file_write.c

   1 /* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file file_write.c simple output plugin for testing purposes */
   4
   5 #include <regex.h>
   6 #include <sys/types.h>
   7 #include <lopsub.h>
   8
   9 #include "write_cmd.lsg.h"
  10 #include "para.h"
  11 #include "list.h"
  12 #include "sched.h"
  13 #include "buffer_tree.h"
  14 #include "write.h"
  15 #include "string.h"
  16 #include "fd.h"
  17 #include "error.h"
  18
  19 /** Data specific to the file writer. */
  20 struct private_file_write_data {
  21         /** The file descriptor of the output file. */
  22         int fd;
  23 };
  24
  25 /*
  26  * Get a random filename.
  27  *
  28  * This is by no means a secure way to create temporary files in a hostile
  29  * directory like \p /tmp. However, we use it only for creating temp files in
  30  * ~/.paraslash, for which it is OK. Result must be freed by the caller.
  31  */
  32 __must_check __malloc static char *random_filename(void)
  33 {
  34         srandom(clock_get_realtime(NULL)->tv_usec);
  35         return make_message("%s/%08ld", get_confdir(), para_random(99999999));
  36 }
  37
  38 static int prepare_output_file(struct writer_node *wn)
  39 {
  40         const unsigned flags = O_WRONLY | O_CREAT, mode = S_IRUSR | S_IWUSR;
  41         int ret, fd;
  42         struct private_file_write_data *pfwd;
  43
  44
  45         if (WRITE_CMD_OPT_GIVEN(FILE, FILENAME, wn->lpr)) {
  46                 const char *path = WRITE_CMD_OPT_STRING_VAL(FILE, FILENAME,
  47                         wn->lpr);
  48                 ret = para_open(path, flags, mode);
  49         } else {
  50                 char *path = random_filename();
  51                 ret = para_open(path, flags, mode);
  52                 free(path);
  53         }
  54         if (ret < 0)
  55                 return ret;
  56         fd = ret;
  57         ret = mark_fd_blocking(fd);
  58         if (ret < 0) {
  59                 close(fd);
  60                 return ret;
  61         }
  62         pfwd = wn->private_data = zalloc(sizeof(*pfwd));
  63         pfwd->fd = fd;
  64         return 1;
  65 }
  66
  67 static void file_write_pre_monitor(struct sched *s, void *context)
  68 {
  69         struct writer_node *wn = context;
  70         struct private_file_write_data *pfwd = wn->private_data;
  71         int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
  72
  73         if (ret == 0)
  74                 return;
  75         if (ret < 0 || !pfwd)
  76                 return sched_min_delay(s);
  77         sched_monitor_writefd(pfwd->fd, s);
  78 }
  79
  80 static void file_write_close(struct writer_node *wn)
  81 {
  82         struct private_file_write_data *pfwd = wn->private_data;
  83
  84         if (!pfwd)
  85                 return;
  86         close(pfwd->fd);
  87         free(pfwd);
  88 }
  89
  90 static int file_write_post_monitor(__a_unused struct sched *s, void *context)
  91 {
  92         struct writer_node *wn = context;
  93         struct private_file_write_data *pfwd = wn->private_data;
  94         struct btr_node *btrn = wn->btrn;
  95         int ret;
  96         char *buf;
  97         size_t bytes;
  98
  99         ret = task_get_notification(wn->task);
 100         if (ret < 0)
 101                 goto out;
 102         ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
 103         if (ret <= 0)
 104                 goto out;
 105         if (!pfwd) {
 106                 ret = prepare_output_file(wn);
 107                 goto out;
 108         }
 109         if (!sched_write_ok(pfwd->fd, s))
 110                 return 0;
 111         bytes = btr_next_buffer(btrn, &buf);
 112         assert(bytes > 0);
 113         //PARA_INFO_LOG("writing %zu\n", bytes);
 114         ret = xwrite(pfwd->fd, buf, bytes);
 115         if (ret < 0)
 116                 goto out;
 117         btr_consume(btrn, ret);
 118 out:
 119         if (ret < 0)
 120                 btr_remove_node(&wn->btrn);
 121         return ret;
 122 }
 123
 124 /** the init function of the file writer */
 125 struct writer lsg_write_cmd_com_file_user_data = {
 126         .pre_monitor = file_write_pre_monitor,
 127         .post_monitor = file_write_post_monitor,
 128         .close = file_write_close,
 129 };