mirror of https://github.com/etcd-io/bbolt.git
49 lines
1015 B
Go
49 lines
1015 B
Go
package bolt
|
|
|
|
import (
|
|
"unsafe"
|
|
)
|
|
|
|
const pageHeaderSize = int(unsafe.Offsetof(((*page)(nil)).ptr))
|
|
|
|
const maxAllocSize = 0xFFFFFFF
|
|
const minKeysPerPage = 2
|
|
const maxNodesPerPage = 65535
|
|
|
|
const (
|
|
p_branch = 0x01
|
|
p_leaf = 0x02
|
|
p_meta = 0x04
|
|
p_freelist = 0x08
|
|
)
|
|
|
|
type pgid uint64
|
|
|
|
type page struct {
|
|
id pgid
|
|
flags uint16
|
|
count uint16
|
|
overflow uint32
|
|
ptr uintptr
|
|
}
|
|
|
|
// meta returns a pointer to the metadata section of the page.
|
|
func (p *page) meta() *meta {
|
|
return (*meta)(unsafe.Pointer(&p.ptr))
|
|
}
|
|
|
|
// lnode retrieves the leaf node by index
|
|
func (p *page) lnode(index int) *lnode {
|
|
return &((*[maxNodesPerPage]lnode)(unsafe.Pointer(&p.ptr)))[index]
|
|
}
|
|
|
|
// bnode retrieves the branch node by index
|
|
func (p *page) bnode(index int) *bnode {
|
|
return &((*[maxNodesPerPage]bnode)(unsafe.Pointer(&p.ptr)))[index]
|
|
}
|
|
|
|
// freelist retrieves a list of page ids from a freelist page.
|
|
func (p *page) freelist() []pgid {
|
|
return ((*[maxNodesPerPage]pgid)(unsafe.Pointer(&p.ptr)))[0:p.count]
|
|
}
|