mirror of
https://github.com/ethereum/go-ethereum.git
synced 2026-06-12 09:51:36 +00:00
ef3217c249
The pooled hash.Hash interface forced the local [StemNodeWidth]common.Hash data array to escape to the heap: h.Sum(data[i][:0]) passes a subslice of data into an interface method, so escape analysis conservatively moves the whole array. pprof (post-rollback) showed this single allocation as 52% of total bytes (5 GB over BenchmarkCollectNodesSparseWrite). Switch to sha256.Sum256 (takes []byte, returns [32]byte by value) — no slice into data ever leaves the frame, so data stays on stack. Also drops per-Hash h.Sum(nil) allocs and the sync.Pool Get/Put round-trip for stems. Benchmark delta (M4 Pro, go1.24.0, --count=5 --benchtime=5s): before: 9095 ns/op 15008 B/op 106 allocs/op after: 9133 ns/op 6526 B/op 95 allocs/op vs upstream/master@53ff723cc: bytes/op -82.7% (was -60%), allocs/op -29.1% (was -20.9%).
102 lines
3 KiB
Go
102 lines
3 KiB
Go
// Copyright 2025 go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package bintrie
|
|
|
|
import (
|
|
"crypto/sha256"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
)
|
|
|
|
// StemNode holds up to 256 values sharing a 31-byte stem.
|
|
//
|
|
// Invariant: dirty=false implies mustRecompute=false. Every mutation that
|
|
// invalidates the cached hash MUST also mark the blob for re-flush.
|
|
type StemNode struct {
|
|
Stem [StemSize]byte
|
|
values [StemNodeWidth][]byte // nil == slot absent
|
|
|
|
depth uint8
|
|
|
|
mustRecompute bool // hash is stale (cleared by Hash)
|
|
dirty bool // on-disk blob is stale (cleared by CollectNodes)
|
|
hash common.Hash // cached hash when mustRecompute == false
|
|
}
|
|
|
|
func (sn *StemNode) getValue(suffix byte) []byte {
|
|
return sn.values[suffix]
|
|
}
|
|
|
|
func (sn *StemNode) hasValue(suffix byte) bool {
|
|
return sn.values[suffix] != nil
|
|
}
|
|
|
|
// allValues returns the underlying slot array as a slice. nil entries mean
|
|
// absent. Callers must treat it as read-only.
|
|
func (sn *StemNode) allValues() [][]byte {
|
|
return sn.values[:]
|
|
}
|
|
|
|
func (sn *StemNode) setValue(suffix byte, value []byte) {
|
|
sn.values[suffix] = value
|
|
}
|
|
|
|
func (sn *StemNode) Hash() common.Hash {
|
|
if !sn.mustRecompute {
|
|
return sn.hash
|
|
}
|
|
|
|
// Use sha256.Sum256 (returns [32]byte by value) instead of a pooled
|
|
// hash.Hash: feeding data[i][:0] into the interface method Sum forces
|
|
// data to heap (escape analysis is conservative through interfaces).
|
|
// Sum256 takes []byte and returns by value, so data stays on stack.
|
|
var data [StemNodeWidth]common.Hash
|
|
|
|
for i, v := range sn.values {
|
|
if v != nil {
|
|
data[i] = sha256.Sum256(v)
|
|
}
|
|
}
|
|
|
|
var pair [2 * HashSize]byte
|
|
for level := 1; level <= 8; level++ {
|
|
for i := range StemNodeWidth / (1 << level) {
|
|
if data[i*2] == (common.Hash{}) && data[i*2+1] == (common.Hash{}) {
|
|
data[i] = common.Hash{}
|
|
continue
|
|
}
|
|
copy(pair[:HashSize], data[i*2][:])
|
|
copy(pair[HashSize:], data[i*2+1][:])
|
|
data[i] = sha256.Sum256(pair[:])
|
|
}
|
|
}
|
|
|
|
var final [StemSize + 1 + HashSize]byte
|
|
copy(final[:StemSize], sn.Stem[:])
|
|
final[StemSize] = 0
|
|
copy(final[StemSize+1:], data[0][:])
|
|
sn.hash = sha256.Sum256(final[:])
|
|
sn.mustRecompute = false
|
|
return sn.hash
|
|
}
|
|
|
|
func (sn *StemNode) Key(i int) []byte {
|
|
var ret [HashSize]byte
|
|
copy(ret[:], sn.Stem[:])
|
|
ret[StemSize] = byte(i)
|
|
return ret[:]
|
|
}
|