private static QueryBuffer.TypeBuffer GetTypeBuffer(HarmonyTableExpression table, List <Tuple <HarmonyTableExpression, QueryBuffer.TypeBuffer> > flatList)
{
var queryTables = table.RootExpression.RootExpressions.Values.OfType <HarmonyTableExpression>().Where(qt => qt != table);
var made = new QueryBuffer.TypeBuffer
{
DataObjectType = table.ItemType,
IsCollection = table.IsCollection,
ParentFieldName = table.Name,
Metadata = DataObjectMetadataBase.LookupType(table.ItemType)
};
if (table.Top != null)
{
var bakedFunction = Expression.Lambda <Func <QueryContext, long> >(Expression.Convert(table.Top, typeof(long)), QueryCompilationContext.QueryContextParameter).Compile();
made.Top = (obj) => bakedFunction(obj as QueryContext);
}
if (table.Skip != null)
{
var bakedFunction = Expression.Lambda <Func <QueryContext, long> >(Expression.Convert(table.Skip, typeof(long)), QueryCompilationContext.QueryContextParameter).Compile();
made.Skip = (obj) => bakedFunction(obj as QueryContext);
}
if (made.Top != null || made.Skip != null)
{
made.SelectResult = CollectionFilterMethod.MakeGenericMethod(made.DataObjectType).CreateDelegate(typeof(Func <QueryBuffer, QueryBuffer.TypeBuffer, object, object>), null) as Func <QueryBuffer, QueryBuffer.TypeBuffer, object, object>;
}
flatList.Add(Tuple.Create(table, made));
var joinedBuffers = queryTables.OfType <HarmonyTableExpression>().Where(qt => !qt.Name.Contains(".")).Select(qt => GetTypeBuffer(qt, flatList)).ToList();
var namedLookup = joinedBuffers.ToDictionary(tb => tb.ParentFieldName);
foreach (var nestedTable in queryTables.OfType <HarmonyTableExpression>().Where(qt => qt.Name.Contains(".")).OrderBy(qt => qt.Name.Length))
{
var nameParts = nestedTable.Name.Split(".");
if (namedLookup.TryGetValue(string.Join(".", nameParts.Take(nameParts.Length - 1)), out var foundBuffer))
{
var fullName = nestedTable.Name;
nestedTable.Name = nameParts.Last();
var madeBuffer = GetTypeBuffer(nestedTable, flatList);
foundBuffer.JoinedBuffers.Add(madeBuffer);
namedLookup.Add(fullName, madeBuffer);
}
else
{
throw new Exception(string.Format("failed to find parent table while processing query {0}", nestedTable.Name));
}
}
made.JoinedBuffers = joinedBuffers;
return(made);
}
public static object CollectionFilter <T>(QueryBuffer query, QueryBuffer.TypeBuffer typeBuf, object result)
{
var typedResult = result as IEnumerable <T>;
if (typedResult != null)
{
if (typeBuf.Skip != null)
{
typedResult = typedResult.Skip((int)typeBuf.Skip(query.Context));
}
if (typeBuf.Top != null)
{
typedResult = typedResult.Take((int)typeBuf.Top(query.Context));
}
return(typedResult.ToList());
}
else
{
return(result);
}
}
public PreparedQueryPlan PrepareQuery(HarmonyQueryCompilationContext compilationContext)
{
var rootExpr = RootExpressions[_valueBufferParameter];
var processedOns = new List <object>();
var flatList = new List <Tuple <HarmonyTableExpression, QueryBuffer.TypeBuffer> >();
var typeBuffers = new QueryBuffer.TypeBuffer[] { GetTypeBuffer(rootExpr, flatList) };
var expressionTableMapping = flatList.ToDictionary(kvp => kvp.Item1.RootExpression.ConvertedParameter as Expression, kvp => kvp.Item1 as IHarmonyQueryTable, new ExpressionValueComparer());
var tableList = flatList.Select(tpl => tpl.Item1 as IHarmonyQueryTable).ToList();
//extract all of expressions that might represent a given table and add them to the mapping dictionary
foreach (var table in tableList)
{
foreach (var alias in ((HarmonyTableExpression)table).Aliases)
{
if (!expressionTableMapping.ContainsKey(alias))
{
expressionTableMapping.Add(alias, table);
}
}
}
var whereBuilder = new WhereExpressionBuilder(rootExpr.IsCaseSensitive, tableList, expressionTableMapping);
var processedWheres = new List <Object>();
var orderBys = new List <Tuple <FileIO.Queryable.FieldReference, bool> >();
foreach (var expr in rootExpr.WhereExpressions)
{
whereBuilder.VisitForWhere(expr, processedWheres, processedOns);
}
foreach (var tpl in flatList)
{
foreach (var expr in tpl.Item1.OnExpressions)
{
var madeOn = whereBuilder.VisitForOn(expr);
if (madeOn != null)
{
processedOns.Add(madeOn);
if (tpl.Item2.JoinOn == null)
{
tpl.Item2.JoinOn = madeOn;
}
else
{
throw new NotImplementedException();
}
}
}
if (tpl.Item1 != rootExpr)
{
foreach (var expr in tpl.Item1.WhereExpressions)
{
var madeOn = whereBuilder.VisitForOn(expr);
if (madeOn != null)
{
processedOns.Add(madeOn);
if (tpl.Item2.JoinOn != null)
{
madeOn = new ConnectorPart()
{
Op = WhereClauseConnector.AndOperator, Left = tpl.Item2.JoinOn, Right = madeOn
}
}
;
tpl.Item2.JoinOn = madeOn;
}
}
}
foreach (var expr in tpl.Item1.OrderByExpressions)
{
var fieldRef = whereBuilder.VisitForOrderBy(expr.Item1);
if (fieldRef != null)
{
orderBys.Add(Tuple.Create(fieldRef, expr.Item2));
}
}
}
var queryBuffer = new QueryBuffer(flatList.Select(tpl => tpl.Item2).ToList());
var fieldReferences = new Dictionary <int, List <FieldDataDefinition> >();
foreach (var queryExpr in flatList)
{
if (queryExpr.Item1.ReferencedFields.Count > 0)
{
var bufferIndex = queryBuffer.TypeBuffers.IndexOf(queryExpr.Item2);
fieldReferences.Add(bufferIndex, queryExpr.Item1.ReferencedFields);
}
}
var queryPlan = new PreparedQueryPlan(true, processedWheres, fieldReferences, processedOns,
orderBys, queryBuffer, "");
return(queryPlan);
}
