replace standard GPL header by a one-line pointer to COPYING
[paraslash.git] / write_common.c
1 /*
2 * Copyright (C) 2006-2007 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 "para.h"
10 #include "string.h"
11 #include "list.h"
12 #include "sched.h"
13 #include "write.h"
14 #include "error.h"
15
16 /** the array containing the names of all supported writers */
17 const char *writer_names[] ={WRITER_NAMES};
18
19 /** the array of supported writers */
20 struct writer writers[NUM_SUPPORTED_WRITERS] = {WRITER_ARRAY};
21
22 static void wng_pre_select(__a_unused struct sched *s, struct task *t)
23 {
24 struct writer_node_group *g = t->private_data;
25 int i;
26
27 FOR_EACH_WRITER_NODE(i, g) {
28 struct writer_node *wn = &g->writer_nodes[i];
29 t->ret = wn->writer->pre_select(s, wn);
30 if (t->ret < 0) {
31 g->eof = 1;
32 return;
33 }
34 }
35 }
36
37 static void wng_post_select(struct sched *s, struct task *t)
38 {
39 struct writer_node_group *g = t->private_data;
40 int i;
41 size_t min_written = 0;
42
43 FOR_EACH_WRITER_NODE(i, g) {
44 struct writer_node *wn = &g->writer_nodes[i];
45 t->ret = wn->writer->post_select(s, wn);
46 if (t->ret < 0) {
47 g->eof = 1;
48 return;
49 }
50 if (!i)
51 min_written = wn->written;
52 else
53 min_written = PARA_MIN(min_written, wn->written);
54 }
55 // PARA_INFO_LOG("loaded: %zd, min_written: %zd bytes\n", *g->loaded, min_written);
56 if (min_written) {
57 *g->loaded -= min_written;
58 FOR_EACH_WRITER_NODE(i, g)
59 g->writer_nodes[i].written -= min_written;
60 }
61 if (!*g->loaded && *g->input_eof) {
62 g->eof = 1;
63 t->ret = -E_WNG_EOF;
64 return;
65 }
66 t->ret = 1;
67 if (*g->loaded && min_written) {
68 // PARA_INFO_LOG("moving %zd bytes\n", *g->loaded);
69 memmove(g->buf, g->buf + min_written, *g->loaded);
70 }
71 }
72
73 /**
74 * call the open function of each writer in the group
75 *
76 * \param g the writer node group
77 *
78 * \return If at least one open function returned an error, all successful
79 * writer notes get closed and this error value is returned. Upon success, a
80 * task associated with \a g is registered to the scheduler and the function
81 * returnes a positive value.
82 * */
83 int wng_open(struct writer_node_group *g)
84 {
85 int i, ret = 1;
86
87 PARA_NOTICE_LOG("opening wng %p with %d writer(s)\n", g, g->num_writers);
88 register_task(&g->task);
89 FOR_EACH_WRITER_NODE(i, g) {
90 struct writer_node *wn = &g->writer_nodes[i];
91 wn->wng = g;
92 ret = wn->writer->open(wn);
93 if (ret < 0)
94 goto err_out;
95 wn->chunk_bytes = ret;
96 g->max_chunk_bytes = PARA_MAX(g->max_chunk_bytes, ret);
97 }
98 sprintf(g->task.status, "%s", "writer node group");
99 g->eof = 0;
100 return 1;
101 err_out:
102 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
103 unregister_task(&g->task);
104 while (i > 0) {
105 struct writer_node *wn = &g->writer_nodes[--i];
106 wn->writer->close(wn);
107 }
108 g->num_writers = 0;
109 g->eof = 1;
110 return ret;
111 }
112
113
114 /**
115 * unregister a writer node group task
116 *
117 * \param g the group whose task is to be closed
118 */
119 void wng_unregister(struct writer_node_group *g)
120 {
121 unregister_task(&g->task);
122 g->eof = 1;
123 }
124
125 /**
126 * call the close function of each writer in the given group
127 *
128 * \param g the writer node group to close
129 *
130 * This function also frees all resources of the given group.
131 */
132 void wng_close(struct writer_node_group *g)
133 {
134 int i;
135
136 if (!g)
137 return;
138 PARA_NOTICE_LOG("closing wng with %d writer(s)\n", g->num_writers);
139 FOR_EACH_WRITER_NODE(i, g) {
140 struct writer_node *wn = &g->writer_nodes[i];
141 wn->writer->close(wn);
142 }
143 free(g->writer_nodes);
144 free(g);
145 }
146
147 /**
148 * allocate and initialize a new writer_node_group struct
149 *
150 * \param num_writers the number of writer nodes for the new group
151 *
152 * \return Pointer to the new writer node group
153 */
154 struct writer_node_group *wng_new(unsigned num_writers)
155 {
156 struct writer_node_group *g = para_calloc(sizeof(struct writer_node_group));
157 g->num_writers = num_writers;
158 g->writer_nodes = para_calloc(num_writers
159 * sizeof(struct writer_node));
160 g->task.private_data = g;
161 g->task.post_select = wng_post_select;
162 g->task.pre_select = wng_pre_select;
163 return g;
164 }
165
166 /**
167 * call the init function of each supported paraslash writer
168 */
169 void init_supported_writers(void)
170 {
171 int i;
172
173 FOR_EACH_WRITER(i)
174 writers[i].init(&writers[i]);
175 }
176 /**
177 * check if given string is a valid command line for any writer
178 *
179 * \param \wa string of the form writer_name:options
180 * \param writer_num contains the number of the writer upon success
181 *
182 * This function checks whether \a wa starts with the name of a supported
183 * paraslash writer, optinally followed by a colon and any options for that
184 * writer. If a valid writer name was found and further are present, the
185 * remaining part of \a wa is passed to that writer's config parser.
186 *
187 * \return On success, a pointer to the gengetopt args info struct is returned
188 * and \a writer_num contains the number of the writer. Otherwise this function
189 * returns \p NULL.
190 */
191 void *check_writer_arg(const char *wa, int *writer_num)
192 {
193 int i;
194
195 *writer_num = -E_WRITE_COMMON_SYNTAX;
196 PARA_INFO_LOG("checking %s\n", wa);
197 FOR_EACH_WRITER(i) {
198 const char *name = writer_names[i];
199 size_t len = strlen(name);
200 char c;
201 if (strlen(wa) < len)
202 continue;
203 if (strncmp(name, wa, len))
204 continue;
205 c = wa[len];
206 if (c && c != ' ')
207 continue;
208 if (c && !writers[i].parse_config)
209 return NULL;
210 *writer_num = i;
211 return writers[i].parse_config(c? wa + len + 1 : "");
212 }
213 PARA_ERROR_LOG("%s", "writer not found\n");
214 return NULL;
215 }
216
217 /**
218 * setup a writer node group with only one writer, the default writer
219 *
220 * The writer which is set up depends on the OS. It defaults to alsa for Linux,
221 * osx_write for OS X, file writer if neither of these is supported.
222 *
223 * \return pointer to the allocated writer node group
224 */
225 struct writer_node_group *setup_default_wng(void)
226 {
227 struct writer_node_group *wng = wng_new(1);
228 wng->writer_nodes[0].writer = &writers[DEFAULT_WRITER];
229 PARA_INFO_LOG("using default writer: %s %p\n",
230 writer_names[DEFAULT_WRITER], writers[DEFAULT_WRITER].parse_config);
231 wng->writer_nodes[0].conf = writers[DEFAULT_WRITER].parse_config("");
232 return wng;
233 }