lnd.xprv/lnwire/short_channel_id.go

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package lnwire
import (
"fmt"
)
// ShortChannelID represents the set of data which is needed to retrieve all
// necessary data to validate the channel existence.
type ShortChannelID struct {
// BlockHeight is the height of the block where funding transaction
// located.
//
// NOTE: This field is limited to 3 bytes.
BlockHeight uint32
// TxIndex is a position of funding transaction within a block.
//
// NOTE: This field is limited to 3 bytes.
TxIndex uint32
// TxPosition indicating transaction output which pays to the channel.
TxPosition uint16
}
// NewShortChanIDFromInt returns a new ShortChannelID which is the decoded
// version of the compact channel ID encoded within the uint64. The format of
// the compact channel ID is as follows: 3 bytes for the block height, 3 bytes
// for the transaction index, and 2 bytes for the output index.
func NewShortChanIDFromInt(chanID uint64) ShortChannelID {
return ShortChannelID{
BlockHeight: uint32(chanID >> 40),
TxIndex: uint32(chanID>>16) & 0xFFFFFF,
TxPosition: uint16(chanID),
}
}
// ToUint64 converts the ShortChannelID into a compact format encoded within a
// uint64 (8 bytes).
func (c ShortChannelID) ToUint64() uint64 {
// TODO(roasbeef): explicit error on overflow?
return ((uint64(c.BlockHeight) << 40) | (uint64(c.TxIndex) << 16) |
(uint64(c.TxPosition)))
}
// String generates a human-readable representation of the channel ID.
func (c ShortChannelID) String() string {
return fmt.Sprintf("%d:%d:%d", c.BlockHeight, c.TxIndex, c.TxPosition)
}