org.apache.sshd.common.util.io.output.LineLevelAppenderStream Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.sshd.common.util.io.output;
import java.io.IOException;
import java.io.StreamCorruptedException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderResult;
import java.util.Objects;
import org.apache.sshd.common.util.ValidateUtils;
/**
*
* Accumulates all written data into a work buffer and calls the actual writing method only when LF detected.
* Note: it strips CR if found before the LF
*
*
* @author Apache MINA SSHD Project
*/
public class LineLevelAppenderStream extends LineOutputStream {
protected final CharsetDecoder csDecoder;
protected final LineLevelAppender appenderInstance;
protected char[] lineBuf;
public LineLevelAppenderStream(LineLevelAppender appender) {
this(Charset.defaultCharset(), appender);
}
public LineLevelAppenderStream(String charset, LineLevelAppender appender) {
this(Charset.forName(ValidateUtils.checkNotNullAndNotEmpty(charset, "No charset name")), appender);
}
public LineLevelAppenderStream(Charset charset, LineLevelAppender appender) {
this(Objects.requireNonNull(charset, "No charset").newDecoder(), appender);
}
public LineLevelAppenderStream(CharsetDecoder decoder, LineLevelAppender appender) {
csDecoder = Objects.requireNonNull(decoder, "No decoder");
appenderInstance = Objects.requireNonNull(appender, "No appender");
}
public final LineLevelAppender getLineLevelAppender() {
return appenderInstance;
}
@Override
protected void handleLine(byte[] b, int off, int len) throws IOException {
LineLevelAppender appender = getLineLevelAppender();
if (len <= 0) {
appender.writeLineData("");
return;
}
ByteBuffer bb = (b[off + len - 1] == '\r') ? ByteBuffer.wrap(b, off, len - 1) : ByteBuffer.wrap(b, off, len);
char[] lineChars = ensureCharDataCapacity(len);
CharBuffer cc = CharBuffer.wrap(lineChars);
csDecoder.reset();
CoderResult res = csDecoder.decode(bb, cc, true);
if (res.isError() || res.isMalformed() || res.isOverflow() || res.isUnmappable()) {
throw new StreamCorruptedException("Failed to decode line bytes: " + res);
}
cc.flip();
appender.writeLineData(cc);
}
protected char[] ensureCharDataCapacity(int numBytes) {
float grwFactor = csDecoder.maxCharsPerByte(); // worst case
int reqChars = (grwFactor > 0.0f) ? (int) (numBytes * grwFactor) : numBytes;
if ((lineBuf == null) || (lineBuf.length < reqChars)) {
reqChars = Math.max(reqChars, LineLevelAppender.TYPICAL_LINE_LENGTH);
lineBuf = new char[reqChars + Byte.SIZE /* a little extra to avoid numerous growths */];
}
return lineBuf;
}
}