org.apache.jackrabbit.oak.segment.SegmentWriterBuilder Maven / Gradle / Ivy
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* 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.segment;
import static com.google.common.base.Preconditions.checkNotNull;
import javax.annotation.Nonnull;
import com.google.common.base.Supplier;
import com.google.common.base.Suppliers;
import org.apache.jackrabbit.oak.segment.WriterCacheManager.Empty;
import org.apache.jackrabbit.oak.segment.file.FileStore;
import org.apache.jackrabbit.oak.segment.http.HttpStore;
import org.apache.jackrabbit.oak.segment.memory.MemoryStore;
/**
* Builder for building {@link SegmentWriter} instances.
* The returned instances are thread safe if {@link #withWriterPool()}
* was specified and not thread sage if {@link #withoutWriterPool()}
* was specified (default).
*
* Default: calling one of the {@code build()} methods without previously
* calling one of the {@code with...()} methods returns a {@code SegmentWriter}
* as would the following chain of calls:
*
segmentWriterBuilder("name")
.with(LATEST_VERSION)
.withGeneration(0)
.withoutWriterPool()
.with(new WriterCacheManager.Default())
.build(store);
*
*/
public final class SegmentWriterBuilder {
@Nonnull
private final String name;
@Nonnull
private Supplier generation = Suppliers.ofInstance(0);
private boolean pooled = false;
@Nonnull
private WriterCacheManager cacheManager = new WriterCacheManager.Default();
private SegmentWriterBuilder(@Nonnull String name) { this.name = checkNotNull(name); }
/**
* Set the {@code name} of this builder. This name will appear in the segment's
* meta data.
*/
@Nonnull
public static SegmentWriterBuilder segmentWriterBuilder(@Nonnull String name) {
return new SegmentWriterBuilder(name);
}
/**
* Specify the {@code generation} for the segment written by the returned
* segment writer.
*
* If {@link #withoutWriterPool()} was specified all segments will be written
* at the generation that {@code generation.get()} returned at the time
* any of the {@code build()} methods is called.
* If {@link #withWriterPool()} was specified a segments will be written
* at the generation that {@code generation.get()} returns when a new segment
* is created by the returned writer.
*/
@Nonnull
public SegmentWriterBuilder withGeneration(@Nonnull Supplier generation) {
this.generation = checkNotNull(generation);
return this;
}
/**
* Specify the {@code generation} for the segment written by the returned
* segment writer.
*/
@Nonnull
public SegmentWriterBuilder withGeneration(int generation) {
this.generation = Suppliers.ofInstance(generation);
return this;
}
/**
* Create a {@code SegmentWriter} backed by a {@link SegmentBufferWriterPool}.
* The returned instance is thread safe.
*/
@Nonnull
public SegmentWriterBuilder withWriterPool() {
this.pooled = true;
return this;
}
/**
* Create a {@code SegmentWriter} backed by a {@link SegmentBufferWriter}.
* The returned instance is not thread safe.
*/
@Nonnull
public SegmentWriterBuilder withoutWriterPool() {
this.pooled = false;
return this;
}
/**
* Specify the {@code cacheManager} used by the returned writer.
*/
@Nonnull
public SegmentWriterBuilder with(WriterCacheManager cacheManager) {
this.cacheManager = checkNotNull(cacheManager);
return this;
}
/**
* Specify that the returned writer should not use a cache.
* @see #with(WriterCacheManager)
*/
@Nonnull
public SegmentWriterBuilder withoutCache() {
this.cacheManager = Empty.INSTANCE;
return this;
}
/**
* Build a {@code SegmentWriter} for a {@code FileStore}.
*/
@Nonnull
public SegmentWriter build(@Nonnull FileStore store) {
return new SegmentWriter(checkNotNull(store), store.getReader(),
store.getBlobStore(), cacheManager, createWriter(store, pooled));
}
/**
* Build a {@code SegmentWriter} for a {@code MemoryStore}.
*/
@Nonnull
public SegmentWriter build(@Nonnull MemoryStore store) {
return new SegmentWriter(checkNotNull(store), store.getReader(),
store.getBlobStore(), cacheManager, createWriter(store, pooled));
}
/**
* Build a {@code SegmentWriter} for a {@code HttpStore}.
*/
@Nonnull
public SegmentWriter build(@Nonnull HttpStore store) {
return new SegmentWriter(checkNotNull(store), store.getReader(),
store.getBlobStore(), cacheManager, createWriter(store, pooled));
}
@Nonnull
private WriteOperationHandler createWriter(@Nonnull FileStore store, boolean pooled) {
if (pooled) {
return new SegmentBufferWriterPool(store,
store.getTracker(), store.getReader(), name, generation);
} else {
return new SegmentBufferWriter(store,
store.getTracker(), store.getReader(), name, generation.get());
}
}
@Nonnull
private WriteOperationHandler createWriter(@Nonnull MemoryStore store, boolean pooled) {
if (pooled) {
return new SegmentBufferWriterPool(store,
store.getTracker(), store.getReader(), name, generation);
} else {
return new SegmentBufferWriter(store,
store.getTracker(), store.getReader(), name, generation.get());
}
}
@Nonnull
private WriteOperationHandler createWriter(@Nonnull HttpStore store, boolean pooled) {
if (pooled) {
return new SegmentBufferWriterPool(store,
store.getTracker(), store.getReader(), name, generation);
} else {
return new SegmentBufferWriter(store,
store.getTracker(), store.getReader(), name, generation.get());
}
}
}