rn);
74 * Add file descriptors to fd_sets and compute timeout for select(2).
76 * The pre_select function gets called from the driving application
77 * before entering its select loop. The receiver may use this hook to
78 * add any file descriptors to the sets of file descriptors given by \a
81 * \sa select(2), \ref time.c, struct \ref sched.
83 void (*pre_select)(struct sched *s, void *context);
85 * Evaluate the result from select().
87 * This hook gets called after the call to select(). It should check
88 * all file descriptors which were added to any of the fd sets during
89 * the previous call to pre_select. According to the result, it may
90 * then use any non-blocking I/O to establish a connection or to
91 * receive the audio data.
93 * \sa select(2), struct \ref receiver.
95 int (*post_select)(struct sched *s, void *context);
98 * Answer a buffer tree query.
100 * This optional function pointer is used for inter node communications
101 * of the buffer tree nodes. See \ref btr_command_handler for details.
103 btr_command_handler execute;
106 #define RECV_CMD(_num) (lls_cmd(_num, recv_cmd_suite))
108 #define RECV_CMD_OPT_RESULT(_recv, _opt, _lpr) \
109 (lls_opt_result(LSG_RECV_CMD_ ## _recv ## _OPT_ ## _opt, _lpr))
110 #define RECV_CMD_OPT_GIVEN(_recv, _opt, _lpr) \
111 (lls_opt_given(RECV_CMD_OPT_RESULT(_recv, _opt, _lpr)))
112 #define RECV_CMD_OPT_STRING_VAL(_recv, _opt, _lpr) \
113 (lls_string_val(0, RECV_CMD_OPT_RESULT(_recv, _opt, _lpr)))
114 #define RECV_CMD_OPT_UINT32_VAL(_recv, _opt, _lpr) \
115 (lls_uint32_val(0, RECV_CMD_OPT_RESULT(_recv, _opt, _lpr)))
116 #define RECV_CMD_OPT_INT32_VAL(_recv, _opt, _lpr) \
117 (lls_int32_val(0, RECV_CMD_OPT_RESULT(_recv, _opt, _lpr)))
119 /** Iterate over all available receivers. */
120 #define FOR_EACH_RECEIVER(i) for (i = 1; lls_cmd(i, recv_cmd_suite); i++)
122 void recv_init(void);
123 int check_receiver_arg(const char *ra, struct lls_parse_result **lprp);
124 void print_receiver_helps(bool detailed);
125 int generic_recv_pre_select(struct sched *s, struct receiver_node *rn);