/// <summary>
/// Load all the exclusions into a HashSet, then loop through the Base Query, until we have pageSize + Skip items that aren't in the HashSet.
/// Expensive when there are LOTS of exclusions, but cheaper when the BaseQuery is large because we don't process all of it (stop when we have enough)
/// </summary>
internal List <Question> BooleanQueryWithExclusionsFastAlternativeVersion(QueryType type, string tag, IList <string> excludedTags, int pageSize, int skip)
{
var gcInfo = new GCCollectionInfo();
var timer = Stopwatch.StartNew();
TagByQueryLookup queryInfo = GetTagByQueryLookup(type);
Func <Question, string> fieldSelector = GetFieldSelector(type);
ThrowIfInvalidParameters(tag, pageSize, queryInfo);
var exclusions = cache.Value.GetCachedHashSet();
foreach (var excludedTag in excludedTags)
{
foreach (var qu in queryInfo[excludedTag])
{
exclusions.Add(qu);
}
}
var allResults = new List <int>(skip + pageSize);
foreach (var qu in queryInfo[tag])
{
// If it's not in the exclusions, we can use it
if (exclusions.Contains(qu) == false)
{
allResults.Add(qu);
}
if (allResults.Count >= (skip + pageSize))
{
break;
}
}
var results = allResults.Skip(skip)
.Take(pageSize)
.Select(i => questions[i])
.ToList();
timer.Stop();
gcInfo.UpdateCollectionInfo();
Logger.Log("Base Query: {0}, there are {1:N0} Excluded Tags", tag, excludedTags.Count);
Results.AddData(timer.Elapsed.TotalMilliseconds.ToString("#.##"));
using (Utils.SetConsoleColour(Utils.GetColorForTimespan(timer.Elapsed)))
{
Logger.Log("Boolean Query {0} against tag \"{1}\", pageSize = {2}, skip = {3}, took {4} ({5:N2} ms) - FAST ALT",
type, tag, pageSize, skip, timer.Elapsed, timer.Elapsed.TotalMilliseconds);
}
Logger.Log("Got {0} results ({1} in allResults), {2:N0} items in exclusions", results.Count(), allResults.Count, exclusions.Count);
Logger.Log(gcInfo.ToString());
//var formattedResults = results.Select(r => string.Format("Id: {0,8}, {1}: {2,4}, Tags: {3}, ", r.Id, type, fieldSelector(r), string.Join(",", r.Tags)));
//Log(" {0}", string.Join("\n ", formattedResults));
Logger.Log("");
return(results);
}
/// <summary>
/// Load up the HashSet with the values from the Base Query, then loop through all the exclusions and remove them
/// Expensive when their are LOTS of exclusions, expensive when there is a large Base Query (we process it all regardless)
/// </summary>
internal List <Question> BooleanQueryWithExclusionsFastVersion(QueryType type, string tag, IList <string> excludedTags, int pageSize, int skip)
{
var gcInfo = new GCCollectionInfo();
var timer = Stopwatch.StartNew();
TagByQueryLookup queryInfo = GetTagByQueryLookup(type);
Func <Question, string> fieldSelector = GetFieldSelector(type);
ThrowIfInvalidParameters(tag, pageSize, queryInfo);
var baseHashSet = cache.Value.GetCachedHashSet(queryInfo[tag]);
foreach (var excludedTag in excludedTags)
{
foreach (var qu in queryInfo[excludedTag])
{
// We don't care if it was present before or not, either way it's removed
baseHashSet.Remove(qu);
}
}
var results = baseHashSet.Skip(skip)
.Take(pageSize)
.Select(i => questions[i])
.ToList();
timer.Stop();
gcInfo.UpdateCollectionInfo();
Logger.Log("Base Query: {0}, there are {1:N0} Excluded Tags", tag, excludedTags.Count);
Results.AddData(timer.Elapsed.TotalMilliseconds.ToString("#.##"));
using (Utils.SetConsoleColour(Utils.GetColorForTimespan(timer.Elapsed)))
{
Logger.Log("Boolean Query {0} against tag \"{1}\", pageSize = {2}, skip = {3}, took {4} ({5:N2} ms) - FAST",
type, tag, pageSize, skip, timer.Elapsed, timer.Elapsed.TotalMilliseconds);
}
Logger.Log("Got {0} results, {1:N0} items left in baseHashSet", results.Count(), baseHashSet.Count);
Logger.Log(gcInfo.ToString());
//var formattedResults = results.Select(r => string.Format("Id: {0,8}, {1}: {2,4}, Tags: {3}, ", r.Id, type, fieldSelector(r), string.Join(",", r.Tags)));
//Log(" {0}", string.Join("\n ", formattedResults));
Logger.Log("");
return(results);
}
internal List <Question> BooleanQueryWithExclusionsLINQVersion(QueryType type, string tag, IList <string> excludedTags, int pageSize, int skip)
{
var gcInfo = new GCCollectionInfo();
var timer = Stopwatch.StartNew();
TagByQueryLookup queryInfo = GetTagByQueryLookup(type);
Func <Question, string> fieldSelector = GetFieldSelector(type);
ThrowIfInvalidParameters(tag, pageSize, queryInfo);
IEnumerable <int> baseQuery = queryInfo[tag];
foreach (var excludedTag in excludedTags)
{
baseQuery = baseQuery.Except(queryInfo[excludedTag]);
}
var results = baseQuery.Skip(skip)
.Take(pageSize)
.Select(i => questions[i])
.ToList();
timer.Stop();
gcInfo.UpdateCollectionInfo();
Results.AddData(timer.Elapsed.TotalMilliseconds.ToString("#.##"));
Logger.Log("Base Query: {0}, there are {1:N0} Excluded Tags", tag, excludedTags.Count);
using (Utils.SetConsoleColour(Utils.GetColorForTimespan(timer.Elapsed)))
{
Logger.Log("Boolean Query {0} against tag \"{1}\", pageSize = {2}, skip = {3}, took {4} ({5:N2} ms) - SLOW",
type, tag, pageSize, skip, timer.Elapsed, timer.Elapsed.TotalMilliseconds);
}
Logger.Log("Got {0} results", results.Count());
Logger.Log(gcInfo.ToString());
//var formattedResults = results.Select(r => string.Format("Id: {0,8}, {1}: {2,4}, Tags: {3}, ", r.Id, type, fieldSelector(r), string.Join(",", r.Tags)));
//Log(" {0}", string.Join("\n ", formattedResults));
Logger.Log("");
return(results);
}
/// <summary>
/// Similar to <seealso cref="BooleanQueryWithExclusionsFastAlternativeVersion"/> using a BloomFilter instead of a HashSet
/// Load up the BloomFilter with the exclusions, then loop through the Base Query, until we have pageSize + Skip items that aren't in the BloomFilter.
/// Expensive when there are LOTS of exclusions, but cheaper when the BaseQuery is large because we don't process all of it (stop when we have enough)
/// </summary>
internal List <Question> BooleanQueryWithExclusionsBloomFilterVersion(QueryType type, string tag, IList <string> excludedTags, int pageSize, int skip)
{
var gcInfo = new GCCollectionInfo();
var timer = Stopwatch.StartNew();
TagByQueryLookup queryInfo = GetTagByQueryLookup(type);
Func <Question, string> fieldSelector = GetFieldSelector(type);
ThrowIfInvalidParameters(tag, pageSize, queryInfo);
//int bloomFilterSize = 40 * 1000 * 1000; // million's, 40mil produces several False +ve's
int bloomFilterSize = 100 * 1000 * 1000; // million's
#if DEBUG
var bloomFilterCreationTimer = Stopwatch.StartNew();
var bloomFilter = new SimpleBloomFilter(bloomFilterSize);
bloomFilterCreationTimer.Stop();
Logger.Log("Took {0} ({1:N2} ms) to create the bloom filter with {2:N0} bits ({3:N2} bytes)",
bloomFilterCreationTimer.Elapsed, bloomFilterCreationTimer.Elapsed.TotalMilliseconds, bloomFilterSize, bloomFilterSize / 8);
#else
var bloomFilter = new SimpleBloomFilter(bloomFilterSize);
#endif
#if DEBUG
//var tests = new[] { 1066589, 2793150, 364114, 910374 }; // These are the Question Id's NOT the array index ([]) values!!
var tests = new[] { 192257, 616585, 53029, 158368 }; // These ARE the array index ([]) values
var debugging = cache.Value.GetCachedHashSet();
#endif
foreach (var excludedTag in excludedTags)
{
foreach (var qu in queryInfo[excludedTag])
{
bloomFilter.Add(qu);
#if DEBUG
debugging.Add(qu);
if (tests.Contains(qu))
{
// It it's false, it's DEFINITELY false
// It it's true, it could really be false (false +ve)
var possiblyExists = bloomFilter.PossiblyExists(qu, debugInfo: true);
Logger.Log("Bloom Filter.PossiblyExists - {0,8} = {1} ****", qu, possiblyExists);
Logger.Log(" DebuggingHashSet.Contains - {0,8} = {1} ****", qu, debugging.Contains(qu));
}
#endif
}
}
var baseQuery = queryInfo[tag];
#if DEBUG
var result =
baseQuery.Where(b =>
{
var possiblyExists = bloomFilter.PossiblyExists(b);
if (possiblyExists == false)
{
return(true); // we can use it
}
if (debugging.Contains(b) == false)
{
var qu = questions[b];
Logger.Log("FALSE +VE: {0,8}, PossiblyExists = {1}, debugging.Contains() = {2}, Id = {3,8}, Tags = {4}",
b, possiblyExists, debugging.Contains(b), qu.Id, string.Join(",", qu.Tags));
}
return(false); // we can't use it
})
#else
var result = baseQuery.Where(b => bloomFilter.PossiblyExists(b) == false)
#endif
.Skip(skip)
.Take(pageSize)
.Select(i => questions[i])
.ToList();
timer.Stop();
gcInfo.UpdateCollectionInfo();
Logger.Log("Base Query: {0}, there are {1:N0} Excluded Tags", tag, excludedTags.Count);
Results.AddData(timer.Elapsed.TotalMilliseconds.ToString("#.##"));
using (Utils.SetConsoleColour(Utils.GetColorForTimespan(timer.Elapsed)))
{
Logger.Log("Boolean Query {0} against tag \"{1}\", pageSize = {2}, skip = {3}, took {4} ({5:N2} ms) - BLOOM",
type, tag, pageSize, skip, timer.Elapsed, timer.Elapsed.TotalMilliseconds);
}
//Log("Got {0} results, Bloom Filter contains {1:N0} items (some could be dupes), Truthiness {2:N2}",
// result.Count(), bloomFilter.NumberOfItems, bloomFilter.Truthiness);
Logger.Log("Got {0} results, Bloom Filter contains {1:N0} items (some could be dupes)", result.Count(), bloomFilter.NumberOfItems);
Logger.Log(gcInfo.ToString());
//var formattedResults = result.Select(r => string.Format("Id: {0,8}, {1}: {2,4}, Tags: {3}, ", r.Id, type, fieldSelector(r), string.Join(",", r.Tags)));
//Log(" {0}", string.Join("\n ", formattedResults));
Logger.Log("");
#if DEBUG
foreach (var item in tests)
{
var possiblyExists = bloomFilter.PossiblyExists(item, debugInfo: true);
Logger.Log("Bloom Filter.PossiblyExists - {0,8} = {1}", item, possiblyExists);
Logger.Log(" DebuggingHashSet.Contains - {0,8} = {1}", item, debugging.Contains(item));
Logger.Log("");
}
// When the values in "tests" represent Question Id
//var testResults = tests.Select(t => questions.First(qu => qu.Id == t))
// .Select(r => string.Format("Id: {0,8}, {1}: {2,4}, Tags: {3}, ", r.Id, type, fieldSelector(r), string.Join(",", r.Tags)));
// When the values in "tests" represent array indexes, i.e. questions[x]
var testResults = tests.Select(t => questions[t])
.Select(r => string.Format("Id: {0,8}, {1}: {2,4}, Tags: {3}, ", r.Id, type, fieldSelector(r), string.Join(",", r.Tags)));
Logger.Log(" {0}", string.Join("\n ", testResults));
#endif
return(result);
}