filter_common.c

   1 /*
   2  * Copyright (C) 2005-2012 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
  12 #include "para.h"
  13 #include "list.h"
  14 #include "sched.h"
  15 #include "fd.h"
  16 #include "ggo.h"
  17 #include "buffer_tree.h"
  18 #include "filter.h"
  19 #include "error.h"
  20 #include "string.h"
  21
  22 /** The array of supported filters. */
  23 struct filter filters[NUM_SUPPORTED_FILTERS] = {FILTER_ARRAY};
  24
  25 /**
  26  * Call the init function of each supported filter.
  27  * \sa filter::init
  28  */
  29 void filter_init(void)
  30 {
  31         int i;
  32
  33         FOR_EACH_SUPPORTED_FILTER(i)
  34                 filters[i].init(filters + i);
  35 }
  36
  37 /*
  38  * If the filter has a command line parser and options is not NULL, run it.
  39  * Returns filter_num on success, negative on errors
  40  */
  41 static int parse_filter_args(int filter_num, char *options, void **conf)
  42 {
  43         struct filter *f = &filters[filter_num];
  44         int ret, i, argc = 2;
  45         char **argv;
  46
  47 //      PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
  48 //              options? options : "(none)", f->parse_config);
  49         if (!f->parse_config)
  50                 return strlen(options)? -E_BAD_FILTER_OPTIONS : filter_num;
  51 //      PARA_DEBUG_LOG("options: %s\n", options);
  52         argc = create_argv(options, " \t", &argv);
  53         if (argc < 0)
  54                 return -E_BAD_FILTER_OPTIONS;
  55         PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
  56         for (i = argc - 1; i >= 0; i--)
  57                 argv[i + 1] = argv[i];
  58         argv[0] = para_strdup(f->name);
  59         argc++;
  60         ret = f->parse_config(argc, argv, conf);
  61         free(argv[argc - 1]);
  62         argv[argc - 1] = NULL;
  63         free_argv(argv);
  64         return ret < 0? ret : filter_num;
  65 }
  66
  67 /**
  68  * Check the filter command line options.
  69  *
  70  * \param fa The command line options.
  71  * \param conf Points to the filter configuration upon successful return.
  72  *
  73  * Check if \a fa starts with a the name of a supported filter, followed by
  74  * a colon. If yes, call the command line parser of that filter.
  75  *
  76  * \return On success, the number of the filter is returned and \a conf
  77  * is initialized to point to the filter configuration determined by \a fa.
  78  * On errors, a negative value is returned.
  79  *
  80  * Note: If \a fa specifies a filter that has no command line parser success is
  81  * returned, and \a conf is initialized to \p NULL.
  82  *
  83  * \sa filter::parse_config
  84  */
  85 int check_filter_arg(char *fa, void **conf)
  86 {
  87         int j;
  88
  89         *conf = NULL;
  90 //      PARA_DEBUG_LOG("arg: %s\n", fa);
  91         FOR_EACH_SUPPORTED_FILTER(j) {
  92                 const char *name = filters[j].name;
  93                 size_t len = strlen(name);
  94                 char c;
  95                 if (strlen(fa) < len)
  96                         continue;
  97                 if (strncmp(name, fa, len))
  98                         continue;
  99                 c = fa[len];
 100                 if (c && c != ' ')
 101                         continue;
 102                 if (c && !filters[j].parse_config)
 103                         return -E_BAD_FILTER_OPTIONS;
 104                 return parse_filter_args(j, c? fa + len + 1 :
 105                         fa + strlen(fa), conf);
 106         }
 107         return -E_UNSUPPORTED_FILTER;
 108 }
 109
 110 /**
 111  * Print help text of each filter to stdout.
 112  *
 113  * \param detailed If non-zero, print detailed help.
 114  */
 115 void print_filter_helps(int detailed)
 116 {
 117         int i;
 118
 119         printf_or_die("\nAvailable filters: \n\t");
 120         FOR_EACH_SUPPORTED_FILTER(i)
 121                 printf_or_die("%s%s", i? " " : "", filters[i].name);
 122         printf_or_die("\n\n");
 123
 124         FOR_EACH_SUPPORTED_FILTER(i) {
 125                 struct filter *f = filters + i;
 126
 127                 if (!f->help.short_help)
 128                         continue;
 129                 printf_or_die("Options for %s:\n", f->name);
 130                 ggo_print_help(&f->help, detailed);
 131         }
 132 }
 133
 134 /**
 135  * Set select timeout of the the scheduler.
 136  *
 137  * \param s The scheduler.
 138  * \param t The task struct of this filter.
 139  *
 140  * This looks at the status of the btr node of the filter. If data is available
 141  * in the input queue of the filter, or if an error occured, a minimal timeout
 142  * for the next select call is requested from the scheduler. Otherwise the
 143  * scheduler timeout is left unchanged.
 144  */
 145 void generic_filter_pre_select(struct sched *s, struct task *t)
 146 {
 147         struct filter_node *fn = container_of(t, struct filter_node, task);
 148
 149         t->error = 0;
 150         if (btr_node_status(fn->btrn, fn->min_iqs, BTR_NT_INTERNAL) != 0)
 151                 sched_min_delay(s);
 152 }
 153
 154 #ifdef WORDS_BIGENDIAN
 155 #define DECODER_SAMPLE_FORMAT SF_S16_BE
 156 #else
 157 #define DECODER_SAMPLE_FORMAT SF_S16_LE
 158 #endif
 159
 160 /**
 161  * Execute a btr command for a decoder.
 162  *
 163  * The buffer tree nodes of the writers ask the parent nodes about sample_rate,
 164  * channels count and sample format. This function is called by all decoders to
 165  * answer these queries.
 166  *
 167  * \param cmd The command to be executed by the child node.
 168  * \param sample_rate Known to the decoder.
 169  * \param channels Known to the decoder.
 170  * \param result Ascii representation on the answer is stored here.
 171  *
 172  * \return Standard.
 173  */
 174 int decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels,
 175                 char **result)
 176 {
 177         if (!strcmp(cmd, "sample_rate")) {
 178                 if (sample_rate == 0)
 179                         return -E_BTR_NAVAIL;
 180                 *result = make_message("%u", sample_rate);
 181                 return 1;
 182         }
 183         if (!strcmp(cmd, "channels")) {
 184                 if (channels == 0)
 185                         return -E_BTR_NAVAIL;
 186                 *result = make_message("%u", channels);
 187                 return 1;
 188         }
 189         if (!strcmp(cmd, "sample_format")) {
 190                 *result = make_message("%u", DECODER_SAMPLE_FORMAT);
 191                 return 1;
 192         }
 193         return -ERRNO_TO_PARA_ERROR(ENOTSUP);
 194 }