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/* * Copyright 2014-2015 Cask Data, Inc. * * 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 co.cask.cdap.common.queue; import co.cask.cdap.proto.Id; import com.google.common.base.Charsets; import com.google.common.base.Preconditions; import com.google.common.base.Splitter; import com.google.common.collect.Iterables; import java.net.URI; import java.util.Iterator; /** * An abstraction over URI of a queue. */ public final class QueueName { /** * URI of the queue. */ private final URI uri; /** * The components of the URI. */ private final String[] components; /** * Represents the queue as byte[]. */ private final byte[] byteName; /** * Represents the queue name as a string. */ private final String stringName; /** * Constructs this class from an URI. * * @param uri of the queue * @return An instance of {@link QueueName} */ public static QueueName from(URI uri) { Preconditions.checkNotNull(uri, "URI cannot be null."); return new QueueName(uri); } /** * Constructs this class from byte array of queue URI. * * @param bytes respresenting URI * @return An instance of {@link QueueName} */ public static QueueName from(byte[] bytes) { return new QueueName(URI.create(new String(bytes, Charsets.US_ASCII))); } public static QueueName fromFlowlet(Id.Flow flow, String flowlet, String output) { return fromFlowlet(flow.getNamespaceId(), flow.getApplicationId(), flow.getId(), flowlet, output); } public static QueueName fromFlowlet(Id.Namespace namespace, String app, String flow, String flowlet, String output) { return fromFlowlet(namespace.getId(), app, flow, flowlet, output); } public static QueueName fromFlowlet(String namespace, String app, String flow, String flowlet, String output) { URI uri = URI.create(String.format("queue:///%s/%s/%s/%s/%s", namespace, app, flow, flowlet, output)); return new QueueName(uri); } public static String prefixForFlow(Id.Flow flowId) { // queue:///namespace/app/flow/ // Note that the trailing / is crucial, otherwise this could match queues of flow1, flowx, etc. return String.format("queue:///%s/%s/%s/", flowId.getNamespaceId(), flowId.getApplicationId(), flowId.getId()); } // Note that like above the trailing '/' in the prefix for namespace is crucial, // otherwise this could match namespaces of ns, ns1, nsx, etc. public static String prefixForNamespacedQueue(String namespace) { // queue:///namespace/ return String.format("queue:///%s/", namespace); } public static String prefixForNamedspacedStream(String namespace) { // stream:///namespace/ return String.format("stream:///%s/", namespace); } /** * Generates an QueueName for the stream. * * @param namespace of the stream * @param stream name of the stream * @return An {@link QueueName} with schema as stream */ public static QueueName fromStream(String namespace, String stream) { // The old stream admin uses full URI of queue name as the name URI uri = URI.create(String.format("stream:///%s/%s", namespace, stream)); return new QueueName(uri); } public static QueueName fromStream(Id.Stream streamId) { return fromStream(streamId.getNamespaceId(), streamId.getId()); } public Id.Stream toStreamId() { return Id.Stream.from(getFirstComponent(), getSecondComponent()); } /** * Called from static method {@code QueueName#from(URI)} and {@code QueueName#from(bytes[])}. * * @param uri of the queue. */ private QueueName(URI uri) { this.uri = uri; this.stringName = uri.toASCIIString(); this.byteName = stringName.getBytes(Charsets.US_ASCII); Iterable<String> comps = Splitter.on('/').omitEmptyStrings().split(uri.getPath()); components = new String[Iterables.size(comps)]; Iterator<String> iter = comps.iterator(); for (int i = 0; i < components.length; i++) { components[i] = iter.next(); } } public boolean isStream() { return "stream".equals(uri.getScheme()); } public boolean isQueue() { return "queue".equals(uri.getScheme()); } private String getNthComponent(int n) { return n < components.length ? components[n] : null; } /** * @return the first component of the of the URI (the namespace) */ public String getFirstComponent() { return getNthComponent(0); } /** * @return the second component of the URI (the app for a queue, the stream name for a stream). */ public String getSecondComponent() { return getNthComponent(1); } /** * @return the third component of the URI (the flow for a queue, null for a stream). */ public String getThirdComponent() { return getNthComponent(2); } /** * @return the fourth component of the URI (the flowlet for a queue, null for a stream). */ public String getFourthComponent() { return getNthComponent(3); } /** * @return Simple name which is the last part of queue URI path and endpoint. */ public String getSimpleName() { return components[components.length - 1]; } /** * @return the number of components in the queue name */ public int getNumComponents() { return components.length; } /** * Gets the bytes representation of the queue uri. Note that mutating the returned array will mutate the underlying * byte array as well. If mutation is needed, one has to copy to a separate array. * * @return bytes representation of queue uri. */ public byte[] toBytes() { return byteName; } /** * @return A {@link URI} representation of the queue name. */ public URI toURI() { return uri; } /** * @return converts to ascii string. */ @Override public String toString() { return stringName; } /** * @return whether the given string represents a queue. */ public static boolean isQueue(String name) { return name.startsWith("queue"); } /** * @return whether the given string represents a queue. */ public static boolean isStream(String name) { return name.startsWith("stream"); } /** * Compares this {@link QueueName} with another {@link QueueName}. * * @param o Other instance of {@link QueueName} * @return true if equal; false otherwise. */ @Override public boolean equals(Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } return uri.equals(((QueueName) o).uri); } /** * @return hash code of this QueueName. */ @Override public int hashCode() { return uri.hashCode(); } }