Merge branch 'master' into next
[paraslash.git] / write.h
1 /*
2 * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file write.h Writer-related structures. */
8
9 /** The list of supported writers. */
10 enum writer_enum {WRITER_ENUM};
11
12 /**
13 * Describes one running instance of a writer.
14 */
15 struct writer_node {
16 /** The number of this writer. */
17 int writer_num;
18 /** Writer-specific data. */
19 void *private_data;
20 /** The writer-specific configuration of this node. */
21 void *conf;
22 struct btr_node *btrn;
23 struct task task;
24 size_t min_iqs;
25 };
26
27 /** Describes one supported writer. */
28 struct writer {
29 /**
30 * The init function of the writer.
31 *
32 * It must fill in all other function pointers of the given
33 * writer structure.
34 */
35 void (*init)(struct writer *w);
36 /**
37 * The command line parser of the writer.
38 *
39 * It should check whether the command line options given by \a options are
40 * valid. On success, it should return a pointer to the writer-specific
41 * configuration data determined by \a options. Note that this might be called
42 * more than once with different values of \a options.
43 */
44 void *(*parse_config)(const char *options);
45 void (*free_config)(void *conf);
46 /**
47 * Open one instance of this writer.
48 *
49 * This function should perform any work necessary to write the incoming
50 * stream. To this aim, it may allocate its private data structure and store
51 * a pointer to that structure via the given writer_node parameter.
52 */
53 int (*open)(struct writer_node *);
54 /**
55 * Prepare the fd sets for select.
56 *
57 * This is called from scheduler. It may use the sched pointer to add
58 * any file descriptors or to decrease the select timeout.
59 */
60 void (*pre_select)(struct sched *s, struct task *t);
61 /**
62 * Write audio data.
63 *
64 * Called from the post_select function of the writer node's task.
65 */
66 void (*post_select)(struct sched *s, struct task *t);
67 /**
68 * Close one instance of the writer.
69 *
70 * This function is assumed to succeed.
71 */
72 void (*close)(struct writer_node *);
73 /**
74 * Shutdown the writer
75 *
76 * This is a optional function pointer used for cleaning up.
77 */
78 void (*shutdown)(struct writer_node *);
79 struct ggo_help help;
80 btr_command_handler execute;
81 };
82
83 /** Loop over each supported writer. */
84 #define FOR_EACH_WRITER(i) for (i = 0; i < NUM_SUPPORTED_WRITERS; i++)
85
86 /** Declare the init functions of all supported writers. */
87 DECLARE_WRITER_INITS;
88
89 /** Array containing the name of each writer. */
90 extern const char *writer_names[];
91
92 /** The writer structure for each supported writer. */
93 extern struct writer writers[NUM_SUPPORTED_WRITERS];