Minor stats fixes.

bucket.go

@@ -371,11 +371,14 @@ func (b *Bucket) Stats() BucketStats {
 	b.forEachPage(func(p *page, depth int) {
 		if (p.flags & leafPageFlag) != 0 {
 			s.KeyN += int(p.count)
+
 			// used totals the used bytes for the page
 			used := pageHeaderSize
+
 			if p.count != 0 {
 				// If page has any elements, add all element headers.
 				used += leafPageElementSize * int(p.count-1)
+
 				// Add all element key, value sizes.
 				// The computation takes advantage of the fact that the position
 				// of the last element's key/value equals to the total of the sizes
@@ -384,6 +387,7 @@ func (b *Bucket) Stats() BucketStats {
 				lastElement := p.leafPageElement(p.count - 1)
 				used += int(lastElement.pos + lastElement.ksize + lastElement.vsize)
 			}
+
 			if b.root == 0 {
 				// For inlined bucket just update the inline stats
 				s.InlineBucketInuse += used
@@ -408,9 +412,11 @@ func (b *Bucket) Stats() BucketStats {
 		} else if (p.flags & branchPageFlag) != 0 {
 			s.BranchPageN++
 			lastElement := p.branchPageElement(p.count - 1)
+
 			// used totals the used bytes for the page
 			// Add header and all element headers.
 			used := pageHeaderSize + (branchPageElementSize * int(p.count-1))
+
 			// Add size of all keys and values.
 			// Again, use the fact that last element's position equals to
 			// the total of key, value sizes of all previous elements.
@@ -418,11 +424,13 @@ func (b *Bucket) Stats() BucketStats {
 			s.BranchInuse += used
 			s.BranchOverflowN += int(p.overflow)
 		}
+
 		// Keep track of maximum page depth.
 		if depth+1 > s.Depth {
 			s.Depth = (depth + 1)
 		}
 	})
+
 	// Alloc stats can be computed from page counts and pageSize.
 	s.BranchAlloc = (s.BranchPageN + s.BranchOverflowN) * pageSize
 	s.LeafAlloc = (s.LeafPageN + s.LeafOverflowN) * pageSize
@@ -568,7 +576,7 @@ func (b *Bucket) maxInlineBucketSize() int {
 func (b *Bucket) write() []byte {
 	// Allocate the appropriate size.
 	var n = b.rootNode
-	var value = make([]byte, bucketHeaderSize+pageHeaderSize+n.size())
+	var value = make([]byte, bucketHeaderSize+n.size())
 
 	// Write a bucket header.
 	var bucket = (*bucket)(unsafe.Pointer(&value[0]))

bucket_test.go

@@ -566,7 +566,7 @@ func TestBucket_Stats(t *testing.T) {
 			b, err := tx.CreateBucket([]byte("woojits"))
 			assert.NoError(t, err)
 			for i := 0; i < 500; i++ {
-				b.Put([]byte(strconv.Itoa(i)), []byte(strconv.Itoa(i)))
+				b.Put([]byte(fmt.Sprintf("%03d", i)), []byte(strconv.Itoa(i)))
 			}
 			b.Put(big_key, []byte(strings.Repeat("*", 10000)))
 
@@ -582,15 +582,24 @@ func TestBucket_Stats(t *testing.T) {
 			assert.Equal(t, 2, stats.LeafOverflowN, "LeafOverflowN")
 			assert.Equal(t, 501, stats.KeyN, "KeyN")
 			assert.Equal(t, 2, stats.Depth, "Depth")
-			assert.Equal(t, 125, stats.BranchInuse, "BranchInuse")
-			used := pageHeaderSize + 501*leafPageElementSize
-			used += 10*2 + 90*4 + 400*6 + len(big_key) + 10000
-			assert.Equal(t, used, stats.LeafInuse, "LeafInuse")
+
+			branchInuse := pageHeaderSize            // branch page header
+			branchInuse += 6 * branchPageElementSize // branch elements
+			branchInuse += 6 * 3                     // branch keys (6 3-byte keys)
+			assert.Equal(t, branchInuse, stats.BranchInuse, "BranchInuse")
+
+			leafInuse := 6 * pageHeaderSize          // leaf page header
+			leafInuse += 501 * leafPageElementSize   // leaf elements
+			leafInuse += 500*3 + len(big_key)        // leaf keys
+			leafInuse += 1*10 + 2*90 + 3*400 + 10000 // leaf values
+			assert.Equal(t, leafInuse, stats.LeafInuse, "LeafInuse")
+
 			if os.Getpagesize() == 4096 {
 				// Incompatible page size
 				assert.Equal(t, 4096, stats.BranchAlloc, "BranchAlloc")
 				assert.Equal(t, 32768, stats.LeafAlloc, "LeafAlloc")
 			}
+
 			assert.Equal(t, 1, stats.BucketN, "BucketN")
 			assert.Equal(t, 0, stats.InlineBucketN, "InlineBucketN")
 			assert.Equal(t, 0, stats.InlineBucketInuse, "InlineBucketInuse")
@@ -672,13 +681,12 @@ func TestBucket_Stats_EmptyBucket(t *testing.T) {
 
 // Ensure a bucket can calculate stats.
 func TestBucket_Stats_Nested(t *testing.T) {
-
 	withOpenDB(func(db *DB, path string) {
 		db.Update(func(tx *Tx) error {
 			b, err := tx.CreateBucket([]byte("foo"))
 			assert.NoError(t, err)
 			for i := 0; i < 100; i++ {
-				b.Put([]byte(strconv.Itoa(i)), []byte(strconv.Itoa(i)))
+				b.Put([]byte(fmt.Sprintf("%02d", i)), []byte(fmt.Sprintf("%02d", i)))
 			}
 			bar, err := b.CreateBucket([]byte("bar"))
 			assert.NoError(t, err)
@@ -692,7 +700,9 @@ func TestBucket_Stats_Nested(t *testing.T) {
 			}
 			return nil
 		})
+
 		mustCheck(db)
+
 		db.View(func(tx *Tx) error {
 			b := tx.Bucket([]byte("foo"))
 			stats := b.Stats()
@@ -703,10 +713,22 @@ 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")
-			baz := pageHeaderSize + 10*leafPageElementSize + 10*2
-			foo := pageHeaderSize + 101*leafPageElementSize + 10*2 + 90*4 + 3 + bucketHeaderSize
-			bar := pageHeaderSize + 11*leafPageElementSize + 10*2 + 3 + bucketHeaderSize + baz
-			assert.Equal(t, foo+bar, stats.LeafInuse, "LeafInuse")
+
+			foo := pageHeaderSize            // foo
+			foo += 101 * leafPageElementSize // foo leaf elements
+			foo += 100*2 + 100*2             // foo leaf key/values
+			foo += 3 + bucketHeaderSize      // foo -> bar key/value
+
+			bar := pageHeaderSize           // bar
+			bar += 11 * leafPageElementSize // bar leaf elements
+			bar += 10 + 10                  // bar leaf key/values
+			bar += 3 + bucketHeaderSize     // bar -> baz key/value
+
+			baz := pageHeaderSize           // baz (inline)
+			baz += 10 * leafPageElementSize // baz leaf elements
+			baz += 10 + 10                  // baz leaf key/values
+
+			assert.Equal(t, foo+bar+baz, stats.LeafInuse, "LeafInuse")
 			if os.Getpagesize() == 4096 {
 				// Incompatible page size
 				assert.Equal(t, 0, stats.BranchAlloc, "BranchAlloc")