org.glassfish.grizzly.http2.hpack.DecodingCallback Maven / Gradle / Ivy
/*
* Copyright (c) 2016, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.grizzly.http2.hpack;
/**
* Delivers results of the {@link Decoder#decode(Buffer, boolean, DecodingCallback) decoding operation}.
*
*
* Methods of the callback are never called by a decoder with any of the arguments being {@code null}.
*
*
* The callback provides methods for all possible binary
* representations. This could be useful for implementing an intermediary, logging, debugging, etc.
*
*
* The callback is an interface in order to interoperate with lambdas (in the most common use case):
*
*
* {
* @code
* DecodingCallback callback = (name, value) -> System.out.println(name + ", " + value);
* }
*
*
*
* Names and values are {@link CharSequence}s rather than {@link String}s in order to allow users to decide whether or
* not they need to create objects. A {@code CharSequence} might be used in-place, for example, to be appended to an
* {@link Appendable} (e.g. {@link StringBuilder}) and then discarded.
*
*
* That said, if a passed {@code CharSequence} needs to outlast the method call, it needs to be copied.
*/
@SuppressWarnings("UnusedParameters")
public abstract class DecodingCallback {
/**
* A method the more specific methods of the callback forward their calls to.
*
* @param name header name
* @param value header value
*/
public abstract void onDecoded(CharSequence name, CharSequence value);
/**
* A more finer-grained version of {@link #onDecoded(CharSequence, CharSequence)} that also reports on value
* sensitivity.
*
*
* Value sensitivity must be considered, for example, when implementing an intermediary. A {@code value} is sensitive if
* it was represented as Literal Header Field Never
* Indexed.
*
*
* It is required that intermediaries MUST use the {@linkplain Encoder#header(CharSequence, CharSequence, boolean) same
* representation} for encoding this header field in order to protect its value which is not to be put at risk by
* compressing it.
*
*
* The default implementation invokes {@code onDecoded(name, value)}.
*
* @param name header name
* @param value header value
* @param sensitive whether or not the value is sensitive
*
* @see #onLiteralNeverIndexed(int, CharSequence, CharSequence, boolean)
* @see #onLiteralNeverIndexed(CharSequence, boolean, CharSequence, boolean)
*/
public void onDecoded(CharSequence name, CharSequence value, boolean sensitive) {
onDecoded(name, value);
}
/**
* An Indexed Header Field decoded.
*
*
* The default implementation invokes {@code onDecoded(name, value, false)}.
*
* @param index index of an entry in the table
* @param name header name
* @param value header value
*/
public void onIndexed(int index, CharSequence name, CharSequence value) {
onDecoded(name, value, false);
}
/**
* A Literal Header Field without Indexing decoded,
* where a {@code name} was referred by an {@code index}.
*
*
* The default implementation invokes {@code onDecoded(name, value, false)}.
*
* @param index index of an entry in the table
* @param name header name
* @param value header value
* @param valueHuffman if the {@code value} was Huffman encoded
*/
public void onLiteral(int index, CharSequence name, CharSequence value, boolean valueHuffman) {
onDecoded(name, value, false);
}
/**
* A Literal Header Field without Indexing decoded,
* where both a {@code name} and a {@code value} were literal.
*
*
* The default implementation invokes {@code onDecoded(name, value, false)}.
*
* @param name header name
* @param nameHuffman if the {@code name} was Huffman encoded
* @param value header value
* @param valueHuffman if the {@code value} was Huffman encoded
*/
public void onLiteral(CharSequence name, boolean nameHuffman, CharSequence value, boolean valueHuffman) {
onDecoded(name, value, false);
}
/**
* A Literal Header Field Never Indexed decoded, where a
* {@code name} was referred by an {@code index}.
*
*
* The default implementation invokes {@code onDecoded(name, value, true)}.
*
* @param index index of an entry in the table
* @param name header name
* @param value header value
* @param valueHuffman if the {@code value} was Huffman encoded
*/
public void onLiteralNeverIndexed(int index, CharSequence name, CharSequence value, boolean valueHuffman) {
onDecoded(name, value, true);
}
/**
* A Literal Header Field Never Indexed decoded, where
* both a {@code
* name} and a {@code value} were literal.
*
*
* The default implementation invokes {@code onDecoded(name, value, true)}.
*
* @param name header name
* @param nameHuffman if the {@code name} was Huffman encoded
* @param value header value
* @param valueHuffman if the {@code value} was Huffman encoded
*/
public void onLiteralNeverIndexed(CharSequence name, boolean nameHuffman, CharSequence value, boolean valueHuffman) {
onDecoded(name, value, true);
}
/**
* A Literal Header Field with Incremental Indexing
* decoded, where a {@code name} was referred by an {@code index}.
*
*
* The default implementation invokes {@code onDecoded(name, value, false)}.
*
* @param index index of an entry in the table
* @param name header name
* @param value header value
* @param valueHuffman if the {@code value} was Huffman encoded
*/
public void onLiteralWithIndexing(int index, CharSequence name, CharSequence value, boolean valueHuffman) {
onDecoded(name, value, false);
}
/**
* A Literal Header Field with Incremental Indexing
* decoded, where both a {@code
* name} and a {@code value} were literal.
*
*
* The default implementation invokes {@code onDecoded(name, value, false)}.
*
* @param name header name
* @param nameHuffman if the {@code name} was Huffman encoded
* @param value header value
* @param valueHuffman if the {@code value} was Huffman encoded
*/
public void onLiteralWithIndexing(CharSequence name, boolean nameHuffman, CharSequence value, boolean valueHuffman) {
onDecoded(name, value, false);
}
/**
* A Dynamic Table Size Update decoded.
*
*
* The default implementation does nothing.
*
* @param capacity new capacity of the header table
*/
public void onSizeUpdate(int capacity) {
}
}