Transaction Ordering

[ncying]

Two ordering methods in Waves,

1. TransactionOrdering.InUTXPool (-txFee, timeStamp, txId)
2. TransactionOrdering.InBlock (-txFee, -timeStamp, txId)
   https://github.com/wavesplatform/Waves/blob/v0.7.9/src/main/scala/scorex/consensus/TransactionsOrdering.scala

in waves v0.7.9 (Aug 14, 2017), they use sort 1 first and choose 100 valid txs, then use sort 2 to package the utxs.

start from waves v0.8.0 ( Oct 13, 2017), an extra parameter (sortInBlock) added to control the sort 2.
if sortInBlock then return utxs with sort 2
else return utxs.reverse (tx +: valid is used to generate the utxs, so reverse is needed)
https://github.com/wavesplatform/Waves/blob/00c59dd68ef19d8dcfc252909295f43c86ae4d50/src/main/scala/com/wavesplatform/UtxPool.scala#L124

the sortInBlock is defined as follows:
sortInBlock = history.height() <= blockchainSettings.functionalitySettings.dontRequireSortedTransactionsAfter
https://github.com/wavesplatform/Waves/blob/00c59dd68ef19d8dcfc252909295f43c86ae4d50/src/main/scala/com/wavesplatform/mining/Miner.scala#L104
dontRequireSortedTransactionsAfter: Long = blockVersion3After
https://github.com/wavesplatform/Waves/blob/00c59dd68ef19d8dcfc252909295f43c86ae4d50/src/main/scala/com/wavesplatform/settings/BlockchainSettings.scala#L29
in waves v0.8.7 (Dec 7, 2017), this value fixed
blockVersion3AfterHeight = 795000
https://github.com/wavesplatform/Waves/blob/de7f53841e6589354062f458e5d3ecdd72c8e902/src/main/scala/com/wavesplatform/settings/BlockchainSettings.scala#L50
before that
blockVersion3AfterHeight = Long.MaxValue

from the blockVersion3, all new blocks will not use the sort 2, which means that the order of txs fixed.

a fixed transaction order can handle the blocks with reliant txs (ex. contend/release txs or smart contract txs)

[virtualeconomy]

thanks for documenting this!

[ncying]

reset the order by (feeScale, fee, timestamp, txType)