func (a *leaf) balanceAt(b *leaf, m int) error {
var lim int = int(a.meta.keyCount) - m
for i := 0; i < lim; i++ {
j := m + i
copy(b.val(i), a.val(j))
fmap.MemClr(a.val(j))
copy(b.key(i), a.key(j))
fmap.MemClr(a.key(j))
}
b.meta.keyCount = a.meta.keyCount - uint16(m)
a.meta.keyCount = uint16(m)
return nil
}
func (a *internal) balance(v *Varchar, b *internal) error {
if b.meta.keyCount != 0 {
return errors.Errorf("b was not empty")
}
m, err := a.balancePoint(v)
if err != nil {
return err
}
var lim int = int(a.meta.keyCount) - m
for i := 0; i < lim; i++ {
j := m + i
copy(b.key(i), a.key(j))
fmap.MemClr(a.key(j))
*b.ptr(i) = *a.ptr(j)
*a.ptr(j) = 0
}
b.meta.keyCount = a.meta.keyCount - uint16(m)
a.meta.keyCount = uint16(m)
/*
err = checkOrder(v, a)
if err != nil {
log.Println("balance point", m)
log.Println(a)
return err
}
err = checkOrder(v, b)
if err != nil {
log.Println("balance point", m)
log.Println(b)
return err
}
*/
return nil
}
func (n *leaf) delItemAt(v *Varchar, idx int) error {
// ok we have our key_idx
if idx+1 == int(n.meta.keyCount) {
// sweet we can just drop the last
// key value
n.meta.keyCount--
// zero out the old ones
fmap.MemClr(n.key(idx))
fmap.MemClr(n.val(idx))
return nil
}
chunk := int(n.meta.keyCount) - idx - 1
// drop the key
{
keys := n.keys()
keySize := int(n.meta.keySize)
chunkSize := chunk * keySize
s := idx * keySize
e := s + chunkSize
from := keys[s+keySize : e+keySize]
to := keys[s:e]
copy(to, from)
}
// drop the value
{
vals := n.vals()
valSize := int(n.meta.valSize)
chunkSize := chunk * valSize
s := idx * valSize
e := s + chunkSize
from := vals[s+valSize : e+valSize]
to := vals[s:e]
copy(to, from)
}
// do the book keeping
n.meta.keyCount--
/*
err := checkOrder(v, n)
if err != nil {
log.Println("del at", idx)
log.Println(n)
return err
}
*/
return nil
}
func (n *internal) delKeyAt(v *Varchar, i int) (err error) {
if n.meta.keyCount == 0 {
return errors.Errorf("The items slice is empty")
}
if i < 0 || i >= int(n.meta.keyCount) {
return errors.Errorf("i was not in range")
}
if n.meta.flags&consts.VARCHAR_KEYS != 0 {
k := n.key(i)
err = v.Deref(*slice.AsUint64(&k))
if err != nil {
return err
}
}
for j := i; j+1 < int(n.meta.keyCount); j++ {
copy(n.key(j), n.key(j+1))
}
// zero the old
fmap.MemClr(n.key(int(n.meta.keyCount - 1)))
return nil
}