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 /**
  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                 if (c && !writers[i].parse_config)
  70                         return NULL;
  71                 *writer_num = i;
  72                 return writers[i].parse_config(c? wa + len + 1 : "");
  73         }
  74         PARA_ERROR_LOG("writer not found\n");
  75         return NULL;
  76 }
  77
  78 void register_writer_node(struct writer_node *wn, struct btr_node *parent)
  79 {
  80         struct writer *w = writers + wn->writer_num;
  81         char *name = make_message("%s writer", writer_names[wn->writer_num]);
  82         int ret;
  83
  84         wn->btrn = btr_new_node(name, parent, w->execute, wn);
  85         strcpy(wn->task.status, name);
  86         free(name);
  87         ret = w->open(wn);
  88         wn->task.post_select = w->post_select;
  89         wn->task.pre_select = w->pre_select;
  90         register_task(&wn->task);
  91 }
  92
  93 /**
  94  * Setup a writer node with the default writer.
  95  *
  96  * If arg is \p NULL, the OS-dependent default writer is used with an empty
  97  * configuration string.  It defaults to alsa for Linux, osx for OS X, oss for
  98  * *BSD and the file writer if neither of these is supported.
  99  *
 100  * Once the writer configuration has been retrieved, a writer node is created,
 101  * its buffer tree node is added to the buffer tree as a child of the given
 102  * parent.
 103  *
 104  * Finally, the new writer node's taks structure is initialized and registered
 105  * to the paraslash scheduler.
 106  *
 107  * \return A pointer to the allocated writer node group.
 108  */
 109 int setup_writer_node(const char *arg, struct btr_node *parent,
 110                 struct writer_node *wn)
 111 {
 112         if (arg)
 113                 wn->conf = check_writer_arg(arg, &wn->writer_num);
 114         else {
 115                 wn->writer_num = DEFAULT_WRITER;
 116                 wn->conf = writers[DEFAULT_WRITER].parse_config("");
 117         }
 118         if (!wn->conf)
 119                 return -E_WRITE_COMMON_SYNTAX;
 120         register_writer_node(wn, parent);
 121         return 1;
 122 }
 123
 124
 125 /**
 126  * Print the help text of all writers to stdout.
 127  *
 128  * \param detailed Whether to print the detailed help text.
 129  */
 130 void print_writer_helps(int detailed)
 131 {
 132         int i;
 133
 134         printf_or_die("\nAvailable writers: \n\t");
 135         FOR_EACH_WRITER(i)
 136                 printf_or_die("%s%s", i? " " : "", writer_names[i]);
 137         printf_or_die("\n\n");
 138         FOR_EACH_WRITER(i) {
 139                 struct writer *w = writers + i;
 140
 141                 if (!w->help.short_help)
 142                         continue;
 143                 printf_or_die("Options for %s:\n", writer_names[i]);
 144                 ggo_print_help(&w->help, detailed);
 145         }
 146 }
 147
 148 static int get_btr_value(struct btr_node *btrn, const char *key, int32_t *result)
 149 {
 150         char *buf = NULL;
 151         int ret = btr_exec_up(btrn, key, &buf);
 152
 153         if (ret < 0)
 154                 return ret;
 155         ret = para_atoi32(buf, result);
 156         free(buf);
 157         return ret;
 158 }
 159
 160 /*
 161  * Ask parent btr nodes for the samplerate of the current stream.
 162  */
 163 int get_btr_samplerate(struct btr_node *btrn, int32_t *result)
 164 {
 165         return get_btr_value(btrn, "samplerate", result);
 166 }
 167
 168 /*
 169  * Ask parent btr nodes for the channel count of the current stream.
 170  */
 171 int get_btr_channels(struct btr_node *btrn, int32_t *result)
 172 {
 173         return get_btr_value(btrn, "channels", result);
 174 }