result_iteration_helper.cpp

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// SPDX-License-Identifier: BSD-3-Clause
 
/*
 * Copyright (c) 2020, Bjarne von Horn
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * * Neither the name of the copyright holder nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL BJARNE VON HORN BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <warehouse_ros_sqlite/result_iteration_helper.h>
 
#include <warehouse_ros_sqlite/metadata.h>
#include <warehouse_ros_sqlite/exceptions.h>
 
#include <sqlite3.h>
#include <cassert>
 
#include <cstring>
#include <boost/make_shared.hpp>
 
bool warehouse_ros_sqlite::ResultIteratorHelper::next()
{
  if (!stmt_)
    return false;
  switch (sqlite3_step(stmt_.get()))
  {
    case SQLITE_ROW:
 
      return true;
    case SQLITE_DONE:
      stmt_.reset();
      return false;
    default:
      throw InternalError("next() failed", stmt_.get());
  }
}
bool warehouse_ros_sqlite::ResultIteratorHelper::hasData() const
{
  if (!stmt_)
    return false;
  switch (sqlite3_column_type(stmt_.get(), schema::DATA_COLUMN_INDEX))
  {
    case SQLITE_BLOB:
      return sqlite3_column_bytes(stmt_.get(), schema::DATA_COLUMN_INDEX) != 0;
    case SQLITE_NULL:
      return false;
    default:
      throw DatatypeMismatch("Data Column has wrong data type");
  }
}
 
warehouse_ros::Metadata::ConstPtr warehouse_ros_sqlite::ResultIteratorHelper::metadata() const
{
  assert(static_cast<bool>(stmt_));
  auto ans = boost::make_shared<warehouse_ros_sqlite::Metadata>();
  for (const auto& col_pair : metadata_cols_)
  {
    ans->append(std::get<0>(col_pair), stmt_.get(), std::get<1>(col_pair));
  }
  return ans;
}
 
std::string warehouse_ros_sqlite::ResultIteratorHelper::message() const
{
  if (!hasData())
    return std::string();
  return std::string(reinterpret_cast<const char*>(sqlite3_column_blob(stmt_.get(), schema::DATA_COLUMN_INDEX)),
                     sqlite3_column_bytes(stmt_.get(), schema::DATA_COLUMN_INDEX));
}
 
namespace
{
int constexpr strlength(const char* str)
{
  return *str ? 1 + strlength(str + 1) : 0;
}
}  // namespace
 
void warehouse_ros_sqlite::ResultIteratorHelper::initMetadataCols()
{
  if (!stmt_)
    return;
  constexpr int max_length = strlength(schema::METADATA_COLUMN_PREFIX);
  for (int i = 0; i < sqlite3_column_count(stmt_.get()); ++i)
  {
    const char* col_name = sqlite3_column_name(stmt_.get(), i);
    if (std::strncmp(schema::METADATA_COLUMN_PREFIX, col_name, max_length) == 0)
    {
      // strip off prefix
      metadata_cols_.emplace_back(col_name + max_length, i);
    }
  }
}