The Android Open Source Project | 96c5af4 | 2009-03-03 19:32:22 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 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 com.android.email; |
| 18 | |
| 19 | import java.io.IOException; |
| 20 | import java.io.InputStream; |
| 21 | |
| 22 | /** |
| 23 | * A filtering InputStream that stops allowing reads after the given length has been read. This |
| 24 | * is used to allow a client to read directly from an underlying protocol stream without reading |
| 25 | * past where the protocol handler intended the client to read. |
| 26 | */ |
| 27 | public class FixedLengthInputStream extends InputStream { |
Makoto Onuki | b3f7dd0 | 2010-05-10 14:20:16 -0700 | [diff] [blame] | 28 | private final InputStream mIn; |
| 29 | private final int mLength; |
The Android Open Source Project | 96c5af4 | 2009-03-03 19:32:22 -0800 | [diff] [blame] | 30 | private int mCount; |
| 31 | |
| 32 | public FixedLengthInputStream(InputStream in, int length) { |
| 33 | this.mIn = in; |
| 34 | this.mLength = length; |
| 35 | } |
| 36 | |
| 37 | @Override |
| 38 | public int available() throws IOException { |
| 39 | return mLength - mCount; |
| 40 | } |
| 41 | |
| 42 | @Override |
| 43 | public int read() throws IOException { |
| 44 | if (mCount < mLength) { |
| 45 | mCount++; |
| 46 | return mIn.read(); |
| 47 | } else { |
| 48 | return -1; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | @Override |
| 53 | public int read(byte[] b, int offset, int length) throws IOException { |
| 54 | if (mCount < mLength) { |
| 55 | int d = mIn.read(b, offset, Math.min(mLength - mCount, length)); |
| 56 | if (d == -1) { |
| 57 | return -1; |
| 58 | } else { |
| 59 | mCount += d; |
| 60 | return d; |
| 61 | } |
| 62 | } else { |
| 63 | return -1; |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | @Override |
| 68 | public int read(byte[] b) throws IOException { |
| 69 | return read(b, 0, b.length); |
| 70 | } |
| 71 | |
Makoto Onuki | 7e5ba0e | 2010-05-19 17:23:23 -0700 | [diff] [blame] | 72 | public int getLength() { |
| 73 | return mLength; |
| 74 | } |
| 75 | |
Makoto Onuki | 165e8bf | 2010-05-07 15:26:31 -0700 | [diff] [blame] | 76 | @Override |
The Android Open Source Project | 96c5af4 | 2009-03-03 19:32:22 -0800 | [diff] [blame] | 77 | public String toString() { |
| 78 | return String.format("FixedLengthInputStream(in=%s, length=%d)", mIn.toString(), mLength); |
| 79 | } |
| 80 | } |