func (f *flt) setHead(h, atoms int64, fi Filer) (err error) {
switch {
case atoms < 1:
panic(atoms)
case atoms >= maxFLTRq:
b := bufs.GCache.Get(7)
defer bufs.GCache.Put(b)
if _, err = fi.WriteAt(h2b(b[:], h), 8*13+1); err != nil {
return
}
f[13].head = h
return
default:
lg := mathutil.Log2Uint16(uint16(atoms))
g := f[lg:]
for i := range f {
if atoms < g[i+1].minSize {
b := bufs.GCache.Get(7)
defer bufs.GCache.Put(b)
if _, err = fi.WriteAt(h2b(b[:], h), 8*int64(i+lg)+1); err != nil {
return
}
g[i].head = h
return
}
}
panic("internal error")
}
}
func (f *flt) head(atoms int64) (h int64) {
switch {
case atoms < 1:
panic(atoms)
case atoms >= maxFLTRq:
return f[13].head
default:
lg := mathutil.Log2Uint16(uint16(atoms))
g := f[lg:]
for i := range g {
if atoms < g[i+1].minSize {
return g[i].head
}
}
panic("internal error")
}
}
func (f *flt) find(rq int) (h int64) {
switch {
case rq < 1:
panic(rq)
case rq >= maxFLTRq:
h, f[13].head = f[13].head, 0
return
default:
g := f[mathutil.Log2Uint16(uint16(rq)):]
for i := range g {
p := &g[i]
if rq <= int(p.minSize) {
if h = p.head; h != 0 {
p.head = 0
return
}
}
}
return
}
}