replicant-packages_apps_Email/provider_src/com/android/email/FixedLengthInputStream.java

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/*
* Copyright (C) 2008 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.email;
import java.io.IOException;
import java.io.InputStream;
/**
* A filtering InputStream that stops allowing reads after the given length has been read. This
* is used to allow a client to read directly from an underlying protocol stream without reading
* past where the protocol handler intended the client to read.
*/
public class FixedLengthInputStream extends InputStream {
private final InputStream mIn;
private final int mLength;
private int mCount;
public FixedLengthInputStream(InputStream in, int length) {
this.mIn = in;
this.mLength = length;
}
@Override
public int available() throws IOException {
return mLength - mCount;
}
@Override
public int read() throws IOException {
if (mCount < mLength) {
mCount++;
return mIn.read();
} else {
return -1;
}
}
@Override
public int read(byte[] b, int offset, int length) throws IOException {
if (mCount < mLength) {
int d = mIn.read(b, offset, Math.min(mLength - mCount, length));
if (d == -1) {
return -1;
} else {
mCount += d;
return d;
}
} else {
return -1;
}
}
@Override
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
public int getLength() {
return mLength;
}
@Override
public String toString() {
return String.format("FixedLengthInputStream(in=%s, length=%d)", mIn.toString(), mLength);
}
}