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 <regex.h>
  10 #include <sys/types.h>
  11 #include <dirent.h>
  12 #include <sys/time.h>
  13
  14 #include "para.h"
  15 #include "list.h"
  16 #include "sched.h"
  17 #include "ggo.h"
  18 #include "write.h"
  19 #include "string.h"
  20 #include "fd.h"
  21 #include "file_write.cmdline.h"
  22 #include "error.h"
  23
  24 /** data specific to the file writer */
  25 struct private_file_write_data {
  26         /** the file descriptor of the output file */
  27         int fd;
  28         /** non-zero if \a fd was added to the write fd set */
  29         int check_fd;
  30 };
  31
  32 /*
  33  * Get a random filename.
  34  *
  35  * This is by no means a secure way to create temporary files in a hostile
  36  * directory like \p /tmp. However, we use it only for creating temp files in
  37  * ~/.paraslash, for which it is OK. Result must be freed by the caller.
  38  */
  39 __must_check __malloc static char *random_filename(void)
  40 {
  41         char *result, *home = para_homedir();
  42         struct timeval tv;
  43
  44         gettimeofday(&tv, NULL);
  45         srandom(tv.tv_usec);
  46         result = make_message("%s/.paraslash/%08lu", home,
  47                 para_random(99999999));
  48         free(home);
  49         return result;
  50 }
  51
  52 static int file_write_open(struct writer_node *wn)
  53 {
  54         struct private_file_write_data *pfwd = para_calloc(
  55                 sizeof(struct private_file_write_data));
  56         struct file_write_args_info *conf = wn->conf;
  57         char *filename;
  58
  59         if (conf->filename_given)
  60                 filename = conf->filename_arg;
  61         else
  62                 filename = random_filename();
  63         wn->private_data = pfwd;
  64         pfwd->fd = open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  65         if (!conf->filename_given)
  66                 free(filename);
  67         if (pfwd->fd >= 0)
  68                 return 1;
  69         free(pfwd);
  70         return -E_FW_OPEN;
  71 }
  72
  73 static int file_write_pre_select(struct sched *s, struct writer_node *wn)
  74 {
  75         struct private_file_write_data *pfwd = wn->private_data;
  76         struct writer_node_group *wng = wn->wng;
  77
  78         pfwd->check_fd = 0;
  79         if (pfwd->fd <= 0)
  80                 return -E_FW_NO_FILE;
  81         if (!*wng->loaded)
  82                 return 1;
  83         para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  84         pfwd->check_fd = 1;
  85         return 1;
  86 }
  87
  88 static int file_write_post_select(struct sched *s, struct writer_node *wn)
  89 {
  90         struct private_file_write_data *pfwd = wn->private_data;
  91         struct writer_node_group *wng = wn->wng;
  92         int ret;
  93
  94         if (!pfwd->check_fd)
  95                 return 1;
  96         if (*wng->loaded <= wn->written)
  97                 return 1;
  98         if (!FD_ISSET(pfwd->fd, &s->wfds))
  99                 return 1;
 100 //      PARA_INFO_LOG("writing %zd\n", *wng->loaded);
 101         ret = write(pfwd->fd, *wng->bufp + wn->written,
 102                 *wng->loaded - wn->written);
 103         if (ret < 0)
 104                 return -E_FW_WRITE;
 105         wn->written += ret;
 106         return 1;
 107 }
 108
 109 static void file_write_close(struct writer_node *wn)
 110 {
 111         struct private_file_write_data *pfwd = wn->private_data;
 112         close(pfwd->fd);
 113         free(pfwd);
 114 }
 115
 116 __malloc static void *file_write_parse_config(const char *options)
 117 {
 118         struct file_write_args_info *conf
 119                 = para_calloc(sizeof(struct file_write_args_info));
 120         int ret = file_cmdline_parser_string(options, conf, "file_write");
 121
 122         PARA_INFO_LOG("conf->filename_given: %d\n", conf->filename_given);
 123         if (!ret)
 124                 return conf;
 125         free(conf);
 126         return NULL;
 127 }
 128
 129 /** the init function of the file writer */
 130 void file_write_init(struct writer *w)
 131 {
 132         struct file_write_args_info dummy;
 133
 134         file_cmdline_parser_init(&dummy);
 135         w->open = file_write_open;
 136         w->pre_select = file_write_pre_select;
 137         w->post_select = file_write_post_select;
 138         w->parse_config = file_write_parse_config;
 139         w->close = file_write_close;
 140         w->shutdown = NULL; /* nothing to do */
 141         w->help = (struct ggo_help) {
 142                 .short_help = file_write_args_info_help,
 143                 .detailed_help = file_write_args_info_detailed_help
 144         };
 145         file_cmdline_parser_free(&dummy);
 146 }