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Fix linksto and zero-costs

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This commit is contained in:
Barak Michener 2014-08-16 06:30:27 -04:00
parent e453385d5e
commit a371155cd2
2 changed files with 23 additions and 14 deletions
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35
graph/iterator/and_iterator_optimize.go
View file

@ -164,7 +164,7 @@ func (it *And) optimizeOrder(its []graph.Iterator) []graph.Iterator {
continue continue
} }
stats := f.Stats() stats := f.Stats()
cost += stats.ContainsCost * (rootStats.Size / (stats.Size + 1)) cost += stats.ContainsCost * (1 + (rootStats.Size / (stats.Size + 1)))
} }
cost *= rootStats.Size cost *= rootStats.Size
if glog.V(3) { if glog.V(3) {
@ -306,9 +306,12 @@ func hasOneUsefulIterator(its []graph.Iterator) graph.Iterator {
func materializeIts(its []graph.Iterator) []graph.Iterator { func materializeIts(its []graph.Iterator) []graph.Iterator {
var out []graph.Iterator var out []graph.Iterator
for _, it := range its {
allStats := getStatsForSlice(its)
out = append(out, its[0])
for _, it := range its[1:] {
stats := it.Stats() stats := it.Stats()
if stats.Size*stats.NextCost < stats.ContainsCost { if stats.Size*stats.NextCost < (stats.ContainsCost * (1 + (stats.Size / (allStats.Size + 1)))) {
if graph.Height(it, graph.Materialize) > 10 { if graph.Height(it, graph.Materialize) > 10 {
out = append(out, NewMaterialize(it)) out = append(out, NewMaterialize(it))
continue continue
@ -319,28 +322,34 @@ func materializeIts(its []graph.Iterator) []graph.Iterator {
return out return out
} }
// and.Stats() lives here in and-iterator-optimize.go because it may func getStatsForSlice(its []graph.Iterator) graph.IteratorStats {
// in the future return different statistics based on how it is optimized. primary := its[0]
// For now, however, it's pretty static. primaryStats := primary.Stats()
func (it *And) Stats() graph.IteratorStats {
primaryStats := it.primaryIt.Stats()
ContainsCost := primaryStats.ContainsCost ContainsCost := primaryStats.ContainsCost
NextCost := primaryStats.NextCost NextCost := primaryStats.NextCost
Size := primaryStats.Size Size := primaryStats.Size
for _, sub := range it.internalIterators { for _, sub := range its[1:] {
stats := sub.Stats() stats := sub.Stats()
NextCost += stats.ContainsCost * (primaryStats.Size / (stats.Size + 1)) NextCost += stats.ContainsCost * (1 + (primaryStats.Size / (stats.Size + 1)))
ContainsCost += stats.ContainsCost ContainsCost += stats.ContainsCost
if Size > stats.Size { if Size > stats.Size {
Size = stats.Size Size = stats.Size
} }
} }
return graph.IteratorStats{ return graph.IteratorStats{
ContainsCost: ContainsCost * 2, ContainsCost: ContainsCost,
NextCost: NextCost, NextCost: NextCost,
Size: Size, Size: Size,
Next: it.runstats.Next,
Contains: it.runstats.Contains,
} }
} }
// and.Stats() lives here in and-iterator-optimize.go because it may
// in the future return different statistics based on how it is optimized.
// For now, however, it's pretty static.
func (it *And) Stats() graph.IteratorStats {
stats := getStatsForSlice(it.SubIterators())
stats.Next = it.runstats.Next
stats.Contains = it.runstats.Contains
return stats
}

2
graph/iterator/linksto_iterator.go
View file

@ -212,5 +212,5 @@ func (it *LinksTo) Stats() graph.IteratorStats {
} }
func (it *LinksTo) Size() (int64, bool) { func (it *LinksTo) Size() (int64, bool) {
return 0, true return it.Stats().Size, false
} }