// fetchTxStoreMain fetches transaction data about the provided set of
// transactions from the point of view of the end of the main chain. It takes
// a flag which specifies whether or not fully spent transaction should be
// included in the results.
func fetchTxStoreMain(db database.Db, txSet map[wire.ShaHash]struct{}, includeSpent bool) TxStore {
// Just return an empty store now if there are no requested hashes.
txStore := make(TxStore)
if len(txSet) == 0 {
return txStore
}
// The transaction store map needs to have an entry for every requested
// transaction. By default, all the transactions are marked as missing.
// Each entry will be filled in with the appropriate data below.
txList := make([]*wire.ShaHash, 0, len(txSet))
for hash := range txSet {
hashCopy := hash
txStore[hash] = &TxData{Hash: &hashCopy, Err: database.ErrTxShaMissing}
txList = append(txList, &hashCopy)
}
// Ask the database (main chain) for the list of transactions. This
// will return the information from the point of view of the end of the
// main chain. Choose whether or not to include fully spent
// transactions depending on the passed flag.
var txReplyList []*database.TxListReply
if includeSpent {
txReplyList = db.FetchTxByShaList(txList)
} else {
txReplyList = db.FetchUnSpentTxByShaList(txList)
}
for _, txReply := range txReplyList {
// Lookup the existing results entry to modify. Skip
// this reply if there is no corresponding entry in
// the transaction store map which really should not happen, but
// be safe.
txD, ok := txStore[*txReply.Sha]
if !ok {
continue
}
// Fill in the transaction details. A copy is used here since
// there is no guarantee the returned data isn't cached and
// this code modifies the data. A bug caused by modifying the
// cached data would likely be difficult to track down and could
// cause subtle errors, so avoid the potential altogether.
txD.Err = txReply.Err
if txReply.Err == nil {
txD.Tx = btcutil.NewTx(txReply.Tx)
txD.BlockHeight = txReply.Height
txD.Spent = make([]bool, len(txReply.TxSpent))
copy(txD.Spent, txReply.TxSpent)
}
}
return txStore
}
