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package com.salesforce.phoenix.expression.function;
import java.sql.SQLException;
import java.util.Collections;
import java.util.List;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import com.salesforce.phoenix.compile.KeyPart;
import com.salesforce.phoenix.expression.Expression;
import com.salesforce.phoenix.parse.FunctionParseNode.Argument;
import com.salesforce.phoenix.parse.FunctionParseNode.BuiltInFunction;
import com.salesforce.phoenix.query.KeyRange;
import com.salesforce.phoenix.schema.ColumnModifier;
import com.salesforce.phoenix.schema.PColumn;
import com.salesforce.phoenix.schema.PDataType;
import com.salesforce.phoenix.schema.tuple.Tuple;
import com.salesforce.phoenix.util.ByteUtil;
import com.salesforce.phoenix.util.StringUtil;
/**
*
* Implementation of the RTrim(<string>) build-in function. It removes from the right end of
* <string> space character and other function bytes in single byte utf8 characters set
*
* @author zhuang
* @since 0.1
*/
@BuiltInFunction(name=RTrimFunction.NAME, args={
@Argument(allowedTypes={PDataType.VARCHAR})})
public class RTrimFunction extends ScalarFunction {
public static final String NAME = "RTRIM";
private Integer byteSize;
public RTrimFunction() { }
public RTrimFunction(List<Expression> children) throws SQLException {
super(children);
if (getStringExpression().getDataType().isFixedWidth()) {
byteSize = getStringExpression().getByteSize();
}
}
private Expression getStringExpression() {
return children.get(0);
}
@Override
public ColumnModifier getColumnModifier() {
return children.get(0).getColumnModifier();
}
@Override
public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
// Starting from the end of the byte, look for all single bytes at the end of the string
// that is below SPACE_UTF8 (space and control characters) or above (control chars).
if (!getStringExpression().evaluate(tuple, ptr)) {
return false;
}
if (ptr.getLength() == 0) {
ptr.set(ByteUtil.EMPTY_BYTE_ARRAY);
return true;
}
byte[] string = ptr.get();
int offset = ptr.getOffset();
int length = ptr.getLength();
ColumnModifier columnModifier = getStringExpression().getColumnModifier();
int i = StringUtil.getFirstNonBlankCharIdxFromEnd(string, offset, length, columnModifier);
if (i == offset - 1) {
ptr.set(ByteUtil.EMPTY_BYTE_ARRAY);
return true;
}
ptr.set(string, offset, i - offset + 1);
return true;
}
@Override
public OrderPreserving preservesOrder() {
return OrderPreserving.YES_IF_LAST;
}
@Override
public int getKeyFormationTraversalIndex() {
return 0;
}
@Override
public KeyPart newKeyPart(final KeyPart childPart) {
return new KeyPart() {
@Override
public KeyRange getKeyRange(CompareOp op, Expression rhs) {
ImmutableBytesWritable ptr = new ImmutableBytesWritable();
rhs.evaluate(null, ptr);
byte[] key = ByteUtil.copyKeyBytesIfNecessary(ptr);
PDataType type = getColumn().getDataType();
KeyRange range;
switch (op) {
case EQUAL:
range = type.getKeyRange(key, true, ByteUtil.nextKey(ByteUtil.concat(key, new byte[] {StringUtil.SPACE_UTF8})), false);
break;
case LESS_OR_EQUAL:
range = type.getKeyRange(KeyRange.UNBOUND, false, ByteUtil.nextKey(ByteUtil.concat(key, new byte[] {StringUtil.SPACE_UTF8})), false);
break;
default:
range = childPart.getKeyRange(op, rhs);
break;
}
Integer length = getColumn().getByteSize();
return length == null ? range : range.fill(length);
}
@Override
public List<Expression> getExtractNodes() {
return Collections.<Expression>emptyList();
}
@Override
public PColumn getColumn() {
return childPart.getColumn();
}
};
}
@Override
public Integer getByteSize() {
return byteSize;
}
@Override
public PDataType getDataType() {
return PDataType.VARCHAR;
}
@Override
public String getName() {
return NAME;
}
}