Alan Viverette | 3da604b | 2020-06-10 18:34:39 +0000 | [diff] [blame] | 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 | } |