file_write.c

   1 /*
   2  * Copyright (C) 2006-2013 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
  12 #include "para.h"
  13 #include "list.h"
  14 #include "sched.h"
  15 #include "ggo.h"
  16 #include "buffer_tree.h"
  17 #include "write.h"
  18 #include "write_common.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 };
  29
  30 /*
  31  * Get a random filename.
  32  *
  33  * This is by no means a secure way to create temporary files in a hostile
  34  * directory like \p /tmp. However, we use it only for creating temp files in
  35  * ~/.paraslash, for which it is OK. Result must be freed by the caller.
  36  */
  37 __must_check __malloc static char *random_filename(void)
  38 {
  39         char *result, *home = para_homedir();
  40
  41         srandom(clock_get_realtime(NULL)->tv_usec);
  42         result = make_message("%s/.paraslash/%08lu", home,
  43                 para_random(99999999));
  44         free(home);
  45         return result;
  46 }
  47
  48 static int prepare_output_file(struct writer_node *wn)
  49 {
  50         struct file_write_args_info *conf = wn->conf;
  51         char *filename;
  52         int ret;
  53         struct private_file_write_data *pfwd = para_calloc(sizeof(*pfwd));
  54
  55         if (conf->filename_given)
  56                 filename = conf->filename_arg;
  57         else
  58                 filename = random_filename();
  59         ret = para_open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  60         if (!conf->filename_given)
  61                 free(filename);
  62         if (ret < 0)
  63                 goto out;
  64         pfwd->fd = ret;
  65         ret = mark_fd_blocking(pfwd->fd);
  66         if (ret < 0)
  67                 goto out_close;
  68         wn->private_data = pfwd;
  69         return 1;
  70 out_close:
  71         close(pfwd->fd);
  72 out:
  73         free(pfwd);
  74         return ret;
  75 }
  76
  77 static void file_write_pre_select(struct sched *s, struct task *t)
  78 {
  79         struct writer_node *wn = container_of(t, struct writer_node, task);
  80         struct private_file_write_data *pfwd = wn->private_data;
  81         int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
  82
  83         if (ret == 0)
  84                 return;
  85         if (ret < 0 || !pfwd)
  86                 return sched_min_delay(s);
  87         para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  88 }
  89
  90 static void file_write_close(struct writer_node *wn)
  91 {
  92         struct private_file_write_data *pfwd = wn->private_data;
  93
  94         if (!pfwd)
  95                 return;
  96         close(pfwd->fd);
  97         free(pfwd);
  98 }
  99
 100 static int file_write_post_select(__a_unused struct sched *s,
 101                 struct task *t)
 102 {
 103         struct writer_node *wn = container_of(t, struct writer_node, task);
 104         struct private_file_write_data *pfwd = wn->private_data;
 105         struct btr_node *btrn = wn->btrn;
 106         int ret;
 107         char *buf;
 108         size_t bytes;
 109
 110         ret = task_get_notification(t);
 111         if (ret < 0)
 112                 goto out;
 113         ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
 114         if (ret <= 0)
 115                 goto out;
 116         if (!pfwd) {
 117                 ret = prepare_output_file(wn);
 118                 goto out;
 119         }
 120         if (!FD_ISSET(pfwd->fd, &s->wfds))
 121                 return 0;
 122         bytes = btr_next_buffer(btrn, &buf);
 123         assert(bytes > 0);
 124         //PARA_INFO_LOG("writing %zu\n", bytes);
 125         ret = xwrite(pfwd->fd, buf, bytes);
 126         if (ret < 0)
 127                 goto out;
 128         btr_consume(btrn, ret);
 129 out:
 130         if (ret < 0)
 131                 btr_remove_node(&wn->btrn);
 132         return ret;
 133 }
 134
 135 __malloc static void *file_write_parse_config_or_die(int argc, char **argv)
 136 {
 137         struct file_write_args_info *conf = para_calloc(sizeof(*conf));
 138
 139         /* exits on errors */
 140         file_write_cmdline_parser(argc, argv, conf);
 141         return conf;
 142 }
 143
 144 static void file_write_free_config(void *conf)
 145 {
 146         file_write_cmdline_parser_free(conf);
 147 }
 148
 149 /** the init function of the file writer */
 150 void file_write_init(struct writer *w)
 151 {
 152         struct file_write_args_info dummy;
 153
 154         file_write_cmdline_parser_init(&dummy);
 155         w->pre_select = file_write_pre_select;
 156         w->post_select = file_write_post_select;
 157         w->parse_config_or_die = file_write_parse_config_or_die;
 158         w->free_config = file_write_free_config;
 159         w->close = file_write_close;
 160         w->help = (struct ggo_help)DEFINE_GGO_HELP(file_write);
 161         file_write_cmdline_parser_free(&dummy);
 162 }