1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
/** \file send.h sender-related defines and structures */
/** the sender subcommands */
enum {SENDER_ADD, SENDER_DELETE, SENDER_ALLOW, SENDER_DENY, SENDER_ON, SENDER_OFF};
/** the number of sender subcommands */
#define NUM_SENDER_CMDS (SENDER_OFF + 1)
/**
* describes one supported sender of para_server
*
* \sa http_send.c ortp_send.c
*/
struct sender {
/** the name of the sender */
const char *name;
/**
* the init function of this sender
*
* It must fill in all function pointers of \a s as well as the \a client_cmds
* array, see below. It should also do all neccessary preparations to init
* this sending facility, for example it could open a tcp port.
*/
void (*init)(struct sender *s);
/** \p SENDER_ON or \p SENDER_OFF */
int status;
/**
* return the help text of this sender
*
* The result must be dynamically allocated and is freed by the caller.
*/
char* (*help)(void);
/**
* return current status info about this sender
*
* The result must be dynamically allocated and is freed by the caller.
*/
char* (*info)(void);
/**
* the send-hook
*
* It gets called whenever para_server is playing and the current
* audio format handler indicates that another chunk of data should
* be sent now. The two parameters \a current_chunk and \a chunks_sent
* only differ if the stream was repositioned by the \a ff or \a jmp
* command. Of course, \a buf is a pointer to the chunk of data which
* should be sent, and \a len is the length of this buffer.
*/
void (*send)(long unsigned current_chunk, long unsigned chunks_sent,
const char *buf, size_t len);
/** add file descriptors to fd_sets
*
* The pre_select function of each supported sender is called just before
* para_server enters its main select loop. Each sender may add its own
* file descriptors to the \a rfds or the \a wfds set.
*
* If a file descriptor was added, \a max_fileno must be increased by
* this function, if neccessary.
*
* \sa select(2)
*/
void (*pre_select)(int *max_fileno, fd_set *rfds, fd_set *wfds);
/**
* handle the file descriptors which are ready for I/O
*
* If the pre_select hook added one ore more file descriptors to the read or write
* set, this is the hook to check the result and do any I/O on those descriptors
* which are ready for reading/writing.
*/
void (*post_select)(fd_set *rfds, fd_set *wfds);
/**
* terminate all connected clients
*
* This is called e.g. if the stop command was executed. It should make the clients
* aware of the end-of-file condition.
*/
void (*shutdown_clients)(void);
/**
* array of function pointers for the sender subcommands
*
* Each sender may implement any subset of the sender commands by filling in
* the aprropriate function pointer in the array. A \p NULL pointer means this
* command is not implemented by this sender.
*/
int (*client_cmds[NUM_SENDER_CMDS])(struct sender_command_data*);
};
/**
* check a file descriptor for writability
*
* \param fd the file desctiptor
*
* \return positive if fd is ready for writing, zero if it isn't, negative if
* an error occured.
*/
static inline int write_ok(int fd)
{
struct timeval tv = {0, 0};
fd_set wfds;
int ret;
again:
FD_ZERO(&wfds);
FD_SET(fd, &wfds);
tv.tv_sec = 0;
tv.tv_usec = 0;
ret = select(fd + 1, NULL, &wfds, NULL, &tv);
if (ret < 0 && errno == EINTR)
goto again;
return ret;
}
|
