package org.h2.table;
import java.util.ArrayList;
import org.h2.api.ErrorCode;
import org.h2.engine.Session;
import org.h2.expression.Expression;
import org.h2.index.Index;
import org.h2.index.IndexType;
import org.h2.index.RangeIndex;
import org.h2.message.DbException;
import org.h2.result.Row;
import org.h2.schema.Schema;
import org.h2.value.Value;
public class RangeTable extends Table {
public static final String NAME = "SYSTEM_RANGE";
public static final String ALIAS = "GENERATE_SERIES";
private Expression min, max, step;
private boolean optimized;
public RangeTable(Schema schema, Expression min, Expression max,
boolean noColumns) {
super(schema, 0, NAME, true, true);
Column[] cols = noColumns ? new Column[0] : new Column[] { new Column(
"X", Value.LONG) };
this.min = min;
this.max = max;
setColumns(cols);
}
public RangeTable(Schema schema, Expression min, Expression max,
Expression step, boolean noColumns) {
this(schema, min, max, noColumns);
this.step = step;
}
@Override
public String getDropSQL() {
return null;
}
@Override
public String getCreateSQL() {
return null;
}
@Override
public StringBuilder getSQL(StringBuilder builder, boolean alwaysQuote) {
builder.append(NAME).append('(');
min.getSQL(builder, alwaysQuote).append(", ");
max.getSQL(builder, alwaysQuote);
if (step != null) {
builder.append(", ");
step.getSQL(builder, alwaysQuote);
}
return builder.append(')');
}
@Override
public boolean lock(Session session, boolean exclusive, boolean forceLockEvenInMvcc) {
return false;
}
@Override
public void close(Session session) {
}
@Override
public void unlock(Session s) {
}
@Override
public boolean isLockedExclusively() {
return false;
}
@Override
public Index addIndex(Session session, String indexName,
int indexId, IndexColumn[] cols, IndexType indexType,
boolean create, String indexComment) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
@Override
public void removeRow(Session session, Row row) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
@Override
public void addRow(Session session, Row row) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
@Override
public void checkSupportAlter() {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
@Override
public void checkRename() {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
@Override
public boolean canGetRowCount() {
return true;
}
@Override
public boolean canDrop() {
return false;
}
@Override
public long getRowCount(Session session) {
long step = getStep(session);
if (step == 0L) {
throw DbException.get(ErrorCode.STEP_SIZE_MUST_NOT_BE_ZERO);
}
long delta = getMax(session) - getMin(session);
if (step > 0) {
if (delta < 0) {
return 0;
}
} else if (delta > 0) {
return 0;
}
return delta / step + 1;
}
@Override
public TableType getTableType() {
return TableType.SYSTEM_TABLE;
}
@Override
public Index getScanIndex(Session session) {
if (getStep(session) == 0) {
throw DbException.get(ErrorCode.STEP_SIZE_MUST_NOT_BE_ZERO);
}
return new RangeIndex(this, IndexColumn.wrap(columns));
}
public long getMin(Session session) {
optimize(session);
return min.getValue(session).getLong();
}
public long getMax(Session session) {
optimize(session);
return max.getValue(session).getLong();
}
public long getStep(Session session) {
optimize(session);
if (step == null) {
return 1;
}
return step.getValue(session).getLong();
}
private void optimize(Session s) {
if (!optimized) {
min = min.optimize(s);
max = max.optimize(s);
if (step != null) {
step = step.optimize(s);
}
optimized = true;
}
}
@Override
public ArrayList<Index> getIndexes() {
return null;
}
@Override
public void truncate(Session session) {
throw DbException.getUnsupportedException("SYSTEM_RANGE");
}
@Override
public long getMaxDataModificationId() {
return 0;
}
@Override
public Index getUniqueIndex() {
return null;
}
@Override
public long getRowCountApproximation() {
return 100;
}
@Override
public long getDiskSpaceUsed() {
return 0;
}
@Override
public boolean isDeterministic() {
return true;
}
@Override
public boolean canReference() {
return false;
}
}