/*******************************************************************************
* Copyright 2011 Netflix
*
* 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 com.netflix.astyanax.impl;
import java.util.List;
import java.util.Map;
import com.google.common.base.Predicate;
import com.google.common.base.Supplier;
import com.google.common.collect.Collections2;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.netflix.astyanax.connectionpool.Host;
/**
* Node discovery supplier that only return suppliers that come from both
* sources
*
* @author elandau
*
*/
public class FilteringHostSupplier implements Supplier<List<Host>> {
private final Supplier<List<Host>> sourceSupplier;
private final Supplier<List<Host>> filterSupplier;
public FilteringHostSupplier(
Supplier<List<Host>> filterSupplier, // This is a ring describe
Supplier<List<Host>> sourceSupplier) {
this.sourceSupplier = sourceSupplier;
this.filterSupplier = filterSupplier;
}
@Override
public List<Host> get() {
// Get a list of hosts from two sources and use the first to filter
// out hosts from the second
List<Host> filterList = Lists.newArrayList();
List<Host> sourceList = Lists.newArrayList();
try {
sourceList = sourceSupplier.get();
filterList = filterSupplier.get();
}
catch (RuntimeException e) {
if (sourceList != null)
return sourceList;
throw e;
}
if (filterList.isEmpty())
return sourceList;
// Generate a lookup of all alternate IP addresses for the hosts in the
// filter list
final Map<String, Host> lookup = Maps.newHashMap();
for (Host host : filterList) {
lookup.put(host.getIpAddress(), host);
for (String addr : host.getAlternateIpAddresses()) {
lookup.put(addr, host);
}
}
List<Host> result = Lists.newArrayList(Collections2.filter(sourceList, new Predicate<Host>() {
@Override
public boolean apply(Host host) {
Host foundHost = lookup.get(host.getHostName());
if (foundHost == null) {
for (String addr : host.getAlternateIpAddresses()) {
foundHost = lookup.get(addr);
if (foundHost != null) {
break;
}
}
}
if (foundHost != null) {
host.setTokenRanges(foundHost.getTokenRanges());
return true;
}
return false;
}
}));
if (result.isEmpty())
return sourceList;
return result;
}
}