mbox.c

mutt-1.5.12 源代码。linux 下邮件接受的工具。

	if ((ctx->magic == M_MBOX && mutt_strncmp ("From ", buffer, 5) == 0) ||
	    (ctx->magic == M_MMDF && mutt_strcmp (MMDF_SEP, buffer) == 0))
	{
	  if (fseeko (ctx->fp, ctx->size, SEEK_SET) != 0)
	    dprint (1, (debugfile, "mbox_check_mailbox: fseek() failed\n"));
	  if (ctx->magic == M_MBOX)
	    mbox_parse_mailbox (ctx);
	  else
	    mmdf_parse_mailbox (ctx);

	  /* Only unlock the folder if it was locked inside of this routine.
	   * It may have been locked elsewhere, like in
	   * mutt_checkpoint_mailbox().
	   */

	  if (unlock)
	  {
	    mbox_unlock_mailbox (ctx);
	    mutt_unblock_signals ();
	  }

	  return (M_NEW_MAIL); /* signal that new mail arrived */
	}
	else
	  modified = 1;
      }
      else
      {
	dprint (1, (debugfile, "mbox_check_mailbox: fgets returned NULL.\n"));
	modified = 1;
      }
    }
    else
      modified = 1;
  }

  if (modified)
  {
    if (mutt_reopen_mailbox (ctx, index_hint) != -1)
    {
      if (unlock)
      {
	mbox_unlock_mailbox (ctx);
	mutt_unblock_signals ();
      }
      return (M_REOPENED);
    }
  }

  /* fatal error */

  mbox_unlock_mailbox (ctx);
  mx_fastclose_mailbox (ctx);
  mutt_unblock_signals ();
  mutt_error _("Mailbox was corrupted!");
  return (-1);
}

/* return values:
 *	0	success
 *	-1	failure
 */
int mbox_sync_mailbox (CONTEXT *ctx, int *index_hint)
{
  char tempfile[_POSIX_PATH_MAX];
  char buf[32];
  int i, j, save_sort = SORT_ORDER;
  int rc = -1;
  int need_sort = 0; /* flag to resort mailbox if new mail arrives */
  int first = -1;	/* first message to be written */
  LOFF_T offset;	/* location in mailbox to write changed messages */
  struct stat statbuf;
  struct utimbuf utimebuf;
  struct m_update_t *newOffset = NULL;
  struct m_update_t *oldOffset = NULL;
  FILE *fp = NULL;

  /* sort message by their position in the mailbox on disk */
  if (Sort != SORT_ORDER)
  {
    save_sort = Sort;
    Sort = SORT_ORDER;
    mutt_sort_headers (ctx, 0);
    Sort = save_sort;
    need_sort = 1;
  }

  /* need to open the file for writing in such a way that it does not truncate
   * the file, so use read-write mode.
   */
  if ((ctx->fp = freopen (ctx->path, "r+", ctx->fp)) == NULL)
  {
    mx_fastclose_mailbox (ctx);
    mutt_error _("Fatal error!  Could not reopen mailbox!");
    return (-1);
  }

  mutt_block_signals ();

  if (mbox_lock_mailbox (ctx, 1, 1) == -1)
  {
    mutt_unblock_signals ();
    mutt_error _("Unable to lock mailbox!");
    goto bail;
  }

  /* Check to make sure that the file hasn't changed on disk */
  if ((i = mbox_check_mailbox (ctx, index_hint)) == M_NEW_MAIL ||  i == M_REOPENED)
  {
    /* new mail arrived, or mailbox reopened */
    need_sort = i;
    rc = i;
    goto bail;
  }
  else if (i < 0)
    /* fatal error */
    return (-1);

  /* Create a temporary file to write the new version of the mailbox in. */
  mutt_mktemp (tempfile);
  if ((i = open (tempfile, O_WRONLY | O_EXCL | O_CREAT, 0600)) == -1 ||
      (fp = fdopen (i, "w")) == NULL)
  {
    if (-1 != i)
    {
      close (i);
      unlink (tempfile);
    }
    mutt_error _("Could not create temporary file!");
    mutt_sleep (5);
    goto bail;
  }

  /* find the first deleted/changed message.  we save a lot of time by only
   * rewriting the mailbox from the point where it has actually changed.
   */
  for (i = 0 ; i < ctx->msgcount && !ctx->hdrs[i]->deleted && 
               !ctx->hdrs[i]->changed && !ctx->hdrs[i]->attach_del; i++)
    ;
  if (i == ctx->msgcount)
  { 
    /* this means ctx->changed or ctx->deleted was set, but no
     * messages were found to be changed or deleted.  This should
     * never happen, is we presume it is a bug in mutt.
     */
    mutt_error _("sync: mbox modified, but no modified messages! (report this bug)");
    mutt_sleep(5); /* the mutt_error /will/ get cleared! */
    dprint(1, (debugfile, "mbox_sync_mailbox(): no modified messages.\n"));
    unlink (tempfile);
    goto bail;
  }

    /* save the index of the first changed/deleted message */
  first = i; 
  /* where to start overwriting */
  offset = ctx->hdrs[i]->offset; 

  /* the offset stored in the header does not include the MMDF_SEP, so make
   * sure we seek to the correct location
   */
  if (ctx->magic == M_MMDF)
    offset -= (sizeof MMDF_SEP - 1);
  
  /* allocate space for the new offsets */
  newOffset = safe_calloc (ctx->msgcount - first, sizeof (struct m_update_t));
  oldOffset = safe_calloc (ctx->msgcount - first, sizeof (struct m_update_t));

  for (i = first, j = 0; i < ctx->msgcount; i++)
  {
    /*
     * back up some information which is needed to restore offsets when
     * something fails.
     */
    
    oldOffset[i-first].valid  = 1;
    oldOffset[i-first].hdr    = ctx->hdrs[i]->offset;
    oldOffset[i-first].body   = ctx->hdrs[i]->content->offset;
    oldOffset[i-first].lines  = ctx->hdrs[i]->lines;
    oldOffset[i-first].length = ctx->hdrs[i]->content->length;
    
    if (! ctx->hdrs[i]->deleted)
    {
      j++;
      if (!ctx->quiet && WriteInc && ((i % WriteInc) == 0 || j == 1))
	mutt_message (_("Writing messages... %d (%d%%)"), i,
		      (int)(ftell (ctx->fp) / (ctx->size / 100 + 1)));

      if (ctx->magic == M_MMDF)
      {
	if (fputs (MMDF_SEP, fp) == EOF)
	{
	  mutt_perror (tempfile);
	  mutt_sleep (5);
	  unlink (tempfile);
	  goto bail;
	}
	  
      }

      /* save the new offset for this message.  we add `offset' because the
       * temporary file only contains saved message which are located after
       * `offset' in the real mailbox
       */
      newOffset[i - first].hdr = ftello (fp) + offset;

      if (mutt_copy_message (fp, ctx, ctx->hdrs[i], M_CM_UPDATE, CH_FROM | CH_UPDATE | CH_UPDATE_LEN) == -1)
      {
	mutt_perror (tempfile);
	mutt_sleep (5);
	unlink (tempfile);
	goto bail;
      }

      /* Since messages could have been deleted, the offsets stored in memory
       * will be wrong, so update what we can, which is the offset of this
       * message, and the offset of the body.  If this is a multipart message,
       * we just flush the in memory cache so that the message will be reparsed
       * if the user accesses it later.
       */
      newOffset[i - first].body = ftello (fp) - ctx->hdrs[i]->content->length + offset;
      mutt_free_body (&ctx->hdrs[i]->content->parts);

      switch(ctx->magic)
      {
	case M_MMDF: 
	  if(fputs(MMDF_SEP, fp) == EOF) 
	  {
	    mutt_perror (tempfile);
	    mutt_sleep (5);
	    unlink (tempfile);
	    goto bail; 
	  }
	  break;
	default:
	  if(fputs("\n", fp) == EOF) 
	  {
	    mutt_perror (tempfile);
	    mutt_sleep (5);
	    unlink (tempfile);
	    goto bail;
	  }
      }
    }
  }
  
  if (fclose (fp) != 0)
  {
    fp = NULL;
    dprint(1, (debugfile, "mbox_sync_mailbox: fclose() returned non-zero.\n"));
    unlink (tempfile);
    mutt_perror (tempfile);
    mutt_sleep (5);
    goto bail;
  }
  fp = NULL;

  /* Save the state of this folder. */
  if (stat (ctx->path, &statbuf) == -1)
  {
    mutt_perror (ctx->path);
    mutt_sleep (5);
    unlink (tempfile);
    goto bail;
  }

  if ((fp = fopen (tempfile, "r")) == NULL)
  {
    mutt_unblock_signals ();
    mx_fastclose_mailbox (ctx);
    dprint (1, (debugfile, "mbox_sync_mailbox: unable to reopen temp copy of mailbox!\n"));
    mutt_perror (tempfile);
    mutt_sleep (5);
    return (-1);
  }

  if (fseeko (ctx->fp, offset, SEEK_SET) != 0 ||  /* seek the append location */
      /* do a sanity check to make sure the mailbox looks ok */
      fgets (buf, sizeof (buf), ctx->fp) == NULL ||
      (ctx->magic == M_MBOX && mutt_strncmp ("From ", buf, 5) != 0) ||
      (ctx->magic == M_MMDF && mutt_strcmp (MMDF_SEP, buf) != 0))
  {
    dprint (1, (debugfile, "mbox_sync_mailbox: message not in expected position."));
    dprint (1, (debugfile, "\tLINE: %s\n", buf));
    i = -1;
  }
  else
  {
    if (fseeko (ctx->fp, offset, SEEK_SET) != 0) /* return to proper offset */
    {
      i = -1;
      dprint (1, (debugfile, "mbox_sync_mailbox: fseek() failed\n"));
    }
    else
    {
      /* copy the temp mailbox back into place starting at the first
       * change/deleted message
       */
      mutt_message _("Committing changes...");
      i = mutt_copy_stream (fp, ctx->fp);

      if (ferror (ctx->fp))
        i = -1;
    }
    if (i == 0)
    {
      ctx->size = ftello (ctx->fp); /* update the size of the mailbox */
      ftruncate (fileno (ctx->fp), ctx->size);
    }
  }

  fclose (fp);
  fp = NULL;
  mbox_unlock_mailbox (ctx);

  if (fclose (ctx->fp) != 0 || i == -1)
  {
    /* error occured while writing the mailbox back, so keep the temp copy
     * around
     */
    
    char savefile[_POSIX_PATH_MAX];
    
    snprintf (savefile, sizeof (savefile), "%s/mutt.%s-%s-%u",
	      NONULL (Tempdir), NONULL(Username), NONULL(Hostname), (unsigned int)getpid ());
    rename (tempfile, savefile);
    mutt_unblock_signals ();
    mx_fastclose_mailbox (ctx);
    mutt_pretty_mailbox (savefile);
    mutt_error (_("Write failed!  Saved partial mailbox to %s"), savefile);
    mutt_sleep (5);
    return (-1);
  }

  /* Restore the previous access/modification times */
  utimebuf.actime = statbuf.st_atime;
  utimebuf.modtime = statbuf.st_mtime;
  utime (ctx->path, &utimebuf);

  /* reopen the mailbox in read-only mode */
  if ((ctx->fp = fopen (ctx->path, "r")) == NULL)
  {
    unlink (tempfile);
    mutt_unblock_signals ();
    mx_fastclose_mailbox (ctx);
    mutt_error _("Fatal error!  Could not reopen mailbox!");
    return (-1);
  }

  /* update the offsets of the rewritten messages */
  for (i = first, j = first; i < ctx->msgcount; i++)
  {
    if (!ctx->hdrs[i]->deleted)
    {
      ctx->hdrs[i]->offset = newOffset[i - first].hdr;
      ctx->hdrs[i]->content->hdr_offset = newOffset[i - first].hdr;
      ctx->hdrs[i]->content->offset = newOffset[i - first].body;
      ctx->hdrs[i]->index = j++;
    }
  }
  FREE (&newOffset);
  FREE (&oldOffset);
  unlink (tempfile); /* remove partial copy of the mailbox */
  mutt_unblock_signals ();

  return (0); /* signal success */

bail:  /* Come here in case of disaster */

  safe_fclose (&fp);

  /* restore offsets, as far as they are valid */
  if (first >= 0 && oldOffset)
  {
    for (i = first; i < ctx->msgcount && oldOffset[i-first].valid; i++)
    {
      ctx->hdrs[i]->offset = oldOffset[i-first].hdr;
      ctx->hdrs[i]->content->hdr_offset = oldOffset[i-first].hdr;
      ctx->hdrs[i]->content->offset = oldOffset[i-first].body;
      ctx->hdrs[i]->lines = oldOffset[i-first].lines;
      ctx->hdrs[i]->content->length = oldOffset[i-first].length;
    }
  }
  
  /* this is ok to call even if we haven't locked anything */
  mbox_unlock_mailbox (ctx);

  mutt_unblock_signals ();
  FREE (&newOffset);
  FREE (&oldOffset);

  if ((ctx->fp = freopen (ctx->path, "r", ctx->fp)) == NULL)
  {
    mutt_error _("Could not reopen mailbox!");
    mx_fastclose_mailbox (ctx);
    return (-1);
  }

  if (need_sort)
    /* if the mailbox was reopened, the thread tree will be invalid so make
     * sure to start threading from scratch.  */
    mutt_sort_headers (ctx, (need_sort == M_REOPENED));

  return rc;
}

/* close a mailbox opened in write-mode */
int mbox_close_mailbox (CONTEXT *ctx)
{
  mx_unlock_file (ctx->path, fileno (ctx->fp), 1);
  mutt_unblock_signals ();
  mx_fastclose_mailbox (ctx);
  return 0;
}

int mutt_reopen_mailbox (CONTEXT *ctx, int *index_hint)
{
  int (*cmp_headers) (const HEADER *, const HEADER *) = NULL;
  HEADER **old_hdrs;
  int old_msgcount;
  int msg_mod = 0;
  int index_hint_set;
  int i, j;
  int rc = -1;

  /* silent operations */
  ctx->quiet = 1;
  
  mutt_message _("Reopening mailbox...");
  
  /* our heuristics require the old mailbox to be unsorted */
  if (Sort != SORT_ORDER)
  {
    short old_sort;

    old_sort = Sort;
    Sort = SORT_ORDER;
    mutt_sort_headers (ctx, 1);
    Sort = old_sort;
  }

  old_hdrs = NULL;
  old_msgcount = 0;
  
  /* simulate a close */
  if (ctx->id_hash)
    hash_destroy (&ctx->id_hash, NULL);
  if (ctx->subj_hash)
    hash_destroy (&ctx->subj_hash, NULL);
  mutt_clear_threads (ctx);
  FREE (&ctx->v2r);
  if (ctx->readonly)
  {
    for (i = 0; i < ctx->msgcount; i++)
      mutt_free_header (&(ctx->hdrs[i])); /* nothing to do! */
    FREE (&ctx->hdrs);
  }
  else
  {
      /* save the old headers */
    old_msgcount = ctx->msgcount;
    old_hdrs = ctx->hdrs;
    ctx->hdrs = NULL;
  }

  ctx->hdrmax = 0;	/* force allocation of new headers */
  ctx->msgcount = 0;
  ctx->vcount = 0;
  ctx->tagged = 0;
  ctx->deleted = 0;
  ctx->new = 0;
  ctx->unread = 0;
  ctx->flagged = 0;
  ctx->changed = 0;
  ctx->id_hash = NULL;
  ctx->subj_hash = NULL;

  switch (ctx->magic)
  {
    case M_MBOX:
    case M_MMDF:
      if (fseek (ctx->fp, 0, SEEK_SET) != 0)
      {
        dprint (1, (debugfile, "mutt_reopen_mailbox: fseek() failed\n"));
        rc = -1;
      } 
      else 
      {
        cmp_headers = mbox_strict_cmp_headers;
        rc = ((ctx->magic == M_MBOX) ? mbox_parse_mailbox
				     : mmdf_parse_mailbox) (ctx);
      }
      break;

    default:
      rc = -1;
      break;
  }
  
  if (rc == -1)
  {
    /* free the old headers */
    for (j = 0; j < old_msgcount; j++)
      mutt_free_header (&(old_hdrs[j]));
    FREE (&old_hdrs);

    ctx->quiet = 0;
    return (-1);
  }

  /* now try to recover the old flags */

  index_hint_set = (index_hint == NULL);

  if (!ctx->readonly)
  {
    for (i = 0; i < ctx->msgcount; i++)
    {
      int found = 0;

      /* some messages have been deleted, and new  messages have been
       * appended at the end; the heuristic is that old messages have then
       * "advanced" towards the beginning of the folder, so we begin the
       * search at index "i"
       */
      for (j = i; j < old_msgcount; j++)
      {
	if (old_hdrs[j] == NULL)
	  continue;
	if (cmp_headers (ctx->hdrs[i], old_hdrs[j]))
	{
	  found = 1;
	  break;
	}
      }
      if (!found)
      {
	for (j = 0; j < i && j < old_msgcount; j++)
	{
	  if (old_hdrs[j] == NULL)
	    continue;
	  if (cmp_headers (ctx->hdrs[i], old_hdrs[j]))
	  {
	    found = 1;
	    break;
	  }
	}
      }

      if (found)
      {
	/* this is best done here */
	if (!index_hint_set && *index_hint == j)
	  *index_hint = i;

	if (old_hdrs[j]->changed)
	{
	  /* Only update the flags if the old header was changed;
	   * otherwise, the header may have been modified externally,
	   * and we don't want to lose _those_ changes
	   */
	  mutt_set_flag (ctx, ctx->hdrs[i], M_FLAG, old_hdrs[j]->flagged);
	  mutt_set_flag (ctx, ctx->hdrs[i], M_REPLIED, old_hdrs[j]->replied);
	  mutt_set_flag (ctx, ctx->hdrs[i], M_OLD, old_hdrs[j]->old);
	  mutt_set_flag (ctx, ctx->hdrs[i], M_READ, old_hdrs[j]->read);
	}
	mutt_set_flag (ctx, ctx->hdrs[i], M_DELETE, old_hdrs[j]->deleted);
	mutt_set_flag (ctx, ctx->hdrs[i], M_TAG, old_hdrs[j]->tagged);

	/* we don't need this header any more */
	mutt_free_header (&(old_hdrs[j]));
      }
    }

    /* free the remaining old headers */
    for (j = 0; j < old_msgcount; j++)
    {
      if (old_hdrs[j])
      {
	mutt_free_header (&(old_hdrs[j]));
	msg_mod = 1;
      }
    }
    FREE (&old_hdrs);
  }

  ctx->quiet = 0;

  return ((ctx->changed || msg_mod) ? M_REOPENED : M_NEW_MAIL);
}

/*
 * Returns:
 * 1 if the mailbox is not empty
 * 0 if the mailbox is empty
 * -1 on error
 */
int mbox_check_empty (const char *path)
{
  struct stat st;

  if (stat (path, &st) == -1)
    return -1;

  return ((st.st_size == 0));
}