/*
* Copyright (C) 2011 the original author or authors.
* See the notice.md file distributed with this work for additional
* information regarding copyright ownership.
*
* Licensed 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.
*/
package org.iq80.leveldb.impl;
import org.iq80.leveldb.util.PureJavaCrc32C;
import org.iq80.leveldb.util.Slice;
import java.io.File;
import java.io.IOException;
public final class Logs
{
private Logs()
{
}
public static LogWriter createLogWriter(File file, long fileNumber)
throws IOException
{
if (Iq80DBFactory.USE_MMAP) {
return new MMapLogWriter(file, fileNumber);
}
else {
return new FileChannelLogWriter(file, fileNumber);
}
}
public static int getChunkChecksum(int chunkTypeId, Slice slice)
{
return getChunkChecksum(chunkTypeId, slice.getRawArray(), slice.getRawOffset(), slice.length());
}
public static int getChunkChecksum(int chunkTypeId, byte[] buffer, int offset, int length)
{
// Compute the crc of the record type and the payload.
PureJavaCrc32C crc32C = new PureJavaCrc32C();
crc32C.update(chunkTypeId);
crc32C.update(buffer, offset, length);
return crc32C.getMaskedValue();
}
}