filter_common.c

   1 /*
   2  * Copyright (C) 2005-2010 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file filter_common.c Common helper functions for filter input/output. */
   8
   9 #include <regex.h>
  10 #include <sys/types.h>
  11 #include <dirent.h>
  12 #include <stdbool.h>
  13
  14 #include "para.h"
  15 #include "list.h"
  16 #include "sched.h"
  17 #include "fd.h"
  18 #include "ggo.h"
  19 #include "buffer_tree.h"
  20 #include "filter.h"
  21 #include "error.h"
  22 #include "string.h"
  23
  24 /** The array of supported filters. */
  25 struct filter filters[NUM_SUPPORTED_FILTERS] = {FILTER_ARRAY};
  26
  27 /**
  28  * Call the init function of each supported filter.
  29  * \sa filter::init
  30  */
  31 void filter_init(void)
  32 {
  33         int i;
  34
  35         FOR_EACH_SUPPORTED_FILTER(i)
  36                 filters[i].init(filters + i);
  37 }
  38
  39 /*
  40  * If the filter has a command line parser and options is not NULL, run it.
  41  * Returns filter_num on success, negative on errors
  42  */
  43 static int parse_filter_args(int filter_num, char *options, void **conf)
  44 {
  45         struct filter *f = &filters[filter_num];
  46         int ret, i, argc = 2;
  47         char **argv;
  48
  49 //      PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
  50 //              options? options : "(none)", f->parse_config);
  51         if (!f->parse_config)
  52                 return strlen(options)? -E_BAD_FILTER_OPTIONS : filter_num;
  53 //      PARA_DEBUG_LOG("options: %s\n", options);
  54         argc = create_argv(options, " \t", &argv);
  55         if (argc < 0)
  56                 return -E_BAD_FILTER_OPTIONS;
  57         PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
  58         for (i = argc - 1; i >= 0; i--)
  59                 argv[i + 1] = argv[i];
  60         argv[0] = para_strdup(f->name);
  61         argc++;
  62         ret = f->parse_config(argc, argv, conf);
  63         free(argv[argc - 1]);
  64         argv[argc - 1] = NULL;
  65         free_argv(argv);
  66         return ret < 0? ret : filter_num;
  67 }
  68
  69 /**
  70  * Check the filter command line options.
  71  *
  72  * \param fa The command line options.
  73  * \param conf Points to the filter configuration upon successful return.
  74  *
  75  * Check if \a fa starts with a the name of a supported filter, followed by
  76  * a colon. If yes, call the command line parser of that filter.
  77  *
  78  * \return On success, the number of the filter is returned and \a conf
  79  * is initialized to point to the filter configuration determined by \a fa.
  80  * On errors, a negative value is returned.
  81  *
  82  * Note: If \a fa specifies a filter that has no command line parser success is
  83  * returned, and \a conf is initialized to \p NULL.
  84  *
  85  * \sa filter::parse_config
  86  */
  87 int check_filter_arg(char *fa, void **conf)
  88 {
  89         int j;
  90
  91         *conf = NULL;
  92 //      PARA_DEBUG_LOG("arg: %s\n", fa);
  93         FOR_EACH_SUPPORTED_FILTER(j) {
  94                 const char *name = filters[j].name;
  95                 size_t len = strlen(name);
  96                 char c;
  97                 if (strlen(fa) < len)
  98                         continue;
  99                 if (strncmp(name, fa, len))
 100                         continue;
 101                 c = fa[len];
 102                 if (c && c != ' ')
 103                         continue;
 104                 if (c && !filters[j].parse_config)
 105                         return -E_BAD_FILTER_OPTIONS;
 106                 return parse_filter_args(j, c? fa + len + 1 :
 107                         fa + strlen(fa), conf);
 108         }
 109         return -E_UNSUPPORTED_FILTER;
 110 }
 111
 112 void print_filter_helps(int detailed)
 113 {
 114         int i;
 115
 116         printf_or_die("\nAvailable filters: \n\t");
 117         FOR_EACH_SUPPORTED_FILTER(i)
 118                 printf_or_die("%s%s", i? " " : "", filters[i].name);
 119         printf_or_die("\n\n");
 120
 121         FOR_EACH_SUPPORTED_FILTER(i) {
 122                 struct filter *f = filters + i;
 123
 124                 if (!f->help.short_help)
 125                         continue;
 126                 printf_or_die("Options for %s:\n", f->name);
 127                 ggo_print_help(&f->help, detailed);
 128         }
 129 }
 130
 131 void generic_filter_pre_select(struct sched *s, struct task *t)
 132 {
 133         struct filter_node *fn = container_of(t, struct filter_node, task);
 134
 135         t->error = 0;
 136         if (btr_node_status(fn->btrn, fn->min_iqs, BTR_NT_INTERNAL) != 0)
 137                 sched_min_delay(s);
 138 }
 139
 140 /**
 141  * Execute a btr command for a decoder.
 142  *
 143  * The buffer tree nodes of the writers ask the parent nodes about sample_rate
 144  * and the channels count. This function is called by all decoders to answer
 145  * these queries.
 146  *
 147  * \param cmd The command to be executed by the child node.
 148  * \param sample_rate Known to the decoder.
 149  * \param channels Known to the decoder.
 150  * \param result Ascii representation on the answer is stored here.
 151  */
 152 int decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels,
 153                 char **result)
 154 {
 155         if (!strcmp(cmd, "sample_rate")) {
 156                 if (sample_rate == 0)
 157                         return -E_BTR_NAVAIL;
 158                 *result = make_message("%u", sample_rate);
 159                 return 1;
 160         }
 161         if (!strcmp(cmd, "channels")) {
 162                 if (channels == 0)
 163                         return -E_BTR_NAVAIL;
 164                 *result = make_message("%u", channels);
 165                 return 1;
 166         }
 167         return -ERRNO_TO_PARA_ERROR(ENOTSUP);
 168 }