mh.c

mutt-1.5.12 源代码。linux 下邮件接受的工具。

    }
  }

#if USE_HCACHE
  if (ctx->magic == M_MAILDIR || ctx->magic == M_MH)
    mutt_hcache_close (hc);
#endif /* USE_HCACHE */

  if (ctx->magic == M_MH)
    mh_update_sequences (ctx);

  /* XXX race condition? */

  maildir_update_mtime (ctx);

  /* adjust indices */

  if (ctx->deleted)
  {
    for (i = 0, j = 0; i < ctx->msgcount; i++)
    {
      if (!ctx->hdrs[i]->deleted
	  || (ctx->magic == M_MAILDIR && option (OPTMAILDIRTRASH)))
	ctx->hdrs[i]->index = j++;
    }
  }

  return 0;

err:
#if USE_HCACHE
  if (ctx->magic == M_MAILDIR || ctx->magic == M_MH)
    mutt_hcache_close (hc);
#endif /* USE_HCACHE */
  return -1;
}

static char *maildir_canon_filename (char *dest, const char *src, size_t l)
{
  char *t, *u;

  if ((t = strrchr (src, '/')))
    src = t + 1;

  strfcpy (dest, src, l);
  if ((u = strrchr (dest, ':')))
    *u = '\0';

  return dest;
}

static void maildir_update_tables (CONTEXT *ctx, int *index_hint)
{
  short old_sort;
  int old_count;
  int i, j;
  
  if (Sort != SORT_ORDER)
  {
    old_sort = Sort;
    Sort = SORT_ORDER;
    mutt_sort_headers (ctx, 1);
    Sort = old_sort;
  }
  
  old_count = ctx->msgcount;
  for (i = 0, j = 0; i < old_count; i++)
  {
    if (ctx->hdrs[i]->active && index_hint && *index_hint == i)
      *index_hint = j;
    
    if (ctx->hdrs[i]->active)
      ctx->hdrs[i]->index = j++;
  }

  mx_update_tables (ctx, 0);
  mutt_clear_threads (ctx);
}

static void maildir_update_flags (CONTEXT *ctx, HEADER *o, HEADER *n)
{
  /* save the global state here so we can reset it at the
   * end of list block if required.
   */
  int context_changed = ctx->changed;
  
  /* user didn't modify this message.  alter the flags to
   * match the current state on disk.  This may not actually
   * do anything, but we can't tell right now.  mutt_set_flag()
   * will just ignore the call if the status bits are
   * already properly set.
   */
  mutt_set_flag (ctx, o, M_FLAG, n->flagged);
  mutt_set_flag (ctx, o, M_REPLIED, n->replied);
  mutt_set_flag (ctx, o, M_READ, n->read);
  mutt_set_flag (ctx, o, M_OLD, n->old);

  /* mutt_set_flag() will set this, but we don't need to
   * sync the changes we made because we just updated the
   * context to match the current on-disk state of the
   * message.
   */
  o->changed = 0;
  
  /* if the mailbox was not modified before we made these
   * changes, unset the changed flag since nothing needs to
   * be synchronized.
   */
  if (!context_changed)
    ctx->changed = 0;
}


/* This function handles arrival of new mail and reopening of
 * maildir folders.  The basic idea here is we check to see if either
 * the new or cur subdirectories have changed, and if so, we scan them
 * for the list of files.  We check for newly added messages, and
 * then merge the flags messages we already knew about.  We don't treat
 * either subdirectory differently, as mail could be copied directly into
 * the cur directory from another agent.
 */
int maildir_check_mailbox (CONTEXT * ctx, int *index_hint)
{
  struct stat st_new;		/* status of the "new" subdirectory */
  struct stat st_cur;		/* status of the "cur" subdirectory */
  char buf[_POSIX_PATH_MAX];
  int changed = 0;		/* bitmask representing which subdirectories
				   have changed.  0x1 = new, 0x2 = cur */
  int occult = 0;		/* messages were removed from the mailbox */
  int have_new = 0;		/* messages were added to the mailbox */
  struct maildir *md;		/* list of messages in the mailbox */
  struct maildir **last, *p;
  int i;
  HASH *fnames;			/* hash table for quickly looking up the base filename
				   for a maildir message */

  /* XXX seems like this check belongs in mx_check_mailbox()
   * rather than here.
   */
  if (!option (OPTCHECKNEW))
    return 0;

  snprintf (buf, sizeof (buf), "%s/new", ctx->path);
  if (stat (buf, &st_new) == -1)
    return -1;

  snprintf (buf, sizeof (buf), "%s/cur", ctx->path);
  if (stat (buf, &st_cur) == -1)
    return -1;

  /* determine which subdirectories need to be scanned */
  if (st_new.st_mtime > ctx->mtime)
    changed = 1;
  if (st_cur.st_mtime > ctx->mtime_cur)
    changed |= 2;

  if (!changed)
    return 0;			/* nothing to do */

  /* update the modification times on the mailbox */
  ctx->mtime_cur = st_cur.st_mtime;
  ctx->mtime = st_new.st_mtime;

  /* do a fast scan of just the filenames in
   * the subdirectories that have changed.
   */
  md = NULL;
  last = &md;
  if (changed & 1)
    maildir_parse_dir (ctx, &last, "new", NULL);
  if (changed & 2)
    maildir_parse_dir (ctx, &last, "cur", NULL);

  /* we create a hash table keyed off the canonical (sans flags) filename
   * of each message we scanned.  This is used in the loop over the
   * existing messages below to do some correlation.
   */
  fnames = hash_create (1031);

  for (p = md; p; p = p->next)
  {
    maildir_canon_filename (buf, p->h->path, sizeof (buf));
    p->canon_fname = safe_strdup (buf);
    hash_insert (fnames, p->canon_fname, p, 0);
  }

  /* check for modifications and adjust flags */
  for (i = 0; i < ctx->msgcount; i++)
  {
    ctx->hdrs[i]->active = 0;
    maildir_canon_filename (buf, ctx->hdrs[i]->path, sizeof (buf));
    p = hash_find (fnames, buf);
    if (p && p->h)
    {
      /* message already exists, merge flags */
      ctx->hdrs[i]->active = 1;

      /* check to see if the message has moved to a different
       * subdirectory.  If so, update the associated filename.
       */
      if (mutt_strcmp (ctx->hdrs[i]->path, p->h->path))
	mutt_str_replace (&ctx->hdrs[i]->path, p->h->path);

      /* if the user hasn't modified the flags on this message, update
       * the flags we just detected.
       */
      if (!ctx->hdrs[i]->changed)
	maildir_update_flags (ctx, ctx->hdrs[i], p->h);

      if (ctx->hdrs[i]->deleted == ctx->hdrs[i]->trash)
	ctx->hdrs[i]->deleted = p->h->deleted;
      ctx->hdrs[i]->trash = p->h->trash;

      /* this is a duplicate of an existing header, so remove it */
      mutt_free_header (&p->h);
    }
    /* This message was not in the list of messages we just scanned.
     * Check to see if we have enough information to know if the
     * message has disappeared out from underneath us.
     */
    else if (((changed & 1) && (!strncmp (ctx->hdrs[i]->path, "new/", 4))) ||
	     ((changed & 2) && (!strncmp (ctx->hdrs[i]->path, "cur/", 4))))
    {
      /* This message disappeared, so we need to simulate a "reopen"
       * event.  We know it disappeared because we just scanned the
       * subdirectory it used to reside in.
       */
      occult = 1;
    }
    else
    {
      /* This message resides in a subdirectory which was not
       * modified, so we assume that it is still present and
       * unchanged.
       */
      ctx->hdrs[i]->active = 1;
    }
  }

  /* destroy the file name hash */
  hash_destroy (&fnames, NULL);

  /* If we didn't just get new mail, update the tables. */
  if (occult)
    maildir_update_tables (ctx, index_hint);
  
  /* do any delayed parsing we need to do. */
  maildir_delayed_parsing (ctx, md);

  /* Incorporate new messages */
  have_new = maildir_move_to_context (ctx, &md);

  return occult ? M_REOPENED : (have_new ? M_NEW_MAIL : 0);
}

/* 
 * This function handles arrival of new mail and reopening of
 * mh/maildir folders. Things are getting rather complex because we
 * don't have a well-defined "mailbox order", so the tricks from
 * mbox.c and mx.c won't work here.
 *
 * Don't change this code unless you _really_ understand what
 * happens.
 *
 */

int mh_check_mailbox (CONTEXT * ctx, int *index_hint)
{
  char buf[_POSIX_PATH_MAX];
  struct stat st, st_cur;
  short modified = 0, have_new = 0, occult = 0;
  struct maildir *md, *p;
  struct maildir **last = NULL;
  struct mh_sequences mhs;
  HASH *fnames;
  int i;

  if (!option (OPTCHECKNEW))
    return 0;

  strfcpy (buf, ctx->path, sizeof (buf));
  if (stat (buf, &st) == -1)
    return -1;
  
  /* create .mh_sequences when there isn't one. */
  snprintf (buf, sizeof (buf), "%s/.mh_sequences", ctx->path);
  if ((i = stat (buf, &st_cur) == -1) && errno == ENOENT)
  {
    char *tmp;
    FILE *fp = NULL;
    
    if (mh_mkstemp (ctx, &fp, &tmp) == 0)
    {
      safe_fclose (&fp);
      if (safe_rename (tmp, buf) == -1)
	unlink (tmp);
      FREE (&tmp);
    }
  }

  if (i == -1 && stat (buf, &st_cur) == -1)
    modified = 1;

  if (st.st_mtime > ctx->mtime || st_cur.st_mtime > ctx->mtime_cur)
    modified = 1;

  if (!modified)
    return 0;

  ctx->mtime_cur = st_cur.st_mtime;
  ctx->mtime = st.st_mtime;

  memset (&mhs, 0, sizeof (mhs));
  
  md   = NULL;
  last = &md;
  maildir_parse_dir (ctx, &last, NULL, NULL);
  mh_read_sequences (&mhs, ctx->path);
  mh_update_maildir (md, &mhs);
  mhs_free_sequences (&mhs);

  /* check for modifications and adjust flags */
  fnames = hash_create (1031);

  for (p = md; p; p = p->next)
    hash_insert (fnames, p->h->path, p, 0);

  for (i = 0; i < ctx->msgcount; i++)
  {
    ctx->hdrs[i]->active = 0;

    if ((p = hash_find (fnames, ctx->hdrs[i]->path)) && p->h &&
	(mbox_strict_cmp_headers (ctx->hdrs[i], p->h)))
    {
      ctx->hdrs[i]->active = 1;
      /* found the right message */
      if (!ctx->hdrs[i]->changed)
	maildir_update_flags (ctx, ctx->hdrs[i], p->h);

      mutt_free_header (&p->h);
    }
    else /* message has disappeared */
      occult = 1;
  }

  /* destroy the file name hash */

  hash_destroy (&fnames, NULL);

  /* If we didn't just get new mail, update the tables. */
  if (occult)
    maildir_update_tables (ctx, index_hint);

  /* Incorporate new messages */
  have_new = maildir_move_to_context (ctx, &md);

  return occult ? M_REOPENED : (have_new ? M_NEW_MAIL : 0);
}




/*
 * These functions try to find a message in a maildir folder when it
 * has moved under our feet.  Note that this code is rather expensive, but
 * then again, it's called rarely.
 */

FILE *_maildir_open_find_message (const char *folder, const char *unique,
				  const char *subfolder)
{
  char dir[_POSIX_PATH_MAX];
  char tunique[_POSIX_PATH_MAX];
  char fname[_POSIX_PATH_MAX];

  DIR *dp;
  struct dirent *de;

  FILE *fp = NULL;
  int oe = ENOENT;

  snprintf (dir, sizeof (dir), "%s/%s", folder, subfolder);

  if ((dp = opendir (dir)) == NULL)
  {
    errno = ENOENT;
    return NULL;
  }

  while ((de = readdir (dp)))
  {
    maildir_canon_filename (tunique, de->d_name, sizeof (tunique));

    if (!mutt_strcmp (tunique, unique))
    {
      snprintf (fname, sizeof (fname), "%s/%s/%s", folder, subfolder,
		de->d_name);
      fp = fopen (fname, "r");	/* __FOPEN_CHECKED__ */
      oe = errno;
      break;
    }
  }

  closedir (dp);

  errno = oe;
  return fp;
}

FILE *maildir_open_find_message (const char *folder, const char *msg)
{
  char unique[_POSIX_PATH_MAX];
  FILE *fp;

  static unsigned int new_hits = 0, cur_hits = 0;	/* simple dynamic optimization */

  maildir_canon_filename (unique, msg, sizeof (unique));

  if (
      (fp =
       _maildir_open_find_message (folder, unique,
				   new_hits > cur_hits ? "new" : "cur"))
      || errno != ENOENT)
  {
    if (new_hits < UINT_MAX && cur_hits < UINT_MAX)
    {
      new_hits += (new_hits > cur_hits ? 1 : 0);
      cur_hits += (new_hits > cur_hits ? 0 : 1);
    }

    return fp;
  }
  if (
      (fp =
       _maildir_open_find_message (folder, unique,
				   new_hits > cur_hits ? "cur" : "new"))
      || errno != ENOENT)
  {
    if (new_hits < UINT_MAX && cur_hits < UINT_MAX)
    {
      new_hits += (new_hits > cur_hits ? 0 : 1);
      cur_hits += (new_hits > cur_hits ? 1 : 0);
    }

    return fp;
  }

  return NULL;
}


/*
 * Returns:
 * 1 if there are no messages in the mailbox
 * 0 if there are messages in the mailbox
 * -1 on error
 */
int maildir_check_empty (const char *path)
{
  DIR *dp;
  struct dirent *de;
  int r = 1; /* assume empty until we find a message */
  char realpath[_POSIX_PATH_MAX];
  int iter = 0;

  /* Strategy here is to look for any file not beginning with a period */

  do {
    /* we do "cur" on the first iteration since its more likely that we'll
     * find old messages without having to scan both subdirs
     */
    snprintf (realpath, sizeof (realpath), "%s/%s", path,
	      iter == 0 ? "cur" : "new");
    if ((dp = opendir (realpath)) == NULL)
      return -1;
    while ((de = readdir (dp)))
    {
      if (*de->d_name != '.')
      {
	r = 0;
	break;
      }
    }
    closedir (dp);
    iter++;
  } while (r && iter < 2);

  return r;
}

/*
 * Returns:
 * 1 if there are no messages in the mailbox
 * 0 if there are messages in the mailbox
 * -1 on error
 */
int mh_check_empty (const char *path)
{
  DIR *dp;
  struct dirent *de;
  int r = 1; /* assume empty until we find a message */
  
  if ((dp = opendir (path)) == NULL)
    return -1;
  while ((de = readdir (dp)))
  {
    if (mh_valid_message (de->d_name))
    {
      r = 0;
      break;
    }
  }
  closedir (dp);
  
  return r;
}