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fq/format/bitcoin/bitcoin_block.go

77 lines
1.8 KiB
Go

package bitcoin
// https://learnmeabitcoin.com/technical/blkdat
import (
"fmt"
"github.com/wader/fq/format"
"github.com/wader/fq/format/registry"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/scalar"
)
var bitcoinTranscationFormat decode.Group
func init() {
registry.MustRegister(decode.Format{
Name: format.BITCOIN_BLOCK,
Description: "Bitcoin block",
Dependencies: []decode.Dependency{
{Names: []string{format.BITCOIN_TRANSACTION}, Group: &bitcoinTranscationFormat},
},
DecodeFn: decodeBitcoinBlock,
})
}
var rawHexReverse = scalar.Fn(func(s scalar.S) (scalar.S, error) {
return scalar.RawSym(s, -1, func(b []byte) string {
decode.ReverseBytes(b)
return fmt.Sprintf("%x", b)
})
})
func decodeBitcoinBlock(d *decode.D, in interface{}) interface{} {
size := d.BitsLeft()
// TODO: move to blkdat but how to model it?
switch d.PeekBits(32) {
case 0xf9beb4d9,
0x0b110907,
0xfabfb5da:
d.FieldU32("magic", scalar.UToSymStr{
0xf9beb4d9: "mainnet",
0x0b110907: "testnet3",
0xfabfb5da: "regtest",
}, scalar.ActualHex)
size = int64(d.FieldU32LE("size")) * 8
}
d.Endian = decode.LittleEndian
d.FramedFn(size, func(d *decode.D) {
d.FieldStruct("header", func(d *decode.D) {
d.FieldU32("version", scalar.ActualHex)
d.FieldRawLen("previous_block_hash", 32*8, rawHexReverse)
d.FieldRawLen("merkle_root", 32*8, rawHexReverse)
d.FieldU32("time", scalar.DescriptionActualUUnixTime)
d.FieldU32("bits", scalar.ActualHex)
d.FieldU32("nonce", scalar.ActualHex)
})
// TODO: remove? support header only decode this way?
if d.BitsLeft() == 0 {
return
}
txCount := d.FieldUFn("tx_count", decodeVarInt)
d.FieldArray("transactions", func(d *decode.D) {
for i := uint64(0); i < txCount; i++ {
d.FieldFormat("transaction", bitcoinTranscationFormat, nil)
}
})
})
return nil
}