file_writer.c

   1 /*
   2  * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file file_writer.c simple output plugin for testing purposes */
  20
  21 #include "para.h"
  22 #include "list.h"
  23 #include "sched.h"
  24 #include "write.h"
  25 #include "string.h"
  26 #include "fd.h"
  27 #include "error.h"
  28
  29 /** data specific to the file writer */
  30 struct private_file_writer_data {
  31 /** the file descriptor of the output file */
  32 int fd;
  33 int check_fd;
  34 };
  35
  36 static int file_writer_open(struct writer_node *wn)
  37 {
  38         struct private_file_writer_data *pfwd = para_calloc(
  39                 sizeof(struct private_file_writer_data));
  40         char *tmp = para_tmpname(), *home = para_homedir(),
  41                 *filename = make_message("%s/.paraslash/%s", home, tmp);
  42
  43         free(home);
  44         free(tmp);
  45         wn->private_data = pfwd;
  46         pfwd->fd = open(filename, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
  47         free(filename);
  48         if (pfwd->fd >= 0)
  49                 return 8192;
  50         free(pfwd);
  51         return -E_FW_OPEN;
  52 }
  53
  54 static int file_writer_write(char *data, size_t nbytes, struct writer_node *wn)
  55 {
  56         struct private_file_writer_data *pfwd = wn->private_data;
  57         int ret = write(pfwd->fd, data, nbytes);
  58         if (ret < 0)
  59                 ret = -E_FW_WRITE;
  60         return ret;
  61 }
  62
  63 static void file_writer_pre_select(struct sched *s, struct task *t)
  64 {
  65         struct writer_node *wn = t->private_data;
  66         struct private_file_writer_data *pfwd = wn->private_data;
  67         struct writer_node_group *wng = wn->wng;
  68
  69 //      PARA_INFO_LOG("task %p check_fd: %d\n", t, pfwd->check_fd);
  70         pfwd->check_fd = 0;
  71         t->ret = -E_FW_NO_FILE;
  72         if (pfwd->fd <= 0)
  73                 return;
  74         t->ret = 0;
  75         if (!*wng->loaded)
  76                 return;
  77         t->ret = 1;
  78         para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  79         pfwd->check_fd = 1;
  80 }
  81
  82 static void file_writer_post_select(struct sched *s, struct task *t)
  83 {
  84         struct writer_node *wn = t->private_data;
  85         struct private_file_writer_data *pfwd = wn->private_data;
  86         struct writer_node_group *wng = wn->wng;
  87
  88         t->ret = 0;
  89         if (!pfwd->check_fd)
  90                 return;
  91         if (!*wng->loaded)
  92                 return;
  93         if (!FD_ISSET(pfwd->fd, &s->wfds))
  94                 return;
  95 //      PARA_INFO_LOG("writing %zd\n", *wng->loaded);
  96         t->ret = write(pfwd->fd, wng->buf, *wng->loaded);
  97         if (t->ret < 0)
  98                 t->ret = -E_FW_WRITE;
  99 }
 100
 101 static void file_writer_close(struct writer_node *wn)
 102 {
 103         struct private_file_writer_data *pfwd = wn->private_data;
 104         close(pfwd->fd);
 105         free(pfwd);
 106 }
 107
 108 /** the init function of the file writer */
 109 void file_writer_init(struct writer *w)
 110 {
 111         w->open = file_writer_open;
 112         w->write = file_writer_write;
 113         w->pre_select = file_writer_pre_select;
 114         w->post_select = file_writer_post_select;
 115         w->close = file_writer_close;
 116         w->shutdown = NULL; /* nothing to do */
 117 }