src/backend/cdb/cdbappendonlystorage.c

/*
 * 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.
 */

/*-------------------------------------------------------------------------
 *
 * cdbappendonlystorage.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
#include "storage/gp_compress.h"
#include "cdb/cdbappendonlystorage_int.h"
#include "cdb/cdbappendonlystorage.h"
#include "utils/pg_crc.h"
#include "port/pg_crc32c.h"
#include "utils/guc.h"

int32 AppendOnlyStorage_GetUsableBlockSize(int32 configBlockSize)
{
	int32 result;

	if (configBlockSize > AOSmallContentHeader_MaxLength)
		result = AOSmallContentHeader_MaxLength;
	else
		result = configBlockSize;

	/*
	 * Round down to 32-bit boundary.
	 */
	result = (result / sizeof(uint32)) * sizeof(uint32);
	
	return result;
}