com.twitter.http2.DefaultHttpHeaders Maven / Gradle / Ivy
/*
* Copyright 2015 Twitter, Inc.
*
* 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.twitter.http2;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.TreeSet;
import io.netty.handler.codec.http.HttpHeaders;
public class DefaultHttpHeaders extends HttpHeaders {
private static final int BUCKET_SIZE = 17;
private static int hash(String name) {
int h = 0;
for (int i = name.length() - 1; i >= 0; i--) {
char c = name.charAt(i);
if (c >= 'A' && c <= 'Z') {
c += 32;
}
h = 31 * h + c;
}
if (h > 0) {
return h;
} else if (h == Integer.MIN_VALUE) {
return Integer.MAX_VALUE;
} else {
return -h;
}
}
private static boolean eq(String name1, String name2) {
int nameLen = name1.length();
if (nameLen != name2.length()) {
return false;
}
for (int i = nameLen - 1; i >= 0; i--) {
char c1 = name1.charAt(i);
char c2 = name2.charAt(i);
if (c1 != c2) {
if (c1 >= 'A' && c1 <= 'Z') {
c1 += 32;
}
if (c2 >= 'A' && c2 <= 'Z') {
c2 += 32;
}
if (c1 != c2) {
return false;
}
}
}
return true;
}
private static int index(int hash) {
return hash % BUCKET_SIZE;
}
private final HeaderEntry[] entries = new HeaderEntry[BUCKET_SIZE];
private final HeaderEntry head = new HeaderEntry(-1, null, null);
public DefaultHttpHeaders() {
head.before = head.after = head;
}
void validateHeaderName0(String headerName) {
validateHeaderName(headerName);
}
@Override
public HttpHeaders add(final String name, final Object value) {
validateHeaderName0(name);
String strVal = toString(value);
validateHeaderValue(strVal);
int h = hash(name);
int i = index(h);
add0(h, i, name, strVal);
return this;
}
@Override
public HttpHeaders add(String name, Iterable values) {
validateHeaderName0(name);
int h = hash(name);
int i = index(h);
for (Object v : values) {
String vstr = toString(v);
validateHeaderValue(vstr);
add0(h, i, name, vstr);
}
return this;
}
private void add0(int h, int i, final String name, final String value) {
// Update the hash table.
HeaderEntry e = entries[i];
HeaderEntry newEntry;
entries[i] = newEntry = new HeaderEntry(h, name, value);
newEntry.next = e;
// Update the linked list.
newEntry.addBefore(head);
}
@Override
public HttpHeaders remove(final String name) {
if (name == null) {
throw new NullPointerException("name");
}
int h = hash(name);
int i = index(h);
remove0(h, i, name);
return this;
}
private void remove0(int h, int i, String name) {
HeaderEntry e = entries[i];
if (e == null) {
return;
}
for (; ; ) {
if (e.hash == h && eq(name, e.key)) {
e.remove();
HeaderEntry next = e.next;
if (next != null) {
entries[i] = next;
e = next;
} else {
entries[i] = null;
return;
}
} else {
break;
}
}
for (; ; ) {
HeaderEntry next = e.next;
if (next == null) {
break;
}
if (next.hash == h && eq(name, next.key)) {
e.next = next.next;
next.remove();
} else {
e = next;
}
}
}
@Override
public HttpHeaders set(final String name, final Object value) {
validateHeaderName0(name);
String strVal = toString(value);
validateHeaderValue(strVal);
int h = hash(name);
int i = index(h);
remove0(h, i, name);
add0(h, i, name, strVal);
return this;
}
@Override
public HttpHeaders set(final String name, final Iterable values) {
if (values == null) {
throw new NullPointerException("values");
}
validateHeaderName0(name);
int h = hash(name);
int i = index(h);
remove0(h, i, name);
for (Object v : values) {
if (v == null) {
break;
}
String strVal = toString(v);
validateHeaderValue(strVal);
add0(h, i, name, strVal);
}
return this;
}
@Override
public HttpHeaders clear() {
for (int i = 0; i < entries.length; i++) {
entries[i] = null;
}
head.before = head.after = head;
return this;
}
@Override
public String get(final String name) {
if (name == null) {
throw new NullPointerException("name");
}
int h = hash(name);
int i = index(h);
HeaderEntry e = entries[i];
while (e != null) {
if (e.hash == h && eq(name, e.key)) {
return e.value;
}
e = e.next;
}
return null;
}
@Override
public List getAll(final String name) {
if (name == null) {
throw new NullPointerException("name");
}
LinkedList values = new LinkedList();
int h = hash(name);
int i = index(h);
HeaderEntry e = entries[i];
while (e != null) {
if (e.hash == h && eq(name, e.key)) {
values.addFirst(e.value);
}
e = e.next;
}
return values;
}
@Override
public List> entries() {
List> all =
new LinkedList>();
HeaderEntry e = head.after;
while (e != head) {
all.add(e);
e = e.after;
}
return all;
}
@Override
public Iterator> iterator() {
return new HeaderIterator();
}
@Override
public boolean contains(String name) {
return get(name) != null;
}
@Override
public boolean isEmpty() {
return head == head.after;
}
@Override
public Set names() {
Set names = new TreeSet(String.CASE_INSENSITIVE_ORDER);
HeaderEntry e = head.after;
while (e != head) {
names.add(e.key);
e = e.after;
}
return names;
}
private static String toString(Object value) {
if (value == null) {
return null;
}
if (value instanceof String) {
return (String) value;
}
if (value instanceof Number) {
return value.toString();
}
return value.toString();
}
private final class HeaderIterator implements Iterator> {
private HeaderEntry current = head;
@Override
public boolean hasNext() {
return current.after != head;
}
@Override
public Entry next() {
current = current.after;
if (current == head) {
throw new NoSuchElementException();
}
return current;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
private static final class HeaderEntry implements Map.Entry {
public final int hash;
public final String key;
public String value;
public HeaderEntry next;
public HeaderEntry before;
public HeaderEntry after;
HeaderEntry(int hash, String key, String value) {
this.hash = hash;
this.key = key;
this.value = value;
}
void remove() {
before.after = after;
after.before = before;
}
void addBefore(HeaderEntry e) {
after = e;
before = e.before;
before.after = this;
after.before = this;
}
@Override
public String getKey() {
return key;
}
@Override
public String getValue() {
return value;
}
@Override
public String setValue(String value) {
if (value == null) {
throw new NullPointerException("value");
}
validateHeaderValue(value);
String oldValue = this.value;
this.value = value;
return oldValue;
}
@Override
public String toString() {
return key + '=' + value;
}
}
/**
* Validates the name of a header
*
* @param headerName The header name being validated
*/
static void validateHeaderName(String headerName) {
//Check to see if the name is null
if (headerName == null) {
throw new NullPointerException("Header names cannot be null");
}
//Go through each of the characters in the name
for (int index = 0; index < headerName.length(); index++) {
//Actually get the character
char character = headerName.charAt(index);
//Check to see if the character is not an ASCII character
if (character > 127) {
throw new IllegalArgumentException(
"Header name cannot contain non-ASCII characters: " + headerName);
}
//Check for prohibited characters.
switch (character) {
case '\t':
case '\n':
case 0x0b:
case '\f':
case '\r':
case ' ':
case ',':
case ';':
case '=':
throw new IllegalArgumentException(
"Header name cannot contain the following prohibited characters: "
+ "=,;: \\t\\r\\n\\v\\f: " + headerName);
default:
}
}
}
/**
* Validates the specified header value
*
* @param headerValue The value being validated
*/
static void validateHeaderValue(String headerValue) {
//Check to see if the value is null
if (headerValue == null) {
throw new NullPointerException("Header values cannot be null");
}
/*
* Set up the state of the validation
*
* States are as follows:
*
* 0: Previous character was neither CR nor LF
* 1: The previous character was CR
* 2: The previous character was LF
*/
int state = 0;
//Start looping through each of the character
for (int index = 0; index < headerValue.length(); index++) {
char character = headerValue.charAt(index);
//Check the absolutely prohibited characters.
switch (character) {
case 0x0b: // Vertical tab
throw new IllegalArgumentException(
"Header value contains a prohibited character '\\v': " + headerValue);
case '\f':
throw new IllegalArgumentException(
"Header value contains a prohibited character '\\f': " + headerValue);
default:
}
// Check the CRLF (HT | SP) pattern
switch (state) {
case 0:
switch (character) {
case '\r':
state = 1;
break;
case '\n':
state = 2;
break;
default:
}
break;
case 1:
switch (character) {
case '\n':
state = 2;
break;
default:
throw new IllegalArgumentException(
"Only '\\n' is allowed after '\\r': " + headerValue);
}
break;
case 2:
switch (character) {
case '\t':
case ' ':
state = 0;
break;
default:
throw new IllegalArgumentException(
"Only ' ' and '\\t' are allowed after '\\n': " + headerValue);
}
break;
default:
}
}
if (state != 0) {
throw new IllegalArgumentException(
"Header value must not end with '\\r' or '\\n':" + headerValue);
}
}
}
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