1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.os; 18 import android.os.RemoteException; 19 20 /** 21 * The Binder transaction failed because it was too large. 22 * <p> 23 * During a remote procedure call, the arguments and the return value of the call 24 * are transferred as {@link Parcel} objects stored in the Binder transaction buffer. 25 * If the arguments or the return value are too large to fit in the transaction buffer, 26 * then the call will fail and {@link TransactionTooLargeException} will be thrown. 27 * </p><p> 28 * The Binder transaction buffer has a limited fixed size, currently 1Mb, which 29 * is shared by all transactions in progress for the process. Consequently this 30 * exception can be thrown when there are many transactions in progress even when 31 * most of the individual transactions are of moderate size. 32 * </p><p> 33 * There are two possible outcomes when a remote procedure call throws 34 * {@link TransactionTooLargeException}. Either the client was unable to send 35 * its request to the service (most likely if the arguments were too large to fit in 36 * the transaction buffer), or the service was unable to send its response back 37 * to the client (most likely if the return value was too large to fit 38 * in the transaction buffer). It is not possible to tell which of these outcomes 39 * actually occurred. The client should assume that a partial failure occurred. 40 * </p><p> 41 * The key to avoiding {@link TransactionTooLargeException} is to keep all 42 * transactions relatively small. Try to minimize the amount of memory needed to create 43 * a {@link Parcel} for the arguments and the return value of the remote procedure call. 44 * Avoid transferring huge arrays of strings or large bitmaps. 45 * If possible, try to break up big requests into smaller pieces. 46 * </p><p> 47 * If you are implementing a service, it may help to impose size or complexity 48 * contraints on the queries that clients can perform. For example, if the result set 49 * could become large, then don't allow the client to request more than a few records 50 * at a time. Alternately, instead of returning all of the available data all at once, 51 * return the essential information first and make the client ask for additional information 52 * later as needed. 53 * </p> 54 */ 55 public class TransactionTooLargeException extends RemoteException { 56 public TransactionTooLargeException() { 57 super(); 58 } 59 60 public TransactionTooLargeException(String msg) { 61 super(msg); 62 } 63 } 64
