crypt_common.c: Add missing doxygen documentation.
[paraslash.git] / write_common.c
1 /*
2 * Copyright (C) 2006-2011 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file write_common.c common functions of para_audiod and para_write */
8
9 #include <regex.h>
10 #include <stdbool.h>
11
12 #include "para.h"
13 #include "string.h"
14 #include "list.h"
15 #include "sched.h"
16 #include "ggo.h"
17 #include "buffer_tree.h"
18 #include "write.h"
19 #include "error.h"
20
21 /** the array containing the names of all supported writers */
22 const char *writer_names[] ={WRITER_NAMES};
23
24 /** the array of supported writers */
25 struct writer writers[NUM_SUPPORTED_WRITERS] = {WRITER_ARRAY};
26
27 /**
28 * Call the init function of each supported paraslash writer.
29 */
30 void writer_init(void)
31 {
32 int i;
33
34 FOR_EACH_WRITER(i)
35 writers[i].init(&writers[i]);
36 }
37 /**
38 * Check if given string is a valid command line for any writer.
39 *
40 * \param \wa String of the form writer_name:options.
41 * \param writer_num Contains the number of the writer upon success.
42 *
43 * This function checks whether \a wa starts with the name of a supported
44 * paraslash writer, optionally followed by a colon and any options for that
45 * writer. If a valid writer name was found and further are present, the
46 * remaining part of \a wa is passed to that writer's config parser.
47 *
48 * \return On success, a pointer to the gengetopt args info struct is returned
49 * and \a writer_num contains the number of the writer. Otherwise this function
50 * returns \p NULL.
51 */
52 void *check_writer_arg(const char *wa, int *writer_num)
53 {
54 int i;
55
56 *writer_num = -E_WRITE_COMMON_SYNTAX;
57 PARA_INFO_LOG("checking %s\n", wa);
58 FOR_EACH_WRITER(i) {
59 const char *name = writer_names[i];
60 size_t len = strlen(name);
61 char c;
62 if (strlen(wa) < len)
63 continue;
64 if (strncmp(name, wa, len))
65 continue;
66 c = wa[len];
67 if (c && c != ' ')
68 continue;
69 *writer_num = i;
70 return writers[i].parse_config_or_die(c? wa + len + 1 : "");
71 }
72 PARA_ERROR_LOG("writer not found\n");
73 return NULL;
74 }
75
76 /**
77 * Open a writer node and register the corresponding task.
78 *
79 * \param wn The writer node to open.
80 * \param parent The parent btr node (the source for the writer node).
81 *
82 * The configuration of the writer node stored in \p wn->conf must be
83 * initialized before this function may be called.
84 */
85 void register_writer_node(struct writer_node *wn, struct btr_node *parent)
86 {
87 struct writer *w = writers + wn->writer_num;
88 char *name = make_message("%s writer", writer_names[wn->writer_num]);
89
90 wn->btrn = btr_new_node(&(struct btr_node_description)
91 EMBRACE(.name = name, .parent = parent,
92 .handler = w->execute, .context = wn));
93 strcpy(wn->task.status, name);
94 free(name);
95 wn->task.post_select = w->post_select;
96 wn->task.pre_select = w->pre_select;
97 register_task(&wn->task);
98 }
99
100 /**
101 * Parse config and register a task for a writer node.
102 *
103 * \param arg Command line arguments.
104 * \param parent The new node will be a child of \a parent.
105 * \param wn The writer node.
106 *
107 * If arg is \p NULL, the OS-dependent default writer is used with no
108 * arguments. The default writers are alsa for Linux, osx for OS X, oss for
109 * *BSD, and the file writer if the default writer is not supported.
110 *
111 * Once the writer configuration has been retrieved from the ->parse_config
112 * callback a writer node is created, its buffer tree node is added to the
113 * buffer tree as a child of the given parent.
114 *
115 * Finally, the new writer node's task structure is initialized and registered
116 * to the paraslash scheduler.
117 *
118 * \return Standard.
119 */
120 int setup_writer_node(const char *arg, struct btr_node *parent,
121 struct writer_node *wn)
122 {
123 if (arg)
124 wn->conf = check_writer_arg(arg, &wn->writer_num);
125 else {
126 wn->writer_num = DEFAULT_WRITER;
127 wn->conf = writers[DEFAULT_WRITER].parse_config_or_die("");
128 }
129 if (!wn->conf)
130 return -E_WRITE_COMMON_SYNTAX;
131 register_writer_node(wn, parent);
132 return 1;
133 }
134
135 /**
136 * Print the help text of all writers to stdout.
137 *
138 * \param detailed Whether to print the detailed help text.
139 */
140 void print_writer_helps(int detailed)
141 {
142 int i;
143
144 printf_or_die("\nAvailable writers: \n\t");
145 FOR_EACH_WRITER(i)
146 printf_or_die("%s%s", i? " " : "", writer_names[i]);
147 printf_or_die("\n\n");
148 FOR_EACH_WRITER(i) {
149 struct writer *w = writers + i;
150
151 if (!w->help.short_help)
152 continue;
153 printf_or_die("Options for %s:\n", writer_names[i]);
154 ggo_print_help(&w->help, detailed);
155 }
156 }
157
158 static void get_btr_value(struct btr_node *btrn, const char *cmd,
159 int32_t *result)
160 {
161 char *buf = NULL;
162 int ret = btr_exec_up(btrn, cmd, &buf);
163
164 if (ret < 0) {
165 /*
166 * This really should not happen. It means one of our parent
167 * nodes died unexpectedly. Proceed with fingers crossed.
168 */
169 PARA_CRIT_LOG("cmd %s: %s\n", cmd, para_strerror(-ret));
170 *result = 0;
171 return;
172 }
173 ret = para_atoi32(buf, result);
174 assert(ret >= 0);
175 free(buf);
176 }
177
178 /**
179 * Ask parent btr nodes for the sample rate of the current stream.
180 *
181 * \param btrn Where to start the search.
182 * \param result Filled in by this function.
183 *
184 * This function is assumed to succeed and terminates on errors.
185 */
186 void get_btr_sample_rate(struct btr_node *btrn, int32_t *result)
187 {
188 get_btr_value(btrn, "sample_rate", result);
189 }
190
191 /**
192 * Ask parent btr nodes for the channel count of the current stream.
193 *
194 * \param btrn See \ref get_btr_sample_rate.
195 * \param result See \ref get_btr_sample_rate.
196 */
197 void get_btr_channels(struct btr_node *btrn, int32_t *result)
198 {
199 get_btr_value(btrn, "channels", result);
200 }
201
202 /**
203 * Ask parent btr nodes for the number of bits per sample and the byte sex.
204 *
205 * \param btrn See \ref get_btr_sample_rate.
206 * \param result Contains the sample format as an enum sample_format type.
207 */
208 void get_btr_sample_format(struct btr_node *btrn, int32_t *result)
209 {
210 get_btr_value(btrn, "sample_format", result);
211 }