org.apache.inlong.sort.filesystem.shaded.software.amazon.ion.impl.IonIteratorImpl Maven / Gradle / Ivy
/*
* Copyright 2007-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at:
*
* http://aws.amazon.com/apache2.0/
*
* or in the "license" file accompanying this file. This file 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 software.amazon.ion.impl;
import java.util.Iterator;
import java.util.NoSuchElementException;
import software.amazon.ion.IonLob;
import software.amazon.ion.IonReader;
import software.amazon.ion.IonSequence;
import software.amazon.ion.IonStruct;
import software.amazon.ion.IonType;
import software.amazon.ion.IonValue;
import software.amazon.ion.SymbolTable;
import software.amazon.ion.SymbolToken;
import software.amazon.ion.ValueFactory;
final class IonIteratorImpl
implements Iterator
{
private final ValueFactory _valueFactory;
private final IonReader _reader;
private boolean _at_eof;
private IonValue _curr;
private IonValue _next;
/**
* @throws NullPointerException if any parameter is null.
*/
public IonIteratorImpl(ValueFactory valueFactory,
IonReader input)
{
if (valueFactory == null || input == null)
{
throw new NullPointerException();
}
_valueFactory = valueFactory;
_reader = input;
}
/**
* Returns true if the iteration has more elements.
* here we actually walk ahead and get the next value (it's
* the only way we know if there are more and clear out the
* various $ion noise out of the way
*/
public boolean hasNext() {
if (_at_eof) return false;
if (_next != null) return true;
return (prefetch() != null);
}
private IonValue prefetch()
{
assert !_at_eof && _next == null;
IonType type = _reader.next();
if (type == null)
{
_at_eof = true;
}
else
{
_next = readValue();
}
return _next;
}
private IonValue readValue()
{
IonType type = _reader.getType();
SymbolToken[] annotations = _reader.getTypeAnnotationSymbols();
IonValue v;
if (_reader.isNullValue())
{
v = _valueFactory.newNull(type);
}
else
{
switch (type) {
case NULL:
// Handled above
throw new IllegalStateException();
case BOOL:
v = _valueFactory.newBool(_reader.booleanValue());
break;
case INT:
v = _valueFactory.newInt(_reader.bigIntegerValue());
break;
case FLOAT:
v = _valueFactory.newFloat(_reader.doubleValue());
break;
case DECIMAL:
v = _valueFactory.newDecimal(_reader.decimalValue());
break;
case TIMESTAMP:
v = _valueFactory.newTimestamp(_reader.timestampValue());
break;
case STRING:
v = _valueFactory.newString(_reader.stringValue());
break;
case SYMBOL:
// TODO always pass the SID? Is it correct?
v = _valueFactory.newSymbol(_reader.symbolValue());
break;
case BLOB:
{
IonLob lob = _valueFactory.newNullBlob();
lob.setBytes(_reader.newBytes());
v = lob;
break;
}
case CLOB:
{
IonLob lob = _valueFactory.newNullClob();
lob.setBytes(_reader.newBytes());
v = lob;
break;
}
case STRUCT:
{
IonStruct struct = _valueFactory.newEmptyStruct();
_reader.stepIn();
while (_reader.next() != null)
{
SymbolToken name = _reader.getFieldNameSymbol();
IonValue child = readValue();
struct.add(name, child);
}
_reader.stepOut();
v = struct;
break;
}
case LIST:
{
IonSequence seq = _valueFactory.newEmptyList();
_reader.stepIn();
while (_reader.next() != null)
{
IonValue child = readValue();
seq.add(child);
}
_reader.stepOut();
v = seq;
break;
}
case SEXP:
{
IonSequence seq = _valueFactory.newEmptySexp();
_reader.stepIn();
while (_reader.next() != null)
{
IonValue child = readValue();
seq.add(child);
}
_reader.stepOut();
v = seq;
break;
}
default:
throw new IllegalStateException();
}
}
// TODO this is too late in the case of system reading
// when v is a local symtab (it will get itself, not the prior symtab)
SymbolTable symtab = _reader.getSymbolTable();
((PrivateIonValue)v).setSymbolTable(symtab);
if (annotations.length != 0) {
((PrivateIonValue)v).setTypeAnnotationSymbols(annotations);
}
return v;
}
public IonValue next() {
if (! _at_eof) {
_curr = null;
if (_next == null) {
prefetch();
}
if (_next != null) {
_curr = _next;
_next = null;
return _curr;
}
}
throw new NoSuchElementException();
}
public void remove() {
throw new UnsupportedOperationException();
}
}