TransactionTooLargeException.java revision e5c42621095a12e7d22ca5ab871dacd28c9bff41 
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
17package android.os;
18import 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 */
55public class TransactionTooLargeException extends RemoteException {
56    public TransactionTooLargeException() {
57        super();
58    }
59
60    public TransactionTooLargeException(String msg) {
61        super(msg);
62    }
63}
64