public void TestCase()
{
var hashes = new Func<string, uint>[]{StringHashFirstHalf,StringHashLastHalf};
var size = Convert.ToInt32(Math.Pow(2, 16));
IBloomFilter<string> bloomFilter = new SimpleBloomFilter<string>(size, hashes);
bloomFilter.Add("haochi");
bloomFilter.Add("chen");
Assert.AreEqual(bloomFilter.Query("haochi"), Existence.MAYBE);
Assert.AreEqual(bloomFilter.Query("chen"), Existence.MAYBE);
Assert.AreEqual(bloomFilter.Query("orlando"), Existence.NO);
Assert.AreEqual(bloomFilter.Query("bloom"), Existence.NO);
}
private static Message CreateMessageBloomFilter()
{
var sampleBf1 = new SimpleBloomFilter <Number160>(2, 5);
sampleBf1.Add(_sample160_1);
var sampleBf2 = new SimpleBloomFilter <Number160>(2, 5);
sampleBf2.Add(_sample160_2);
sampleBf2.Add(_sample160_1);
var sampleBf3 = new SimpleBloomFilter <Number160>(2, 5);
sampleBf3.Add(_sample160_1);
sampleBf3.Add(_sample160_2);
sampleBf3.Add(_sample160_3);
var sampleBf4 = new SimpleBloomFilter <Number160>(2, 5);
sampleBf4.Add(_sample160_1);
sampleBf4.Add(_sample160_2);
sampleBf4.Add(_sample160_3);
sampleBf4.Add(_sample160_4);
var sampleBf5 = new SimpleBloomFilter <Number160>(2, 5);
sampleBf5.Add(_sample160_1);
sampleBf5.Add(_sample160_2);
sampleBf5.Add(_sample160_3);
sampleBf5.Add(_sample160_4);
sampleBf5.Add(_sample160_5);
var m = Utils2.CreateDummyMessage();
m.SetBloomFilter(sampleBf1);
m.SetBloomFilter(sampleBf2);
m.SetBloomFilter(sampleBf3);
m.SetBloomFilter(sampleBf4);
m.SetBloomFilter(sampleBf5);
m.SetBloomFilter(sampleBf1);
m.SetBloomFilter(sampleBf2);
m.SetBloomFilter(sampleBf3);
return(m);
}
/// <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);
}
