write_common.c

   1 /*
   2  * Copyright (C) 2006-2010 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(&(struct btr_node_description)
  85                 EMBRACE(.name = name, .parent = parent,
  86                 .handler = w->execute, .context = wn));
  87         strcpy(wn->task.status, name);
  88         free(name);
  89         ret = w->open(wn);
  90         wn->task.post_select = w->post_select;
  91         wn->task.pre_select = w->pre_select;
  92         register_task(&wn->task);
  93 }
  94
  95 /**
  96  * Setup a writer node with the default writer.
  97  *
  98  * If arg is \p NULL, the OS-dependent default writer is used with an empty
  99  * configuration string.  It defaults to alsa for Linux, osx for OS X, oss for
 100  * *BSD and the file writer if neither of these is supported.
 101  *
 102  * Once the writer configuration has been retrieved, a writer node is created,
 103  * its buffer tree node is added to the buffer tree as a child of the given
 104  * parent.
 105  *
 106  * Finally, the new writer node's taks structure is initialized and registered
 107  * to the paraslash scheduler.
 108  *
 109  * \return A pointer to the allocated writer node group.
 110  */
 111 int setup_writer_node(const char *arg, struct btr_node *parent,
 112                 struct writer_node *wn)
 113 {
 114         if (arg)
 115                 wn->conf = check_writer_arg(arg, &wn->writer_num);
 116         else {
 117                 wn->writer_num = DEFAULT_WRITER;
 118                 wn->conf = writers[DEFAULT_WRITER].parse_config("");
 119         }
 120         if (!wn->conf)
 121                 return -E_WRITE_COMMON_SYNTAX;
 122         register_writer_node(wn, parent);
 123         return 1;
 124 }
 125
 126
 127 /**
 128  * Print the help text of all writers to stdout.
 129  *
 130  * \param detailed Whether to print the detailed help text.
 131  */
 132 void print_writer_helps(int detailed)
 133 {
 134         int i;
 135
 136         printf_or_die("\nAvailable writers: \n\t");
 137         FOR_EACH_WRITER(i)
 138                 printf_or_die("%s%s", i? " " : "", writer_names[i]);
 139         printf_or_die("\n\n");
 140         FOR_EACH_WRITER(i) {
 141                 struct writer *w = writers + i;
 142
 143                 if (!w->help.short_help)
 144                         continue;
 145                 printf_or_die("Options for %s:\n", writer_names[i]);
 146                 ggo_print_help(&w->help, detailed);
 147         }
 148 }
 149
 150 static int get_btr_value(struct btr_node *btrn, const char *key, int32_t *result)
 151 {
 152         char *buf = NULL;
 153         int ret = btr_exec_up(btrn, key, &buf);
 154
 155         if (ret < 0)
 156                 return ret;
 157         ret = para_atoi32(buf, result);
 158         free(buf);
 159         return ret;
 160 }
 161
 162 /*
 163  * Ask parent btr nodes for the samplerate of the current stream.
 164  */
 165 int get_btr_samplerate(struct btr_node *btrn, int32_t *result)
 166 {
 167         return get_btr_value(btrn, "samplerate", result);
 168 }
 169
 170 /*
 171  * Ask parent btr nodes for the channel count of the current stream.
 172  */
 173 int get_btr_channels(struct btr_node *btrn, int32_t *result)
 174 {
 175         return get_btr_value(btrn, "channels", result);
 176 }