file_write.c

   1 /*
   2  * Copyright (C) 2006-2010 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 "write_common.h"
  22 #include "string.h"
  23 #include "fd.h"
  24 #include "file_write.cmdline.h"
  25 #include "error.h"
  26
  27 /** Data specific to the file writer. */
  28 struct private_file_write_data {
  29         /** The file descriptor of the output file. */
  30         int fd;
  31 };
  32
  33 /*
  34  * Get a random filename.
  35  *
  36  * This is by no means a secure way to create temporary files in a hostile
  37  * directory like \p /tmp. However, we use it only for creating temp files in
  38  * ~/.paraslash, for which it is OK. Result must be freed by the caller.
  39  */
  40 __must_check __malloc static char *random_filename(void)
  41 {
  42         char *result, *home = para_homedir();
  43         struct timeval tv;
  44
  45         gettimeofday(&tv, NULL);
  46         srandom(tv.tv_usec);
  47         result = make_message("%s/.paraslash/%08lu", home,
  48                 para_random(99999999));
  49         free(home);
  50         return result;
  51 }
  52
  53 static int file_write_open(struct writer_node *wn)
  54 {
  55         struct private_file_write_data *pfwd = para_calloc(
  56                 sizeof(struct private_file_write_data));
  57         struct file_write_args_info *conf = wn->conf;
  58         char *filename;
  59         int ret;
  60
  61         if (conf->filename_given)
  62                 filename = conf->filename_arg;
  63         else
  64                 filename = random_filename();
  65         wn->private_data = pfwd;
  66         ret = para_open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  67         if (!conf->filename_given)
  68                 free(filename);
  69         if (ret < 0)
  70                 goto out;
  71         pfwd->fd = ret;
  72         ret = mark_fd_blocking(pfwd->fd);
  73         if (ret >= 0)
  74                 return 1;
  75         close(pfwd->fd);
  76 out:
  77         free(pfwd);
  78         return ret;
  79 }
  80
  81 static void file_write_pre_select(struct sched *s, struct task *t)
  82 {
  83         struct writer_node *wn = container_of(t, struct writer_node, task);
  84         struct private_file_write_data *pfwd = wn->private_data;
  85         int ret;
  86
  87         t->error = 0;
  88         ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
  89         if (ret > 0)
  90                 para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  91         else if (ret < 0)
  92                 sched_min_delay(s);
  93 }
  94
  95 static void file_write_close(struct writer_node *wn)
  96 {
  97         struct private_file_write_data *pfwd = wn->private_data;
  98
  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 (!FD_ISSET(pfwd->fd, &s->wfds))
 118                 return;
 119         bytes = btr_next_buffer(btrn, &buf);
 120         assert(bytes > 0);
 121         //PARA_INFO_LOG("writing %zu\n", bytes);
 122         ret = write(pfwd->fd, buf, bytes);
 123         if (ret < 0)
 124                 goto out;
 125         btr_consume(btrn, ret);
 126 out:
 127         if (ret < 0)
 128                 btr_remove_node(btrn);
 129         t->error = ret;
 130 }
 131
 132 __malloc static void *file_write_parse_config(const char *options)
 133 {
 134         struct file_write_args_info *conf
 135                 = para_calloc(sizeof(struct file_write_args_info));
 136         int ret = file_cmdline_parser_string(options, conf, "file_write");
 137
 138         PARA_INFO_LOG("conf->filename_given: %d\n", conf->filename_given);
 139         if (!ret)
 140                 return conf;
 141         free(conf);
 142         return NULL;
 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->open = file_write_open;
 157         w->pre_select = file_write_pre_select;
 158         w->post_select = file_write_post_select;
 159         w->parse_config = file_write_parse_config;
 160         w->free_config = file_write_free_config;
 161         w->close = file_write_close;
 162         w->shutdown = NULL; /* nothing to do */
 163         w->help = (struct ggo_help) {
 164                 .short_help = file_write_args_info_help,
 165                 .detailed_help = file_write_args_info_detailed_help
 166         };
 167         file_cmdline_parser_free(&dummy);
 168 }