file_write.c

   1 /*
   2  * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file file_write.c simple output plugin for testing purposes */
   8
   9 #include <sys/types.h>
  10 #include <dirent.h>
  11 #include <sys/time.h>
  12
  13 #include "para.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "ggo.h"
  17 #include "write.h"
  18 #include "string.h"
  19 #include "fd.h"
  20 #include "file_write.cmdline.h"
  21 #include "error.h"
  22
  23 /** data specific to the file writer */
  24 struct private_file_write_data {
  25         /** the file descriptor of the output file */
  26         int fd;
  27         /** non-zero if \a fd was added to the write fd set */
  28         int check_fd;
  29 };
  30
  31 /*
  32  * Get a random filename.
  33  *
  34  * This is by no means a secure way to create temporary files in a hostile
  35  * directory like \p /tmp. However, we use it only for creating temp files in
  36  * ~/.paraslash, for which it is OK. Result must be freed by the caller.
  37  */
  38 __must_check __malloc static char *random_filename(void)
  39 {
  40         char *result, *home = para_homedir();
  41         struct timeval tv;
  42
  43         gettimeofday(&tv, NULL);
  44         srandom(tv.tv_usec);
  45         result = make_message("%s/.paraslash/%08lu", home,
  46                 para_random(99999999));
  47         free(home);
  48         return result;
  49 }
  50
  51 static int file_write_open(struct writer_node *wn)
  52 {
  53         struct private_file_write_data *pfwd = para_calloc(
  54                 sizeof(struct private_file_write_data));
  55         struct file_write_args_info *conf = wn->conf;
  56         char *filename;
  57
  58         if (conf->filename_given)
  59                 filename = conf->filename_arg;
  60         else
  61                 filename = random_filename();
  62         wn->private_data = pfwd;
  63         pfwd->fd = open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  64         if (!conf->filename_given)
  65                 free(filename);
  66         if (pfwd->fd >= 0)
  67                 return 1;
  68         free(pfwd);
  69         return -E_FW_OPEN;
  70 }
  71
  72 static int file_write_pre_select(struct sched *s, struct writer_node *wn)
  73 {
  74         struct private_file_write_data *pfwd = wn->private_data;
  75         struct writer_node_group *wng = wn->wng;
  76
  77         pfwd->check_fd = 0;
  78         if (pfwd->fd <= 0)
  79                 return -E_FW_NO_FILE;
  80         if (!*wng->loaded)
  81                 return 1;
  82         para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  83         pfwd->check_fd = 1;
  84         return 1;
  85 }
  86
  87 static int file_write_post_select(struct sched *s, struct writer_node *wn)
  88 {
  89         struct private_file_write_data *pfwd = wn->private_data;
  90         struct writer_node_group *wng = wn->wng;
  91         int ret;
  92
  93         if (!pfwd->check_fd)
  94                 return 1;
  95         if (*wng->loaded <= wn->written)
  96                 return 1;
  97         if (!FD_ISSET(pfwd->fd, &s->wfds))
  98                 return 1;
  99 //      PARA_INFO_LOG("writing %zd\n", *wng->loaded);
 100         ret = write(pfwd->fd, *wng->bufp + wn->written,
 101                 *wng->loaded - wn->written);
 102         if (ret < 0)
 103                 return -E_FW_WRITE;
 104         wn->written += ret;
 105         return 1;
 106 }
 107
 108 static void file_write_close(struct writer_node *wn)
 109 {
 110         struct private_file_write_data *pfwd = wn->private_data;
 111         close(pfwd->fd);
 112         free(pfwd);
 113 }
 114
 115 __malloc static void *file_write_parse_config(const char *options)
 116 {
 117         struct file_write_args_info *conf
 118                 = para_calloc(sizeof(struct file_write_args_info));
 119         int ret = file_cmdline_parser_string(options, conf, "file_write");
 120
 121         PARA_INFO_LOG("conf->filename_given: %d\n", conf->filename_given);
 122         if (!ret)
 123                 return conf;
 124         free(conf);
 125         return NULL;
 126 }
 127
 128 /** the init function of the file writer */
 129 void file_write_init(struct writer *w)
 130 {
 131         struct file_write_args_info dummy;
 132
 133         file_cmdline_parser_init(&dummy);
 134         w->open = file_write_open;
 135         w->pre_select = file_write_pre_select;
 136         w->post_select = file_write_post_select;
 137         w->parse_config = file_write_parse_config;
 138         w->close = file_write_close;
 139         w->shutdown = NULL; /* nothing to do */
 140         w->help = (struct ggo_help) {
 141                 .short_help = file_write_args_info_help,
 142                 .detailed_help = file_write_args_info_detailed_help
 143         };
 144 }