| /* |
| * Copyright 2000-2011 JetBrains s.r.o. |
| * |
| * 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.intellij.cvsSupport2.javacvsImpl.io; |
| |
| import com.intellij.util.ArrayUtil; |
| import org.jetbrains.annotations.Nullable; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * @author Bas Leijdekkers |
| */ |
| public class LineReader { |
| |
| private static final int DEFAULT_BUFFER_SIZE = 10 * 1024; |
| |
| private final byte[] myBuffer; |
| private final InputStream myInputStream; |
| private final ByteArrayOutputStream myOutputStream = new ByteArrayOutputStream(); |
| private int myBytesExpected; |
| private int myPosition = 0; |
| private int myBytesBuffered = 0; |
| private int myLastEol = 0; |
| |
| public LineReader(InputStream in, int bytesExpected) { |
| this(in, bytesExpected, DEFAULT_BUFFER_SIZE); |
| } |
| |
| public LineReader(InputStream in, int bytesExpected, final int bufferSize) { |
| if (bufferSize < 2) { |
| throw new IllegalArgumentException("buffer size must be greater than 1"); |
| } |
| myInputStream = in; |
| myBytesExpected = bytesExpected; |
| myBuffer = new byte[bufferSize]; |
| } |
| |
| private void fillBuffer() throws IOException { |
| if (myBytesExpected == 0) { |
| myBytesBuffered = -1; |
| return; |
| } |
| myBytesBuffered = myInputStream.read(myBuffer, 0, Math.min(myBuffer.length, myBytesExpected)); |
| if (myBytesBuffered > 0) { |
| myBytesExpected -= myBytesBuffered; |
| myPosition = 0; |
| } |
| } |
| |
| private byte[] getLineArray() { |
| myPosition++; |
| if (myOutputStream.size() == 0) { |
| return ArrayUtil.EMPTY_BYTE_ARRAY; |
| } |
| final byte[] bytes = myOutputStream.toByteArray(); |
| myOutputStream.reset(); |
| return bytes; |
| } |
| |
| @Nullable |
| public byte[] readLine() throws IOException { |
| if (myBytesBuffered == -1) { |
| if (myLastEol != 0) { |
| myLastEol = 0; |
| return getLineArray(); |
| } |
| return null; |
| } else if (myPosition >= myBytesBuffered) { |
| fillBuffer(); |
| if (myBytesBuffered == -1) { |
| return getLineArray(); |
| } |
| } |
| final byte[] buffer = myBuffer; |
| while (myBytesBuffered != -1) { |
| for (; myPosition < myBytesBuffered; myPosition++) { |
| final byte c = buffer[myPosition]; |
| switch (c) { |
| case '\r': |
| if (myLastEol == '\r') { |
| return getLineArray(); |
| } else { |
| myLastEol = '\r'; |
| } |
| break; |
| case '\n': |
| if (myLastEol == '\n') { |
| return getLineArray(); |
| } else { |
| myLastEol = '\n'; |
| } |
| break; |
| default: |
| if (myLastEol != 0) { |
| myLastEol = 0; |
| final byte[] line = getLineArray(); |
| myOutputStream.write(c); |
| return line; |
| } else { |
| myOutputStream.write(c); |
| } |
| break; |
| } |
| } |
| fillBuffer(); |
| } |
| return getLineArray(); |
| } |
| } |