private Table MatchRegexNotEqual(Predicate p)
{
int col = this.ColumnDefinitions.IndexOf(p.FieldName);
List<Element[]> selRows = new List<Element[]>();
Regex regex = p.Value.RegexValue();
for (int i = 0; i < this.Rows; i++) {
if (!regex.IsMatch((string)this[i, col])) {
selRows.Add(this.Row(i));
}
}
return new Table(this.Name, this.ColumnDefinitions, selRows);
}
private Table MatchNotEqual(Predicate p)
{
int col = this.ColumnDefinitions.IndexOf(p.FieldName);
List<Element[]> selRows = new List<Element[]>();
TableIndex index = this.GetIndex(col);
if (index != null) {
HashSet<int> exclude = new HashSet<int>();
foreach (int i in index.FindEqual(p.Value)) {
exclude.Add(i);
}
for (int i = 0; i < this.Rows; i++) {
if (exclude.Contains(i)) continue;
selRows.Add(this.Row(i));
}
return new Table(this.Name, this.ColumnDefinitions, selRows);
}
for (int i = 0; i < this.Rows; i++) {
if (this[i, col].CompareTo(p.Value) != 0) {
selRows.Add(this.Row(i));
}
}
return new Table(this.Name, this.ColumnDefinitions, selRows);
}
private Table MatchLike(Predicate p)
{
Regex regex = LikeToRegex((string)p.Value);
Predicate q = new Predicate(p.FieldName, p.Operator, new Element(regex));
return MatchRegexEqual(q);
}
private Table MatchLessThanEqual(Predicate p)
{
int col = this.ColumnDefinitions.IndexOf(p.FieldName);
List<Element[]> selRows = new List<Element[]>();
for (int i = 0; i < this.Rows; i++) {
if (this[i, col].CompareTo(p.Value) <= 0) {
selRows.Add(this.Row(i));
}
}
return new Table(this.Name, this.ColumnDefinitions, selRows);
}
private Table MatchEqual(Predicate p)
{
int col = this.ColumnDefinitions.IndexOf(p.FieldName);
List<Element[]> selRows = new List<Element[]>();
TableIndex index = this.GetIndex(col);
if (index!=null) {
foreach (int i in index.FindEqual(p.Value)) {
selRows.Add(this.Row(i));
}
}
else {
for (int i = 0; i < this.Rows; i++) {
if (this[i, col].CompareTo(p.Value) == 0) {
selRows.Add(this.Row(i));
}
}
}
return new Table(this.Name, this.ColumnDefinitions, selRows);
}
public Table Select(Predicate p)
{
int col = this.ColumnDefinitions.IndexOf(p.FieldName);
if (this.ColumnDefinitions[col].Indexed && this.GetIndex(col) == null) {
if (this.Rows > MIN_ROWS_FOR_INDEX) {
this.CreateIndex(col, true);
}
}
switch (p.Operator) {
case Predicate.PredicateOperator.EQ:
return MatchEqual(p);
case Predicate.PredicateOperator.NEQ:
return MatchNotEqual(p);
case Predicate.PredicateOperator.LIKE:
return MatchLike(p);
case Predicate.PredicateOperator.REGEXEQ:
return MatchRegexEqual(p);
case Predicate.PredicateOperator.REGEXNEQ:
return MatchRegexNotEqual(p);
case Predicate.PredicateOperator.GT:
return MatchGreaterThan(p);
case Predicate.PredicateOperator.GTE:
return MatchGreaterThanEqual(p);
case Predicate.PredicateOperator.LT:
return MatchLessThan(p);
case Predicate.PredicateOperator.LTE:
return MatchLessThanEqual(p);
}
return null;
}