src/javaexample/com/google/ipc/invalidation/examples/android2/ExampleListenerState.java - external/google-cache-invalidation-api - Git at Google

 /*
  * Copyright 2011 Google 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 com.google.ipc.invalidation.examples.android2;

 import com.google.ipc.invalidation.examples.android2.ExampleListenerProto.ExampleListenerStateProto;
 import com.google.ipc.invalidation.examples.android2.ExampleListenerProto.ExampleListenerStateProto.ObjectIdProto;
 import com.google.ipc.invalidation.examples.android2.ExampleListenerProto.ExampleListenerStateProto.ObjectStateProto;
 import com.google.ipc.invalidation.external.client.types.ObjectId;
 import com.google.protobuf.nano.InvalidProtocolBufferNanoException;
 import com.google.protobuf.nano.MessageNano;

 import android.util.Base64;
 import android.util.Log;

 import java.util.ArrayList;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;


 /**
  * Wrapper around persistent state for {@link ExampleListener}.
  *
  */
 public class ExampleListenerState {

   /** Wrapper around persistent state for an object tracked by the {@link ExampleListener}. */
   private static class ObjectState {
     /** Object id for the object being tracked. */
     final ObjectId objectId;

     /** Indicates whether the example listener wants to be registered for this object. */
     boolean isRegistered;

     /**
      * Payload of the invalidation with the highest version received so far. {@code null} before
      * any invalidations have been received or after an unknown-version invalidation is received.
      */
     byte[] payload;

     /**
      * Highest version invalidation received so far. {@code null} before any invalidations have
      * been received or after an unknown-version invalidation is received.
      */
     Long highestVersion;

     /** Wall time in milliseconds at which most recent invalidation was received. */
     Long invalidationTimeMillis;

     /** Indicates whether the last invalidation received was a background invalidation. */
     boolean isBackground;

     ObjectState(ObjectStateProto objectStateProto) {
       objectId = deserializeObjectId(objectStateProto.objectId);
       isRegistered = objectStateProto.isRegistered;
       payload = objectStateProto.payload;
       highestVersion = objectStateProto.highestVersion;
       invalidationTimeMillis = objectStateProto.invalidationTimeMillis;
       isBackground = objectStateProto.isBackground;
     }

     ObjectState(ObjectId objectId, boolean isRegistered) {
       this.objectId = objectId;
       this.isRegistered = isRegistered;
     }

     ObjectStateProto serialize() {
       ObjectStateProto proto = new ObjectStateProto();
       proto.objectId = serializeObjectId(objectId);
       proto.isRegistered = isRegistered;
       proto.isBackground = isBackground;
       proto.payload = payload;
       proto.highestVersion = highestVersion;
       proto.invalidationTimeMillis = invalidationTimeMillis;
       return proto;
     }

     @Override
     public String toString() {
       StringBuilder builder = new StringBuilder();
       toString(builder);
       return builder.toString();
     }

     void toString(StringBuilder builder) {
       builder.append(isRegistered ? "REG " : "UNREG ").append(objectId);
       if (payload != null) {
         builder.append(", |payload|=").append(payload.length);
       }
       if (highestVersion != null) {
         builder.append(", highestVersion=").append(highestVersion.longValue());
       }
       if (isBackground) {
         builder.append(", isBackground");
       }
       if (invalidationTimeMillis != null) {
         builder.append(", invalidationTime=").append(new Date(invalidationTimeMillis.longValue()));
       }
     }
   }

   /** The tag used for logging in the listener state class. */
   private static final String TAG = "TEA2:ELS";

   /** Number of objects we're interested in tracking by default. */

   static final int NUM_INTERESTING_OBJECTS = 4;

   /** Object source for objects the client is initially tracking. */
   private static final int DEMO_SOURCE = 4;

   /** Prefix for object names the client is initially tracking. */
   private static final String OBJECT_ID_PREFIX = "Obj";

   /** State for all tracked objects. */
   private final Map<ObjectId, ObjectState> trackedObjects;

   /** Client id reported by {@code AndroidListener#ready} call. */
   private byte[] clientId;

   private ExampleListenerState(Map<ObjectId, ObjectState> trackedObjects,
       byte[] clientId) {
     if (trackedObjects == null) {
       throw new NullPointerException();
     }
     this.trackedObjects = trackedObjects;
     this.clientId = clientId;
   }

   public static ExampleListenerState deserialize(String data) {
     HashMap<ObjectId, ObjectState> trackedObjects = new HashMap<ObjectId, ObjectState>();
     byte[] clientId;
     ExampleListenerStateProto stateProto = tryParseStateProto(data);
     if (stateProto == null) {
       // By default, we're interested in objects with ids Obj1, Obj2, ...
       for (int i = 1; i <= NUM_INTERESTING_OBJECTS; ++i) {
         ObjectId objectId = ObjectId.newInstance(DEMO_SOURCE, (OBJECT_ID_PREFIX + i).getBytes());
         trackedObjects.put(objectId, new ObjectState(objectId, true));
       }
       clientId = null;
     } else {
       // Load interesting objects from state proto.
       for (ObjectStateProto objectStateProto : stateProto.objectState) {
         ObjectState objectState = new ObjectState(objectStateProto);
         trackedObjects.put(objectState.objectId, objectState);
       }
       clientId = stateProto.clientId;
     }
     return new ExampleListenerState(trackedObjects, clientId);
   }

   /** Returns proto serialized in data or null if it cannot be decoded. */
   private static ExampleListenerStateProto tryParseStateProto(String data) {
     if (data == null) {
       return null;
     }
     final byte[] bytes;
     try {
       bytes = Base64.decode(data, Base64.DEFAULT);
     } catch (IllegalArgumentException exception) {
       Log.e(TAG, String.format(Locale.ROOT, "Illegal base 64 encoding. data='%s', error='%s'", data,
           exception.getMessage()));
       return null;
     }
     try {
       ExampleListenerStateProto proto =
           MessageNano.mergeFrom(new ExampleListenerStateProto(), bytes);
       return proto;
     } catch (InvalidProtocolBufferNanoException exception) {
       Log.e(TAG, String.format(Locale.ROOT, "Error parsing state bytes. data='%s', error='%s'",
           data, exception.getMessage()));
       return null;
     }
   }

   /** Serializes example listener state to string. */
   public String serialize() {
     ExampleListenerStateProto proto = new ExampleListenerStateProto();
     proto.objectState = new ObjectStateProto[trackedObjects.size()];
     int index = 0;
     for (ObjectState objectState : trackedObjects.values()) {
       ObjectStateProto objectStateProto = objectState.serialize();
       proto.objectState[index++] = objectStateProto;
     }
     proto.clientId = clientId;
     return Base64.encodeToString(MessageNano.toByteArray(proto), Base64.DEFAULT);
   }

   Iterable<ObjectId> getInterestingObjects() {
     List<ObjectId> interestingObjects = new ArrayList<ObjectId>(trackedObjects.size());
     for (ObjectState objectState : trackedObjects.values()) {
       if (objectState.isRegistered) {
         interestingObjects.add(objectState.objectId);
       }
     }
     return interestingObjects;
   }

   byte[] getClientId() {
     return clientId;
   }

   /** Sets the client id passed to the example listener via the {@code ready()} call. */
   void setClientId(byte[] value) {
     clientId = value;
   }

   /**
    * Returns {@code true} if the state indicates a registration should exist for the given object.
    */
   boolean isInterestedInObject(ObjectId objectId) {
     ObjectState objectState = trackedObjects.get(objectId);
     return (objectState != null) && objectState.isRegistered;
   }

   /** Updates state for the given object to indicate it should be registered. */
   boolean addObjectOfInterest(ObjectId objectId) {
     ObjectState objectState = trackedObjects.get(objectId);
     if (objectState == null) {
       objectState = new ObjectState(objectId, true);
       trackedObjects.put(objectId, objectState);
       return true;
     }

     if (objectState.isRegistered) {
       return false;
     }
     objectState.isRegistered = true;
     return true;
   }

   /** Updates state for the given object to indicate it should not be registered. */
   boolean removeObjectOfInterest(ObjectId objectId) {
     ObjectState objectState = trackedObjects.get(objectId);
     if (objectState == null) {
       return false;
     }

     if (objectState.isRegistered) {
       objectState.isRegistered = false;
       return true;
     }
     return false;
   }

   /** Updates state for an object after an unknown-version invalidation is received. */
   void informUnknownVersionInvalidation(ObjectId objectId) {
     ObjectState objectState = getObjectStateForInvalidation(objectId);
     objectState.invalidationTimeMillis = System.currentTimeMillis();
     objectState.highestVersion = null;
     objectState.payload = null;
   }

   /** Updates state for an object after an invalidation is received. */
   void informInvalidation(ObjectId objectId, long version, byte[] payload,
       boolean isBackground) {
     ObjectState objectState = getObjectStateForInvalidation(objectId);
     if (objectState.highestVersion == null || objectState.highestVersion.longValue() < version) {
       objectState.highestVersion = version;
       objectState.payload = payload;
       objectState.invalidationTimeMillis = System.currentTimeMillis();
       objectState.isBackground = isBackground;
     }
   }

   /**
    * Updates state when an invalidate all request is received (unknown version is marked for all
    * objects).
    */
   public void informInvalidateAll() {
     for (ObjectState objectState : trackedObjects.values()) {
       informUnknownVersionInvalidation(objectState.objectId);
     }
   }

   /** Returns existing object state for an object or updates state. */
   private ObjectState getObjectStateForInvalidation(ObjectId objectId) {
     ObjectState objectState = trackedObjects.get(objectId);
     if (objectState == null) {
       // Invalidation for unregistered object.
       objectState = new ObjectState(objectId, false);
       trackedObjects.put(objectId, objectState);
     }
     return objectState;
   }

   /** Returns an object given its serialized form. */
   static ObjectId deserializeObjectId(ObjectIdProto objectIdProto) {
     return ObjectId.newInstance(objectIdProto.source, objectIdProto.name);
   }

   /** Serializes the given object id. */
   static ObjectIdProto serializeObjectId(ObjectId objectId) {
     ObjectIdProto proto = new ObjectIdProto();
     proto.source = objectId.getSource();
     proto.name = objectId.getName();
     return proto;
   }

   /** Clears all state for the example listener. */
   void clear() {
     trackedObjects.clear();
     clientId = null;
   }

   @Override
   public String toString() {
     StringBuilder builder = new StringBuilder();
     if (clientId != null) {
       builder.append("ready!\n");
     }
     for (ObjectState objectState : trackedObjects.values()) {
       objectState.toString(builder);
       builder.append("\n");
     }
     return builder.toString();
   }
 }
	/*
	* Copyright 2011 Google 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 com.google.ipc.invalidation.examples.android2;

	import com.google.ipc.invalidation.examples.android2.ExampleListenerProto.ExampleListenerStateProto;
	import com.google.ipc.invalidation.examples.android2.ExampleListenerProto.ExampleListenerStateProto.ObjectIdProto;
	import com.google.ipc.invalidation.examples.android2.ExampleListenerProto.ExampleListenerStateProto.ObjectStateProto;
	import com.google.ipc.invalidation.external.client.types.ObjectId;
	import com.google.protobuf.nano.InvalidProtocolBufferNanoException;
	import com.google.protobuf.nano.MessageNano;

	import android.util.Base64;
	import android.util.Log;

	import java.util.ArrayList;
	import java.util.Date;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;


	/**
	* Wrapper around persistent state for {@link ExampleListener}.
	*
	*/
	public class ExampleListenerState {

	/** Wrapper around persistent state for an object tracked by the {@link ExampleListener}. */
	private static class ObjectState {
	/** Object id for the object being tracked. */
	final ObjectId objectId;

	/** Indicates whether the example listener wants to be registered for this object. */
	boolean isRegistered;

	/**
	* Payload of the invalidation with the highest version received so far. {@code null} before
	* any invalidations have been received or after an unknown-version invalidation is received.
	*/
	byte[] payload;

	/**
	* Highest version invalidation received so far. {@code null} before any invalidations have
	* been received or after an unknown-version invalidation is received.
	*/
	Long highestVersion;

	/** Wall time in milliseconds at which most recent invalidation was received. */
	Long invalidationTimeMillis;

	/** Indicates whether the last invalidation received was a background invalidation. */
	boolean isBackground;

	ObjectState(ObjectStateProto objectStateProto) {
	objectId = deserializeObjectId(objectStateProto.objectId);
	isRegistered = objectStateProto.isRegistered;
	payload = objectStateProto.payload;
	highestVersion = objectStateProto.highestVersion;
	invalidationTimeMillis = objectStateProto.invalidationTimeMillis;
	isBackground = objectStateProto.isBackground;
	}

	ObjectState(ObjectId objectId, boolean isRegistered) {
	this.objectId = objectId;
	this.isRegistered = isRegistered;
	}

	ObjectStateProto serialize() {
	ObjectStateProto proto = new ObjectStateProto();
	proto.objectId = serializeObjectId(objectId);
	proto.isRegistered = isRegistered;
	proto.isBackground = isBackground;
	proto.payload = payload;
	proto.highestVersion = highestVersion;
	proto.invalidationTimeMillis = invalidationTimeMillis;
	return proto;
	}

	@Override
	public String toString() {
	StringBuilder builder = new StringBuilder();
	toString(builder);
	return builder.toString();
	}

	void toString(StringBuilder builder) {
	builder.append(isRegistered ? "REG " : "UNREG ").append(objectId);
	if (payload != null) {
	builder.append(", \|payload\|=").append(payload.length);
	}
	if (highestVersion != null) {
	builder.append(", highestVersion=").append(highestVersion.longValue());
	}
	if (isBackground) {
	builder.append(", isBackground");
	}
	if (invalidationTimeMillis != null) {
	builder.append(", invalidationTime=").append(new Date(invalidationTimeMillis.longValue()));
	}
	}
	}

	/** The tag used for logging in the listener state class. */
	private static final String TAG = "TEA2:ELS";

	/** Number of objects we're interested in tracking by default. */

	static final int NUM_INTERESTING_OBJECTS = 4;

	/** Object source for objects the client is initially tracking. */
	private static final int DEMO_SOURCE = 4;

	/** Prefix for object names the client is initially tracking. */
	private static final String OBJECT_ID_PREFIX = "Obj";

	/** State for all tracked objects. */
	private final Map<ObjectId, ObjectState> trackedObjects;

	/** Client id reported by {@code AndroidListener#ready} call. */
	private byte[] clientId;

	private ExampleListenerState(Map<ObjectId, ObjectState> trackedObjects,
	byte[] clientId) {
	if (trackedObjects == null) {
	throw new NullPointerException();
	}
	this.trackedObjects = trackedObjects;
	this.clientId = clientId;
	}

	public static ExampleListenerState deserialize(String data) {
	HashMap<ObjectId, ObjectState> trackedObjects = new HashMap<ObjectId, ObjectState>();
	byte[] clientId;
	ExampleListenerStateProto stateProto = tryParseStateProto(data);
	if (stateProto == null) {
	// By default, we're interested in objects with ids Obj1, Obj2, ...
	for (int i = 1; i <= NUM_INTERESTING_OBJECTS; ++i) {
	ObjectId objectId = ObjectId.newInstance(DEMO_SOURCE, (OBJECT_ID_PREFIX + i).getBytes());
	trackedObjects.put(objectId, new ObjectState(objectId, true));
	}
	clientId = null;
	} else {
	// Load interesting objects from state proto.
	for (ObjectStateProto objectStateProto : stateProto.objectState) {
	ObjectState objectState = new ObjectState(objectStateProto);
	trackedObjects.put(objectState.objectId, objectState);
	}
	clientId = stateProto.clientId;
	}
	return new ExampleListenerState(trackedObjects, clientId);
	}

	/** Returns proto serialized in data or null if it cannot be decoded. */
	private static ExampleListenerStateProto tryParseStateProto(String data) {
	if (data == null) {
	return null;
	}
	final byte[] bytes;
	try {
	bytes = Base64.decode(data, Base64.DEFAULT);
	} catch (IllegalArgumentException exception) {
	Log.e(TAG, String.format(Locale.ROOT, "Illegal base 64 encoding. data='%s', error='%s'", data,
	exception.getMessage()));
	return null;
	}
	try {
	ExampleListenerStateProto proto =
	MessageNano.mergeFrom(new ExampleListenerStateProto(), bytes);
	return proto;
	} catch (InvalidProtocolBufferNanoException exception) {
	Log.e(TAG, String.format(Locale.ROOT, "Error parsing state bytes. data='%s', error='%s'",
	data, exception.getMessage()));
	return null;
	}
	}

	/** Serializes example listener state to string. */
	public String serialize() {
	ExampleListenerStateProto proto = new ExampleListenerStateProto();
	proto.objectState = new ObjectStateProto[trackedObjects.size()];
	int index = 0;
	for (ObjectState objectState : trackedObjects.values()) {
	ObjectStateProto objectStateProto = objectState.serialize();
	proto.objectState[index++] = objectStateProto;
	}
	proto.clientId = clientId;
	return Base64.encodeToString(MessageNano.toByteArray(proto), Base64.DEFAULT);
	}

	Iterable<ObjectId> getInterestingObjects() {
	List<ObjectId> interestingObjects = new ArrayList<ObjectId>(trackedObjects.size());
	for (ObjectState objectState : trackedObjects.values()) {
	if (objectState.isRegistered) {
	interestingObjects.add(objectState.objectId);
	}
	}
	return interestingObjects;
	}

	byte[] getClientId() {
	return clientId;
	}

	/** Sets the client id passed to the example listener via the {@code ready()} call. */
	void setClientId(byte[] value) {
	clientId = value;
	}

	/**
	* Returns {@code true} if the state indicates a registration should exist for the given object.
	*/
	boolean isInterestedInObject(ObjectId objectId) {
	ObjectState objectState = trackedObjects.get(objectId);
	return (objectState != null) && objectState.isRegistered;
	}

	/** Updates state for the given object to indicate it should be registered. */
	boolean addObjectOfInterest(ObjectId objectId) {
	ObjectState objectState = trackedObjects.get(objectId);
	if (objectState == null) {
	objectState = new ObjectState(objectId, true);
	trackedObjects.put(objectId, objectState);
	return true;
	}

	if (objectState.isRegistered) {
	return false;
	}
	objectState.isRegistered = true;
	return true;
	}

	/** Updates state for the given object to indicate it should not be registered. */
	boolean removeObjectOfInterest(ObjectId objectId) {
	ObjectState objectState = trackedObjects.get(objectId);
	if (objectState == null) {
	return false;
	}

	if (objectState.isRegistered) {
	objectState.isRegistered = false;
	return true;
	}
	return false;
	}

	/** Updates state for an object after an unknown-version invalidation is received. */
	void informUnknownVersionInvalidation(ObjectId objectId) {
	ObjectState objectState = getObjectStateForInvalidation(objectId);
	objectState.invalidationTimeMillis = System.currentTimeMillis();
	objectState.highestVersion = null;
	objectState.payload = null;
	}

	/** Updates state for an object after an invalidation is received. */
	void informInvalidation(ObjectId objectId, long version, byte[] payload,
	boolean isBackground) {
	ObjectState objectState = getObjectStateForInvalidation(objectId);
	if (objectState.highestVersion == null \|\| objectState.highestVersion.longValue() < version) {
	objectState.highestVersion = version;
	objectState.payload = payload;
	objectState.invalidationTimeMillis = System.currentTimeMillis();
	objectState.isBackground = isBackground;
	}
	}

	/**
	* Updates state when an invalidate all request is received (unknown version is marked for all
	* objects).
	*/
	public void informInvalidateAll() {
	for (ObjectState objectState : trackedObjects.values()) {
	informUnknownVersionInvalidation(objectState.objectId);
	}
	}

	/** Returns existing object state for an object or updates state. */
	private ObjectState getObjectStateForInvalidation(ObjectId objectId) {
	ObjectState objectState = trackedObjects.get(objectId);
	if (objectState == null) {
	// Invalidation for unregistered object.
	objectState = new ObjectState(objectId, false);
	trackedObjects.put(objectId, objectState);
	}
	return objectState;
	}

	/** Returns an object given its serialized form. */
	static ObjectId deserializeObjectId(ObjectIdProto objectIdProto) {
	return ObjectId.newInstance(objectIdProto.source, objectIdProto.name);
	}

	/** Serializes the given object id. */
	static ObjectIdProto serializeObjectId(ObjectId objectId) {
	ObjectIdProto proto = new ObjectIdProto();
	proto.source = objectId.getSource();
	proto.name = objectId.getName();
	return proto;
	}

	/** Clears all state for the example listener. */
	void clear() {
	trackedObjects.clear();
	clientId = null;
	}

	@Override
	public String toString() {
	StringBuilder builder = new StringBuilder();
	if (clientId != null) {
	builder.append("ready!\n");
	}
	for (ObjectState objectState : trackedObjects.values()) {
	objectState.toString(builder);
	builder.append("\n");
	}
	return builder.toString();
	}
	}