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                 return sched_min_delay(s);
  53         sched_request_timeout(&diff, s);
  54 }
  55
  56 static void prebuffer_close(struct filter_node *fn)
  57 {
  58         free(fn->private_data);
  59         free(fn->buf);
  60 }
  61
  62 static void prebuffer_post_select(__a_unused struct sched *s, struct task *t)
  63 {
  64         struct filter_node *fn = container_of(t, struct filter_node, task);
  65         struct btr_node *btrn = fn->btrn;
  66         size_t iqs = btr_get_input_queue_size(btrn);
  67         struct private_prebuffer_data *ppd = fn->private_data;
  68         struct prebuffer_filter_args_info *conf = ppd->conf;
  69
  70         t->error = 0;
  71         if (ppd->barrier.tv_sec == 0)
  72                 return;
  73         if (tv_diff(now, &ppd->barrier, NULL) < 0)
  74                 return;
  75         if (iqs < conf->size_arg)
  76                 return;
  77         btr_splice_out_node(btrn);
  78         prebuffer_close(fn);
  79         t->error = -E_PREBUFFER_SUCCESS;
  80 }
  81
  82 static int prebuffer_parse_config(int argc, char **argv, void **config)
  83 {
  84         struct prebuffer_filter_args_info *prebuffer_conf
  85                 = para_calloc(sizeof(*prebuffer_conf));
  86         int ret = -E_PREBUFFER_SYNTAX;
  87
  88         if (prebuffer_cmdline_parser(argc, argv, prebuffer_conf))
  89                 goto err;
  90         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  91         if (prebuffer_conf->duration_arg < 0)
  92                 goto err;
  93         if (prebuffer_conf->size_arg < 0)
  94                 goto err;
  95         PARA_NOTICE_LOG("prebuffering %ims, %i bytes\n",
  96                 prebuffer_conf->duration_arg, prebuffer_conf->size_arg);
  97         *config = prebuffer_conf;
  98         return 1;
  99 err:
 100         free(prebuffer_conf);
 101         return ret;
 102 }
 103
 104 static void prebuffer_open(struct filter_node *fn)
 105 {
 106         struct private_prebuffer_data *ppd = para_calloc(sizeof(*ppd));
 107
 108         ppd->conf = fn->conf;
 109         fn->private_data = ppd;
 110         fn->bufsize = 8192; /* gets increased on demand */
 111         fn->buf = para_malloc(fn->bufsize);
 112 }
 113
 114 static void prebuffer_free_config(void *conf)
 115 {
 116         prebuffer_cmdline_parser_free(conf);
 117 }
 118
 119 /**
 120  * The init function of the prebuffer filter.
 121  *
 122  * \param f Pointer to the struct to initialize.
 123  */
 124 void prebuffer_filter_init(struct filter *f)
 125 {
 126         struct prebuffer_filter_args_info dummy;
 127
 128         prebuffer_cmdline_parser_init(&dummy);
 129         f->open = prebuffer_open;
 130         f->close = prebuffer_close;
 131         f->parse_config = prebuffer_parse_config;
 132         f->free_config = prebuffer_free_config;
 133         f->pre_select = prebuffer_pre_select;
 134         f->post_select = prebuffer_post_select;
 135         f->help = (struct ggo_help) {
 136                 .short_help = prebuffer_filter_args_info_help,
 137                 .detailed_help = prebuffer_filter_args_info_detailed_help
 138         };
 139 }