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  * prints an error message and calls exit().
  51  */
  52 void *check_writer_arg_or_die(const char *wa, int *writer_num)
  53 {
  54         int i;
  55
  56         PARA_INFO_LOG("checking %s\n", wa);
  57         FOR_EACH_WRITER(i) {
  58                 const char *name = writer_names[i];
  59                 size_t len = strlen(name);
  60                 char c;
  61                 if (strlen(wa) < len)
  62                         continue;
  63                 if (strncmp(name, wa, len))
  64                         continue;
  65                 c = wa[len];
  66                 if (c && c != ' ')
  67                         continue;
  68                 *writer_num = i;
  69                 return writers[i].parse_config_or_die(c? wa + len + 1 : "");
  70         }
  71         PARA_EMERG_LOG("invalid writer %s\n", wa);
  72         exit(EXIT_FAILURE);
  73 }
  74
  75 /**
  76  * Open a writer node and register the corresponding task.
  77  *
  78  * \param wn The writer node to open.
  79  * \param parent The parent btr node (the source for the writer node).
  80  *
  81  * The configuration of the writer node stored in \p wn->conf must be
  82  * initialized before this function may be called.
  83  */
  84 void register_writer_node(struct writer_node *wn, struct btr_node *parent)
  85 {
  86         struct writer *w = writers + wn->writer_num;
  87         char *name = make_message("%s writer", writer_names[wn->writer_num]);
  88
  89         wn->btrn = btr_new_node(&(struct btr_node_description)
  90                 EMBRACE(.name = name, .parent = parent,
  91                 .handler = w->execute, .context = wn));
  92         strcpy(wn->task.status, name);
  93         free(name);
  94         wn->task.post_select = w->post_select;
  95         wn->task.pre_select = w->pre_select;
  96         register_task(&wn->task);
  97 }
  98
  99 /**
 100  * Print the help text of all writers to stdout.
 101  *
 102  * \param detailed Whether to print the detailed help text.
 103  */
 104 void print_writer_helps(int detailed)
 105 {
 106         int i;
 107
 108         printf_or_die("\nAvailable writers: \n\t");
 109         FOR_EACH_WRITER(i)
 110                 printf_or_die("%s%s", i? " " : "", writer_names[i]);
 111         printf_or_die("\n\n");
 112         FOR_EACH_WRITER(i) {
 113                 struct writer *w = writers + i;
 114
 115                 if (!w->help.short_help)
 116                         continue;
 117                 printf_or_die("Options for %s:\n", writer_names[i]);
 118                 ggo_print_help(&w->help, detailed);
 119         }
 120 }
 121
 122 static void get_btr_value(struct btr_node *btrn, const char *cmd,
 123                 int32_t *result)
 124 {
 125         char *buf = NULL;
 126         int ret = btr_exec_up(btrn, cmd, &buf);
 127
 128         if (ret < 0) {
 129                 /*
 130                  * This really should not happen. It means one of our parent
 131                  * nodes died unexpectedly. Proceed with fingers crossed.
 132                  */
 133                 PARA_CRIT_LOG("cmd %s: %s\n", cmd, para_strerror(-ret));
 134                 *result = 0;
 135                 return;
 136         }
 137         ret = para_atoi32(buf, result);
 138         assert(ret >= 0);
 139         free(buf);
 140 }
 141
 142 /**
 143  * Ask parent btr nodes for the sample rate of the current stream.
 144  *
 145  * \param btrn Where to start the search.
 146  * \param result Filled in by this function.
 147  *
 148  * This function is assumed to succeed and terminates on errors.
 149  */
 150 void get_btr_sample_rate(struct btr_node *btrn, int32_t *result)
 151 {
 152         get_btr_value(btrn, "sample_rate", result);
 153 }
 154
 155 /**
 156  * Ask parent btr nodes for the channel count of the current stream.
 157  *
 158  * \param btrn See \ref get_btr_sample_rate.
 159  * \param result See \ref get_btr_sample_rate.
 160  */
 161 void get_btr_channels(struct btr_node *btrn, int32_t *result)
 162 {
 163         get_btr_value(btrn, "channels", result);
 164 }
 165
 166 /**
 167  * Ask parent btr nodes for the number of bits per sample and the byte sex.
 168  *
 169  * \param btrn See \ref get_btr_sample_rate.
 170  * \param result Contains the sample format as an enum sample_format type.
 171  */
 172 void get_btr_sample_format(struct btr_node *btrn, int32_t *result)
 173 {
 174         get_btr_value(btrn, "sample_format", result);
 175 }