Function read_identifier

sql/sql_digest.cc:92–128

Read an identifier from token array. */

  Read an identifier from token array.
*/
inline uint read_identifier(const sql_digest_storage* digest_storage,
                            uint index, char ** id_string, int *id_length)
{
  uint new_index;
  uint safe_byte_count= digest_storage->m_byte_count;

  DBUG_ASSERT(index <= safe_byte_count);
  DBUG_ASSERT(safe_byte_count <= digest_storage->m_token_array_length);

  /*
    token + length + string are written in an atomic way,
    so we do always expect a length + string here
  */

  uint bytes_needed= SIZE_OF_A_TOKEN;
  /* If we can read token and identifier length */
  if ((index + bytes_needed) <= safe_byte_count)
  {
    const unsigned char *src= & digest_storage->m_token_array[index];
    /* Read the length of identifier */
    uint length= src[0] | (src[1] << 8);
    bytes_needed+= length;
    /* If we can read entire identifier from token array */
    if ((index + bytes_needed) <= safe_byte_count)
    {
      *id_string= (char *) (src + 2);
      *id_length= length;

      new_index= index + bytes_needed;
      DBUG_ASSERT(new_index <= safe_byte_count);
      return new_index;
    }
  }

  /* The input byte stream is exhausted. */
  return MAX_DIGEST_STORAGE_SIZE + 1;
}

/**
  Store an identifier in token array.