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(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                 struct writer *w = writers + wn->writer_num;
  31                 if (!w->pre_select)
  32                         continue;
  33                 t->error = w->pre_select(s, wn);
  34                 if (t->error < 0)
  35                         return;
  36         }
  37         /*
  38          * Force a minimal delay if something was written during the previous
  39          * call to wng_post_select(). This is necessary because the filter
  40          * chain might still have data for us which it couldn't convert during
  41          * the previous run due to its buffer size constraints. In this case we
  42          * do not want to wait until the next input data arrives as this could
  43          * lead to buffer underruns.
  44          */
  45         if (g->last_written == 0)
  46                 return;
  47         s->timeout.tv_sec = 0;
  48         s->timeout.tv_usec = 1;
  49 }
  50
  51 static void wng_post_select(struct sched *s, struct task *t)
  52 {
  53         struct writer_node_group *g = container_of(t, struct writer_node_group, task);
  54         int i;
  55         size_t min_written = 0, max_written = 0;
  56
  57         FOR_EACH_WRITER_NODE(i, g) {
  58                 struct writer_node *wn = &g->writer_nodes[i];
  59                 struct writer *w = writers + wn->writer_num;
  60                 t->error = w->post_select(s, wn);
  61                 if (t->error < 0)
  62                         return;
  63                 if (!i)
  64                         min_written = wn->written;
  65                 else
  66                         min_written = PARA_MIN(min_written, wn->written);
  67                 max_written = PARA_MAX(max_written, wn->written);
  68         }
  69         g->last_written = max_written;
  70         //PARA_INFO_LOG("loaded: %zd, min_written: %zd bytes\n", *g->loaded, min_written);
  71         if (min_written) {
  72                 *g->loaded -= min_written;
  73                 FOR_EACH_WRITER_NODE(i, g)
  74                         g->writer_nodes[i].written -= min_written;
  75         }
  76         if (!*g->loaded && *g->input_error) {
  77                 t->error = *g->input_error;
  78                 return;
  79         }
  80         if (*g->loaded && min_written) {
  81 //              PARA_INFO_LOG("moving %zd bytes\n", *g->loaded);
  82                 memmove(*g->bufp, *g->bufp + min_written, *g->loaded);
  83         }
  84 }
  85
  86 /**
  87  * call the open function of each writer in the group
  88  *
  89  * \param g the writer node group
  90  *
  91  * \return If at least one open function returned an error, all successful
  92  * writer notes get closed and this error value is returned. Upon success, a
  93  * task associated with \a g is registered to the scheduler and the function
  94  * returns a positive value.
  95  * */
  96 int wng_open(struct writer_node_group *g)
  97 {
  98         int i, ret = 1;
  99
 100         PARA_NOTICE_LOG("opening wng %p with %d writer(s)\n", g, g->num_writers);
 101         FOR_EACH_WRITER_NODE(i, g) {
 102                 struct writer_node *wn = &g->writer_nodes[i];
 103                 struct writer *w = writers + wn->writer_num;
 104                 wn->wng = g;
 105                 ret = w->open(wn);
 106                 if (ret < 0)
 107                         goto err_out;
 108         }
 109         sprintf(g->task.status, "%s", "writer node group");
 110         register_task(&g->task);
 111         g->open = 1;
 112         return 1;
 113 err_out:
 114         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 115         while (i > 0) {
 116                 struct writer_node *wn = &g->writer_nodes[--i];
 117                 struct writer *w = writers + wn->writer_num;
 118                 w->close(wn);
 119         }
 120         free(g->writer_nodes);
 121         g->num_writers = 0;
 122         g->task.error = -E_TASK_UNREGISTERED;
 123         return ret;
 124 }
 125
 126 /**
 127  * call the close function of each writer in the given group
 128  *
 129  * \param g the writer node group to close
 130  *
 131  * This function also frees all resources of the given group.
 132  */
 133 void wng_close(struct writer_node_group *g)
 134 {
 135         int i;
 136
 137         if (!g || !g->open)
 138                 return;
 139         PARA_NOTICE_LOG("closing wng with %d writer(s)\n", g->num_writers);
 140         FOR_EACH_WRITER_NODE(i, g) {
 141                 struct writer_node *wn = &g->writer_nodes[i];
 142                 struct writer *w = writers + wn->writer_num;
 143                 w->close(wn);
 144         }
 145         free(g->writer_nodes);
 146         free(g);
 147 }
 148
 149 /**
 150  * allocate and initialize a new writer_node_group struct
 151  *
 152  * \param num_writers the number of writer nodes for the new group
 153  *
 154  * \return Pointer to the new writer node group
 155  */
 156 struct writer_node_group *wng_new(unsigned num_writers)
 157 {
 158         struct writer_node_group *g = para_calloc(sizeof(struct writer_node_group));
 159         g->num_writers = num_writers;
 160         g->writer_nodes = para_calloc(num_writers
 161                 * sizeof(struct writer_node));
 162         g->task.post_select = wng_post_select;
 163         g->task.pre_select = wng_pre_select;
 164         return g;
 165 }
 166
 167 /**
 168  * Call the init function of each supported paraslash writer.
 169  */
 170 void writer_init(void)
 171 {
 172         int i;
 173
 174         FOR_EACH_WRITER(i)
 175                 writers[i].init(&writers[i]);
 176 }
 177 /**
 178  * check if given string is a valid command line for any writer
 179  *
 180  * \param \wa string of the form writer_name:options
 181  * \param writer_num contains the number of the writer upon success
 182  *
 183  * This function checks whether \a wa starts with the name of a supported
 184  * paraslash writer, optionally followed by a colon and any options for that
 185  * writer.  If a valid writer name was found and further are present, the
 186  * remaining part of \a wa is passed to that writer's config parser.
 187  *
 188  * \return On success, a pointer to the gengetopt args info struct is returned
 189  * and \a writer_num contains the number of the writer. Otherwise this function
 190  * returns \p NULL.
 191  */
 192 void *check_writer_arg(const char *wa, int *writer_num)
 193 {
 194         int i;
 195
 196         *writer_num = -E_WRITE_COMMON_SYNTAX;
 197         PARA_INFO_LOG("checking  %s\n", wa);
 198         FOR_EACH_WRITER(i) {
 199                 const char *name = writer_names[i];
 200                 size_t len = strlen(name);
 201                 char c;
 202                 if (strlen(wa) < len)
 203                         continue;
 204                 if (strncmp(name, wa, len))
 205                         continue;
 206                 c = wa[len];
 207                 if (c && c != ' ')
 208                         continue;
 209                 if (c && !writers[i].parse_config)
 210                         return NULL;
 211                 *writer_num = i;
 212                 return writers[i].parse_config(c? wa + len + 1 : "");
 213         }
 214         PARA_ERROR_LOG("writer not found\n");
 215         return NULL;
 216 }
 217
 218 /**
 219  * setup a writer node group with only one writer, the default writer
 220  *
 221  * The writer which is set up depends on the OS. It defaults to alsa for Linux,
 222  * osx_write for OS X, file writer if neither of these is supported.
 223  *
 224  * \return pointer to the allocated writer node group
 225  */
 226 struct writer_node_group *setup_default_wng(void)
 227 {
 228         struct writer_node_group *wng = wng_new(1);
 229         wng->writer_nodes[0].writer_num = DEFAULT_WRITER;
 230         PARA_INFO_LOG("using default writer: %s %p\n",
 231                 writer_names[DEFAULT_WRITER], writers[DEFAULT_WRITER].parse_config);
 232         wng->writer_nodes[0].conf = writers[DEFAULT_WRITER].parse_config("");
 233         return wng;
 234 }
 235 /**
 236  * Print the help text of all writers to stdout.
 237  *
 238  * \param detailed Whether to print the detailed help text.
 239  */
 240 void print_writer_helps(int detailed)
 241 {
 242         int i;
 243
 244         printf_or_die("\nAvailable writers: \n\t");
 245         FOR_EACH_WRITER(i)
 246                 printf_or_die("%s%s", i? " " : "", writer_names[i]);
 247         printf_or_die("\n\n");
 248         FOR_EACH_WRITER(i) {
 249                 struct writer *w = writers + i;
 250
 251                 if (!w->help.short_help)
 252                         continue;
 253                 printf_or_die("Options for %s:\n", writer_names[i]);
 254                 ggo_print_help(&w->help, detailed);
 255         }
 256 }