Merge remote branch 'refs/remotes/fml/master'
[paraslash.git] / write.h
1 /*
2 * Copyright (C) 2006-2010 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. \sa \ref free_config().
43 */
44 void *(*parse_config)(const char *options);
45 /**
46 * Dellocate all configuration resources.
47 *
48 * This should free whatever was allocated by \ref parse_config().
49 */
50 void (*free_config)(void *config);
51 /**
52 * Open one instance of this writer.
53 *
54 * This function should perform any work necessary to write the incoming
55 * stream. To this aim, it may allocate its private data structure and store
56 * a pointer to that structure via the given writer_node parameter.
57 */
58 int (*open)(struct writer_node *);
59 /**
60 * Prepare the fd sets for select.
61 *
62 * This is called from scheduler. It may use the sched pointer to add
63 * any file descriptors or to decrease the select timeout.
64 */
65 void (*pre_select)(struct sched *s, struct task *t);
66 /**
67 * Write audio data.
68 *
69 * Called from the post_select function of the writer node's task.
70 */
71 void (*post_select)(struct sched *s, struct task *t);
72 /**
73 * Close one instance of the writer.
74 *
75 * This function is assumed to succeed.
76 */
77 void (*close)(struct writer_node *);
78 /**
79 * Shutdown the writer
80 *
81 * This is a optional function pointer used for cleaning up.
82 */
83 void (*shutdown)(struct writer_node *);
84 struct ggo_help help;
85 btr_command_handler execute;
86 };
87
88 /** Loop over each supported writer. */
89 #define FOR_EACH_WRITER(i) for (i = 0; i < NUM_SUPPORTED_WRITERS; i++)
90
91 /** Declare the init functions of all supported writers. */
92 DECLARE_WRITER_INITS;
93
94 /** Array containing the name of each writer. */
95 extern const char *writer_names[];
96
97 /** The writer structure for each supported writer. */
98 extern struct writer writers[NUM_SUPPORTED_WRITERS];