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A general programming library in Java/Android. It's easy to learn and simple to use with concise and powerful APIs.
/*
* Copyright (C) 2016, 2017, 2018, 2019 HaiYang Li
*
* 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.landawn.abacus.util.stream;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.function.Supplier;
import com.landawn.abacus.annotation.Internal;
import com.landawn.abacus.util.ByteIterator;
import com.landawn.abacus.util.ByteList;
import com.landawn.abacus.util.N;
/**
*
*/
@Internal
public abstract class ByteIteratorEx extends ByteIterator implements IteratorEx {
public static final ByteIteratorEx EMPTY = new ByteIteratorEx() { //NOSONAR
@Override
public boolean hasNext() {
return false;
}
@Override
public byte nextByte() {
throw new NoSuchElementException();
}
@Override
public void advance(long n) {
// Do nothing.
}
@Override
public long count() {
return 0;
}
@Override
public byte[] toArray() {
return N.EMPTY_BYTE_ARRAY;
}
@Override
public void close() {
// Do nothing.
}
};
public static ByteIteratorEx empty() { //NOSONAR
return EMPTY;
}
@SafeVarargs
public static ByteIteratorEx of(final byte... a) {
return N.isNullOrEmpty(a) ? EMPTY : of(a, 0, a.length);
}
public static ByteIteratorEx of(final byte[] a, final int fromIndex, final int toIndex) {
N.checkFromToIndex(fromIndex, toIndex, N.len(a));
if (fromIndex == toIndex) {
return EMPTY;
}
return new ByteIteratorEx() {
private int cursor = fromIndex;
@Override
public boolean hasNext() {
return cursor < toIndex;
}
@Override
public byte nextByte() {
if (cursor >= toIndex) {
throw new NoSuchElementException();
}
return a[cursor++];
}
@Override
public void advance(long n) {
cursor = n < toIndex - cursor ? cursor + (int) n : toIndex;
}
@Override
public long count() {
return toIndex - cursor; //NOSONAR
}
@Override
public byte[] toArray() {
return N.copyOfRange(a, cursor, toIndex);
}
@Override
public ByteList toList() {
return ByteList.of(N.copyOfRange(a, cursor, toIndex));
}
@Override
public void close() {
// Do nothing.
}
};
}
public static ByteIteratorEx of(final ByteIterator iter) {
if (iter == null) {
return empty();
} else if (iter instanceof ByteIteratorEx) {
return ((ByteIteratorEx) iter);
}
return new ByteIteratorEx() {
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public byte nextByte() {
return iter.nextByte();
}
@Override
public void close() {
// Do nothing.
}
};
}
public static ByteIteratorEx from(final Iterator iter) {
if (iter == null) {
return empty();
} else if (iter instanceof ObjIteratorEx) {
final ObjIteratorEx iteratorEx = ((ObjIteratorEx) iter);
return new ByteIteratorEx() {
@Override
public boolean hasNext() {
return iteratorEx.hasNext();
}
@Override
public byte nextByte() {
return iteratorEx.next();
}
@Override
public void advance(long n) {
N.checkArgNotNegative(n, "n");
iteratorEx.advance(n);
}
@Override
public long count() {
return iteratorEx.count();
}
@Override
public void close() {
iteratorEx.close();
}
};
} else {
return new ByteIteratorEx() {
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public byte nextByte() {
return iter.next();
}
@Override
public void close() {
// Do nothing.
}
};
}
}
// /**
// * Lazy evaluation.
// *
// * @param arraySupplier
// * @return
// */
// public static ByteIteratorEx from(final Supplier arraySupplier) {
// N.checkArgNotNull(arraySupplier, "arraySupplier");
//
// return new ByteIteratorEx() {
// private ByteIteratorEx iterEx = null;
// private boolean isInitialized = false;
//
// @Override
// public boolean hasNext() {
// if (!isInitialized) {
// init();
// }
//
// return iterEx.hasNext();
// }
//
// @Override
// public byte nextByte() {
// if (!isInitialized) {
// init();
// }
//
// return iterEx.nextByte();
// }
//
// @Override
// public void advance(long n) {
// if (!isInitialized) {
// init();
// }
//
// iterEx.advance(n);
// }
//
// @Override
// public long count() {
// if (!isInitialized) {
// init();
// }
//
// return iterEx.count();
// }
//
// private void init() {
// if (!isInitialized) {
// isInitialized = true;
// byte[] aar = arraySupplier.get();
// iterEx = ByteIteratorEx.of(aar);
// }
// }
// };
// }
/**
* Lazy evaluation.
*
* @param iteratorSupplier
* @return
*/
public static ByteIteratorEx defer(final Supplier iteratorSupplier) {
N.checkArgNotNull(iteratorSupplier, "iteratorSupplier");
return new ByteIteratorEx() {
private ByteIterator iter = null;
private ByteIteratorEx iterEx = null;
private boolean isInitialized = false;
@Override
public boolean hasNext() {
if (!isInitialized) {
init();
}
return iter.hasNext();
}
@Override
public byte nextByte() {
if (!isInitialized) {
init();
}
return iter.nextByte();
}
@Override
public void advance(long n) {
if (!isInitialized) {
init();
}
if (iterEx != null) {
iterEx.advance(n);
} else {
super.advance(n);
}
}
@Override
public long count() {
if (!isInitialized) {
init();
}
if (iterEx != null) {
return iterEx.count();
} else {
return super.count();
}
}
@Override
public void close() {
if (!isInitialized) {
init();
}
if (iterEx != null) {
iterEx.close();
}
}
private void init() {
if (!isInitialized) {
isInitialized = true;
iter = iteratorSupplier.get();
iterEx = iter instanceof ByteIteratorEx ? (ByteIteratorEx) iter : null;
}
}
};
}
@Override
public void advance(long n) {
N.checkArgNotNegative(n, "n");
while (n > 0 && hasNext()) {
nextByte();
n--;
}
}
@Override
public long count() {
long result = 0;
while (hasNext()) {
nextByte();
result++;
}
return result;
}
@Override
public void close() {
// Do nothing.
}
}