1
1
mirror of https://github.com/wader/fq.git synced 2024-11-30 09:58:13 +03:00
fq/format/bitcoin/bitcoin_block.go
2023-05-01 13:19:04 +02:00

89 lines
2.0 KiB
Go

package bitcoin
// https://learnmeabitcoin.com/technical/blkdat
import (
"fmt"
"time"
"github.com/wader/fq/format"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/interp"
"github.com/wader/fq/pkg/scalar"
)
var bitcoinTranscationGroup decode.Group
func init() {
interp.RegisterFormat(
format.Bitcoin_Block,
&decode.Format{
Description: "Bitcoin block",
Dependencies: []decode.Dependency{
{Groups: []*decode.Group{format.Bitcoin_Transaction}, Out: &bitcoinTranscationGroup},
},
DecodeFn: decodeBitcoinBlock,
DefaultInArg: format.Bitcoin_Block_In{
HasHeader: false,
},
})
}
var rawHexReverse = scalar.BitBufFn(func(s scalar.BitBuf) (scalar.BitBuf, error) {
return scalar.RawSym(s, -1, func(b []byte) string {
decode.ReverseBytes(b)
return fmt.Sprintf("%x", b)
})
})
func decodeBitcoinBlock(d *decode.D) any {
var bbi format.Bitcoin_Block_In
d.ArgAs(&bbi)
size := d.BitsLeft()
if bbi.HasHeader {
magic := d.PeekUintBits(32)
switch magic {
case 0xf9beb4d9,
0x0b110907,
0xfabfb5da:
d.FieldU32("magic", scalar.UintMapSymStr{
0xf9beb4d9: "mainnet",
0x0b110907: "testnet3",
0xfabfb5da: "regtest",
}, scalar.UintHex)
size = int64(d.FieldU32LE("size")) * 8
default:
d.Fatalf("unknown magic %x", magic)
}
}
d.Endian = decode.LittleEndian
d.FramedFn(size, func(d *decode.D) {
d.FieldStruct("header", func(d *decode.D) {
d.FieldU32("version", scalar.UintHex)
d.FieldRawLen("previous_block_hash", 32*8, rawHexReverse)
d.FieldRawLen("merkle_root", 32*8, rawHexReverse)
d.FieldU32("time", scalar.UintActualUnixTime(time.RFC3339))
d.FieldU32("bits", scalar.UintHex)
d.FieldU32("nonce", scalar.UintHex)
})
// TODO: remove? support header only decode this way?
if d.BitsLeft() == 0 {
return
}
txCount := d.FieldUintFn("tx_count", decodeVarInt)
d.FieldArray("transactions", func(d *decode.D) {
for i := uint64(0); i < txCount; i++ {
d.FieldFormat("transaction", &bitcoinTranscationGroup, nil)
}
})
})
return nil
}