internal QueryResult Query(QueryInfo info, EwahCompressedBitArray exclusionBitMap = null, bool printLoggingMessages = false)
{
var bitMap = GetTagByQueryBitMapLookup(info.Type);
var questionLookup = GetTagByQueryLookup(info.Type)[TagServer.ALL_TAGS_KEY];
// Calculating the Cardinality can be (is?) expensive, we don't want to do it in Queries unless we really need to!?
bool calculateCardinality = true; // false
if (printLoggingMessages)
{
Logger.Log("Tag \"{0}\" is in {1:N0} Questions, Tag \"{2}\" is in {3:N0} Questions",
info.Tag, allTags[info.Tag], info.OtherTag, allTags[info.OtherTag]);
}
//PrintResults(Enumerable.Range(0, questionLookup.Length), qu => questionLookup[qu], TagServer.ALL_TAGS_KEY, info.Type);
//PrintResults(bitMap[info.Tag], qu => questionLookup[qu], info.Tag, info.Type);
//PrintResults(bitMap[info.OtherTag], qu => questionLookup[qu], info.OtherTag, info.Type);
var timer = Stopwatch.StartNew();
var tag1BitMap = bitMap[info.Tag];
var tag2BitMap = bitMap[info.OtherTag];
EwahCompressedBitArray bitMapResult = new EwahCompressedBitArray();
switch (info.Operator)
{
case "AND":
bitMapResult = tag1BitMap.And(tag2BitMap);
break;
case "AND-NOT":
bitMapResult = tag1BitMap.AndNot(tag2BitMap);
break;
case "OR":
bitMapResult = tag1BitMap.Or(tag2BitMap);
break;
case "OR-NOT": //"i.e. .net+or+jquery-"
bitMapResult = tag1BitMap.OrNot(tag2BitMap);
break;
// TODO Work out what a "NOT" query really means, the LINQ version was "result = tag1Query.Except(tag2Query)" (which is the same as AND-NOT?!)
//case "NOT":
// var bitMapResult = (EwahCompressedBitArray)tag2BitMap.Clone();
// bitMapResult.Not();
// break;
default:
throw new InvalidOperationException(string.Format("Invalid operator specified: {0}", info.Operator ?? "<NULL>"));
}
if (exclusionBitMap != null)
{
ulong cardinalityBeforeExclusions = 0;
if (printLoggingMessages)
{
cardinalityBeforeExclusions = bitMapResult.GetCardinality();
}
// The Exclusiong BitMap is Set (i.e. 1) in places where you CAN use the question, i.e. it's NOT excluded
// That way we can efficiently apply the exclusions by ANDing this BitMap to the previous results
var exclusionTimer = Stopwatch.StartNew();
bitMapResult = bitMapResult.AndNot(exclusionBitMap);
exclusionTimer.Stop();
if (printLoggingMessages)
{
if (calculateCardinality)
{
Logger.Log("Took {0,5:N2} ms to apply exclusion BitMap (Cardinality={1:N0}), Results Cardinality: Before={2:N0}, After={3:N0}",
exclusionTimer.Elapsed.TotalMilliseconds, exclusionBitMap.GetCardinality(), cardinalityBeforeExclusions, bitMapResult.GetCardinality());
}
else
{
Logger.Log("Took {0,5:N2} ms to apply exclusion BitMap", exclusionTimer.Elapsed.TotalMilliseconds);
}
}
}
var resultCollectionTimer = Stopwatch.StartNew();
var result = bitMapResult.Skip(info.Skip)
.Take(info.PageSize)
.Select(i => questions[questionLookup[i]])
.ToList();
resultCollectionTimer.Stop();
if (printLoggingMessages)
{
Logger.Log("Took {0,5:N2} ms to collect the results", resultCollectionTimer.Elapsed.TotalMilliseconds);
}
timer.Stop();
Results.AddData(timer.Elapsed.TotalMilliseconds.ToString("#.##"));
if (printLoggingMessages)
{
using (Utils.SetConsoleColour(ConsoleColor.DarkYellow))
{
if (calculateCardinality)
{
Logger.Log("Took {0,5:N2} ms in TOTAL to calculate \"{1} {2} {3}\", Got {4} results, (Result Cardinality={5:N0})",
timer.Elapsed.TotalMilliseconds, info.Tag, info.Operator, info.OtherTag, result.Count, bitMapResult.GetCardinality());
}
else
{
Logger.Log("Took {0,5:N2} ms in TOTAL to calculate \"{1} {2} {3}\", Got {4} results",
timer.Elapsed.TotalMilliseconds, info.Tag, info.Operator, info.OtherTag, result.Count);
}
}
//PrintResults(bitMapResult, qu => questionLookup[qu], string.Format("{0} {1} {2}", info.Tag, info.Operator, info.OtherTag), info.Type);
Logger.Log();
}
return(new QueryResult
{
Questions = result,
// TODO see if we can get meaningful numbers here, WITHOUT calling GetCardinality() (because it's expensive)
//Counters = new Dictionary<string, int>
//{
// { "TagCounter", tagCounter },
// { "OtherTagCounter", otherTagCounter },
// { "ExclusionCounter", exclusionCounter.Counter }
//}
});
}
