prebuffer_filter.c

   1 /*
   2  * Copyright (C) 2009 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 #include <stdbool.h>
  11
  12 #include "para.h"
  13 #include "prebuffer_filter.cmdline.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "ggo.h"
  17 #include "buffer_tree.h"
  18 #include "filter.h"
  19 #include "string.h"
  20 #include "error.h"
  21
  22 /** Data specific to the prebuffer filter. */
  23 struct private_prebuffer_data {
  24         /** The configuration data for this instance of the filter. */
  25         struct prebuffer_filter_args_info *conf;
  26         /** Number of bytes prebuffered or -1 if no longer prebuffering. */
  27         int prebuffered;
  28         /** End of prebuffering period. */
  29         struct timeval barrier;
  30 };
  31
  32 static void prebuffer_pre_select(struct sched *s, struct task *t)
  33 {
  34         struct filter_node *fn = container_of(t, struct filter_node, task);
  35         struct btr_node *btrn = fn->btrn;
  36         size_t iqs = btr_get_input_queue_size(btrn);
  37         struct private_prebuffer_data *ppd = fn->private_data;
  38         struct prebuffer_filter_args_info *conf = ppd->conf;
  39         struct timeval diff;
  40
  41         t->error = 0;
  42         if (iqs == 0)
  43                 return;
  44         if (ppd->barrier.tv_sec == 0) {
  45                 struct timeval tv;
  46                 PARA_INFO_LOG("prebuffer period %dms\n",
  47                         conf->duration_arg);
  48                 ms2tv(conf->duration_arg, &tv);
  49                 tv_add(&tv, now, &ppd->barrier);
  50         }
  51         if (tv_diff(&ppd->barrier, now, &diff) < 0)
  52                 goto min_delay;
  53         if (tv_diff(&diff, &s->timeout, NULL) < 0)
  54                 s->timeout = diff;
  55         return;
  56 min_delay:
  57         s->timeout.tv_sec = 0;
  58         s->timeout.tv_usec = 1;
  59 }
  60
  61 static void prebuffer_close(struct filter_node *fn)
  62 {
  63         free(fn->private_data);
  64         free(fn->buf);
  65 }
  66
  67 static void prebuffer_post_select(__a_unused struct sched *s, struct task *t)
  68 {
  69         struct filter_node *fn = container_of(t, struct filter_node, task);
  70         struct btr_node *btrn = fn->btrn;
  71         size_t iqs = btr_get_input_queue_size(btrn);
  72         struct private_prebuffer_data *ppd = fn->private_data;
  73         struct prebuffer_filter_args_info *conf = ppd->conf;
  74
  75         t->error = 0;
  76         if (ppd->barrier.tv_sec == 0)
  77                 return;
  78         if (tv_diff(now, &ppd->barrier, NULL) < 0)
  79                 return;
  80         if (iqs < conf->size_arg)
  81                 return;
  82         btr_splice_out_node(btrn);
  83         prebuffer_close(fn);
  84         t->error = -E_PREBUFFER_SUCCESS;
  85 }
  86
  87 static int prebuffer_parse_config(int argc, char **argv, void **config)
  88 {
  89         struct prebuffer_filter_args_info *prebuffer_conf
  90                 = para_calloc(sizeof(*prebuffer_conf));
  91         int ret = -E_PREBUFFER_SYNTAX;
  92
  93         if (prebuffer_cmdline_parser(argc, argv, prebuffer_conf))
  94                 goto err;
  95         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  96         if (prebuffer_conf->duration_arg < 0)
  97                 goto err;
  98         if (prebuffer_conf->size_arg < 0)
  99                 goto err;
 100         PARA_NOTICE_LOG("prebuffering %ims, %i bytes\n",
 101                 prebuffer_conf->duration_arg, prebuffer_conf->size_arg);
 102         *config = prebuffer_conf;
 103         return 1;
 104 err:
 105         free(prebuffer_conf);
 106         return ret;
 107 }
 108
 109 static void prebuffer_open(struct filter_node *fn)
 110 {
 111         struct private_prebuffer_data *ppd = para_calloc(sizeof(*ppd));
 112
 113         ppd->conf = fn->conf;
 114         fn->private_data = ppd;
 115         fn->bufsize = 8192; /* gets increased on demand */
 116         fn->buf = para_malloc(fn->bufsize);
 117 }
 118
 119 static void prebuffer_free_config(void *conf)
 120 {
 121         prebuffer_cmdline_parser_free(conf);
 122 }
 123
 124 /**
 125  * The init function of the prebuffer filter.
 126  *
 127  * \param f Pointer to the struct to initialize.
 128  */
 129 void prebuffer_filter_init(struct filter *f)
 130 {
 131         struct prebuffer_filter_args_info dummy;
 132
 133         prebuffer_cmdline_parser_init(&dummy);
 134         f->open = prebuffer_open;
 135         f->close = prebuffer_close;
 136         f->parse_config = prebuffer_parse_config;
 137         f->free_config = prebuffer_free_config;
 138         f->pre_select = prebuffer_pre_select;
 139         f->post_select = prebuffer_post_select;
 140         f->help = (struct ggo_help) {
 141                 .short_help = prebuffer_filter_args_info_help,
 142                 .detailed_help = prebuffer_filter_args_info_detailed_help
 143         };
 144 }