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package common
import (
"fmt"
"unsafe"
)
const BucketHeaderSize = int(unsafe.Sizeof(InBucket{}))
// InBucket represents the on-file representation of a bucket.
// This is stored as the "value" of a bucket key. If the bucket is small enough,
// then its root page can be stored inline in the "value", after the bucket
// header. In the case of inline buckets, the "root" will be 0.
type InBucket struct {
root Pgid // page id of the bucket's root-level page
sequence uint64 // monotonically incrementing, used by NextSequence()
}
func NewInBucket(root Pgid, seq uint64) InBucket {
return InBucket{
root: root,
sequence: seq,
}
}
func (b *InBucket) RootPage() Pgid {
return b.root
}
func (b *InBucket) SetRootPage(id Pgid) {
b.root = id
}
// InSequence returns the sequence. The reason why not naming it `Sequence`
// is to avoid duplicated name as `(*Bucket) Sequence()`
func (b *InBucket) InSequence() uint64 {
return b.sequence
}
func (b *InBucket) SetInSequence(v uint64) {
b.sequence = v
}
func (b *InBucket) IncSequence() {
b.sequence++
}
func (b *InBucket) InlinePage(v []byte) *Page {
return (*Page)(unsafe.Pointer(&v[BucketHeaderSize]))
}
func (b *InBucket) String() string {
return fmt.Sprintf("<pgid=%d,seq=%d>", b.root, b.sequence)
}
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