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         char *result, *home = para_homedir();
  35
  36         srandom(clock_get_realtime(NULL)->tv_usec);
  37         result = make_message("%s/.paraslash/%08ld", home,
  38                 para_random(99999999));
  39         free(home);
  40         return result;
  41 }
  42
  43 static int prepare_output_file(struct writer_node *wn)
  44 {
  45         const unsigned flags = O_WRONLY | O_CREAT, mode = S_IRUSR | S_IWUSR;
  46         int ret, fd;
  47         struct private_file_write_data *pfwd;
  48
  49
  50         if (WRITE_CMD_OPT_GIVEN(FILE, FILENAME, wn->lpr)) {
  51                 const char *path = WRITE_CMD_OPT_STRING_VAL(FILE, FILENAME,
  52                         wn->lpr);
  53                 ret = para_open(path, flags, mode);
  54         } else {
  55                 char *path = random_filename();
  56                 ret = para_open(path, flags, mode);
  57                 free(path);
  58         }
  59         if (ret < 0)
  60                 return ret;
  61         fd = ret;
  62         ret = mark_fd_blocking(fd);
  63         if (ret < 0) {
  64                 close(fd);
  65                 return ret;
  66         }
  67         pfwd = wn->private_data = para_calloc(sizeof(*pfwd));
  68         pfwd->fd = fd;
  69         return 1;
  70 }
  71
  72 static void file_write_pre_select(struct sched *s, void *context)
  73 {
  74         struct writer_node *wn = context;
  75         struct private_file_write_data *pfwd = wn->private_data;
  76         int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
  77
  78         if (ret == 0)
  79                 return;
  80         if (ret < 0 || !pfwd)
  81                 return sched_min_delay(s);
  82         para_fd_set(pfwd->fd, &s->wfds, &s->max_fileno);
  83 }
  84
  85 static void file_write_close(struct writer_node *wn)
  86 {
  87         struct private_file_write_data *pfwd = wn->private_data;
  88
  89         if (!pfwd)
  90                 return;
  91         close(pfwd->fd);
  92         free(pfwd);
  93 }
  94
  95 static int file_write_post_select(__a_unused struct sched *s, void *context)
  96 {
  97         struct writer_node *wn = context;
  98         struct private_file_write_data *pfwd = wn->private_data;
  99         struct btr_node *btrn = wn->btrn;
 100         int ret;
 101         char *buf;
 102         size_t bytes;
 103
 104         ret = task_get_notification(wn->task);
 105         if (ret < 0)
 106                 goto out;
 107         ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
 108         if (ret <= 0)
 109                 goto out;
 110         if (!pfwd) {
 111                 ret = prepare_output_file(wn);
 112                 goto out;
 113         }
 114         if (!FD_ISSET(pfwd->fd, &s->wfds))
 115                 return 0;
 116         bytes = btr_next_buffer(btrn, &buf);
 117         assert(bytes > 0);
 118         //PARA_INFO_LOG("writing %zu\n", bytes);
 119         ret = xwrite(pfwd->fd, buf, bytes);
 120         if (ret < 0)
 121                 goto out;
 122         btr_consume(btrn, ret);
 123 out:
 124         if (ret < 0)
 125                 btr_remove_node(&wn->btrn);
 126         return ret;
 127 }
 128
 129 /** the init function of the file writer */
 130 struct writer lsg_write_cmd_com_file_user_data = {
 131         .pre_select = file_write_pre_select,
 132         .post_select = file_write_post_select,
 133         .close = file_write_close,
 134 };