f4c54ca31de240b13056e684986483a05c980bf0
[paraslash.git] / write.h
1 /*
2 * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file write.h writer-related structures */
20
21 /** the list of supported writers */
22 enum writer_enum {WRITER_ENUM};
23
24 /**
25 * decbribes one running instance of a writer
26 */
27 struct writer_node {
28 /** points to the writer structure associated with this node */
29 struct writer *writer;
30 /** writer-specific data */
31 void *private_data;
32 /** send that many bytes in one go */
33 int chunk_bytes;
34 struct task task;
35 struct writer_node_group *wng;
36 /** the writer-specific configuration of this node */
37 void *conf;
38 };
39
40 /** describes one supported writer */
41 struct writer {
42 /**
43 * the init function of the writer
44 *
45 * It must fill in all other function pointers of the given
46 * writer structure.
47 *
48 */
49 void (*init)(struct writer *w);
50 /**
51 *
52 *
53 * the command line parser of the writer
54 *
55 * It should check whether the command line options given by \a options are
56 * valid. On success, it should return a pointer to the writer-specific
57 * configuration data determined by \a options. Note that this might be called
58 * more than once with different values of \a options.
59 *
60 */
61 void * (*parse_config)(char *options);
62 /**
63 *
64 * open one instance of this writer
65 *
66 * This function should perform any work necessary to write the incoming
67 * stream. If To this aim, it may allocate its private data structure and store
68 * a pointer to that structure via the given writer_node paramenter.
69 */
70 int (*open)(struct writer_node *);
71 /**
72 *
73 * write a chunk of audio data
74 *
75 * This is called from the driving application whenever a data block of \a
76 * chunk_bytes is available. It must return the number of bytes consumed from
77 * \a data on success, and negative on errors.
78 *
79 */
80 int (*write)(char *data, size_t nbytes, struct writer_node *);
81 void (*pre_select)(struct sched *s, struct task *t);
82 void (*post_select)(struct sched *s, struct task *t);
83 /**
84 * close one instance of the writer
85 *
86 * This function is assumed to succeed.
87 */
88 void (*close)(struct writer_node *);
89 /**
90 * shutdown the writer
91 *
92 * This is a optional function pointer used for cleaning
93 * up.
94 */
95 void (*shutdown)(struct writer_node *);
96 };
97
98 /**
99 * describes a set of writer nodes that all write the same stream.
100 */
101 struct writer_node_group {
102 /** number of nodes belonging to this group */
103 unsigned num_writers;
104 /** array of pointers to the corresponding writer nodes */
105 struct writer_node *writer_nodes;
106 /** keeps track of how many bytes have been written by each node */
107 int *written;
108 /** the maximum of the chunk_bytes values of the writer nodes in this group */
109 size_t max_chunk_bytes;
110 /** non-zero if end of file was encountered */
111 int *input_eof;
112 int eof;
113 char *buf;
114 size_t *loaded;
115 struct task task;
116 };
117
118 /** loop over each writer node in a writer group */
119 #define FOR_EACH_WRITER_NODE(i, wng) for (i = 0; i < (wng)->num_writers; i++)
120 /** loop over each supported writer */
121 #define FOR_EACH_WRITER(i) for (i = 0; i < NUM_SUPPORTED_WRITERS; i++)
122
123 /** declare the init functions of all supported writers */
124 DECLARE_WRITER_INITS;
125
126 /** array containing the name of each writer */
127 extern const char *writer_names[];
128
129 /** the writer structure for each supported writer */
130 extern struct writer writers[NUM_SUPPORTED_WRITERS];