/*
* Copyright 2014 The Netty Project
*
* The Netty Project 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 io.netty.handler.codec;
import java.util.Map.Entry;
import io.netty.buffer.ByteBuf;
import io.netty.handler.codec.TextHeaders.EntryVisitor;
public final class AsciiHeadersEncoder implements EntryVisitor {
/**
* The separator characters to insert between a header name and a header value.
*/
public enum SeparatorType {
/**
* {@code ':'}
*/
COLON,
/**
* {@code ': '}
*/
COLON_SPACE,
}
/**
* The newline characters to insert between header entries.
*/
public enum NewlineType {
/**
* {@code '\n'}
*/
LF,
/**
* {@code '\r\n'}
*/
CRLF
}
private final ByteBuf buf;
private final SeparatorType separatorType;
private final NewlineType newlineType;
public AsciiHeadersEncoder(ByteBuf buf) {
this(buf, SeparatorType.COLON_SPACE, NewlineType.CRLF);
}
public AsciiHeadersEncoder(ByteBuf buf, SeparatorType separatorType, NewlineType newlineType) {
if (buf == null) {
throw new NullPointerException("buf");
}
if (separatorType == null) {
throw new NullPointerException("separatorType");
}
if (newlineType == null) {
throw new NullPointerException("newlineType");
}
this.buf = buf;
this.separatorType = separatorType;
this.newlineType = newlineType;
}
@Override
public boolean visit(Entry<CharSequence, CharSequence> entry) throws Exception {
final CharSequence name = entry.getKey();
final CharSequence value = entry.getValue();
final ByteBuf buf = this.buf;
final int nameLen = name.length();
final int valueLen = value.length();
final int entryLen = nameLen + valueLen + 4;
int offset = buf.writerIndex();
buf.ensureWritable(entryLen);
writeAscii(buf, offset, name, nameLen);
offset += nameLen;
switch (separatorType) {
case COLON:
buf.setByte(offset ++, ':');
break;
case COLON_SPACE:
buf.setByte(offset ++, ':');
buf.setByte(offset ++, ' ');
break;
default:
throw new Error();
}
writeAscii(buf, offset, value, valueLen);
offset += valueLen;
switch (newlineType) {
case LF:
buf.setByte(offset ++, '\n');
break;
case CRLF:
buf.setByte(offset ++, '\r');
buf.setByte(offset ++, '\n');
break;
default:
throw new Error();
}
buf.writerIndex(offset);
return true;
}
private static void writeAscii(ByteBuf buf, int offset, CharSequence value, int valueLen) {
if (value instanceof AsciiString) {
writeAsciiString(buf, offset, (AsciiString) value, valueLen);
} else {
writeCharSequence(buf, offset, value, valueLen);
}
}
private static void writeAsciiString(ByteBuf buf, int offset, AsciiString value, int valueLen) {
value.copy(0, buf, offset, valueLen);
}
private static void writeCharSequence(ByteBuf buf, int offset, CharSequence value, int valueLen) {
for (int i = 0; i < valueLen; i ++) {
buf.setByte(offset ++, c2b(value.charAt(i)));
}
}
private static int c2b(char ch) {
return ch < 256? (byte) ch : '?';
}
}