// Insert a new node.
  $node->is_new = empty($node->nid);

  if ($node->is_new || !empty($node->revision)) {
    // When inserting a node, $node->log must be set because
    // {node_revisions}.log does not (and cannot) have a default
    // value.  If the user does not have permission to create
    // revisions, however, the form will not contain an element for
    // log so $node->log will be unset at this point.
    if (!isset($node->log)) {
      $node->log = '';
    }
  }
  elseif (empty($node->log)) {
    // When updating a node, however, avoid clobbering an existing
    // log entry with an empty one.
    unset($node->log);
  }

  // For the same reasons, make sure we have $node->teaser and
  // $node->body set.
  if (!isset($node->teaser)) {
    $node->teaser = '';
  }
  if (!isset($node->body)) {
    $node->body = '';
  }

  // Save the old revision if needed.
  if (!$node->is_new && !empty($node->revision) && $node->vid) {
    $node->old_vid = $node->vid;
  }

  $time = time();
  if (empty($node->created)) {
    $node->created = $time;
  }
  // The changed timestamp is always updated for bookkeeping purposes (revisions, searching, ...)
  $node->changed = $time;

  $node->timestamp = $time;
  $node->format = isset($node->format) ? $node->format : FILTER_FORMAT_DEFAULT;

  // Generate the node table query and the node_revisions table query.
  if ($node->is_new) {
    _node_save_revision($node, $user->uid);
    drupal_write_record('node', $node);
    db_query('UPDATE {node_revisions} SET nid = %d WHERE vid = %d', $node->nid, $node->vid);
    $op = 'insert';
  }
  else {
    drupal_write_record('node', $node, 'nid');
    if (!empty($node->revision)) {
      _node_save_revision($node, $user->uid);
      db_query('UPDATE {node} SET vid = %d WHERE nid = %d', $node->vid, $node->nid);
    }
    else {
      _node_save_revision($node, $user->uid, 'vid');
    }
    $op = 'update';
  }

// Нода уже сохранена и имеет $node->nid.
// Вызывается hook_nodeapi с $op='update' или 'insert' в зависимости от того, что было раньше задано.

  // Call the node specific callback (if any).
  node_invoke($node, $op);
  node_invoke_nodeapi($node, $op);

  // Update the node access table for this node.
  node_access_acquire_grants($node);

  // Clear the page and block caches.
  cache_clear_all();
}