+++ /dev/null
-/**
-* Copyright (C) 2016 ZTE, Inc. and others. All rights reserved. (ZTE)
-*
-* 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 org.openo.msb.wrapper.consul.cache;
-
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Function;
-import com.google.common.collect.ImmutableMap;
-
-import org.openo.msb.wrapper.consul.async.ConsulResponseCallback;
-import org.openo.msb.wrapper.consul.model.ConsulResponse;
-import org.openo.msb.wrapper.consul.option.QueryOptions;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.math.BigInteger;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicReference;
-
-import static com.google.common.base.Preconditions.checkState;
-
-/**
- * A cache structure that can provide an up-to-date read-only
- * map backed by consul data
- *
- * @param <V>
- */
-public class ConsulCache<K, V> {
-
- enum State {latent, starting, started, stopped }
-
- private final static Logger LOGGER = LoggerFactory.getLogger(ConsulCache.class);
-
- private final AtomicReference<BigInteger> latestIndex = new AtomicReference<BigInteger>(null);
- private final AtomicReference<ImmutableMap<K, V>> lastResponse = new AtomicReference<ImmutableMap<K, V>>(ImmutableMap.<K, V>of());
- private final AtomicReference<State> state = new AtomicReference<State>(State.latent);
- private final CountDownLatch initLatch = new CountDownLatch(1);
- private final ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
- private final CopyOnWriteArrayList<Listener<K, V>> listeners = new CopyOnWriteArrayList<Listener<K, V>>();
-
- private final Function<V, K> keyConversion;
- private final CallbackConsumer<V> callBackConsumer;
- private final ConsulResponseCallback<List<V>> responseCallback;
-
- ConsulCache(
- Function<V, K> keyConversion,
- CallbackConsumer<V> callbackConsumer) {
- this(keyConversion, callbackConsumer, 10, TimeUnit.SECONDS);
- }
-
- ConsulCache(
- Function<V, K> keyConversion,
- CallbackConsumer<V> callbackConsumer,
- final long backoffDelayQty,
- final TimeUnit backoffDelayUnit) {
-
- this.keyConversion = keyConversion;
- this.callBackConsumer = callbackConsumer;
-
- this.responseCallback = new ConsulResponseCallback<List<V>>() {
- @Override
- public void onComplete(ConsulResponse<List<V>> consulResponse) {
-
- if (!isRunning()) {
- return;
- }
- updateIndex(consulResponse);
- ImmutableMap<K, V> full = convertToMap(consulResponse);
-
- boolean changed = !full.equals(lastResponse.get());
-// LOGGER.info("node changed:"+changed+"----"+full);
- if (changed) {
- // changes
- lastResponse.set(full);
- }
-
- if (changed) {
- for (Listener<K, V> l : listeners) {
- l.notify(full);
- }
- }
-
- if (state.compareAndSet(State.starting, State.started)) {
- initLatch.countDown();
- }
- runCallback();
- }
-
- @Override
- public void onFailure(Throwable throwable) {
-
- if (!isRunning()) {
- return;
- }
- LOGGER.error(String.format("Error getting response from consul. will retry in %d %s", backoffDelayQty, backoffDelayUnit), throwable);
-
- executorService.schedule(new Runnable() {
- @Override
- public void run() {
- runCallback();
- }
- }, backoffDelayQty, backoffDelayUnit);
- }
- };
- }
-
- public void start() throws Exception {
- checkState(state.compareAndSet(State.latent, State.starting),"Cannot transition from state %s to %s", state.get(), State.starting);
- runCallback();
- }
-
- public void stop() throws Exception {
- State previous = state.getAndSet(State.stopped);
- if (previous != State.stopped) {
- executorService.shutdownNow();
- }
- }
-
- private void runCallback() {
- if (isRunning()) {
- callBackConsumer.consume(latestIndex.get(), responseCallback);
- }
- }
-
- private boolean isRunning() {
- return state.get() == State.started || state.get() == State.starting;
- }
-
- public boolean awaitInitialized(long timeout, TimeUnit unit) throws InterruptedException {
- return initLatch.await(timeout, unit);
- }
-
- public ImmutableMap<K, V> getMap() {
- return lastResponse.get();
- }
-
- @VisibleForTesting
- ImmutableMap<K, V> convertToMap(final ConsulResponse<List<V>> response) {
- if (response == null || response.getResponse() == null || response.getResponse().isEmpty()) {
- return ImmutableMap.of();
- }
-
- final ImmutableMap.Builder<K, V> builder = ImmutableMap.builder();
- final Set<K> keySet = new HashSet<>();
- for (final V v : response.getResponse()) {
- final K key = keyConversion.apply(v);
- if (key != null) {
- if (!keySet.contains(key)) {
- builder.put(key, v);
- } else {
- System.out.println(key.toString());
- LOGGER.warn("Duplicate service encountered. May differ by tags. Try using more specific tags? " + key.toString());
- }
- }
- keySet.add(key);
- }
- return builder.build();
- }
-
- private void updateIndex(ConsulResponse<List<V>> consulResponse) {
- if (consulResponse != null && consulResponse.getIndex() != null) {
- this.latestIndex.set(consulResponse.getIndex());
- }
- }
-
- protected static QueryOptions watchParams(BigInteger index, int blockSeconds) {
- if (index == null) {
- return QueryOptions.BLANK;
- } else {
- return QueryOptions.blockSeconds(blockSeconds, index).build();
- }
- }
-
- /**
- * passed in by creators to vary the content of the cached values
- *
- * @param <V>
- */
- protected interface CallbackConsumer<V> {
- void consume(BigInteger index, ConsulResponseCallback<List<V>> callback);
- }
-
- /**
- * Implementers can register a listener to receive
- * a new map when it changes
- *
- * @param <V>
- */
- public interface Listener<K, V> {
- void notify(Map<K, V> newValues);
- }
-
- public boolean addListener(Listener<K, V> listener) {
- boolean added = listeners.add(listener);
- if (state.get() == State.started) {
- listener.notify(lastResponse.get());
- }
- return added;
- }
-
- public boolean removeListener(Listener<K, V> listener) {
- return listeners.remove(listener);
- }
-
- @VisibleForTesting
- protected State getState() {
- return state.get();
- }
-}
Code Review / msb / apigateway.git / blobdiff