prebuffer_filter.c

   1 /* Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file prebuffer_filter.c Paraslash's prebuffering filter. */
   4
   5 #include <regex.h>
   6 #include <lopsub.h>
   7
   8 #include "para.h"
   9 #include "filter_cmd.lsg.h"
  10 #include "list.h"
  11 #include "sched.h"
  12 #include "buffer_tree.h"
  13 #include "filter.h"
  14 #include "string.h"
  15 #include "error.h"
  16
  17 /** Data specific to the prebuffer filter. */
  18 struct private_prebuffer_data {
  19         /** Number of bytes prebuffered or -1 if no longer prebuffering. */
  20         int prebuffered;
  21         /** End of prebuffering period. */
  22         struct timeval barrier;
  23 };
  24
  25 static void prebuffer_pre_select(struct sched *s, void *context)
  26 {
  27         struct filter_node *fn = context;
  28         struct btr_node *btrn = fn->btrn;
  29         size_t iqs = btr_get_input_queue_size(btrn);
  30         struct private_prebuffer_data *ppd = fn->private_data;
  31         struct timeval diff;
  32
  33         if (iqs == 0)
  34                 return;
  35         if (ppd->barrier.tv_sec == 0) {
  36                 uint32_t duration = FILTER_CMD_OPT_UINT32_VAL(PREBUFFER,
  37                         DURATION, fn->lpr);
  38                 struct timeval tv;
  39                 PARA_INFO_LOG("prebuffer period %" PRIu32 "ms\n", duration);
  40                 ms2tv(duration, &tv);
  41                 tv_add(&tv, now, &ppd->barrier);
  42         }
  43         if (tv_diff(&ppd->barrier, now, &diff) < 0)
  44                 return sched_min_delay(s);
  45         sched_request_timeout(&diff, s);
  46 }
  47
  48 static void prebuffer_close(struct filter_node *fn)
  49 {
  50         free(fn->private_data);
  51 }
  52
  53 static int prebuffer_post_select(__a_unused struct sched *s, void *context)
  54 {
  55         struct filter_node *fn = context;
  56         struct btr_node *btrn = fn->btrn;
  57         size_t iqs = btr_get_input_queue_size(btrn);
  58         struct private_prebuffer_data *ppd = fn->private_data;
  59         uint32_t size = FILTER_CMD_OPT_UINT32_VAL(PREBUFFER, SIZE, fn->lpr);
  60
  61         if (ppd->barrier.tv_sec == 0)
  62                 return 0;
  63         if (tv_diff(now, &ppd->barrier, NULL) < 0)
  64                 return 0;
  65         if (iqs < size)
  66                 return 0;
  67         btr_splice_out_node(&fn->btrn);
  68         return -E_PREBUFFER_SUCCESS;
  69 }
  70
  71 static void prebuffer_open(struct filter_node *fn)
  72 {
  73         struct private_prebuffer_data *ppd = para_calloc(sizeof(*ppd));
  74         fn->private_data = ppd;
  75 }
  76
  77 const struct filter lsg_filter_cmd_com_prebuffer_user_data = {
  78         .open = prebuffer_open,
  79         .close = prebuffer_close,
  80         .pre_select = prebuffer_pre_select,
  81         .post_select = prebuffer_post_select,
  82 };