diff options
Diffstat (limited to 'java/com/android/voicemailomtp/mail/PeekableInputStream.java')
-rw-r--r-- | java/com/android/voicemailomtp/mail/PeekableInputStream.java | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/java/com/android/voicemailomtp/mail/PeekableInputStream.java b/java/com/android/voicemailomtp/mail/PeekableInputStream.java new file mode 100644 index 000000000..c1181d189 --- /dev/null +++ b/java/com/android/voicemailomtp/mail/PeekableInputStream.java @@ -0,0 +1,80 @@ +/* + * Copyright (C) 2015 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.voicemailomtp.mail; + +import java.io.IOException; +import java.io.InputStream; + +/** + * A filtering InputStream that allows single byte "peeks" without consuming the byte. The + * client of this stream can call peek() to see the next available byte in the stream + * and a subsequent read will still return the peeked byte. + */ +public class PeekableInputStream extends InputStream { + private final InputStream mIn; + private boolean mPeeked; + private int mPeekedByte; + + public PeekableInputStream(InputStream in) { + this.mIn = in; + } + + @Override + public int read() throws IOException { + if (!mPeeked) { + return mIn.read(); + } else { + mPeeked = false; + return mPeekedByte; + } + } + + public int peek() throws IOException { + if (!mPeeked) { + mPeekedByte = read(); + mPeeked = true; + } + return mPeekedByte; + } + + @Override + public int read(byte[] b, int offset, int length) throws IOException { + if (!mPeeked) { + return mIn.read(b, offset, length); + } else { + b[0] = (byte)mPeekedByte; + mPeeked = false; + int r = mIn.read(b, offset + 1, length - 1); + if (r == -1) { + return 1; + } else { + return r + 1; + } + } + } + + @Override + public int read(byte[] b) throws IOException { + return read(b, 0, b.length); + } + + @Override + public String toString() { + return String.format("PeekableInputStream(in=%s, peeked=%b, peekedByte=%d)", + mIn.toString(), mPeeked, mPeekedByte); + } +}
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