prebuffer_filter.c

   1 /*
   2  * Copyright (C) 2009-2014 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file prebuffer_filter.c Paraslash's prebuffering filter. */
   8
   9 #include <regex.h>
  10
  11 #include "para.h"
  12 #include "prebuffer_filter.cmdline.h"
  13 #include "list.h"
  14 #include "sched.h"
  15 #include "ggo.h"
  16 #include "buffer_tree.h"
  17 #include "filter.h"
  18 #include "string.h"
  19 #include "error.h"
  20
  21 /** Data specific to the prebuffer filter. */
  22 struct private_prebuffer_data {
  23         /** The configuration data for this instance of the filter. */
  24         struct prebuffer_filter_args_info *conf;
  25         /** Number of bytes prebuffered or -1 if no longer prebuffering. */
  26         int prebuffered;
  27         /** End of prebuffering period. */
  28         struct timeval barrier;
  29 };
  30
  31 static void prebuffer_pre_select(struct sched *s, struct task *t)
  32 {
  33         struct filter_node *fn = container_of(t, struct filter_node, task);
  34         struct btr_node *btrn = fn->btrn;
  35         size_t iqs = btr_get_input_queue_size(btrn);
  36         struct private_prebuffer_data *ppd = fn->private_data;
  37         struct prebuffer_filter_args_info *conf = ppd->conf;
  38         struct timeval diff;
  39
  40         if (iqs == 0)
  41                 return;
  42         if (ppd->barrier.tv_sec == 0) {
  43                 struct timeval tv;
  44                 PARA_INFO_LOG("prebuffer period %dms\n",
  45                         conf->duration_arg);
  46                 ms2tv(conf->duration_arg, &tv);
  47                 tv_add(&tv, now, &ppd->barrier);
  48         }
  49         if (tv_diff(&ppd->barrier, now, &diff) < 0)
  50                 return sched_min_delay(s);
  51         sched_request_timeout(&diff, s);
  52 }
  53
  54 static void prebuffer_close(struct filter_node *fn)
  55 {
  56         free(fn->private_data);
  57 }
  58
  59 static int prebuffer_post_select(__a_unused struct sched *s, struct task *t)
  60 {
  61         struct filter_node *fn = container_of(t, struct filter_node, task);
  62         struct btr_node *btrn = fn->btrn;
  63         size_t iqs = btr_get_input_queue_size(btrn);
  64         struct private_prebuffer_data *ppd = fn->private_data;
  65         struct prebuffer_filter_args_info *conf = ppd->conf;
  66
  67         if (ppd->barrier.tv_sec == 0)
  68                 return 0;
  69         if (tv_diff(now, &ppd->barrier, NULL) < 0)
  70                 return 0;
  71         if (iqs < conf->size_arg)
  72                 return 0;
  73         btr_splice_out_node(&fn->btrn);
  74         return -E_PREBUFFER_SUCCESS;
  75 }
  76
  77 static int prebuffer_parse_config(int argc, char **argv, void **config)
  78 {
  79         struct prebuffer_filter_args_info *conf = para_calloc(sizeof(*conf));
  80         int ret = -E_PREBUFFER_SYNTAX;
  81
  82         prebuffer_filter_cmdline_parser(argc, argv, conf);
  83         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  84         if (conf->duration_arg < 0)
  85                 goto err;
  86         if (conf->size_arg < 0)
  87                 goto err;
  88         PARA_NOTICE_LOG("prebuffering %ims, %i bytes\n", conf->duration_arg,
  89                 conf->size_arg);
  90         *config = conf;
  91         return 1;
  92 err:
  93         free(conf);
  94         return ret;
  95 }
  96
  97 static void prebuffer_open(struct filter_node *fn)
  98 {
  99         struct private_prebuffer_data *ppd = para_calloc(sizeof(*ppd));
 100
 101         ppd->conf = fn->conf;
 102         fn->private_data = ppd;
 103 }
 104
 105 static void prebuffer_free_config(void *conf)
 106 {
 107         prebuffer_filter_cmdline_parser_free(conf);
 108 }
 109
 110 /**
 111  * The init function of the prebuffer filter.
 112  *
 113  * \param f Pointer to the struct to initialize.
 114  */
 115 void prebuffer_filter_init(struct filter *f)
 116 {
 117         struct prebuffer_filter_args_info dummy;
 118
 119         prebuffer_filter_cmdline_parser_init(&dummy);
 120         f->open = prebuffer_open;
 121         f->close = prebuffer_close;
 122         f->parse_config = prebuffer_parse_config;
 123         f->free_config = prebuffer_free_config;
 124         f->pre_select = prebuffer_pre_select;
 125         f->post_select = prebuffer_post_select;
 126         f->help = (struct ggo_help)DEFINE_GGO_HELP(prebuffer_filter);
 127 }