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
  11 #include "para.h"
  12 #include "prebuffer_filter.cmdline.h"
  13 #include "list.h"
  14 #include "sched.h"
  15 #include "ggo.h"
  16 #include "filter.h"
  17 #include "string.h"
  18 #include "error.h"
  19
  20 /** Data specific to the prebuffer filter. */
  21 struct private_prebuffer_data {
  22         /** The configuration data for this instance of the filter. */
  23         struct prebuffer_filter_args_info *conf;
  24         /** Number of bytes prebuffered or -1 if no longer prebuffering. */
  25         int prebuffered;
  26         /** End of prebuffering period. */
  27         struct timeval barrier;
  28 };
  29
  30 static ssize_t prebuffer_convert(char *inbuf, size_t inbuf_len,
  31                 struct filter_node *fn)
  32 {
  33         struct private_prebuffer_data *ppd = fn->private_data;
  34         struct prebuffer_filter_args_info *conf = ppd->conf;
  35
  36         if (inbuf_len == 0) {
  37                 if (*fn->fc->input_error < 0 && ppd->prebuffered >= 0)
  38                         goto prebuffer_end;
  39                 return 0;
  40         }
  41         if (ppd->prebuffered < 0) {
  42                 size_t copy = PARA_MIN(inbuf_len, fn->bufsize - fn->loaded);
  43                 memcpy(fn->buf + fn->loaded, inbuf, copy);
  44                 fn->loaded += copy;
  45                 return copy;
  46         }
  47         if (ppd->prebuffered + inbuf_len > fn->bufsize) {
  48                 fn->bufsize = PARA_MAX(2 * fn->bufsize,
  49                         ppd->prebuffered + inbuf_len);
  50                 fn->buf = para_realloc(fn->buf, fn->bufsize);
  51         }
  52         memcpy(fn->buf + ppd->prebuffered, inbuf, inbuf_len);
  53         if (ppd->prebuffered == 0) {
  54                 struct timeval tv;
  55                 PARA_INFO_LOG("prebuffer period %dms\n",
  56                         conf->duration_arg);
  57                 ms2tv(conf->duration_arg, &tv);
  58                 tv_add(&tv, now, &ppd->barrier);
  59         }
  60         ppd->prebuffered += inbuf_len;
  61         PARA_DEBUG_LOG("%d bytes prebuffered\n", ppd->prebuffered);
  62         if (*fn->fc->input_error >= 0) {
  63                 struct timeval diff;
  64                 if (tv_diff(now, &ppd->barrier, &diff) < 0)
  65                         goto out;
  66                 if (ppd->prebuffered < conf->size_arg)
  67                         goto out;
  68         }
  69 prebuffer_end:
  70         fn->loaded = ppd->prebuffered;
  71         ppd->prebuffered = -1;
  72 out:
  73         return inbuf_len;
  74 }
  75
  76 static void prebuffer_close(struct filter_node *fn)
  77 {
  78         free(fn->private_data);
  79         free(fn->buf);
  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 /**
 115  * The init function of the prebuffer filter.
 116  *
 117  * \param f Pointer to the struct to initialize.
 118  */
 119 void prebuffer_filter_init(struct filter *f)
 120 {
 121         struct prebuffer_filter_args_info dummy;
 122
 123         prebuffer_cmdline_parser_init(&dummy);
 124         f->open = prebuffer_open;
 125         f->close = prebuffer_close;
 126         f->convert = prebuffer_convert;
 127         f->parse_config = prebuffer_parse_config;
 128         f->help = (struct ggo_help) {
 129                 .short_help = prebuffer_filter_args_info_help,
 130                 .detailed_help = prebuffer_filter_args_info_detailed_help
 131         };
 132 }