google-nomulus/java/google/registry/model/index/EppResourceIndexBucket.java
Michael Muller c458c05801 Rename Java packages to use the .google TLD
The dark lord Gosling designed the Java package naming system so that
ownership flows from the DNS system. Since we own the domain name
registry.google, it seems only appropriate that we should use
google.registry as our package name.
2016-05-13 20:04:42 -04:00

67 lines
2.7 KiB
Java

// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
//
// 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 google.registry.model.index;
import com.google.common.collect.ImmutableList;
import com.google.common.hash.Hashing;
import com.googlecode.objectify.Key;
import com.googlecode.objectify.annotation.Entity;
import com.googlecode.objectify.annotation.Id;
import google.registry.config.RegistryEnvironment;
import google.registry.model.EppResource;
import google.registry.model.ImmutableObject;
import google.registry.model.annotations.VirtualEntity;
/** A virtual entity to represent buckets to which EppResourceIndex objects are randomly added. */
@Entity
@VirtualEntity
public class EppResourceIndexBucket extends ImmutableObject {
@Id
private long bucketId;
/**
* Deterministic function that returns a bucket id based on the resource's roid.
* NB: At the moment, nothing depends on this being deterministic, so we have the ability to
* change the number of buckets and utilize a random distribution once we do.
*/
private static long getBucketIdFromEppResource(Key<? extends EppResource> resourceKey) {
int numBuckets = RegistryEnvironment.get().config().getEppResourceIndexBucketCount();
// IDs can't be 0, so add 1 to the hash.
return Hashing.consistentHash(resourceKey.getName().hashCode(), numBuckets) + 1;
}
/** Gets a bucket key as a function of an EppResource to be indexed. */
public static Key<EppResourceIndexBucket> getBucketKey(Key<? extends EppResource> resourceKey) {
return Key.create(EppResourceIndexBucket.class, getBucketIdFromEppResource(resourceKey));
}
/** Gets the specified numbered bucket key. */
public static Key<EppResourceIndexBucket> getBucketKey(int bucketId) {
return Key.create(EppResourceIndexBucket.class, bucketId);
}
/** Returns the keys to all buckets. */
public static Iterable<Key<EppResourceIndexBucket>> getAllBuckets() {
ImmutableList.Builder<Key<EppResourceIndexBucket>> builder = new ImmutableList.Builder<>();
int numBuckets = RegistryEnvironment.get().config().getEppResourceIndexBucketCount();
for (int bucketId = 1; bucketId <= numBuckets; bucketId++) {
builder.add(getBucketKey(bucketId));
}
return builder.build();
}
}