io.zeebe.logstreams.impl.log.fs.FsLogSegments Maven / Gradle / Ivy

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/*
 * Copyright © 2017 camunda services GmbH ([email protected])
 *
 * 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 io.zeebe.logstreams.impl.log.fs;

public class FsLogSegments
{
    protected int initalSegmentId = -1;

    protected FsLogSegment[] segments = new FsLogSegment[0];

    protected volatile int segmentCount = 0;

    public void init(int initalSegmentId, FsLogSegment[] initialSegments)
    {
        this.segments = initialSegments;
        this.initalSegmentId = initalSegmentId;
        this.segmentCount = initialSegments.length; // volatile store
    }

    /**
     * invoked by the conductor after a new segment has been allocated
     */
    public void addSegment(FsLogSegment segment)
    {
        final FsLogSegment[] newSegments = new FsLogSegment[segments.length + 1];

        System.arraycopy(segments, 0, newSegments, 0, segments.length);
        newSegments[segments.length] = segment;
        this.segments = newSegments;

        this.segmentCount = newSegments.length; // volatile store
    }

    public FsLogSegment getSegment(int segmentId)
    {
        final int segmentCount = this.segmentCount; // volatile load

        final FsLogSegment[] segments = this.segments;

        final int segmentIdx = segmentId - initalSegmentId;

        if (0 <= segmentIdx && segmentIdx < segmentCount)
        {
            return segments[segmentIdx];
        }
        else
        {
            return null;
        }
    }

    public FsLogSegment getFirst()
    {
        if (segmentCount > 0)
        {
            return segments[0];
        }
        else
        {
            return null;
        }
    }

    public void closeAll()
    {
        final FsLogSegment[] segments = this.segments;
        for (FsLogSegment readableLogSegment : segments)
        {
            readableLogSegment.closeSegment();
        }

        this.segments = new FsLogSegment[0];
        this.segmentCount = 0;
    }

    public int getSegmentCount()
    {
        return segmentCount;
    }

}