ssz: update uint256 and use 0-alloc IntoBig (#17)

* push

* remove debug

* bet

decoder.go

@@ -227,14 +227,14 @@ func DecodeUint256BigInt(dec *Decoder, n **big.Int) {
 		dec.inRead += 32
 
 		dec.bufInt.UnmarshalSSZ(dec.buf[:32])
-		*n = dec.bufInt.ToBig() // TODO(karalabe): make this alloc free (https://github.com/holiman/uint256/pull/177)
+		dec.bufInt.IntoBig(n)
 	} else {
 		if len(dec.inBuffer) < 32 {
 			dec.err = io.ErrUnexpectedEOF
 			return
 		}
 		dec.bufInt.UnmarshalSSZ(dec.inBuffer[:32])
-		*n = dec.bufInt.ToBig() // TODO(karalabe): make this alloc free (https://github.com/holiman/uint256/pull/177)
+		dec.bufInt.IntoBig(n)
 		dec.inBuffer = dec.inBuffer[32:]
 	}
 }

go.mod

@@ -4,15 +4,15 @@ go 1.21
 
 require (
 	github.com/golang/snappy v0.0.4
-	github.com/holiman/uint256 v1.3.0
+	github.com/holiman/uint256 v1.3.1
 	github.com/prysmaticlabs/go-bitfield v0.0.0-20240618144021-706c95b2dd15
 	github.com/prysmaticlabs/gohashtree v0.0.4-beta
+	golang.org/x/sync v0.7.0
 	golang.org/x/tools v0.22.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
 	github.com/klauspost/cpuid/v2 v2.0.9 // indirect
 	golang.org/x/mod v0.18.0 // indirect
-	golang.org/x/sync v0.7.0 // indirect
 )

go.sum

@@ -1,7 +1,7 @@
 github.com/golang/snappy v0.0.4 h1:yAGX7huGHXlcLOEtBnF4w7FQwA26wojNCwOYAEhLjQM=
 github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
-github.com/holiman/uint256 v1.3.0 h1:4wdcm/tnd0xXdu7iS3ruNvxkWwrb4aeBQv19ayYn8F4=
-github.com/holiman/uint256 v1.3.0/go.mod h1:EOMSn4q6Nyt9P6efbI3bueV4e1b3dGlUCXeiRV4ng7E=
+github.com/holiman/uint256 v1.3.1 h1:JfTzmih28bittyHM8z360dCjIA9dbPIBlcTI6lmctQs=
+github.com/holiman/uint256 v1.3.1/go.mod h1:EOMSn4q6Nyt9P6efbI3bueV4e1b3dGlUCXeiRV4ng7E=
 github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
 github.com/minio/sha256-simd v1.0.0 h1:v1ta+49hkWZyvaKwrQB8elexRqm6Y0aMLjCNsrYxo6g=