/*
* Copyright 2004-2023 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.mode;
import org.h2.engine.SessionLocal;
import org.h2.expression.ExpressionVisitor;
import org.h2.expression.Operation0;
import org.h2.expression.function.NamedExpression;
import org.h2.util.DateTimeUtils;
import org.h2.util.TimeZoneProvider;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
import org.h2.value.ValueTimestamp;
import org.h2.value.ValueTimestampTimeZone;
/**
* Current datetime value function.
*/
final class CompatibilityDateTimeValueFunction extends Operation0 implements NamedExpression {
/**
* The function "SYSDATE"
*/
static final int SYSDATE = 0;
/**
* The function "SYSTIMESTAMP"
*/
static final int SYSTIMESTAMP = 1;
private static final String[] NAMES = { "SYSDATE", "SYSTIMESTAMP" };
private final int function, scale;
private final TypeInfo type;
CompatibilityDateTimeValueFunction(int function, int scale) {
this.function = function;
this.scale = scale;
if (function == SYSDATE) {
type = TypeInfo.getTypeInfo(Value.TIMESTAMP, 0L, 0, null);
} else {
type = TypeInfo.getTypeInfo(Value.TIMESTAMP_TZ, 0L, scale, null);
}
}
@Override
public Value getValue(SessionLocal session) {
ValueTimestampTimeZone v = session.currentTimestamp();
long dateValue = v.getDateValue();
long timeNanos = v.getTimeNanos();
int offsetSeconds = v.getTimeZoneOffsetSeconds();
int newOffset = TimeZoneProvider.getDefault()
.getTimeZoneOffsetUTC(DateTimeUtils.getEpochSeconds(dateValue, timeNanos, offsetSeconds));
if (offsetSeconds != newOffset) {
v = DateTimeUtils.timestampTimeZoneAtOffset(dateValue, timeNanos, offsetSeconds, newOffset);
}
if (function == SYSDATE) {
return ValueTimestamp.fromDateValueAndNanos(v.getDateValue(),
v.getTimeNanos() / DateTimeUtils.NANOS_PER_SECOND * DateTimeUtils.NANOS_PER_SECOND);
}
return v.castTo(type, session);
}
@Override
public StringBuilder getUnenclosedSQL(StringBuilder builder, int sqlFlags) {
builder.append(getName());
if (scale >= 0) {
builder.append('(').append(scale).append(')');
}
return builder;
}
@Override
public boolean isEverything(ExpressionVisitor visitor) {
switch (visitor.getType()) {
case ExpressionVisitor.DETERMINISTIC:
return false;
}
return true;
}
@Override
public TypeInfo getType() {
return type;
}
@Override
public int getCost() {
return 1;
}
@Override
public String getName() {
return NAMES[function];
}
}