prebuffer_filter.c

   1 /*
   2  * Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>
   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 <lopsub.h>
  11
  12 #include "para.h"
  13 #include "filter_cmd.lsg.h"
  14 #include "list.h"
  15 #include "sched.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         /** Number of bytes prebuffered or -1 if no longer prebuffering. */
  24         int prebuffered;
  25         /** End of prebuffering period. */
  26         struct timeval barrier;
  27 };
  28
  29 static void prebuffer_pre_select(struct sched *s, void *context)
  30 {
  31         struct filter_node *fn = context;
  32         struct btr_node *btrn = fn->btrn;
  33         size_t iqs = btr_get_input_queue_size(btrn);
  34         struct private_prebuffer_data *ppd = fn->private_data;
  35         struct timeval diff;
  36
  37         if (iqs == 0)
  38                 return;
  39         if (ppd->barrier.tv_sec == 0) {
  40                 uint32_t duration = FILTER_CMD_OPT_UINT32_VAL(PREBUFFER,
  41                         DURATION, fn->lpr);
  42                 struct timeval tv;
  43                 PARA_INFO_LOG("prebuffer period %" PRIu32 "ms\n", duration);
  44                 ms2tv(duration, &tv);
  45                 tv_add(&tv, now, &ppd->barrier);
  46         }
  47         if (tv_diff(&ppd->barrier, now, &diff) < 0)
  48                 return sched_min_delay(s);
  49         sched_request_timeout(&diff, s);
  50 }
  51
  52 static void prebuffer_close(struct filter_node *fn)
  53 {
  54         free(fn->private_data);
  55 }
  56
  57 static int prebuffer_post_select(__a_unused struct sched *s, void *context)
  58 {
  59         struct filter_node *fn = context;
  60         struct btr_node *btrn = fn->btrn;
  61         size_t iqs = btr_get_input_queue_size(btrn);
  62         struct private_prebuffer_data *ppd = fn->private_data;
  63         uint32_t size = FILTER_CMD_OPT_UINT32_VAL(PREBUFFER, SIZE, fn->lpr);
  64
  65         if (ppd->barrier.tv_sec == 0)
  66                 return 0;
  67         if (tv_diff(now, &ppd->barrier, NULL) < 0)
  68                 return 0;
  69         if (iqs < size)
  70                 return 0;
  71         btr_splice_out_node(&fn->btrn);
  72         return -E_PREBUFFER_SUCCESS;
  73 }
  74
  75 static void prebuffer_open(struct filter_node *fn)
  76 {
  77         struct private_prebuffer_data *ppd = para_calloc(sizeof(*ppd));
  78         fn->private_data = ppd;
  79 }
  80
  81 const struct filter lsg_filter_cmd_com_prebuffer_user_data = {
  82         .open = prebuffer_open,
  83         .close = prebuffer_close,
  84         .pre_select = prebuffer_pre_select,
  85         .post_select = prebuffer_post_select,
  86 };