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 <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 static void wng_pre_select(struct sched *s, struct task *t)
  28 {
  29         struct writer_node_group *g = container_of(t, struct writer_node_group, task);
  30         int i;
  31
  32         FOR_EACH_WRITER_NODE(i, g) {
  33                 struct writer_node *wn = &g->writer_nodes[i];
  34                 struct writer *w = writers + wn->writer_num;
  35                 if (!w->pre_select)
  36                         continue;
  37                 t->error = w->pre_select(s, wn);
  38                 if (t->error < 0)
  39                         return;
  40         }
  41         /*
  42          * Force a minimal delay if something was written during the previous
  43          * call to wng_post_select(). This is necessary because the filter
  44          * chain might still have data for us which it couldn't convert during
  45          * the previous run due to its buffer size constraints. In this case we
  46          * do not want to wait until the next input data arrives as this could
  47          * lead to buffer underruns.
  48          */
  49         if (g->last_written == 0)
  50                 return;
  51         s->timeout.tv_sec = 0;
  52         s->timeout.tv_usec = 1;
  53 }
  54
  55 static void wng_post_select(struct sched *s, struct task *t)
  56 {
  57         struct writer_node_group *g = container_of(t, struct writer_node_group, task);
  58         int i;
  59         size_t min_written = 0, max_written = 0;
  60
  61         FOR_EACH_WRITER_NODE(i, g) {
  62                 struct writer_node *wn = &g->writer_nodes[i];
  63                 struct writer *w = writers + wn->writer_num;
  64                 t->error = w->post_select(s, wn);
  65                 if (t->error < 0)
  66                         return;
  67                 if (!i)
  68                         min_written = wn->written;
  69                 else
  70                         min_written = PARA_MIN(min_written, wn->written);
  71                 max_written = PARA_MAX(max_written, wn->written);
  72         }
  73         g->last_written = max_written;
  74         //PARA_INFO_LOG("loaded: %zd, min_written: %zd bytes\n", *g->loaded, min_written);
  75         if (min_written) {
  76                 *g->loaded -= min_written;
  77                 FOR_EACH_WRITER_NODE(i, g)
  78                         g->writer_nodes[i].written -= min_written;
  79         }
  80         if (!*g->loaded && *g->input_error) {
  81                 t->error = *g->input_error;
  82                 return;
  83         }
  84         if (*g->loaded && min_written) {
  85 //              PARA_INFO_LOG("moving %zd bytes\n", *g->loaded);
  86                 memmove(*g->bufp, *g->bufp + min_written, *g->loaded);
  87         }
  88 }
  89
  90 /**
  91  * call the open function of each writer in the group
  92  *
  93  * \param g the writer node group
  94  *
  95  * \return If at least one open function returned an error, all successful
  96  * writer notes get closed and this error value is returned. Upon success, a
  97  * task associated with \a g is registered to the scheduler and the function
  98  * returns a positive value.
  99  * */
 100 int wng_open(struct writer_node_group *g)
 101 {
 102         int i, ret = 1;
 103
 104         PARA_NOTICE_LOG("opening wng %p with %d writer(s)\n", g, g->num_writers);
 105         FOR_EACH_WRITER_NODE(i, g) {
 106                 struct writer_node *wn = &g->writer_nodes[i];
 107                 struct writer *w = writers + wn->writer_num;
 108                 wn->wng = g;
 109                 ret = w->open(wn);
 110                 if (ret < 0)
 111                         goto err_out;
 112         }
 113         sprintf(g->task.status, "%s", "writer node group");
 114         register_task(&g->task);
 115         g->open = 1;
 116         return 1;
 117 err_out:
 118         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 119         while (i > 0) {
 120                 struct writer_node *wn = &g->writer_nodes[--i];
 121                 struct writer *w = writers + wn->writer_num;
 122                 w->close(wn);
 123         }
 124         free(g->writer_nodes);
 125         g->num_writers = 0;
 126         g->task.error = -E_TASK_UNREGISTERED;
 127         return ret;
 128 }
 129
 130 /**
 131  * call the close function of each writer in the given group
 132  *
 133  * \param g the writer node group to close
 134  *
 135  * This function also frees all resources of the given group.
 136  */
 137 void wng_close(struct writer_node_group *g)
 138 {
 139         int i;
 140
 141         if (!g || !g->open)
 142                 return;
 143         PARA_NOTICE_LOG("closing wng with %d writer(s)\n", g->num_writers);
 144         FOR_EACH_WRITER_NODE(i, g) {
 145                 struct writer_node *wn = &g->writer_nodes[i];
 146                 struct writer *w = writers + wn->writer_num;
 147                 w->close(wn);
 148         }
 149         free(g->writer_nodes);
 150         free(g);
 151 }
 152
 153 /**
 154  * allocate and initialize a new writer_node_group struct
 155  *
 156  * \param num_writers the number of writer nodes for the new group
 157  *
 158  * \return Pointer to the new writer node group
 159  */
 160 struct writer_node_group *wng_new(unsigned num_writers)
 161 {
 162         struct writer_node_group *g = para_calloc(sizeof(struct writer_node_group));
 163         g->num_writers = num_writers;
 164         g->writer_nodes = para_calloc(num_writers
 165                 * sizeof(struct writer_node));
 166         g->task.post_select = wng_post_select;
 167         g->task.pre_select = wng_pre_select;
 168         return g;
 169 }
 170
 171 /**
 172  * Call the init function of each supported paraslash writer.
 173  */
 174 void writer_init(void)
 175 {
 176         int i;
 177
 178         FOR_EACH_WRITER(i)
 179                 writers[i].init(&writers[i]);
 180 }
 181 /**
 182  * check if given string is a valid command line for any writer
 183  *
 184  * \param \wa string of the form writer_name:options
 185  * \param writer_num contains the number of the writer upon success
 186  *
 187  * This function checks whether \a wa starts with the name of a supported
 188  * paraslash writer, optionally followed by a colon and any options for that
 189  * writer.  If a valid writer name was found and further are present, the
 190  * remaining part of \a wa is passed to that writer's config parser.
 191  *
 192  * \return On success, a pointer to the gengetopt args info struct is returned
 193  * and \a writer_num contains the number of the writer. Otherwise this function
 194  * returns \p NULL.
 195  */
 196 void *check_writer_arg(const char *wa, int *writer_num)
 197 {
 198         int i;
 199
 200         *writer_num = -E_WRITE_COMMON_SYNTAX;
 201         PARA_INFO_LOG("checking  %s\n", wa);
 202         FOR_EACH_WRITER(i) {
 203                 const char *name = writer_names[i];
 204                 size_t len = strlen(name);
 205                 char c;
 206                 if (strlen(wa) < len)
 207                         continue;
 208                 if (strncmp(name, wa, len))
 209                         continue;
 210                 c = wa[len];
 211                 if (c && c != ' ')
 212                         continue;
 213                 if (c && !writers[i].parse_config)
 214                         return NULL;
 215                 *writer_num = i;
 216                 return writers[i].parse_config(c? wa + len + 1 : "");
 217         }
 218         PARA_ERROR_LOG("writer not found\n");
 219         return NULL;
 220 }
 221
 222 /**
 223  * setup a writer node group with only one writer, the default writer
 224  *
 225  * The writer which is set up depends on the OS. It defaults to alsa for Linux,
 226  * osx_write for OS X, file writer if neither of these is supported.
 227  *
 228  * \return pointer to the allocated writer node group
 229  */
 230 struct writer_node_group *setup_default_wng(void)
 231 {
 232         struct writer_node_group *wng = wng_new(1);
 233         wng->writer_nodes[0].writer_num = DEFAULT_WRITER;
 234         PARA_INFO_LOG("using default writer: %s %p\n",
 235                 writer_names[DEFAULT_WRITER], writers[DEFAULT_WRITER].parse_config);
 236         wng->writer_nodes[0].conf = writers[DEFAULT_WRITER].parse_config("");
 237         return wng;
 238 }
 239
 240 /**
 241  * Setup a writer node with the default writer.
 242  *
 243  * If arg is \p NULL, the OS-dependent default writer is used with an empty
 244  * configuration string.  It defaults to alsa for Linux, osx for OS X, oss for
 245  * *BSD and the file writer if neither of these is supported.
 246  *
 247  * Once the writer configuration has been retrieved, a writer node is created,
 248  * its buffer tree node is added to the buffer tree as a child of the given
 249  * parent.
 250  *
 251  * Finally, the new writer node's taks structure is initialized and registered
 252  * to the paraslash scheduler.
 253  *
 254  * \return A pointer to the allocated writer node group.
 255  */
 256 struct writer_node *setup_writer_node(const char *arg, struct btr_node *parent)
 257 {
 258         struct writer_node *wn = para_calloc(sizeof(*wn));
 259         struct writer *w;
 260         char *name;
 261
 262         if (arg)
 263                 wn->conf = check_writer_arg(arg, &wn->writer_num);
 264         else {
 265                 wn->writer_num = DEFAULT_WRITER;
 266                 wn->conf = writers[DEFAULT_WRITER].parse_config("");
 267         }
 268         if (!wn->conf) {
 269                 free(wn);
 270                 return NULL;
 271         }
 272         w = writers + wn->writer_num;
 273         name = make_message("%s writer", writer_names[wn->writer_num]);
 274         wn->btrn = btr_new_node(name, parent, w->execute, wn);
 275         strcpy(wn->task.status, name);
 276         free(name);
 277         w->open(wn);
 278         wn->task.post_select = w->post_select_btr;
 279         wn->task.pre_select = w->pre_select_btr;
 280         register_task(&wn->task);
 281         return wn;
 282 }
 283
 284
 285 /**
 286  * Print the help text of all writers to stdout.
 287  *
 288  * \param detailed Whether to print the detailed help text.
 289  */
 290 void print_writer_helps(int detailed)
 291 {
 292         int i;
 293
 294         printf_or_die("\nAvailable writers: \n\t");
 295         FOR_EACH_WRITER(i)
 296                 printf_or_die("%s%s", i? " " : "", writer_names[i]);
 297         printf_or_die("\n\n");
 298         FOR_EACH_WRITER(i) {
 299                 struct writer *w = writers + i;
 300
 301                 if (!w->help.short_help)
 302                         continue;
 303                 printf_or_die("Options for %s:\n", writer_names[i]);
 304                 ggo_print_help(&w->help, detailed);
 305         }
 306 }
 307
 308 static int get_btr_value(struct btr_node *btrn, const char *key, int32_t *result)
 309 {
 310         char *buf = NULL;
 311         int ret = btr_exec_up(btrn, key, &buf);
 312
 313         if (ret < 0)
 314                 return ret;
 315         ret = para_atoi32(buf, result);
 316         free(buf);
 317         return ret;
 318 }
 319
 320 /*
 321  * Ask parent btr nodes for the samplerate of the current stream.
 322  */
 323 int get_btr_samplerate(struct btr_node *btrn, int32_t *result)
 324 {
 325         return get_btr_value(btrn, "samplerate", result);
 326 }
 327
 328 /*
 329  * Ask parent btr nodes for the channel count of the current stream.
 330  */
 331 int get_btr_channels(struct btr_node *btrn, int32_t *result)
 332 {
 333         return get_btr_value(btrn, "channels", result);
 334 }