file_write.c

   1 /*
   2  * Copyright (C) 2006-2012 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 <sys/time.h>
  12
  13 #include "para.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "ggo.h"
  17 #include "buffer_tree.h"
  18 #include "write.h"
  19 #include "write_common.h"
  20 #include "string.h"
  21 #include "fd.h"
  22 #include "file_write.cmdline.h"
  23 #include "error.h"
  24
  25 /** Data specific to the file writer. */
  26 struct private_file_write_data {
  27         /** The file descriptor of the output file. */
  28         int 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 prepare_output_file(struct writer_node *wn)
  52 {
  53         struct file_write_args_info *conf = wn->conf;
  54         char *filename;
  55         int ret;
  56         struct private_file_write_data *pfwd = para_calloc(sizeof(*pfwd));
  57
  58         if (conf->filename_given)
  59                 filename = conf->filename_arg;
  60         else
  61                 filename = random_filename();
  62         ret = para_open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  63         if (!conf->filename_given)
  64                 free(filename);
  65         if (ret < 0)
  66                 goto out;
  67         pfwd->fd = ret;
  68         ret = mark_fd_blocking(pfwd->fd);
  69         if (ret < 0)
  70                 goto out_close;
  71         wn->private_data = pfwd;
  72         return 1;
  73 out_close:
  74         close(pfwd->fd);
  75 out:
  76         free(pfwd);
  77         return ret;
  78 }
  79
  80 static void file_write_pre_select(struct sched *s, struct task *t)
  81 {
  82         struct writer_node *wn = container_of(t, struct writer_node, task);
  83         struct private_file_write_data *pfwd = wn->private_data;
  84         int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
  85
  86         if (ret == 0)
  87                 return;
  88         if (ret < 0 || !pfwd)
  89                 return sched_min_delay(s);
  90         para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  91 }
  92
  93 static void file_write_close(struct writer_node *wn)
  94 {
  95         struct private_file_write_data *pfwd = wn->private_data;
  96
  97         if (!pfwd)
  98                 return;
  99         close(pfwd->fd);
 100         free(pfwd);
 101 }
 102
 103 static void file_write_post_select(__a_unused struct sched *s,
 104                 struct task *t)
 105 {
 106         struct writer_node *wn = container_of(t, struct writer_node, task);
 107         struct private_file_write_data *pfwd = wn->private_data;
 108         struct btr_node *btrn = wn->btrn;
 109         int ret;
 110         char *buf;
 111         size_t bytes;
 112
 113         t->error = 0;
 114         ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
 115         if (ret <= 0)
 116                 goto out;
 117         if (!pfwd) {
 118                 ret = prepare_output_file(wn);
 119                 goto out;
 120         }
 121         if (!FD_ISSET(pfwd->fd, &s->wfds))
 122                 return;
 123         bytes = btr_next_buffer(btrn, &buf);
 124         assert(bytes > 0);
 125         //PARA_INFO_LOG("writing %zu\n", bytes);
 126         ret = write(pfwd->fd, buf, bytes);
 127         if (ret < 0)
 128                 goto out;
 129         btr_consume(btrn, ret);
 130 out:
 131         if (ret < 0)
 132                 btr_remove_node(btrn);
 133         t->error = ret;
 134 }
 135
 136 __malloc static void *file_write_parse_config_or_die(const char *options)
 137 {
 138         struct file_write_args_info *conf = para_calloc(sizeof(*conf));
 139
 140         /* exits on errors */
 141         file_cmdline_parser_string(options, conf, "file_write");
 142         return conf;
 143 }
 144
 145 static void file_write_free_config(void *conf)
 146 {
 147         file_cmdline_parser_free(conf);
 148 }
 149
 150 /** the init function of the file writer */
 151 void file_write_init(struct writer *w)
 152 {
 153         struct file_write_args_info dummy;
 154
 155         file_cmdline_parser_init(&dummy);
 156         w->pre_select = file_write_pre_select;
 157         w->post_select = file_write_post_select;
 158         w->parse_config_or_die = file_write_parse_config_or_die;
 159         w->free_config = file_write_free_config;
 160         w->close = file_write_close;
 161         w->shutdown = NULL; /* nothing to do */
 162         w->help = (struct ggo_help) {
 163                 .short_help = file_write_args_info_help,
 164                 .detailed_help = file_write_args_info_detailed_help
 165         };
 166         file_cmdline_parser_free(&dummy);
 167 }