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