/// <summary>
/// Creates jobs for the parallel group by.
/// Note that the last job in the array has the end set to the end of the result table.
/// Each job will receive a range from result table, hasher, comparer and aggregates.
/// Note that they are all copies, because they contain a private stete (hasher contains reference to the equality comparers to enable caching when computing the hash, aggregates
/// contain references to storage arrays to avoid casting in a tight loop).
/// The comparers and hashers build in the constructor of this class are given to the last job, just like the aggregates passed to the construtor.
/// The global Dictionary recieves a comparer that has no internal comparers set to some hasher.
/// </summary>
private GroupByJob[] CreateJobs(ITableResults resTable, Aggregate[] aggs, ExpressionComparer[] comparers, ExpressionHasher[] hashers)
{
GroupByJob[] jobs = new GroupByJob[this.ThreadCount];
int current = 0;
int addition = resTable.NumberOfMatchedElements / this.ThreadCount;
if (addition == 0)
{
throw new ArgumentException($"{this.GetType()}, a range for a thread cannot be 0.");
}
var lastComp = RowEqualityComparerGroupKey.Factory(resTable, comparers, true);
var lastHasher = new RowHasher(hashers);
lastHasher.SetCache(lastComp.comparers);
// It needs only comparator that has no comparers set as a cache to some hasher.
var globalGroups = new ConcurrentDictionary <GroupDictKey, AggregateBucketResult[]>(lastComp.Clone(cacheResults: false));
for (int i = 0; i < jobs.Length - 1; i++)
{
var tmpComp = lastComp.Clone(cacheResults: true);
var tmpHash = lastHasher.Clone();
tmpHash.SetCache(tmpComp.comparers);
jobs[i] = CreateJob(tmpHash, tmpComp, aggs, resTable, current, current + addition, globalGroups);
current += addition;
}
jobs[jobs.Length - 1] = CreateJob(lastHasher, lastComp, aggs, resTable, current, resTable.NumberOfMatchedElements, globalGroups);
return(jobs);
}
/// <summary>
/// Creates jobs for the parallel group by.
/// Note that the last job in the array has the end set to the end of the result table.
/// Each job will receive a range from result table, hasher, comparer (cache on) and aggregates.
/// Note that they are all copies, because they contain a private state (hasher contains reference to the equality comparers to enable caching when computing the hash).
/// The comparers and hashers build in the constructor of this class are given to the last job, just like the aggregates passed to the construtor.
/// </summary>
private GroupByJob[] CreateJobs(ITableResults resTable, Aggregate[] aggs, ExpressionComparer[] comparers, ExpressionHasher[] hashers)
{
GroupByJob[] jobs = new GroupByJob[this.ThreadCount];
int current = 0;
int addition = resTable.NumberOfMatchedElements / this.ThreadCount;
if (addition == 0)
{
throw new ArgumentException($"{this.GetType()}, a range for a thread cannot be 0.");
}
// Set their internal cache.
var lastComp = RowEqualityComparerGroupKey.Factory(resTable, comparers, true);
var lastHasher = new RowHasher(hashers);
lastHasher.SetCache(lastComp.comparers);
for (int i = 0; i < jobs.Length - 1; i++)
{
var tmpComp = lastComp.Clone(cacheResults: true);
var tmpHash = lastHasher.Clone();
tmpHash.SetCache(tmpComp.comparers);
jobs[i] = CreateJob(tmpHash, tmpComp, aggs, resTable, current, current + addition);
current += addition;
}
jobs[jobs.Length - 1] = CreateJob(lastHasher, lastComp, aggs, resTable, current, resTable.NumberOfMatchedElements);
return(jobs);
}
public override GroupByResults Group(ITableResults resTable)
{
//if (this.InParallel) throw new ArgumentException($"{this.GetType()}, cannot perform a parallel group by.");
CreateHashersAndComparers(out ExpressionComparer[] comparers, out ExpressionHasher[] hashers);
return(this.SingleThreadGroupBy(new RowHasher(hashers), RowEqualityComparerGroupKey.Factory(resTable, comparers, true), resTable));
}
public TwoStepHalfStreamedBucket(QueryExpressionInfo expressionInfo, IGroupByExecutionHelper executionHelper, int columnCount, int[] usedVars) : base(expressionInfo, executionHelper, columnCount, usedVars)
{
this.groupJobs = new GroupJob[this.executionHelper.ThreadCount];
// Create an initial job, comparers and hashers
this.CreateHashersAndComparers(out ExpressionComparer[] comparers, out ExpressionHasher[] hashers);
var firstComp = RowEqualityComparerGroupKey.Factory(null, comparers, true);
var firstHasher = new RowHasher(hashers);
firstHasher.SetCache(firstComp.comparers);
this.groupJobs[0] = new GroupJob(firstComp, firstHasher, new TableResults(this.ColumnCount, this.executionHelper.FixedArraySize, this.usedVars));
for (int i = 1; i < this.executionHelper.ThreadCount; i++)
{
CloneHasherAndComparer(firstComp, firstHasher, out RowEqualityComparerGroupKey newComp, out RowHasher newHasher);
groupJobs[i] = new GroupJob(newComp, newHasher, new TableResults(this.ColumnCount, this.executionHelper.FixedArraySize, this.usedVars));
}
this.globalGroups = new ConcurrentDictionary <GroupDictKeyFull, AggregateBucketResult[]>(RowEqualityComparerGroupDickKeyFull.Factory(comparers, false));
}
