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 }