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Add check for multiple all iterators

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Update test to reflect that the two Alls will be collapsed,
also fix the test of tag optimization to use fixed iterators.
This commit is contained in:
Barak Michener 2015-08-12 14:50:57 -04:00
parent f54a84ff0b
commit ac1fa668e7
2 changed files with 51 additions and 3 deletions
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9
graph/iterator/and_iterator_optimize.go
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@ -292,12 +292,15 @@ func hasAnyNullIterators(its []graph.Iterator) bool {
// nothing, and graph.All which returns everything. Particularly, we want
// to see if we're intersecting with a bunch of graph.All iterators, and,
// if we are, then we have only one useful iterator.
//
// We already checked for hasAnyNullIteratators() -- so now we're considering
// All iterators.
func hasOneUsefulIterator(its []graph.Iterator) graph.Iterator {
usefulCount := 0
var usefulIt graph.Iterator
for _, it := range its {
switch it.Type() {
case graph.Null, graph.All:
case graph.All:
continue
case graph.Optional:
// Optional is weird -- it's not useful, but we can't optimize
@ -313,6 +316,10 @@ func hasOneUsefulIterator(its []graph.Iterator) graph.Iterator {
if usefulCount == 1 {
return usefulIt
}
if usefulCount == 0 {
// It's full of All iterators. We can safely return one of them.
return its[0]
}
return nil
}