jkimmel
/
sub
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

correctly precalculate the minimum free prefix length on alloc, so recalculation can be skipped for deeply nested inserts

This commit is contained in:
Johannes Kimmel 2023-11-13 23:50:26 +01:00
parent c124d3c614
commit b7216e783d
1 changed files with 15 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
ipalloc/ipalloc.go
View File

@ -112,12 +112,14 @@ func (t *tree) Alloc(bits int) *tree {
return nil
}
tofix := best
// the first insert can be into a new hi branch
if best.lo != nil {
best.hi = &tree{
prefix: SplitPrefixHi(best.prefix),
parent: best,
minfreelen: best.prefix.Bits() + 1,
minfreelen: best.prefix.Bits() + 2,
}
best = best.hi
}
@ -127,12 +129,14 @@ func (t *tree) Alloc(bits int) *tree {
best.lo = &tree{
prefix: SplitPrefixLo(best.prefix),
parent: best,
minfreelen: best.prefix.Bits() + 1,
minfreelen: best.prefix.Bits() + 2,
}
best = best.lo
}
best.fixMinFreeAll()
best.fixMinFree()
tofix.fixMinFreeAll()
return best
}
@ -142,26 +146,25 @@ func (t *tree) fixMinFree() {
}
if t.Leaf() {
t.minfreelen = t.prefix.Addr().BitLen() + 1
return
}
lofree := t.lo.calcfreelen(t)
hifree := t.hi.calcfreelen(t)
minfreelen := max(min(lofree, hifree), t.prefix.Bits()+1)
if t.minfreelen != minfreelen {
//log.Printf("lo:%v, hi:%v\n", fixfree.lo == nil, fixfree.hi == nil)
//log.Printf("Fixing space for %q, lo: %d, hi: %d, old: %d, new: %d", fixfree.prefix, lofree, hifree, fixfree.minfreelen, minfreelen)
t.minfreelen = minfreelen
}
//if t.minfreelen != minfreelen {
// log.Printf("lo:%v, hi:%v\n", t.lo == nil, t.hi == nil)
// log.Printf("Fixing space for %q, lo: %d, hi: %d, old: %d, new: %d", t.prefix, lofree, hifree, t.minfreelen, minfreelen)
//}
t.minfreelen = minfreelen
}
func (t *tree) fixMinFreeAll() {
if t == nil {
return
}
if t.Leaf() {
t.minfreelen = t.prefix.Addr().BitLen() + 1
}
fixfree := t.parent
fixfree := t
for fixfree != nil {
fixfree.fixMinFree()