// AbsorbTx absorbs money into wallet from a tx
func (t *TxStore) AbsorbTx(tx *wire.MsgTx) error {
	if tx == nil {
		return fmt.Errorf("Tried to add nil tx")
	}
	var hits uint32
	var acq int64
	// check if any of the tx's outputs match my adrs
	for i, out := range tx.TxOut { // in each output of tx
		for _, a := range t.Adrs { // compare to each adr we have
			// more correct would be to check for full script
			// contains could have false positive? (p2sh/p2pkh same hash ..?)
			if bytes.Contains(out.PkScript, a.ScriptAddress()) { // hit
				hits++
				acq += out.Value
				var newu Utxo
				newu.KeyIdx = a.KeyIdx
				newu.Txo = *out

				var newop wire.OutPoint
				newop.Hash = tx.TxSha()
				newop.Index = uint32(i)
				newu.Op = newop

				t.Utxos = append(t.Utxos, newu)
				break
			}
		}
	}
	log.Printf("%d hits, acquired %d", hits, acq)
	t.Sum += acq
	return nil
}

func readCanonicalOutPoint(k []byte, op *wire.OutPoint) error {
	if len(k) < 36 {
		str := "short canonical outpoint"
		return storeError(ErrData, str, nil)
	}
	copy(op.Hash[:], k)
	op.Index = byteOrder.Uint32(k[32:36])
	return nil
}

// removeOrphan is the internal function which implements the public
// RemoveOrphan.  See the comment for RemoveOrphan for more details.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *TxPool) removeOrphan(tx *btcutil.Tx, removeRedeemers bool) {
	// Nothing to do if passed tx is not an orphan.
	txHash := tx.Hash()
	otx, exists := mp.orphans[*txHash]
	if !exists {
		return
	}

	// Remove the reference from the previous orphan index.
	for _, txIn := range otx.tx.MsgTx().TxIn {
		orphans, exists := mp.orphansByPrev[txIn.PreviousOutPoint]
		if exists {
			delete(orphans, *txHash)

			// Remove the map entry altogether if there are no
			// longer any orphans which depend on it.
			if len(orphans) == 0 {
				delete(mp.orphansByPrev, txIn.PreviousOutPoint)
			}
		}
	}

	// Remove any orphans that redeem outputs from this one if requested.
	if removeRedeemers {
		prevOut := wire.OutPoint{Hash: *txHash}
		for txOutIdx := range tx.MsgTx().TxOut {
			prevOut.Index = uint32(txOutIdx)
			for _, orphan := range mp.orphansByPrev[prevOut] {
				mp.removeOrphan(orphan, true)
			}
		}
	}

	// Remove the transaction from the orphan pool.
	delete(mp.orphans, *txHash)
}

// processOrphans is the internal function which implements the public
// ProcessOrphans.  See the comment for ProcessOrphans for more details.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *TxPool) processOrphans(acceptedTx *btcutil.Tx) []*TxDesc {
	var acceptedTxns []*TxDesc

	// Start with processing at least the passed transaction.
	processList := list.New()
	processList.PushBack(acceptedTx)
	for processList.Len() > 0 {
		// Pop the transaction to process from the front of the list.
		firstElement := processList.Remove(processList.Front())
		processItem := firstElement.(*btcutil.Tx)

		prevOut := wire.OutPoint{Hash: *processItem.Hash()}
		for txOutIdx := range processItem.MsgTx().TxOut {
			// Look up all orphans that redeem the output that is
			// now available.  This will typically only be one, but
			// it could be multiple if the orphan pool contains
			// double spends.  While it may seem odd that the orphan
			// pool would allow this since there can only possibly
			// ultimately be a single redeemer, it's important to
			// track it this way to prevent malicious actors from
			// being able to purposely constructing orphans that
			// would otherwise make outputs unspendable.
			//
			// Skip to the next available output if there are none.
			prevOut.Index = uint32(txOutIdx)
			orphans, exists := mp.orphansByPrev[prevOut]
			if !exists {
				continue
			}

			// Potentially accept an orphan into the tx pool.
			for _, tx := range orphans {
				missing, txD, err := mp.maybeAcceptTransaction(
					tx, true, true, false)
				if err != nil {
					// The orphan is now invalid, so there
					// is no way any other orphans which
					// redeem any of its outputs can be
					// accepted.  Remove them.
					mp.removeOrphan(tx, true)
					break
				}

				// Transaction is still an orphan.  Try the next
				// orphan which redeems this output.
				if len(missing) > 0 {
					continue
				}

				// Transaction was accepted into the main pool.
				//
				// Add it to the list of accepted transactions
				// that are no longer orphans, remove it from
				// the orphan pool, and add it to the list of
				// transactions to process so any orphans that
				// depend on it are handled too.
				acceptedTxns = append(acceptedTxns, txD)
				mp.removeOrphan(tx, false)
				processList.PushBack(tx)

				// Only one transaction for this outpoint can be
				// accepted, so the rest are now double spends
				// and are removed later.
				break
			}
		}
	}

	// Recursively remove any orphans that also redeem any outputs redeemed
	// by the accepted transactions since those are now definitive double
	// spends.
	mp.removeOrphanDoubleSpends(acceptedTx)
	for _, txD := range acceptedTxns {
		mp.removeOrphanDoubleSpends(txD.Tx)
	}

	return acceptedTxns
}

func (s *Store) rollback(ns walletdb.Bucket, height int32) error {
	minedBalance, err := fetchMinedBalance(ns)
	if err != nil {
		return err
	}

	// Keep track of all credits that were removed from coinbase
	// transactions.  After detaching all blocks, if any transaction record
	// exists in unmined that spends these outputs, remove them and their
	// spend chains.
	//
	// It is necessary to keep these in memory and fix the unmined
	// transactions later since blocks are removed in increasing order.
	var coinBaseCredits []wire.OutPoint

	it := makeBlockIterator(ns, height)
	for it.next() {
		b := &it.elem

		log.Infof("Rolling back %d transactions from block %v height %d",
			len(b.transactions), b.Hash, b.Height)

		for i := range b.transactions {
			txHash := &b.transactions[i]

			recKey := keyTxRecord(txHash, &b.Block)
			recVal := existsRawTxRecord(ns, recKey)
			var rec TxRecord
			err = readRawTxRecord(txHash, recVal, &rec)
			if err != nil {
				return err
			}

			err = deleteTxRecord(ns, txHash, &b.Block)
			if err != nil {
				return err
			}

			// Handle coinbase transactions specially since they are
			// not moved to the unconfirmed store.  A coinbase cannot
			// contain any debits, but all credits should be removed
			// and the mined balance decremented.
			if blockchain.IsCoinBaseTx(&rec.MsgTx) {
				op := wire.OutPoint{Hash: rec.Hash}
				for i, output := range rec.MsgTx.TxOut {
					k, v := existsCredit(ns, &rec.Hash,
						uint32(i), &b.Block)
					if v == nil {
						continue
					}
					op.Index = uint32(i)

					coinBaseCredits = append(coinBaseCredits, op)

					unspentKey, credKey := existsUnspent(ns, &op)
					if credKey != nil {
						minedBalance -= btcutil.Amount(output.Value)
						err = deleteRawUnspent(ns, unspentKey)
						if err != nil {
							return err
						}
					}
					err = deleteRawCredit(ns, k)
					if err != nil {
						return err
					}
				}

				continue
			}

			err = putRawUnmined(ns, txHash[:], recVal)
			if err != nil {
				return err
			}

			// For each debit recorded for this transaction, mark
			// the credit it spends as unspent (as long as it still
			// exists) and delete the debit.  The previous output is
			// recorded in the unconfirmed store for every previous
			// output, not just debits.
			for i, input := range rec.MsgTx.TxIn {
				prevOut := &input.PreviousOutPoint
				prevOutKey := canonicalOutPoint(&prevOut.Hash,
					prevOut.Index)
				err = putRawUnminedInput(ns, prevOutKey, rec.Hash[:])
				if err != nil {
					return err
				}

				// If this input is a debit, remove the debit
				// record and mark the credit that it spent as
				// unspent, incrementing the mined balance.
				debKey, credKey, err := existsDebit(ns,
					&rec.Hash, uint32(i), &b.Block)
				if err != nil {
					return err
				}
				if debKey == nil {
					continue
//.........这里部分代码省略.........

// Ingest puts a tx into the DB atomically.  This can result in a
// gain, a loss, or no result.  Gain or loss in satoshis is returned.
func (ts *TxStore) Ingest(tx *wire.MsgTx, height int32) (uint32, error) {
	var hits uint32
	var err error
	var spentOPs [][]byte
	var nUtxoBytes [][]byte

	// tx has been OK'd by SPV; check tx sanity
	utilTx := btcutil.NewTx(tx) // convert for validation
	// checks basic stuff like there are inputs and ouputs
	err = blockchain.CheckTransactionSanity(utilTx)
	if err != nil {
		return hits, err
	}
	// note that you can't check signatures; this is SPV.
	// 0 conf SPV means pretty much nothing.  Anyone can say anything.

	// before entering into db, serialize all inputs of the ingested tx
	for _, txin := range tx.TxIn {
		nOP, err := outPointToBytes(&txin.PreviousOutPoint)
		if err != nil {
			return hits, err
		}
		spentOPs = append(spentOPs, nOP)
	}
	// also generate PKscripts for all addresses (maybe keep storing these?)
	for _, adr := range ts.Adrs {
		// iterate through all our addresses
		aPKscript, err := txscript.PayToAddrScript(adr.PkhAdr)
		if err != nil {
			return hits, err
		}
		// iterate through all outputs of this tx
		for i, out := range tx.TxOut {
			if bytes.Equal(out.PkScript, aPKscript) { // new utxo for us
				var newu Utxo
				newu.AtHeight = height
				newu.KeyIdx = adr.KeyIdx
				newu.Value = out.Value
				var newop wire.OutPoint
				newop.Hash = tx.TxSha()
				newop.Index = uint32(i)
				newu.Op = newop
				b, err := newu.ToBytes()
				if err != nil {
					return hits, err
				}
				nUtxoBytes = append(nUtxoBytes, b)
				hits++
				break // only one match
			}
		}
	}

	err = ts.StateDB.Update(func(btx *bolt.Tx) error {
		// get all 4 buckets
		duf := btx.Bucket(BKTUtxos)
		//		sta := btx.Bucket(BKTState)
		old := btx.Bucket(BKTStxos)
		txns := btx.Bucket(BKTTxns)
		if duf == nil || old == nil || txns == nil {
			return fmt.Errorf("error: db not initialized")
		}

		// first see if we lose utxos
		// iterate through duffel bag and look for matches
		// this makes us lose money, which is regrettable, but we need to know.
		for _, nOP := range spentOPs {
			duf.ForEach(func(k, v []byte) error {
				if bytes.Equal(k, nOP) { // matched, we lost utxo
					// do all this just to figure out value we lost
					x := make([]byte, len(k)+len(v))
					copy(x, k)
					copy(x[len(k):], v)
					lostTxo, err := UtxoFromBytes(x)
					if err != nil {
						return err
					}
					hits++
					// then delete the utxo from duf, save to old
					err = duf.Delete(k)
					if err != nil {
						return err
					}
					// after deletion, save stxo to old bucket
					var st Stxo               // generate spent txo
					st.Utxo = lostTxo         // assign outpoint
					st.SpendHeight = height   // spent at height
					st.SpendTxid = tx.TxSha() // spent by txid
					stxb, err := st.ToBytes() // serialize
					if err != nil {
						return err
					}
					err = old.Put(k, stxb) // write k:v outpoint:stxo bytes
					if err != nil {
						return err
					}
					// store this relevant tx
					sha := tx.TxSha()
//.........这里部分代码省略.........