/*
* Copyright 2015 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.http;
import io.netty.handler.codec.DefaultHeaders;
import io.netty.handler.codec.Headers;
import io.netty.handler.codec.ValueConverter;
import io.netty.util.HashingStrategy;
import io.netty.util.internal.StringUtil;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import static io.netty.util.AsciiString.CASE_INSENSITIVE_HASHER;
import static io.netty.util.internal.StringUtil.COMMA;
/**
* Will add multiple values for the same header as single header with a comma separated list of values.
* <p>
* Please refer to section <a href="https://tools.ietf.org/html/rfc7230#section-3.2.2">RFC 7230, 3.2.2</a>.
*/
public class CombinedHttpHeaders extends DefaultHttpHeaders {
public CombinedHttpHeaders(boolean validate) {
super(new CombinedHttpHeadersImpl(CASE_INSENSITIVE_HASHER, valueConverter(validate), nameValidator(validate)));
}
@Override
public boolean containsValue(CharSequence name, CharSequence value, boolean ignoreCase) {
return super.containsValue(name, StringUtil.trimOws(value), ignoreCase);
}
private static final class CombinedHttpHeadersImpl
extends DefaultHeaders<CharSequence, CharSequence, CombinedHttpHeadersImpl> {
/**
* An estimate of the size of a header value.
*/
private static final int VALUE_LENGTH_ESTIMATE = 10;
private CsvValueEscaper<Object> objectEscaper;
private CsvValueEscaper<CharSequence> charSequenceEscaper;
private CsvValueEscaper<Object> objectEscaper() {
if (objectEscaper == null) {
objectEscaper = new CsvValueEscaper<Object>() {
@Override
public CharSequence escape(Object value) {
return StringUtil.escapeCsv(valueConverter().convertObject(value), true);
}
};
}
return objectEscaper;
}
private CsvValueEscaper<CharSequence> charSequenceEscaper() {
if (charSequenceEscaper == null) {
charSequenceEscaper = new CsvValueEscaper<CharSequence>() {
@Override
public CharSequence escape(CharSequence value) {
return StringUtil.escapeCsv(value, true);
}
};
}
return charSequenceEscaper;
}
public CombinedHttpHeadersImpl(HashingStrategy<CharSequence> nameHashingStrategy,
ValueConverter<CharSequence> valueConverter,
io.netty.handler.codec.DefaultHeaders.NameValidator<CharSequence> nameValidator) {
super(nameHashingStrategy, valueConverter, nameValidator);
}
@Override
public List<CharSequence> getAll(CharSequence name) {
List<CharSequence> values = super.getAll(name);
if (values.isEmpty()) {
return values;
}
if (values.size() != 1) {
throw new IllegalStateException("CombinedHttpHeaders should only have one value");
}
return StringUtil.unescapeCsvFields(values.get(0));
}
@Override
public CombinedHttpHeadersImpl add(Headers<? extends CharSequence, ? extends CharSequence, ?> headers) {
// Override the fast-copy mechanism used by DefaultHeaders
if (headers == this) {
throw new IllegalArgumentException("can't add to itself.");
}
if (headers instanceof CombinedHttpHeadersImpl) {
if (isEmpty()) {
// Can use the fast underlying copy
addImpl(headers);
} else {
// Values are already escaped so don't escape again
for (Map.Entry<? extends CharSequence, ? extends CharSequence> header : headers) {
addEscapedValue(header.getKey(), header.getValue());
}
}
} else {
for (Map.Entry<? extends CharSequence, ? extends CharSequence> header : headers) {
add(header.getKey(), header.getValue());
}
}
return this;
}
@Override
public CombinedHttpHeadersImpl set(Headers<? extends CharSequence, ? extends CharSequence, ?> headers) {
if (headers == this) {
return this;
}
clear();
return add(headers);
}
@Override
public CombinedHttpHeadersImpl setAll(Headers<? extends CharSequence, ? extends CharSequence, ?> headers) {
if (headers == this) {
return this;
}
for (CharSequence key : headers.names()) {
remove(key);
}
return add(headers);
}
@Override
public CombinedHttpHeadersImpl add(CharSequence name, CharSequence value) {
return addEscapedValue(name, charSequenceEscaper().escape(value));
}
@Override
public CombinedHttpHeadersImpl add(CharSequence name, CharSequence... values) {
return addEscapedValue(name, commaSeparate(charSequenceEscaper(), values));
}
@Override
public CombinedHttpHeadersImpl add(CharSequence name, Iterable<? extends CharSequence> values) {
return addEscapedValue(name, commaSeparate(charSequenceEscaper(), values));
}
@Override
public CombinedHttpHeadersImpl addObject(CharSequence name, Object value) {
return addEscapedValue(name, commaSeparate(objectEscaper(), value));
}
@Override
public CombinedHttpHeadersImpl addObject(CharSequence name, Iterable<?> values) {
return addEscapedValue(name, commaSeparate(objectEscaper(), values));
}
@Override
public CombinedHttpHeadersImpl addObject(CharSequence name, Object... values) {
return addEscapedValue(name, commaSeparate(objectEscaper(), values));
}
@Override
public CombinedHttpHeadersImpl set(CharSequence name, CharSequence... values) {
super.set(name, commaSeparate(charSequenceEscaper(), values));
return this;
}
@Override
public CombinedHttpHeadersImpl set(CharSequence name, Iterable<? extends CharSequence> values) {
super.set(name, commaSeparate(charSequenceEscaper(), values));
return this;
}
@Override
public CombinedHttpHeadersImpl setObject(CharSequence name, Object value) {
super.set(name, commaSeparate(objectEscaper(), value));
return this;
}
@Override
public CombinedHttpHeadersImpl setObject(CharSequence name, Object... values) {
super.set(name, commaSeparate(objectEscaper(), values));
return this;
}
@Override
public CombinedHttpHeadersImpl setObject(CharSequence name, Iterable<?> values) {
super.set(name, commaSeparate(objectEscaper(), values));
return this;
}
private CombinedHttpHeadersImpl addEscapedValue(CharSequence name, CharSequence escapedValue) {
CharSequence currentValue = super.get(name);
if (currentValue == null) {
super.add(name, escapedValue);
} else {
super.set(name, commaSeparateEscapedValues(currentValue, escapedValue));
}
return this;
}
private static <T> CharSequence commaSeparate(CsvValueEscaper<T> escaper, T... values) {
StringBuilder sb = new StringBuilder(values.length * VALUE_LENGTH_ESTIMATE);
if (values.length > 0) {
int end = values.length - 1;
for (int i = 0; i < end; i++) {
sb.append(escaper.escape(values[i])).append(COMMA);
}
sb.append(escaper.escape(values[end]));
}
return sb;
}
private static <T> CharSequence commaSeparate(CsvValueEscaper<T> escaper, Iterable<? extends T> values) {
@SuppressWarnings("rawtypes")
final StringBuilder sb = values instanceof Collection
? new StringBuilder(((Collection) values).size() * VALUE_LENGTH_ESTIMATE) : new StringBuilder();
Iterator<? extends T> iterator = values.iterator();
if (iterator.hasNext()) {
T next = iterator.next();
while (iterator.hasNext()) {
sb.append(escaper.escape(next)).append(COMMA);
next = iterator.next();
}
sb.append(escaper.escape(next));
}
return sb;
}
private static CharSequence commaSeparateEscapedValues(CharSequence currentValue, CharSequence value) {
return new StringBuilder(currentValue.length() + 1 + value.length())
.append(currentValue)
.append(COMMA)
.append(value);
}
/**
* Escapes comma separated values (CSV).
*
* @param <T> The type that a concrete implementation handles
*/
private interface CsvValueEscaper<T> {
/**
* Appends the value to the specified {@link StringBuilder}, escaping if necessary.
*
* @param value the value to be appended, escaped if necessary
*/
CharSequence escape(T value);
}
}
}