io.camunda.zeebe.journal.file.SegmentAllocator Maven / Gradle / Ivy
/*
* Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH under
* one or more contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright ownership.
* Licensed under the Camunda License 1.0. You may not use this file
* except in compliance with the Camunda License 1.0.
*/
package io.camunda.zeebe.journal.file;
import java.io.IOException;
import java.nio.channels.FileChannel;
import org.agrona.IoUtil;
/** Defines the strategy when it comes to pre-allocating segment files. */
@FunctionalInterface
interface SegmentAllocator {
/**
* Pre-allocates {@code segmentSize} disk space for file corresponding to the given descriptor and
* channel.
*
* @param channel an open channel to the file to pre-allocate
* @param segmentSize the desired size of the segment on disk, in bytes
* @throws IOException if any error occur during pre-allocation; if this is thrown, no guarantees
* are made about the state of the file on disk, and no resources are closed
*/
void allocate(FileChannel channel, final long segmentSize) throws IOException;
/** Returns an allocator which does nothing, i.e. does not allocate disk space. */
static SegmentAllocator noop() {
return (c, s) -> {};
}
/** Returns an allocator which fills the file by writing chunks of zeros to disk. */
static SegmentAllocator fill() {
return (channel, size) -> IoUtil.fill(channel, 0, size, (byte) 0);
}
}