/// <summary> Reads a map reduce delcaration </summary>
///
/// <remarks> Vasko, 06-Dec-17. </remarks>
///
/// <returns> The map reduce expression. </returns>
public MapReduceExpression ReadMapReduce()
{
if (Reader.Current.TokenType != TokenType.Reduce)
{
return(null);
}
Reader.DiscardToken(TokenType.Reduce);
var currentCursor = Reader.Marker.Clone();
var reduceKeyExpressions = ReadExpressions(Filters.Keyword(currentCursor));
Reader.DiscardToken(TokenType.ReduceMap);
currentCursor = Reader.Marker.Clone();
var valueExpressions = ReadExpressions(Filters.Keyword(currentCursor));
IEnumerable <IExpression> aggregate = new List <IExpression>();
if (Reader.Current.TokenType == TokenType.ReduceAggregate)
{
Reader.DiscardToken(TokenType.ReduceAggregate);
currentCursor = Reader.Marker.Clone();
aggregate = ReadExpressions(Filters.Keyword(currentCursor));
}
var mapReduce = new MapReduceExpression()
{
Keys = reduceKeyExpressions.Cast <AssignmentExpression>(),
ValueMembers = valueExpressions.Cast <AssignmentExpression>(),
Aggregate = new MapAggregateExpression(aggregate.Cast <AssignmentExpression>())
};
return(mapReduce);
}
public static MapReduceJsScript Create(MapReduceExpression mapReduce)
{
var keyGenerator = mapReduce.GetCodeGenerator();
var aggGenerator = mapReduce.Aggregate.GetCodeGenerator();
var keyValue = keyGenerator.GenerateFromExpression(mapReduce);
var aggValue = aggGenerator.GenerateFromExpression(mapReduce.Aggregate);
var sc = new MapReduceJsScript()
{
Reduce = aggValue,
Map = keyValue
};
return(sc);
}
/// <summary>
///
/// </summary>
/// <param name="mapReduce"></param>
/// <param name="keyBuff"></param>
/// <param name="valueBuff"></param>
private static void GetMapReduceContent(MapReduceExpression mapReduce, ref StringBuilder keyBuff, ref StringBuilder valueBuff)
{
if (keyBuff == null)
{
keyBuff = new StringBuilder();
}
if (valueBuff == null)
{
valueBuff = new StringBuilder();
}
var lstKeys = VisitVariables(mapReduce.Keys, keyBuff, new JsGeneratingExpressionVisitor());
var lstValues = VisitVariables(mapReduce.ValueMembers, valueBuff, new JsGeneratingExpressionVisitor());
var keyParts = lstKeys.Select(x => $"'{x}' : {x}").ToArray();
var valueParts = lstValues.Select(x => $"'{x}' : {x}").ToArray();
var keysPart = String.Join(",", keyParts) + '\n';
var valuesPart = String.Join(",", valueParts) + '\n';
keyBuff.AppendLine("var __key = { " + keysPart + "};");
valueBuff.AppendLine("var __value = { " + valuesPart + "};");
}
