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