org.apache.jackrabbit.oak.plugins.segment.SegmentStore Maven / Gradle / Ivy
/*
* 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.
*/
package org.apache.jackrabbit.oak.plugins.segment;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import org.apache.jackrabbit.oak.api.Blob;
import org.apache.jackrabbit.oak.spi.blob.BlobStore;
/**
* The backend storage interface used by the segment node store.
*/
public interface SegmentStore {
SegmentTracker getTracker();
/**
* Returns the head state.
*
* @return head state
*/
@Nonnull
SegmentNodeState getHead();
boolean setHead(SegmentNodeState base, SegmentNodeState head);
/**
* Checks whether the identified segment exists in this store.
*
* @param id segment identifier
* @return {@code true} if the segment exists, {@code false} otherwise
*/
boolean containsSegment(SegmentId id);
/**
* Reads the identified segment from this store.
*
* @param segmentId segment identifier
* @return identified segment, or a {@link SegmentNotFoundException} thrown if not found
*/
@CheckForNull
Segment readSegment(SegmentId segmentId);
/**
* Writes the given segment to the segment store.
*
* @param id segment identifier
* @param bytes byte buffer that contains the raw contents of the segment
* @param offset start offset within the byte buffer
* @param length length of the segment
*/
void writeSegment(SegmentId id, byte[] bytes, int offset, int length);
void close();
/**
* Read a blob from external storage.
*
* @param reference blob reference
* @return external blob
*/
Blob readBlob(String reference);
/**
* Returns the external BlobStore (if configured) with this store
*/
@CheckForNull
BlobStore getBlobStore();
/**
* Triggers removal of segments that are no longer referenceable.
*/
void gc();
}