From 93257af5d2fddd9269533d574d87d9a055ec9f79 Mon Sep 17 00:00:00 2001
From: Todd Gruben <tgruben@umbel.com>
Date: Wed, 9 Aug 2017 14:06:22 -0500
Subject: [PATCH 1/3] CountRange was incorrect if rangekey was prior to inital
 container

---
 fragment.go             |  3 ++-
 roaring/roaring.go      | 17 ++++++++++++++---
 roaring/roaring_test.go | 21 +++++++++++++++++++++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/fragment.go b/fragment.go
index 5458ee34a..027f0bd56 100644
--- a/fragment.go
+++ b/fragment.go
@@ -274,7 +274,8 @@ func (f *Fragment) openCache() error {
 	// Read in all rows by ID.
 	// This will cause them to be added to the cache.
 	for _, id := range pb.IDs {
-		n := f.row(id, false, false).Count()
+		//n := f.row(id, false, false).Count()
+		n := f.storage.CountRange(id*SliceWidth, (id+1)*SliceWidth)
 		f.cache.BulkAdd(id, n)
 	}
 	f.cache.Invalidate()
diff --git a/roaring/roaring.go b/roaring/roaring.go
index 67799631f..14818f683 100644
--- a/roaring/roaring.go
+++ b/roaring/roaring.go
@@ -197,9 +197,14 @@ func (b *Bitmap) Count() (n uint64) {
 
 // CountRange returns the number of bits set between [start, end).
 func (b *Bitmap) CountRange(start, end uint64) (n uint64) {
+	if len(b.keys) == 0 {
+		return
+	}
+	skey := highbits(start)
+	ekey := highbits(end)
 
-	i := search64(b.keys, highbits(start))
-	j := search64(b.keys, highbits(end))
+	i := search64(b.keys, skey)
+	j := search64(b.keys, ekey)
 
 	// If range is entirely in one container then just count that range.
 	if i >= 0 && i == j {
@@ -208,7 +213,13 @@ func (b *Bitmap) CountRange(start, end uint64) (n uint64) {
 
 	// Count first partial container.
 	if i < 0 {
-		i = -i
+		// start is before container, so we should start counting
+		// at first container that has value
+		if skey < b.keys[0] {
+			i = -1
+		} else {
+			i = -i
+		}
 	} else {
 		n += uint64(b.containers[i].countRange(int(lowbits(start)), maxContainerVal+1))
 	}
diff --git a/roaring/roaring_test.go b/roaring/roaring_test.go
index 8de92eb4e..a720692e6 100644
--- a/roaring/roaring_test.go
+++ b/roaring/roaring_test.go
@@ -191,6 +191,27 @@ func TestBitmap_Max(t *testing.T) {
 		}
 	}
 }
+func TestBitmap_BitmapCountRangeBug(t *testing.T) {
+	s := uint64(2009 * 1048576)
+	e := uint64(2010 * 1048576)
+
+	start := s + (39314024 % 1048576)
+	bm0 := roaring.NewBitmap()
+	for i := uint64(0); i < 65536; i++ {
+		if (i+1)%4096 == 0 {
+			start += 16384
+		} else {
+			start += 2
+		}
+		bm0.Add(start)
+	}
+	a := bm0.Count()
+	r := bm0.CountRange(s, e)
+	if a != r {
+		t.Fatalf("Counts != CountRange %v %v", a, r)
+
+	}
+}
 
 func TestBitmap_BitmapCountRange(t *testing.T) {
 	bm0 := roaring.NewBitmap(0, 2683177)

From 5d39bc0b1c8dc226ea09ed0fe63ac627dcb3fe67 Mon Sep 17 00:00:00 2001
From: Todd Gruben <tgruben@umbel.com>
Date: Wed, 9 Aug 2017 15:34:59 -0500
Subject: [PATCH 2/3] addressing concerns

---
 fragment.go             | 1 -
 roaring/roaring_test.go | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/fragment.go b/fragment.go
index 027f0bd56..db0d3fb13 100644
--- a/fragment.go
+++ b/fragment.go
@@ -274,7 +274,6 @@ func (f *Fragment) openCache() error {
 	// Read in all rows by ID.
 	// This will cause them to be added to the cache.
 	for _, id := range pb.IDs {
-		//n := f.row(id, false, false).Count()
 		n := f.storage.CountRange(id*SliceWidth, (id+1)*SliceWidth)
 		f.cache.BulkAdd(id, n)
 	}
diff --git a/roaring/roaring_test.go b/roaring/roaring_test.go
index a720692e6..cf4fc44e7 100644
--- a/roaring/roaring_test.go
+++ b/roaring/roaring_test.go
@@ -191,7 +191,7 @@ func TestBitmap_Max(t *testing.T) {
 		}
 	}
 }
-func TestBitmap_BitmapCountRangeBug(t *testing.T) {
+func TestBitmap_BitmapCountRangeEdgeCase(t *testing.T) {
 	s := uint64(2009 * 1048576)
 	e := uint64(2010 * 1048576)
 

From 8f3cb3e761b67ee97d1825a4eea2d9a1830ae4d0 Mon Sep 17 00:00:00 2001
From: Travis <travis@pilosa.com>
Date: Thu, 10 Aug 2017 08:42:44 -0500
Subject: [PATCH 3/3] add a comment to TestBitmap_BitmapCountRangeEdgeCase

---
 roaring/roaring_test.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/roaring/roaring_test.go b/roaring/roaring_test.go
index cf4fc44e7..c721f3804 100644
--- a/roaring/roaring_test.go
+++ b/roaring/roaring_test.go
@@ -191,6 +191,8 @@ func TestBitmap_Max(t *testing.T) {
 		}
 	}
 }
+
+// Ensure CountRange is correct even if rangekey is prior to inital container.
 func TestBitmap_BitmapCountRangeEdgeCase(t *testing.T) {
 	s := uint64(2009 * 1048576)
 	e := uint64(2010 * 1048576)