1 files changed, 17 insertions, 21 deletions
diff --git a/vendor/github.com/RoaringBitmap/roaring/arraycontainer.go b/vendor/github.com/RoaringBitmap/roaring/arraycontainer.go
index 12fe6cf530..f8bb29b96f 100644
--- a/vendor/github.com/RoaringBitmap/roaring/arraycontainer.go
+++ b/vendor/github.com/RoaringBitmap/roaring/arraycontainer.go
@@ -359,28 +359,17 @@ func (ac *arrayContainer) iorArray(value2 *arrayContainer) container {
 	len1 := value1.getCardinality()
 	len2 := value2.getCardinality()
 	maxPossibleCardinality := len1 + len2
-	if maxPossibleCardinality > arrayDefaultMaxSize { // it could be a bitmap!
-		bc := newBitmapContainer()
-		for k := 0; k < len(value2.content); k++ {
-			v := value2.content[k]
-			i := uint(v) >> 6
-			mask := uint64(1) << (v % 64)
-			bc.bitmap[i] |= mask
-		}
-		for k := 0; k < len(ac.content); k++ {
-			v := ac.content[k]
-			i := uint(v) >> 6
-			mask := uint64(1) << (v % 64)
-			bc.bitmap[i] |= mask
-		}
-		bc.cardinality = int(popcntSlice(bc.bitmap))
-		if bc.cardinality <= arrayDefaultMaxSize {
-			return bc.toArrayContainer()
-		}
-		return bc
-	}
 	if maxPossibleCardinality > cap(value1.content) {
-		newcontent := make([]uint16, 0, maxPossibleCardinality)
+		// doubling the capacity reduces new slice allocations in the case of
+		// repeated calls to iorArray().
+		newSize := 2 * maxPossibleCardinality
+		// the second check is to handle overly large array containers
+		// and should not occur in normal usage,
+		// as all array containers should be at most arrayDefaultMaxSize
+		if newSize > 2*arrayDefaultMaxSize && maxPossibleCardinality <= 2*arrayDefaultMaxSize {
+			newSize = 2 * arrayDefaultMaxSize
+		}
+		newcontent := make([]uint16, 0, newSize)
 		copy(newcontent[len2:maxPossibleCardinality], ac.content[0:len1])
 		ac.content = newcontent
 	} else {
@@ -388,6 +377,13 @@ func (ac *arrayContainer) iorArray(value2 *arrayContainer) container {
 	}
 	nl := union2by2(value1.content[len2:maxPossibleCardinality], value2.content, ac.content)
 	ac.content = ac.content[:nl] // reslice to match actual used capacity
+
+	if nl > arrayDefaultMaxSize {
+		// Only converting to a bitmap when arrayDefaultMaxSize
+		// is actually exceeded minimizes conversions in the case of repeated
+		// calls to iorArray().
+		return ac.toBitmapContainer()
+	}
 	return ac
 }