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 #include <stdbool.h>
  14
  15 #include "para.h"
  16 #include "list.h"
  17 #include "sched.h"
  18 #include "ggo.h"
  19 #include "buffer_tree.h"
  20 #include "write.h"
  21 #include "string.h"
  22 #include "fd.h"
  23 #include "file_write.cmdline.h"
  24 #include "error.h"
  25
  26 /** data specific to the file writer */
  27 struct private_file_write_data {
  28         /** the file descriptor of the output file */
  29         int fd;
  30         /** non-zero if \a fd was added to the write fd set */
  31         int check_fd;
  32 };
  33
  34 /*
  35  * Get a random filename.
  36  *
  37  * This is by no means a secure way to create temporary files in a hostile
  38  * directory like \p /tmp. However, we use it only for creating temp files in
  39  * ~/.paraslash, for which it is OK. Result must be freed by the caller.
  40  */
  41 __must_check __malloc static char *random_filename(void)
  42 {
  43         char *result, *home = para_homedir();
  44         struct timeval tv;
  45
  46         gettimeofday(&tv, NULL);
  47         srandom(tv.tv_usec);
  48         result = make_message("%s/.paraslash/%08lu", home,
  49                 para_random(99999999));
  50         free(home);
  51         return result;
  52 }
  53
  54 static int file_write_open(struct writer_node *wn)
  55 {
  56         struct private_file_write_data *pfwd = para_calloc(
  57                 sizeof(struct private_file_write_data));
  58         struct file_write_args_info *conf = wn->conf;
  59         char *filename;
  60
  61         if (conf->filename_given)
  62                 filename = conf->filename_arg;
  63         else
  64                 filename = random_filename();
  65         wn->private_data = pfwd;
  66         pfwd->fd = open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  67         if (!conf->filename_given)
  68                 free(filename);
  69         if (pfwd->fd >= 0)
  70                 return 1;
  71         free(pfwd);
  72         return -E_FW_OPEN;
  73 }
  74
  75 static int file_write_pre_select(struct sched *s, struct writer_node *wn)
  76 {
  77         struct private_file_write_data *pfwd = wn->private_data;
  78         struct writer_node_group *wng = wn->wng;
  79
  80         pfwd->check_fd = 0;
  81         if (pfwd->fd <= 0)
  82                 return -E_FW_NO_FILE;
  83         if (!*wng->loaded)
  84                 return 1;
  85         para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  86         pfwd->check_fd = 1;
  87         return 1;
  88 }
  89
  90 static int file_write_post_select(struct sched *s, struct writer_node *wn)
  91 {
  92         struct private_file_write_data *pfwd = wn->private_data;
  93         struct writer_node_group *wng = wn->wng;
  94         int ret;
  95
  96         if (!pfwd->check_fd)
  97                 return 1;
  98         if (*wng->loaded <= wn->written)
  99                 return 1;
 100         if (!FD_ISSET(pfwd->fd, &s->wfds))
 101                 return 1;
 102 //      PARA_INFO_LOG("writing %zd\n", *wng->loaded);
 103         ret = write(pfwd->fd, *wng->bufp + wn->written,
 104                 *wng->loaded - wn->written);
 105         if (ret < 0)
 106                 return -E_FW_WRITE;
 107         wn->written += ret;
 108         return 1;
 109 }
 110
 111 static void file_write_close(struct writer_node *wn)
 112 {
 113         struct private_file_write_data *pfwd = wn->private_data;
 114         close(pfwd->fd);
 115         free(pfwd);
 116 }
 117
 118 __malloc static void *file_write_parse_config(const char *options)
 119 {
 120         struct file_write_args_info *conf
 121                 = para_calloc(sizeof(struct file_write_args_info));
 122         int ret = file_cmdline_parser_string(options, conf, "file_write");
 123
 124         PARA_INFO_LOG("conf->filename_given: %d\n", conf->filename_given);
 125         if (!ret)
 126                 return conf;
 127         free(conf);
 128         return NULL;
 129 }
 130
 131 /** the init function of the file writer */
 132 void file_write_init(struct writer *w)
 133 {
 134         struct file_write_args_info dummy;
 135
 136         file_cmdline_parser_init(&dummy);
 137         w->open = file_write_open;
 138         w->pre_select = file_write_pre_select;
 139         w->post_select = file_write_post_select;
 140         w->parse_config = file_write_parse_config;
 141         w->close = file_write_close;
 142         w->shutdown = NULL; /* nothing to do */
 143         w->help = (struct ggo_help) {
 144                 .short_help = file_write_args_info_help,
 145                 .detailed_help = file_write_args_info_detailed_help
 146         };
 147         file_cmdline_parser_free(&dummy);
 148 }