| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * 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.android.internal.util; |
| |
| import libcore.io.Streams; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * Reads exact number of bytes from wrapped stream, returning EOF once those |
| * bytes have been read. |
| */ |
| public class SizedInputStream extends InputStream { |
| private final InputStream mWrapped; |
| private long mLength; |
| |
| public SizedInputStream(InputStream wrapped, long length) { |
| mWrapped = wrapped; |
| mLength = length; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| super.close(); |
| mWrapped.close(); |
| } |
| |
| @Override |
| public int read() throws IOException { |
| return Streams.readSingleByte(this); |
| } |
| |
| @Override |
| public int read(byte[] buffer, int byteOffset, int byteCount) throws IOException { |
| if (mLength <= 0) { |
| return -1; |
| } else if (byteCount > mLength) { |
| byteCount = (int) mLength; |
| } |
| |
| final int n = mWrapped.read(buffer, byteOffset, byteCount); |
| if (n == -1) { |
| if (mLength > 0) { |
| throw new IOException("Unexpected EOF; expected " + mLength + " more bytes"); |
| } |
| } else { |
| mLength -= n; |
| } |
| return n; |
| } |
| } |