From 0dbfa3f08a0d2657cc7fc9b7b46af1f0aa271d45 Mon Sep 17 00:00:00 2001
From: Martin Kobetic <mkobetic@gmail.com>
Date: Mon, 12 May 2014 18:22:45 +0000
Subject: [PATCH] merge inline branch into leaf branch

---
 bucket.go      | 37 +++++++++++++++++--------------------
 bucket_test.go | 40 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 54 insertions(+), 23 deletions(-)

diff --git a/bucket.go b/bucket.go
index a2463a3..fdc9852 100644
--- a/bucket.go
+++ b/bucket.go
@@ -369,29 +369,26 @@ func (b *Bucket) Stats() BucketStats {
 		s.InlineBucketN += 1
 	}
 	b.forEachPage(func(p *page, depth int) {
-		if b.root == 0 { // inline bucket
+		if (p.flags & leafPageFlag) != 0 {
 			s.KeyN += int(p.count)
-			lastElement := p.leafPageElement(p.count - 1)
-			used := bucketHeaderSize + pageHeaderSize + (leafPageElementSize * int(p.count-1))
-			used += int(lastElement.pos + lastElement.ksize + lastElement.vsize)
-			s.InlineBucketInuse += used
-		} else if (p.flags & leafPageFlag) != 0 {
-			s.LeafPageN++
-			if p.count == 0 {
-				return
+			used := pageHeaderSize + (leafPageElementSize * int(p.count))
+			if p.count != 0 {
+				lastElement := p.leafPageElement(p.count - 1)
+				used += int(lastElement.pos + lastElement.ksize + lastElement.vsize)
 			}
-			s.KeyN += int(p.count)
-			lastElement := p.leafPageElement(p.count - 1)
-			used := pageHeaderSize + (leafPageElementSize * int(p.count-1))
-			used += int(lastElement.pos + lastElement.ksize + lastElement.vsize)
-			s.LeafInuse += used
-			s.LeafOverflowN += int(p.overflow)
+			if b.root == 0 {
+				s.InlineBucketInuse += used
+			} else {
+				s.LeafPageN++
+				s.LeafInuse += used
+				s.LeafOverflowN += int(p.overflow)
 
-			// Collect stats from sub-buckets
-			for i := uint16(0); i < p.count; i++ {
-				e := p.leafPageElement(i)
-				if (e.flags & bucketLeafFlag) != 0 {
-					subStats.Add(b.openBucket(e.value()).Stats())
+				// Collect stats from sub-buckets
+				for i := uint16(0); i < p.count; i++ {
+					e := p.leafPageElement(i)
+					if (e.flags & bucketLeafFlag) != 0 {
+						subStats.Add(b.openBucket(e.value()).Stats())
+					}
 				}
 			}
 		} else if (p.flags & branchPageFlag) != 0 {
diff --git a/bucket_test.go b/bucket_test.go
index b53a74b..11d1d77 100644
--- a/bucket_test.go
+++ b/bucket_test.go
@@ -583,7 +583,7 @@ func TestBucket_Stats(t *testing.T) {
 			assert.Equal(t, 501, stats.KeyN, "KeyN")
 			assert.Equal(t, 2, stats.Depth, "Depth")
 			assert.Equal(t, 125, stats.BranchInuse, "BranchInuse")
-			assert.Equal(t, 20908, stats.LeafInuse, "LeafInuse")
+			assert.Equal(t, 21004, stats.LeafInuse, "LeafInuse")
 			if os.Getpagesize() == 4096 {
 				// Incompatible page size
 				assert.Equal(t, 4096, stats.BranchAlloc, "BranchAlloc")
@@ -634,6 +634,40 @@ func TestBucket_Stats_Small(t *testing.T) {
 	})
 }
 
+func TestBucket_Stats_EmptyBucket(t *testing.T) {
+
+	withOpenDB(func(db *DB, path string) {
+		db.Update(func(tx *Tx) error {
+			// Add a bucket that fits on a single root leaf.
+			_, err := tx.CreateBucket([]byte("whozawhats"))
+			assert.NoError(t, err)
+			return nil
+		})
+		mustCheck(db)
+		db.View(func(tx *Tx) error {
+			b := tx.Bucket([]byte("whozawhats"))
+			stats := b.Stats()
+			assert.Equal(t, 0, stats.BranchPageN, "BranchPageN")
+			assert.Equal(t, 0, stats.BranchOverflowN, "BranchOverflowN")
+			assert.Equal(t, 0, stats.LeafPageN, "LeafPageN")
+			assert.Equal(t, 0, stats.LeafOverflowN, "LeafOverflowN")
+			assert.Equal(t, 0, stats.KeyN, "KeyN")
+			assert.Equal(t, 1, stats.Depth, "Depth")
+			assert.Equal(t, 0, stats.BranchInuse, "BranchInuse")
+			assert.Equal(t, 0, stats.LeafInuse, "LeafInuse")
+			if os.Getpagesize() == 4096 {
+				// Incompatible page size
+				assert.Equal(t, 0, stats.BranchAlloc, "BranchAlloc")
+				assert.Equal(t, 0, stats.LeafAlloc, "LeafAlloc")
+			}
+			assert.Equal(t, 1, stats.BucketN, "BucketN")
+			assert.Equal(t, 1, stats.InlineBucketN, "InlineBucketN")
+			assert.Equal(t, pageHeaderSize, stats.InlineBucketInuse, "InlineBucketInuse")
+			return nil
+		})
+	})
+}
+
 // Ensure a bucket can calculate stats.
 func TestBucket_Stats_Nested(t *testing.T) {
 
@@ -667,7 +701,7 @@ func TestBucket_Stats_Nested(t *testing.T) {
 			assert.Equal(t, 122, stats.KeyN, "KeyN")
 			assert.Equal(t, 3, stats.Depth, "Depth")
 			assert.Equal(t, 0, stats.BranchInuse, "BranchInuse")
-			assert.Equal(t, 2474, stats.LeafInuse, "LeafInuse")
+			assert.Equal(t, 2506, stats.LeafInuse, "LeafInuse")
 			if os.Getpagesize() == 4096 {
 				// Incompatible page size
 				assert.Equal(t, 0, stats.BranchAlloc, "BranchAlloc")
@@ -712,7 +746,7 @@ func TestBucket_Stats_Large(t *testing.T) {
 			assert.Equal(t, 100000, stats.KeyN, "KeyN")
 			assert.Equal(t, 3, stats.Depth, "Depth")
 			assert.Equal(t, 27007, stats.BranchInuse, "BranchInuse")
-			assert.Equal(t, 2598436, stats.LeafInuse, "LeafInuse")
+			assert.Equal(t, 2619092, stats.LeafInuse, "LeafInuse")
 			if os.Getpagesize() == 4096 {
 				// Incompatible page size
 				assert.Equal(t, 77824, stats.BranchAlloc, "BranchAlloc")