public override Expression Evaluate(EvalStore store)
{
Stopwatch watch;
store.Remove("$DATA");
var facts = store.Get<Table>("Facts");
var fromList = store.Get<Dictionary<string, Table>>("$FROM_LIST");
if (fromList == null || fromList.Count == 0) {
return ConstExpr.Empty;
}
HashSet<string> refIds = store.Get<HashSet<string>>("$REFIDS");
var selFacts = SelectFactTableRows(fromList, facts);
for (int i = 0; i < _exprs.Count; i++) {
_exprs[i] = Reduce(store, _exprs[i]);
}
Dictionary<int, List<Expression>> exprGroups;
Dictionary<string, Expression> idExprMap;
NormalizeExpressions(selFacts, _exprs, out exprGroups, out idExprMap);
//find out the time range
if (exprGroups[TIME_FILTER].Count == 0) {
throw new Exception("Time range expression is not specified.");
}
DateTime min = DateTime.MaxValue;
DateTime max = DateTime.MinValue;
DateTime[] range = ExtraTimeRange(store, exprGroups[TIME_FILTER][0]);
if (range != null) {
if (range[0] < min) min = range[0];
if (range[1] > max) max = range[1];
}
else {
throw new Exception("Time range is not specified.");
}
//find a list of data log by applying filters of various properties from the fact table
Table sel = null;
using (EvalScope scope = new EvalScope(store, new EvalContext(EvalContext.ContextType.SEARCH))) {
if (exprGroups[ATTR_FILTER].Count == 0) {
sel = (Table) selFacts["_"];
}
else {
store.Put<Dictionary<string, Table>>("$SEL_FACTS", selFacts);
foreach (Expression expr in exprGroups[ATTR_FILTER]) {
Expression e = expr.Evaluate(store);
if (e.ExpressionType != Language.ExpressionType.CONST) {
throw new Exception("The expression should be evaluated to a value. " + e.ToString());
}
ConstExpr c = e as ConstExpr;
if (c.Value.DataType == ElementType.TABLE) {
Table s = c.Value.GetObject<Table>();
if (sel == null) sel = s;
else sel.IntersectWith(s);
}
else {
if (c.Value.DataType != ElementType.EMPTY) {
throw new Exception("The expression should be evaluated to a set of rows or an empty set. " + e.ToString());
}
}
}
}
}
if (sel == null || sel.Rows == 0) return ConstExpr.Empty;
//creating additional filters for the metric loading queries
string resFilter = CreateResourceFilters(sel);
string ctxFilter = CreateContextFilter(store, exprGroups);
string filters;
if (!string.IsNullOrEmpty(resFilter) && !string.IsNullOrEmpty(ctxFilter)) {
filters = (resFilter + " AND " + ctxFilter);
}
else if (string.IsNullOrEmpty(resFilter)) {
filters = ctxFilter;
}
else {
filters = resFilter;
}
MetricsDataLoader dataLoader = new MetricsDataLoader();
Table data = dataLoader.Load(sel, min, max, filters, refIds);
Trace.WriteLine("WhereClase.Evaluate.TotalRows: " + data.Rows);
//applies filters that involve result columns
watch = Stopwatch.StartNew();
if (exprGroups[OTHER_FILTER].Count > 0) {
using (EvalScope scope = new EvalScope(store, new EvalContext(EvalContext.ContextType.FILTER))) {
store.Put<Table>("$DATA", data);
HashSet<int> selRows = new HashSet<int>();
for (int i = 0; i < data.Rows; i++) {
store.Put<Element[]>("$ROW", data.Row(i));
bool include = true;
foreach (Expression expr in exprGroups[OTHER_FILTER]) {
ConstExpr c = expr.Evaluate(store) as ConstExpr;
if (!((bool)c.Value)) {
include = false;
break;
}
}
if (include) {
selRows.Add(i);
}
}
data = data.Select(selRows);
}
}
if (data == null) data = new Table();
watch.Stop();
Trace.WriteLine("WhereClase.Evaluate.Filter: " + watch.ElapsedMilliseconds + "ms");
Trace.WriteLine("WhereClase.Evaluate.SelectedRows: " + data.Rows);
store.Put<Table>("$DATA", data);
return new ConstExpr(data);
}