TX_Output_Data

交易核心数据 + 及其上下游关键数据

看名字，它记录的是“交易”的核心数据，但实际却增加记录和此交易相关的链、区块、交易、输入、输出、签名等关键数据。

抽取交易、区块的部分数据（数据都是公开的），然后进行补充，可以方便后续使用。

产生：当把一个完整的区块加入到链的时候，就会生成它们（当前只有这一个入口）。直接存储到数据库

使用：数据格式化，提供给几个API/客户端使用。

// this structure is way blockchain sends outputs to wallet
// this structure is also used internal by blockchain itself, when TXs are expanded and verified

// this structure needs to be expandable without breaking legacy
// This structure is the only information needed by wallet to decode previous and send new txs
// This opens up the case for mobile wallets without downloading entire blockchain
// Some of the fields get duplicated if a tx has multiple vouts
type TX_Output_Data struct {
    BLID          crypto.Hash `msgpack:"L" json:"blid,omitempty"`       // the block id in which this was found, we are duplicating it for all
    TXID          crypto.Hash `msgpack:"T" json:"txid,omitempty"`       // the transaction id in which this was found, we are duplicating it for all vouts
    Tx_Public_Key crypto.Key  `msgpack:"P"  json:"publickey,omitempty"` // the public key of the tx ,  we are duplicating it for all vouts within the TX
    // this is extracted from the extra field

    // this data is consumed by the blockchain itself while expanding tx
    InKey           ringct.CtKey     `msgpack:"D"  json:"inkey,omitempty"`           // contains the vout key and encrypted commitment
    ECDHTuple       ringct.ECdhTuple `msgpack:"E" json:"ecdhtuple,omitempty"`        // encrypted Amounts, will be empty for miner tx
    SenderPk        crypto.Key       `msgpack:"K" json:"senderpk,omitempty"`         // from the outpk
    Amount          uint64           `msgpack:"A,omitempty" json:"amount,omitempty"` // amount used for miner tx
    SigType         uint64           `msgpack:"S" json:"sigtype,omitempty"`          // which ringct type the output was of
    Index_within_tx uint64           `msgpack:"W" json:"indexwithintx,omitempty"`    // output index  of vout within the tx
    Index_Global    uint64           `msgpack:"G" json:"indexglobal,omitempty"`      // position in global index
    Height          uint64           `msgpack:"H" json:"height,omitempty"`           // height to which this belongs
    Unlock_Height   uint64           `msgpack:"U" json:"unlockheight,omitempty"`     // height at which it will unlock
    TopoHeight      int64            `msgpack:"TH" json:"Topoheight,omitempty"`      // Topoheight
    Block_Time      uint64           `msgpack:"B"`                                   // when was this block found in epoch

    Key_Images []crypto.Key `msgpack:"KI,omitempty"`                           // all the key images consumed within the TX
    PaymentID  []byte       `msgpack:"I,omitempty" json:"paymentid,omitempty"` // payment ID contains both unencrypted (33byte)/encrypted (9 bytes)

    // TODO this structure must also keep payment ids and encrypted payment ids
}

和 Index_Data 关系很亲近。

区块上链后，才记录 Tx Output Data 来源有3个：挖矿交易、普通转账交易、合约里的对外转账交易。

它的总数量应该和“交易”一样。