Method Stats

bucket.go:614–697

Stats returns stats on a bucket.

()

// Stats returns stats on a bucket.
func (b *Bucket) Stats() BucketStats {
	var s, subStats BucketStats
	pageSize := b.tx.db.pageSize
	s.BucketN += 1
	if b.RootPage() == 0 {
		s.InlineBucketN += 1
	}
	b.forEachPage(func(p *common.Page, depth int, pgstack []common.Pgid) {
		if p.IsLeafPage() {
			s.KeyN += int(p.Count())

			// used totals the used bytes for the page
			used := common.PageHeaderSize

			if p.Count() != 0 {
				// If page has any elements, add all element headers.
				used += common.LeafPageElementSize * uintptr(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
				// of all previous elements' keys and values.
				// It also includes the last element's header.
				lastElement := p.LeafPageElement(p.Count() - 1)
				used += uintptr(lastElement.Pos() + lastElement.Ksize() + lastElement.Vsize())
			}

			if b.RootPage() == 0 {
				// For inlined bucket just update the inline stats
				s.InlineBucketInuse += int(used)
			} else {
				// For non-inlined bucket update all the leaf stats
				s.LeafPageN++
				s.LeafInuse += int(used)
				s.LeafOverflowN += int(p.Overflow())

				// Collect stats from sub-buckets.
				// Do that by iterating over all element headers
				// looking for the ones with the bucketLeafFlag.
				for i := uint16(0); i < p.Count(); i++ {
					e := p.LeafPageElement(i)
					if (e.Flags() & common.BucketLeafFlag) != 0 {
						// For any bucket element, open the element value
						// and recursively call Stats on the contained bucket.
						subStats.Add(b.openBucket(e.Value()).Stats())
					}
				}
			}
		} else if p.IsBranchPage() {
			s.BranchPageN++

			used := common.PageHeaderSize
			if p.Count() != 0 {
				lastElement := p.BranchPageElement(p.Count() - 1)

				// Add all element headers.
				used += common.BranchPageElementSize * uintptr(p.Count()-1)