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 "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
  60         if (conf->filename_given)
  61                 filename = conf->filename_arg;
  62         else
  63                 filename = random_filename();
  64         wn->private_data = pfwd;
  65         pfwd->fd = open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  66         if (!conf->filename_given)
  67                 free(filename);
  68         if (pfwd->fd >= 0)
  69                 return 1;
  70         free(pfwd);
  71         return -E_FW_OPEN;
  72 }
  73
  74 static void file_write_pre_select_btr(struct sched *s, struct task *t)
  75 {
  76         struct writer_node *wn = container_of(t, struct writer_node, task);
  77         struct private_file_write_data *pfwd = wn->private_data;
  78         int ret;
  79
  80         t->error = 0;
  81         ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
  82         if (ret > 0) {
  83                 para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  84         } else if (ret < 0) {
  85                 s->timeout.tv_sec = 0;
  86                 s->timeout.tv_usec = 1;
  87         }
  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         close(pfwd->fd);
  95         free(pfwd);
  96 }
  97
  98 static void file_write_post_select_btr(__a_unused struct sched *s,
  99                 struct task *t)
 100 {
 101         struct writer_node *wn = container_of(t, struct writer_node, task);
 102         struct private_file_write_data *pfwd = wn->private_data;
 103         struct btr_node *btrn = wn->btrn;
 104         int ret;
 105         char *buf;
 106         size_t bytes;
 107
 108         t->error = 0;
 109         ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
 110         if (ret <= 0)
 111                 goto out;
 112         if (!FD_ISSET(pfwd->fd, &s->wfds))
 113                 return;
 114         bytes = btr_next_buffer(btrn, &buf);
 115         assert(bytes > 0);
 116         //PARA_INFO_LOG("writing %zu\n", bytes);
 117         ret = write(pfwd->fd, buf, bytes);
 118         if (ret < 0)
 119                 goto out;
 120         btr_consume(btrn, ret);
 121 out:
 122         if (ret < 0)
 123                 btr_remove_node(btrn);
 124         t->error = ret;
 125 }
 126
 127 __malloc static void *file_write_parse_config(const char *options)
 128 {
 129         struct file_write_args_info *conf
 130                 = para_calloc(sizeof(struct file_write_args_info));
 131         int ret = file_cmdline_parser_string(options, conf, "file_write");
 132
 133         PARA_INFO_LOG("conf->filename_given: %d\n", conf->filename_given);
 134         if (!ret)
 135                 return conf;
 136         free(conf);
 137         return NULL;
 138 }
 139
 140 static void file_write_free_config(void *conf)
 141 {
 142         file_cmdline_parser_free(conf);
 143 }
 144
 145 /** the init function of the file writer */
 146 void file_write_init(struct writer *w)
 147 {
 148         struct file_write_args_info dummy;
 149
 150         file_cmdline_parser_init(&dummy);
 151         w->open = file_write_open;
 152         w->pre_select_btr = file_write_pre_select_btr;
 153         w->post_select_btr = file_write_post_select_btr;
 154         w->parse_config = file_write_parse_config;
 155         w->free_config = file_write_free_config;
 156         w->close = file_write_close;
 157         w->shutdown = NULL; /* nothing to do */
 158         w->help = (struct ggo_help) {
 159                 .short_help = file_write_args_info_help,
 160                 .detailed_help = file_write_args_info_detailed_help
 161         };
 162         file_cmdline_parser_free(&dummy);
 163 }