org.wildfly.common.iteration.Base64EncodingIterator Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* JBoss, Home of Professional Open Source.
* Copyright 2017 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 org.wildfly.common.iteration;
import java.util.NoSuchElementException;
import org.wildfly.common.Assert;
/**
*/
abstract class Base64EncodingIterator extends CodePointIterator {
private final ByteIterator iter;
private final boolean addPadding;
private int c0, c1, c2, c3;
private int state;
private int offset;
Base64EncodingIterator(final ByteIterator iter, final boolean addPadding) {
this.iter = iter;
this.addPadding = addPadding;
}
// states:
// 0 - need another three data bytes
// 1 - 4 characters to read
// 2 - 3 characters to read
// 3 - 2 characters to read
// 4 - 1 character to read
// 5 - 2 characters + == to read
// 6 - 1 character (c1) + == to read
// 7 - == to read
// 8 - second = to read
// 9 - 3 characters + = to read
// a - 2 characters (c1, c2) + = to read
// b - 1 character (c2) + = to read
// c - = to read
// d - after ==
// e - after =
// f - clean end
public boolean hasNext() {
return state == 0 && iter.hasNext() || state > 0 && state < 0xd;
}
public boolean hasPrevious() {
return offset > 0;
}
abstract int calc0(int b0);
abstract int calc1(int b0, int b1);
abstract int calc2(int b1, int b2);
abstract int calc3(int b2);
public int next() throws NoSuchElementException {
if (! hasNext()) throw new NoSuchElementException();
offset++;
switch (state) {
case 0: {
assert iter.hasNext();
int b0 = iter.next();
c0 = calc0(b0);
if (! iter.hasNext()) {
c1 = calc1(b0, 0);
state = 6;
return c0;
}
int b1 = iter.next();
c1 = calc1(b0, b1);
if (! iter.hasNext()) {
c2 = calc2(b1, 0);
state = 0xa;
return c0;
}
int b2 = iter.next();
c2 = calc2(b1, b2);
c3 = calc3(b2);
state = 2;
return c0;
}
case 1: {
state = 2;
return c0;
}
case 2: {
state = 3;
return c1;
}
case 3: {
state = 4;
return c2;
}
case 4: {
state = 0;
return c3;
}
case 5: {
state = 6;
return c0;
}
case 6: {
state = addPadding ? 7 : 0xd;
return c1;
}
case 7: {
state = 8;
return '=';
}
case 8: {
state = 0xd;
return '=';
}
case 9: {
state = 0xa;
return c0;
}
case 0xa: {
state = 0xb;
return c1;
}
case 0xb: {
state = addPadding ? 0xc : 0xe;
return c2;
}
case 0xc: {
state = 0xe;
return '=';
}
default: {
throw Assert.impossibleSwitchCase(state);
}
}
}
public int peekNext() throws NoSuchElementException {
if (! hasNext()) throw new NoSuchElementException();
switch (state) {
case 0: {
assert iter.hasNext();
int b0 = iter.next();
c0 = calc0(b0);
if (! iter.hasNext()) {
c1 = calc1(b0, 0);
state = 5;
return c0;
}
int b1 = iter.next();
c1 = calc1(b0, b1);
if (! iter.hasNext()) {
c2 = calc2(b1, 0);
state = 9;
return c0;
}
int b2 = iter.next();
c2 = calc2(b1, b2);
c3 = calc3(b2);
state = 1;
return c0;
}
case 1: {
return c0;
}
case 2: {
return c1;
}
case 3: {
return c2;
}
case 4: {
return c3;
}
case 5: {
return c0;
}
case 6: {
return c1;
}
case 7: {
return '=';
}
case 8: {
return '=';
}
case 9: {
return c0;
}
case 0xa: {
return c1;
}
case 0xb: {
return c2;
}
case 0xc: {
return '=';
}
default: {
throw Assert.impossibleSwitchCase(state);
}
}
}
public int previous() throws NoSuchElementException {
if (! hasPrevious()) throw new NoSuchElementException();
offset--;
switch (state) {
case 0:
case 1:
case 5:
case 9:
case 0xf: {
int b2 = iter.previous();
int b1 = iter.previous();
int b0 = iter.previous();
c0 = calc0(b0);
c1 = calc1(b0, b1);
c2 = calc2(b1, b2);
c3 = calc3(b2);
state = 4;
return c3;
}
case 2: {
state = 1;
return c0;
}
case 3: {
state = 2;
return c1;
}
case 4: {
state = 3;
return c2;
}
case 6: {
state = 5;
return c0;
}
case 7: {
state = 6;
return c1;
}
case 8: {
state = 7;
return '=';
}
case 0xa: {
state = 9;
return c0;
}
case 0xb: {
state = 0xa;
return c1;
}
case 0xc: {
state = 0xb;
return c2;
}
case 0xd: {
state = 8;
return '=';
}
case 0xe: {
state = 0xc;
return '=';
}
default: {
throw Assert.impossibleSwitchCase(state);
}
}
}
public int peekPrevious() throws NoSuchElementException {
if (! hasPrevious()) throw new NoSuchElementException();
switch (state) {
case 0:
case 1:
case 5:
case 9:
case 0xf: {
return calc3(iter.peekPrevious());
}
case 2: {
return c0;
}
case 3: {
return c1;
}
case 4: {
return c2;
}
case 6: {
return c0;
}
case 7: {
return c1;
}
case 8: {
return '=';
}
case 0xa: {
return c0;
}
case 0xb: {
return c1;
}
case 0xc: {
return c2;
}
case 0xd: {
return '=';
}
case 0xe: {
return '=';
}
default: {
throw Assert.impossibleSwitchCase(state);
}
}
}
public long getIndex() {
return offset;
}
}