src/checkpoint.c

   1 /* Checkpoint management for tar.
   2
   3    Copyright (C) 2007 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by the
   7    Free Software Foundation; either version 3, or (at your option) any later
   8    version.
   9
  10    This program is distributed in the hope that it will be useful, but
  11    WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
  13    Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License along
  16    with this program.  If not, see <http://www.gnu.org/licenses/>. */
  17
  18 #include <system.h>
  19 #include "common.h"
  20
  21 enum checkpoint_opcode
  22   {
  23     cop_dot,
  24     cop_bell,
  25     cop_echo,
  26     cop_ttyout,
  27     cop_sleep,
  28     cop_exec
  29   };
  30
  31 struct checkpoint_action
  32 {
  33   struct checkpoint_action *next;
  34   enum checkpoint_opcode opcode;
  35   union
  36   {
  37     time_t time;
  38     char *command;
  39   } v;
  40 };
  41
  42 /* Checkpointing counter */
  43 static unsigned checkpoint;
  44
  45 /* List of checkpoint actions */
  46 static struct checkpoint_action *checkpoint_action, *checkpoint_action_tail;
  47
  48 static struct checkpoint_action *
  49 alloc_action (enum checkpoint_opcode opcode)
  50 {
  51   struct checkpoint_action *p = xzalloc (sizeof *p);
  52   if (checkpoint_action_tail)
  53     checkpoint_action_tail->next = p;
  54   else
  55     checkpoint_action = p;
  56   checkpoint_action_tail = p;
  57   p->opcode = opcode;
  58   return p;
  59 }
  60
  61 static char *
  62 copy_string_unquote (const char *str)
  63 {
  64   char *output = xstrdup (str);
  65   size_t len = strlen (output);
  66   if ((*output == '"' || *output == '\'')
  67       && output[len-1] == *output)
  68     {
  69       memmove (output, output+1, len-2);
  70       output[len-2] = 0;
  71     }
  72   unquote_string (output);
  73   return output;
  74 }
  75
  76 void
  77 checkpoint_compile_action (const char *str)
  78 {
  79   struct checkpoint_action *act;
  80
  81   if (strcmp (str, ".") == 0 || strcmp (str, "dot") == 0)
  82     alloc_action (cop_dot);
  83   else if (strcmp (str, "bell") == 0)
  84     alloc_action (cop_bell);
  85   else if (strcmp (str, "echo") == 0)
  86     alloc_action (cop_echo);
  87   else if (strncmp (str, "echo=", 5) == 0)
  88     {
  89       act = alloc_action (cop_echo);
  90       act->v.command = copy_string_unquote (str + 5);
  91     }
  92   else if (strncmp (str, "exec=", 5) == 0)
  93     {
  94       act = alloc_action (cop_exec);
  95       act->v.command = copy_string_unquote (str + 5);
  96     }
  97   else if (strncmp (str, "ttyout=", 7) == 0)
  98     {
  99       act = alloc_action (cop_ttyout);
 100       act->v.command = copy_string_unquote (str + 7);
 101     }
 102   else if (strncmp (str, "sleep=", 6) == 0)
 103     {
 104       char *p;
 105       time_t n = strtoul (str+6, &p, 10);
 106       if (*p)
 107         FATAL_ERROR ((0, 0, _("%s: not a valid timeout"), str));
 108       act = alloc_action (cop_sleep);
 109       act->v.time = n;
 110     }
 111   else
 112     FATAL_ERROR ((0, 0, _("%s: unknown checkpoint action"), str));
 113 }
 114
 115 void
 116 checkpoint_finish_compile ()
 117 {
 118   if (checkpoint_option)
 119     {
 120       if (!checkpoint_action)
 121         /* Provide a historical default */
 122         checkpoint_compile_action ("echo");
 123     }
 124   else if (checkpoint_action)
 125     /* Otherwise, set default checkpoint rate */
 126     checkpoint_option = DEFAULT_CHECKPOINT;
 127 }
 128
 129 static char *
 130 expand_checkpoint_string (const char *input, bool do_write, unsigned cpn)
 131 {
 132   const char *opstr = do_write ? gettext ("write") : gettext ("read");
 133   size_t opstrlen = strlen (opstr);
 134   char uintbuf[UINTMAX_STRSIZE_BOUND];
 135   char *cps = STRINGIFY_BIGINT (cpn, uintbuf);
 136   size_t cpslen = strlen (cps);
 137   const char *ip;
 138   char *op;
 139   char *output;
 140   size_t outlen = strlen (input); /* Initial guess */
 141
 142   /* Fix the initial length guess */
 143   for (ip = input; (ip = strchr (ip, '%')) != NULL; )
 144     {
 145       switch (ip[1])
 146         {
 147         case 'u':
 148           outlen += cpslen - 2;
 149           break;
 150
 151         case 's':
 152           outlen += opstrlen - 2;
 153         }
 154       ip++;
 155     }
 156
 157   output = xmalloc (outlen + 1);
 158   for (ip = input, op = output; *ip; )
 159     {
 160       if (*ip == '%')
 161         {
 162           switch (*++ip)
 163             {
 164             case 'u':
 165               op = stpcpy (op, cps);
 166               break;
 167
 168             case 's':
 169               op = stpcpy (op, opstr);
 170               break;
 171
 172             default:
 173               *op++ = '%';
 174               *op++ = *ip;
 175               break;
 176             }
 177           ip++;
 178         }
 179       else
 180         *op++ = *ip++;
 181     }
 182   *op = 0;
 183   return output;
 184 }
 185
 186 static void
 187 run_checkpoint_actions (bool do_write)
 188 {
 189   struct checkpoint_action *p;
 190   FILE *tty = NULL;
 191
 192   for (p = checkpoint_action; p; p = p->next)
 193     {
 194       switch (p->opcode)
 195         {
 196         case cop_dot:
 197           fputc ('.', stdlis);
 198           fflush (stdlis);
 199           break;
 200
 201         case cop_bell:
 202           if (!tty)
 203             tty = fopen ("/dev/tty", "w");
 204           if (tty)
 205             {
 206               fputc ('\a', tty);
 207               fflush (tty);
 208             }
 209           break;
 210
 211         case cop_echo:
 212           {
 213             char *tmp;
 214             const char *str = p->v.command;
 215             if (!str)
 216               {
 217                 if (do_write)
 218                   /* TRANSLATORS: This is a ``checkpoint of write operation'',
 219                      *not* ``Writing a checkpoint''.
 220                      E.g. in Spanish ``Punto de comprobaci@'on de escritura'',
 221                      *not* ``Escribiendo un punto de comprobaci@'on'' */
 222                   str = gettext ("Write checkpoint %u");
 223                 else
 224                   /* TRANSLATORS: This is a ``checkpoint of read operation'',
 225                      *not* ``Reading a checkpoint''.
 226                      E.g. in Spanish ``Punto de comprobaci@'on de lectura'',
 227                      *not* ``Leyendo un punto de comprobaci@'on'' */
 228                   str = gettext ("Read checkpoint %u");
 229               }
 230             tmp = expand_checkpoint_string (str, do_write, checkpoint);
 231             WARN ((0, 0, "%s", tmp));
 232             free (tmp);
 233           }
 234           break;
 235
 236         case cop_ttyout:
 237           if (!tty)
 238             tty = fopen ("/dev/tty", "w");
 239           if (tty)
 240             {
 241               char *tmp = expand_checkpoint_string (p->v.command, do_write,
 242                                                     checkpoint);
 243               fprintf (tty, "%s", tmp);
 244               fflush (tty);
 245               free (tmp);
 246             }
 247           break;
 248
 249         case cop_sleep:
 250           sleep (p->v.time);
 251           break;
 252
 253         case cop_exec:
 254           sys_exec_checkpoint_script (p->v.command,
 255                                       archive_name_cursor[0],
 256                                       checkpoint);
 257           break;
 258         }
 259     }
 260   if (tty)
 261     fclose (tty);
 262 }
 263
 264 void
 265 checkpoint_run (bool do_write)
 266 {
 267   if (checkpoint_option && !(++checkpoint % checkpoint_option))
 268     run_checkpoint_actions (do_write);
 269 }