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 ssize_t prebuffer_convert(char *inbuf, size_t inbuf_len,
  33                 struct filter_node *fn)
  34 {
  35         struct private_prebuffer_data *ppd = fn->private_data;
  36         struct prebuffer_filter_args_info *conf = ppd->conf;
  37
  38         if (inbuf_len == 0) {
  39                 if (*fn->fc->input_error < 0 && ppd->prebuffered >= 0)
  40                         goto prebuffer_end;
  41                 return 0;
  42         }
  43         if (ppd->prebuffered < 0) {
  44                 size_t copy = PARA_MIN(inbuf_len, fn->bufsize - fn->loaded);
  45                 memcpy(fn->buf + fn->loaded, inbuf, copy);
  46                 fn->loaded += copy;
  47                 return copy;
  48         }
  49         if (ppd->prebuffered + inbuf_len > fn->bufsize) {
  50                 fn->bufsize = PARA_MAX(2 * fn->bufsize,
  51                         ppd->prebuffered + inbuf_len);
  52                 fn->buf = para_realloc(fn->buf, fn->bufsize);
  53         }
  54         memcpy(fn->buf + ppd->prebuffered, inbuf, inbuf_len);
  55         if (ppd->prebuffered == 0) {
  56                 struct timeval tv;
  57                 PARA_INFO_LOG("prebuffer period %dms\n",
  58                         conf->duration_arg);
  59                 ms2tv(conf->duration_arg, &tv);
  60                 tv_add(&tv, now, &ppd->barrier);
  61         }
  62         ppd->prebuffered += inbuf_len;
  63         PARA_DEBUG_LOG("%d bytes prebuffered\n", ppd->prebuffered);
  64         if (*fn->fc->input_error >= 0) {
  65                 struct timeval diff;
  66                 if (tv_diff(now, &ppd->barrier, &diff) < 0)
  67                         goto out;
  68                 if (ppd->prebuffered < conf->size_arg)
  69                         goto out;
  70         }
  71 prebuffer_end:
  72         fn->loaded = ppd->prebuffered;
  73         ppd->prebuffered = -1;
  74 out:
  75         return inbuf_len;
  76 }
  77
  78 static void prebuffer_close(struct filter_node *fn)
  79 {
  80         free(fn->private_data);
  81         free(fn->buf);
  82 }
  83
  84 static int prebuffer_parse_config(int argc, char **argv, void **config)
  85 {
  86         struct prebuffer_filter_args_info *prebuffer_conf
  87                 = para_calloc(sizeof(*prebuffer_conf));
  88         int ret = -E_PREBUFFER_SYNTAX;
  89
  90         if (prebuffer_cmdline_parser(argc, argv, prebuffer_conf))
  91                 goto err;
  92         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
  93         if (prebuffer_conf->duration_arg < 0)
  94                 goto err;
  95         if (prebuffer_conf->size_arg < 0)
  96                 goto err;
  97         PARA_NOTICE_LOG("prebuffering %ims, %i bytes\n",
  98                 prebuffer_conf->duration_arg, prebuffer_conf->size_arg);
  99         *config = prebuffer_conf;
 100         return 1;
 101 err:
 102         free(prebuffer_conf);
 103         return ret;
 104 }
 105
 106 static void prebuffer_open(struct filter_node *fn)
 107 {
 108         struct private_prebuffer_data *ppd = para_calloc(sizeof(*ppd));
 109
 110         ppd->conf = fn->conf;
 111         fn->private_data = ppd;
 112         fn->bufsize = 8192; /* gets increased on demand */
 113         fn->buf = para_malloc(fn->bufsize);
 114 }
 115
 116 /**
 117  * The init function of the prebuffer filter.
 118  *
 119  * \param f Pointer to the struct to initialize.
 120  */
 121 void prebuffer_filter_init(struct filter *f)
 122 {
 123         struct prebuffer_filter_args_info dummy;
 124
 125         prebuffer_cmdline_parser_init(&dummy);
 126         f->open = prebuffer_open;
 127         f->close = prebuffer_close;
 128         f->convert = prebuffer_convert;
 129         f->parse_config = prebuffer_parse_config;
 130         f->help = (struct ggo_help) {
 131                 .short_help = prebuffer_filter_args_info_help,
 132                 .detailed_help = prebuffer_filter_args_info_detailed_help
 133         };
 134 }