nimbus-eth1/nimbus/core/tx_pool.nim

606 lines
23 KiB
Nim
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Nimbus
# Copyright (c) 2018-2024 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed except
# according to those terms.
## TODO:
## =====
## * No uncles are handled by this pool
##
## * Impose a size limit to the bucket database. Which items would be removed?
##
## * There is a conceivable problem with the per-account optimisation. The
## algorithm chooses an account and does not stop packing until all txs
## of the account are packed or the block is full. In the latter case,
## there might be some txs left unpacked from the account which might be
## the most lucrative ones. Should this be tackled (see also next item)?
##
## * The classifier throws out all txs with negative gas tips. This implies
## that all subsequent txs must also be suspended for this account even
## though these following txs might be extraordinarily profitable so that
## packing the whole account might be woth wile. Should this be considered,
## somehow (see also previous item)?
##
##
## Transaction Pool
## ================
##
## The transaction pool collects transactions and holds them in a database.
## This database consists of the three buckets *pending*, *staged*, and
## *packed* and a *waste basket*. These database entities are discussed in
## more detail, below.
##
## At some point, there will be some transactions in the *staged* bucket.
## Upon request, the pool will pack as many of those transactions as possible
## into to *packed* bucket which will subsequently be used to generate a
## new Ethereum block.
##
## When packing transactions from *staged* into *packed* bucked, the staged
## transactions are sorted by *sender account* and *nonce*. The *sender
## account* values are ordered by a *ranking* function (highest ranking first)
## and the *nonce* values by their natural integer order. Then, transactions
## are greedily picked from the ordered set until there are enough
## transactions in the *packed* bucket. Some boundary condition applies which
## roughly says that for a given account, all the transactions packed must
## leave no gaps between nonce values when sorted.
##
## The rank function applied to the *sender account* sorting is chosen as a
## guess for higher profitability which goes with a higher rank account.
##
##
## Rank calculator
## ---------------
## Let *tx()* denote the mapping
## ::
## tx: (account,nonce) -> tx
##
## from an index pair *(account,nonce)* to a transaction *tx*. Also, for some
## external parameter *baseFee*, let
## ::
## maxProfit: (tx,baseFee) -> tx.effectiveGasTip(baseFee) * tx.gasLimit
##
## be the maximal tip a single transation can achieve (where unit of the
## *effectiveGasTip()* is a *price* and *gasLimit* is a *commodity value*.).
## Then the rank function
## ::
## rank(account) = Σ maxProfit(tx(account,ν),baseFee) / Σ tx(account,ν).gasLimit
## ν ν
##
## is a *price* estimate of the maximal avarage tip per gas unit over all
## transactions for the given account. The nonces `ν` for the summation
## run over all transactions from the *staged* and *packed* bucket.
##
##
##
##
## Pool database:
## --------------
## ::
## <Transactions> . <Status buckets> . <Terminal state>
## . .
## . . +----------+
## add() ----+---------------------------------> | |
## | . +-----------+ . | disposed |
## +-----------> | pending | ------> | |
## . +-----------+ . | |
## . | ^ ^ . | waste |
## . v | | . | basket |
## . +----------+ | . | |
## . | staged | | . | |
## . +----------+ | . | |
## . | | ^ | . | |
## . | v | | . | |
## . | +----------+ . | |
## . | | packed | -------> | |
## . | +----------+ . | |
## . +----------------------> | |
## . . +----------+
##
## The three columns *Batch queue*, *State bucket*, and *Terminal state*
## represent three different accounting (or database) systems. The pool
## database is continuosly updated while new transactions are added.
## Transactions are bundled with meta data which holds the full datanbase
## state in addition to other cached information like the sender account.
##
##
## New transactions
## ----------------
## When entering the pool, new transactions are bundled with meta data and
## appended to the batch queue. These bundles are called *items* which are
## forwarded to one of the following entites:
##
## * the *staged* bucket if the transaction is valid and match some constraints
## on expected minimum mining fees (or a semblance of that for *non-PoW*
## networks)
## * the *pending* bucket if the transaction is valid but is not subject to be
## held in the *staged* bucket
## * the *waste basket* if the transaction is invalid
##
## If a valid transaction item supersedes an existing one, the existing
## item is moved to the waste basket and the new transaction replaces the
## existing one in the current bucket if the gas price of the transaction is
## at least `priceBump` per cent higher (see adjustable parameters, below.)
##
## Status buckets
## --------------
## The term *bucket* is a nickname for a set of *items* (i.e. transactions
## bundled with meta data as mentioned earlier) all labelled with the same
## `status` symbol and not marked *waste*. In particular, bucket membership
## for an item is encoded as
##
## * the `status` field indicates the particular *bucket* membership
## * the `reject` field is reset/unset and has zero-equivalent value
##
## The following boundary conditions hold for the union of all buckets:
##
## * *Unique index:*
## Let **T** be the union of all buckets and **Q** be the
## set of *(sender,nonce)* pairs derived from the items of **T**. Then
## **T** and **Q** are isomorphic, i.e. for each pair *(sender,nonce)*
## from **Q** there is exactly one item from **T**, and vice versa.
##
## * *Consecutive nonces:*
## For each *(sender0,nonce0)* of **Q**, either
## *(sender0,nonce0-1)* is in **Q** or *nonce0* is the current nonce as
## registered with the *sender account* (implied by the block chain),
##
## The *consecutive nonces* requirement involves the *sender account*
## which depends on the current state of the block chain as represented by the
## internally cached head (i.e. insertion point where a new block is to be
## appended.)
##
## The following notation describes sets of *(sender,nonce)* pairs for
## per-bucket items. It will be used for boundary conditions similar to the
## ones above.
##
## * **Pending** denotes the set of *(sender,nonce)* pairs for the
## *pending* bucket
##
## * **Staged** denotes the set of *(sender,nonce)* pairs for the
## *staged* bucket
##
## * **Packed** denotes the set of *(sender,nonce)* pairs for the
## *packed* bucket
##
## The pending bucket
## ^^^^^^^^^^^^^^^^^^
## Items in this bucket hold valid transactions that are not in any of the
## other buckets. All itmes might be promoted form here into other buckets if
## the current state of the block chain as represented by the internally cached
## head changes.
##
## The staged bucket
## ^^^^^^^^^^^^^^^^^
## Items in this bucket are ready to be added to a new block. They typycally
## imply some expected minimum reward when mined on PoW networks. Some
## boundary condition holds:
##
## * *Consecutive nonces:*
## For any *(sender0,nonce0)* pair from **Staged**, the pair
## *(sender0,nonce0-1)* is not in **Pending**.
##
## Considering the respective boundary condition on the union of buckets
## **T**, this condition here implies that a *staged* per sender nonce has a
## predecessor in the *staged* or *packed* bucket or is a nonce as registered
## with the *sender account*.
##
## The packed bucket
## ^^^^^^^^^^^^^^^^^
## All items from this bucket have been selected from the *staged* bucket, the
## transactions of which (i.e. unwrapped items) can go right away into a new
## ethernet block. How these items are selected was described at the beginning
## of this chapter. The following boundary conditions holds:
##
## * *Consecutive nonces:*
## For any *(sender0,nonce0)* pair from **Packed**, the pair
## *(sender0,nonce0-1)* is neither in **Pending**, nor in **Staged**.
##
## Considering the respective boundary condition on the union of buckets
## **T**, this condition here implies that a *packed* per-sender nonce has a
## predecessor in the very *packed* bucket or is a nonce as registered with the
## *sender account*.
##
##
## Terminal state
## --------------
## After use, items are disposed into a waste basket *FIFO* queue which has a
## maximal length. If the length is exceeded, the oldest items are deleted.
## The waste basket is used as a cache for discarded transactions that need to
## re-enter the system. Recovering from the waste basket saves the effort of
## recovering the sender account from the signature. An item is identified
## *waste* if
##
## * the `reject` field is explicitely set and has a value different
## from a zero-equivalent.
##
## So a *waste* item is clearly distinguishable from any active one as a
## member of one of the *status buckets*.
##
##
##
## Pool coding
## ===========
## A piece of code using this pool architecture could look like as follows:
## ::
## # see also unit test examples, e.g. "Block packer tests"
## var db: CoreDbRef # to be initialised
## var txs: seq[Transaction] # to be initialised
##
## proc mineThatBlock(blk: EthBlock) # external function
##
## ..
##
## var xq = TxPoolRef.new(db) # initialise tx-pool
## ..
##
## xq.add(txs) # add transactions ..
## .. # .. into the buckets
##
## let newBlock = xq.assembleBlock # fetch current mining block
##
## ..
## mineThatBlock(newBlock) ... # external mining & signing process
## ..
##
## xp.smartHead(newBlock.header) # update pool, new insertion point
##
##
## Discussion of example
## ---------------------
## In the example, transactions are processed into buckets via `add()`.
##
## The `ethBlock()` directive assembles and retrieves a new block for mining
## derived from the current pool state. It invokes the block packer which
## accumulates txs from the `pending` buscket into the `packed` bucket which
## then go into the block.
##
## Then mining and signing takes place ...
##
## After mining and signing, the view of the block chain as seen by the pool
## must be updated to be ready for a new mining process. In the best case, the
## canonical head is just moved to the currently mined block which would imply
## just to discard the contents of the *packed* bucket with some additional
## transactions from the *staged* bucket. A more general block chain state
## head update would be more complex, though.
##
## In the most complex case, the newly mined block was added to some block
## chain branch which has become an uncle to the new canonical head retrieved
## by `getCanonicalHead()`. In order to update the pool to the very state
## one would have arrived if worked on the retrieved canonical head branch
## in the first place, the directive `smartHead()` calculates the actions of
## what is needed to get just there from the locally cached head state of the
## pool. These actions are applied by `smartHead()` after the internal head
## position was moved.
##
## The *setter* behind the internal head position adjustment also caches
## updated internal parameters as base fee, state, fork, etc.
##
##
## Adjustable Parameters
## ---------------------
##
## flags
## The `flags` parameter holds a set of strategy symbols for how to process
## items and buckets.
##
## *autoUpdateBucketsDB*
## Automatically update the state buckets after running batch jobs if the
## `dirtyBuckets` flag is also set.
##
## *autoZombifyUnpacked*
## Automatically dispose *pending* or *staged* tx items that were added to
## the state buckets database at least `lifeTime` ago.
##
## lifeTime
## Txs that stay longer in one of the buckets will be moved to a waste
## basket. From there they will be eventually deleted oldest first when
## the maximum size would be exceeded.
##
## priceBump
## There can be only one transaction in the database for the same `sender`
## account and `nonce` value. When adding a transaction with the same
## (`sender`, `nonce`) pair, the new transaction will replace the current one
## if it has a gas price which is at least `priceBump` per cent higher.
##
##
## Read-Only Parameters
## --------------------
## head
## Cached block chain insertion point, not necessarily the same header as
## retrieved by the `getCanonicalHead()`. This insertion point can be
## adjusted with the `smartHead()` function.
import
std/[sequtils, tables],
./tx_pool/[tx_packer, tx_desc, tx_info, tx_item],
./tx_pool/tx_tabs,
./tx_pool/tx_tasks/[
tx_add,
tx_bucket,
tx_head,
tx_dispose],
chronicles,
eth/keys,
stew/keyed_queue,
results,
../common/common,
./chain/forked_chain,
./casper
export
TxItemRef,
TxItemStatus,
TxPoolFlags,
TxPoolRef,
TxTabsItemsCount,
results,
tx_desc.startDate,
tx_info,
tx_item.effectiveGasTip,
tx_item.info,
tx_item.itemID,
tx_item.sender,
tx_item.status,
tx_item.timeStamp,
tx_item.tx,
tx_desc.head
{.push raises: [].}
logScope:
topics = "tx-pool"
# ------------------------------------------------------------------------------
# Private functions: tasks processor
# ------------------------------------------------------------------------------
proc maintenanceProcessing(xp: TxPoolRef)
{.gcsafe,raises: [CatchableError].} =
## Tasks to be done after add/del txs processing
# Purge expired items
if autoZombifyUnpacked in xp.pFlags:
# Move transactions older than `xp.lifeTime` to the waste basket.
xp.disposeExpiredItems
# Update buckets
if autoUpdateBucketsDB in xp.pFlags:
if xp.pDirtyBuckets:
# For all items, re-calculate item status values (aka bucket labels).
# If the `force` flag is set, re-calculation is done even though the
# change flag has remained unset.
discard xp.bucketUpdateAll
xp.pDirtyBuckets = false
proc setHead(xp: TxPoolRef; val: BlockHeader)
{.gcsafe,raises: [CatchableError].} =
## Update cached block chain insertion point. This will also update the
## internally cached `baseFee` (depends on the block chain state.)
if xp.head != val:
xp.head = val # calculates the new baseFee
xp.txDB.baseFee = xp.baseFee
xp.pDirtyBuckets = true
xp.bucketFlushPacked
# ------------------------------------------------------------------------------
# Public constructor/destructor
# ------------------------------------------------------------------------------
proc new*(T: type TxPoolRef; com: CommonRef): T
{.gcsafe,raises: [CatchableError].} =
## Constructor, returns a new tx-pool descriptor.
new result
result.init(com)
# ------------------------------------------------------------------------------
# Public functions, task manager, pool actions serialiser
# ------------------------------------------------------------------------------
# core/tx_pool.go(848): func (pool *TxPool) AddLocals(txs []..
# core/tx_pool.go(864): func (pool *TxPool) AddRemotes(txs []..
proc add*(xp: TxPoolRef; txs: openArray[PooledTransaction]; info = "")
{.gcsafe,raises: [CatchableError].} =
## Add a list of transactions to be processed and added to the buckets
## database. It is OK pass an empty list in which case some maintenance
## check can be forced.
##
## The argument Transactions `txs` may come in any order, they will be
## sorted by `<account,nonce>` before adding to the database with the
## least nonce first. For this reason, it is suggested to pass transactions
## in larger groups. Calling single transaction jobs, they must strictly be
## passed *smaller nonce* before *larger nonce*.
xp.pDoubleCheckAdd xp.addTxs(txs, info).topItems
xp.maintenanceProcessing
# core/tx_pool.go(854): func (pool *TxPool) AddLocals(txs []..
# core/tx_pool.go(883): func (pool *TxPool) AddRemotes(txs []..
proc add*(xp: TxPoolRef; tx: PooledTransaction; info = "")
{.gcsafe,raises: [CatchableError].} =
## Variant of `add()` for a single transaction.
xp.add(@[tx], info)
proc smartHead*(xp: TxPoolRef; pos: BlockHeader, chain: ForkedChainRef): bool
{.gcsafe,raises: [CatchableError].} =
## This function moves the internal head cache (i.e. tx insertion point,
## vmState) and ponts it to a now block on the chain.
##
## it calculates the
## txs that need to be added or deleted after moving the insertion point
## head so that the tx-pool will not fail to re-insert quered txs that are
## on the chain, already. Neither will it loose any txs. After updating the
## the internal head cache, the previously calculated actions will be
## applied.
##
let rcDiff = xp.headDiff(pos, chain)
if rcDiff.isOk:
let changes = rcDiff.value
# Need to move head before adding txs which may rightly be rejected in
# `addTxs()` otherwise.
xp.setHead(pos)
# Delete already *mined* transactions
if 0 < changes.remTxs.len:
debug "queuing delta txs",
mode = "remove",
num = changes.remTxs.len
xp.disposeById(toSeq(changes.remTxs.keys), txInfoChainHeadUpdate)
xp.maintenanceProcessing
return true
# ------------------------------------------------------------------------------
# Public functions, getters
# ------------------------------------------------------------------------------
func com*(xp: TxPoolRef): CommonRef =
## Getter
xp.vmState.com
type EthBlockAndBlobsBundle* = object
blk*: EthBlock
blobsBundle*: Opt[BlobsBundle]
blockValue*: UInt256
proc assembleBlock*(
xp: TxPoolRef,
someBaseFee: bool = false
): Result[EthBlockAndBlobsBundle, string] {.gcsafe,raises: [CatchableError].} =
## Getter, retrieves a packed block ready for mining and signing depending
## on the internally cached block chain head, the txs in the pool and some
## tuning parameters. The following block header fields are left
## uninitialised:
##
## * *extraData*: Blob
## * *mixHash*: Hash256
## * *nonce*: BlockNonce
##
## Note that this getter runs *ad hoc* all the txs through the VM in
## order to build the block.
let pst = xp.packerVmExec().valueOr: # updates vmState
return err(error)
var blk = EthBlock(
header: pst.assembleHeader # uses updated vmState
)
var blobsBundle: BlobsBundle
for _, nonceList in xp.txDB.packingOrderAccounts(txItemPacked):
for item in nonceList.incNonce:
let tx = item.pooledTx
blk.txs.add tx.tx
if tx.networkPayload != nil:
for k in tx.networkPayload.commitments:
blobsBundle.commitments.add k
for p in tx.networkPayload.proofs:
blobsBundle.proofs.add p
for blob in tx.networkPayload.blobs:
blobsBundle.blobs.add blob
let com = xp.vmState.com
if com.isShanghaiOrLater(blk.header.timestamp):
blk.withdrawals = Opt.some(com.pos.withdrawals)
if not com.isCancunOrLater(blk.header.timestamp) and blobsBundle.commitments.len > 0:
return err("PooledTransaction contains blobs prior to Cancun")
let blobsBundleOpt =
if com.isCancunOrLater(blk.header.timestamp):
doAssert blobsBundle.commitments.len == blobsBundle.blobs.len
doAssert blobsBundle.proofs.len == blobsBundle.blobs.len
Opt.some blobsBundle
else:
Opt.none BlobsBundle
if someBaseFee:
# make sure baseFee always has something
blk.header.baseFeePerGas = Opt.some(blk.header.baseFeePerGas.get(0.u256))
ok EthBlockAndBlobsBundle(
blk: blk,
blobsBundle: blobsBundleOpt,
blockValue: pst.blockValue)
# core/tx_pool.go(474): func (pool SetGasPrice,*TxPool) Stats() (int, int) {
# core/tx_pool.go(1728): func (t *txLookup) Count() int {
# core/tx_pool.go(1737): func (t *txLookup) LocalCount() int {
# core/tx_pool.go(1745): func (t *txLookup) RemoteCount() int {
func nItems*(xp: TxPoolRef): TxTabsItemsCount =
## Getter, retrieves the current number of items per bucket and
## some totals.
xp.txDB.nItems
# ------------------------------------------------------------------------------
# Public functions, per-tx-item operations
# ------------------------------------------------------------------------------
# core/tx_pool.go(979): func (pool *TxPool) Get(hash common.Hash) ..
# core/tx_pool.go(985): func (pool *TxPool) Has(hash common.Hash) bool {
func getItem*(xp: TxPoolRef; hash: Hash256): Result[TxItemRef,void] =
## Returns a transaction if it is contained in the pool.
xp.txDB.byItemID.eq(hash)
func disposeItems*(xp: TxPoolRef; item: TxItemRef;
reason = txInfoExplicitDisposal;
otherReason = txInfoImpliedDisposal): int
{.discardable,gcsafe,raises: [CatchableError].} =
## Move item to wastebasket. All items for the same sender with nonces
## greater than the current one are deleted, as well. The function returns
## the number of items eventally removed.
xp.disposeItemAndHigherNonces(item, reason, otherReason)
iterator txHashes*(xp: TxPoolRef): Hash256 =
for txHash in nextKeys(xp.txDB.byItemID):
yield txHash
iterator okPairs*(xp: TxPoolRef): (Hash256, TxItemRef) =
for x in nextPairs(xp.txDB.byItemID):
if x.data.reject == txInfoOk:
yield (x.key, x.data)
func numTxs*(xp: TxPoolRef): int =
xp.txDB.byItemID.len
func disposeAll*(xp: TxPoolRef) {.raises: [CatchableError].} =
let numTx = xp.numTxs
var list = newSeqOfCap[TxItemRef](numTx)
for x in nextPairs(xp.txDB.byItemID):
list.add x.data
for x in list:
xp.disposeItems(x)
# ------------------------------------------------------------------------------
# Public functions, local/remote accounts
# ------------------------------------------------------------------------------
func inPoolAndOk*(xp: TxPoolRef; txHash: Hash256): bool =
let res = xp.getItem(txHash)
if res.isErr: return false
res.get().reject == txInfoOk
func inPoolAndReason*(xp: TxPoolRef; txHash: Hash256): Result[void, string] =
let res = xp.getItem(txHash)
if res.isErr:
# try to look in rejecteds
let r = xp.txDB.byRejects.eq(txHash)
if r.isErr:
return err("cannot find tx in txpool")
else:
return err(r.get().rejectInfo)
let item = res.get()
if item.reject == txInfoOk:
return ok()
else:
return err(item.rejectInfo)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------