c_glib/arrow-glib/internal-hash-table.hpp

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#pragma once

#include <glib.h>

#include <arrow/api.h>

static inline std::shared_ptr<arrow::KeyValueMetadata>
garrow_internal_hash_table_to_metadata(GHashTable *metadata)
{
  auto arrow_metadata = std::make_shared<arrow::KeyValueMetadata>();
  g_hash_table_foreach(
    metadata,
    [](gpointer key, gpointer value, gpointer user_data) {
      auto arrow_metadata =
        static_cast<std::shared_ptr<arrow::KeyValueMetadata> *>(user_data);
      (*arrow_metadata)->Append(static_cast<gchar *>(key), static_cast<gchar *>(value));
    },
    &arrow_metadata);
  return arrow_metadata;
}

static inline GHashTable *
garrow_internal_hash_table_from_metadata(
  const std::shared_ptr<arrow::KeyValueMetadata> &arrow_metadata)
{
  auto metadata = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
  const auto &keys = arrow_metadata->keys();
  const auto &values = arrow_metadata->values();
  auto n = arrow_metadata->size();
  for (int64_t i = 0; i < n; ++i) {
    const auto &key = keys[i];
    const auto &value = values[i];
    g_hash_table_insert(metadata,
                        g_strndup(key.data(), key.size()),
                        g_strndup(value.data(), value.size()));
  }
  return metadata;
}