Function ProcessWildcardIndex

be/src/exprs/string-functions.cc:230–251

Process wildcard(*) in array selection. path_idx is the index after the wildcard in path_str. Return next unprocessed index in path_str. Return -1 for errors.

/// Process wildcard(*) in array selection. path_idx is the index after the wildcard in
/// path_str. Return next unprocessed index in path_str. Return -1 for errors.
static int ProcessWildcardIndex(FunctionContext* ctx, const StringVal& path_str,
    int path_idx, JsonUdfValue* queue, JsonUdfAllocator* allocator) {
  const uint8_t* path = path_str.ptr;
  while (path_idx < path_str.len && path[path_idx] != ']') {
    if (path[path_idx] != ' ') { // have something else illegal
      string msg = Substitute("Failed to parse json path '$0': "
          "Encountered '$1' in position $2, expects ' ' or ']'",
          AnyValUtil::ToString(path_str), static_cast<char>(path[path_idx]), path_idx);
      ctx->SetError(msg.c_str());
      return -1;
    }
    ++path_idx;
  }
  if (path_idx == path_str.len) {
    string msg = Substitute("Unclosed brackets in json path '$0'",
        AnyValUtil::ToString(path_str));
    ctx->SetError(msg.c_str());
    return -1;
  }
  RETURN_IF_OOM(ExpandArrays(queue, allocator), -1);
  return path_idx + 1;  // path_idx points at ']'
}

/// Process number in array selection. path_idx points at the start of the number in
/// path_str. Return next unprocessed index in path_str. Return -1 for errors.