mempool

README

mempool

[] (https://travis-ci.org/btcsuite/btcd) ![ISC License] (http://img.shields.io/badge/license-ISC-blue.svg) [] (http://godoc.org/github.com/adiabat/btcd/mempool)

Overview

This package is currently a work in progress.

Installation and Updating

$ go get -u github.com/adiabat/btcd/mempool

License

Package mempool is licensed under the copyfree ISC License.

Documentation

Index

• Constants
• func CalcPriority(tx *wire.MsgTx, utxoView *blockchain.UtxoViewpoint, nextBlockHeight int32) float64
• func DisableLog()
• func ErrToRejectErr(err error) (wire.RejectCode, string)
• func UseLogger(logger btclog.Logger)
• type Config
• type Policy
• type RuleError
  • func (e RuleError) Error() string
• type TxDesc
• type TxPool
  • func New(cfg *Config) *TxPool
  • func (mp *TxPool) Count() int
  • func (mp *TxPool) FetchTransaction(txHash *chainhash.Hash) (*btcutil.Tx, error)
  • func (mp *TxPool) HaveTransaction(hash *chainhash.Hash) bool
  • func (mp *TxPool) IsOrphanInPool(hash *chainhash.Hash) bool
  • func (mp *TxPool) IsTransactionInPool(hash *chainhash.Hash) bool
  • func (mp *TxPool) LastUpdated() time.Time
  • func (mp *TxPool) MaybeAcceptTransaction(tx *btcutil.Tx, isNew, rateLimit bool) ([]*chainhash.Hash, error)
  • func (mp *TxPool) MiningDescs() []*mining.TxDesc
  • func (mp *TxPool) ProcessOrphans(hash *chainhash.Hash) []*btcutil.Tx
  • func (mp *TxPool) ProcessTransaction(tx *btcutil.Tx, allowOrphan, rateLimit bool) ([]*btcutil.Tx, error)
  • func (mp *TxPool) RawMempoolVerbose() map[string]*btcjson.GetRawMempoolVerboseResult
  • func (mp *TxPool) RemoveDoubleSpends(tx *btcutil.Tx)
  • func (mp *TxPool) RemoveOrphan(txHash *chainhash.Hash)
  • func (mp *TxPool) RemoveTransaction(tx *btcutil.Tx, removeRedeemers bool)
  • func (mp *TxPool) TxDescs() []*TxDesc
  • func (mp *TxPool) TxHashes() []*chainhash.Hash
• type TxRuleError
  • func (e TxRuleError) Error() string

Constants

const (
	// DefaultBlockPrioritySize is the default size in bytes for high-
	// priority / low-fee transactions.  It is used to help determine which
	// are allowed into the mempool and consequently affects their relay and
	// inclusion when generating block templates.
	DefaultBlockPrioritySize = 50000

	// MinHighPriority is the minimum priority value that allows a
	// transaction to be considered high priority.
	MinHighPriority = btcutil.SatoshiPerBitcoin * 144.0 / 250
)

const (

	// DefaultMinRelayTxFee is the minimum fee in satoshi that is required
	// for a transaction to be treated as free for relay and mining
	// purposes.  It is also used to help determine if a transaction is
	// considered dust and as a base for calculating minimum required fees
	// for larger transactions.  This value is in Satoshi/1000 bytes.
	DefaultMinRelayTxFee = btcutil.Amount(1000)
)

Functions

func CalcPriority

func CalcPriority(tx *wire.MsgTx, utxoView *blockchain.UtxoViewpoint, nextBlockHeight int32) float64

CalcPriority returns a transaction priority given a transaction and the sum of each of its input values multiplied by their age (# of confirmations). Thus, the final formula for the priority is: sum(inputValue * inputAge) / adjustedTxSize

func DisableLog

func DisableLog()

DisableLog disables all library log output. Logging output is disabled by default until either UseLogger or SetLogWriter are called.

func ErrToRejectErr

func ErrToRejectErr(err error) (wire.RejectCode, string)

ErrToRejectErr examines the underlying type of the error and returns a reject code and string appropriate to be sent in a wire.MsgReject message.

func UseLogger

func UseLogger(logger btclog.Logger)

UseLogger uses a specified Logger to output package logging info. This should be used in preference to SetLogWriter if the caller is also using btclog.

Types

type Config

type Config struct {
	// Policy defines the various mempool configuration options related
	// to policy.
	Policy Policy

	// ChainParams identifies which chain parameters the txpool is
	// associated with.
	ChainParams *chaincfg.Params

	// FetchUtxoView defines the function to use to fetch unspent
	// transaction output information.
	FetchUtxoView func(*btcutil.Tx) (*blockchain.UtxoViewpoint, error)

	// BestHeight defines the function to use to access the block height of
	// the current best chain.
	BestHeight func() int32

	// SigCache defines a signature cache to use.
	SigCache *txscript.SigCache

	// HashCache defines the transaction hash mid-state cache to use.
	HashCache *txscript.HashCache

	// TimeSource defines the timesource to use.
	TimeSource blockchain.MedianTimeSource

	// AddrIndex defines the optional address index instance to use for
	// indexing the unconfirmed transactions in the memory pool.
	// This can be nil if the address index is not enabled.
	AddrIndex *indexers.AddrIndex
}

Config is a descriptor containing the memory pool configuration.

type Policy

type Policy struct {
	// DisableRelayPriority defines whether to relay free or low-fee
	// transactions that do not have enough priority to be relayed.
	DisableRelayPriority bool

	// RelayNonStd defines whether to relay non-standard transactions. If
	// true, non-standard transactions will be accepted into the mempool
	// and relayed. Otherwise, all non-standard transactions will be
	// rejected.
	RelayNonStd bool

	// FreeTxRelayLimit defines the given amount in thousands of bytes
	// per minute that transactions with no fee are rate limited to.
	FreeTxRelayLimit float64

	// MaxOrphanTxs is the maximum number of orphan transactions
	// that can be queued.
	MaxOrphanTxs int

	// MaxOrphanTxSize is the maximum size allowed for orphan transactions.
	// This helps prevent memory exhaustion attacks from sending a lot of
	// of big orphans.
	MaxOrphanTxSize int

	// MaxSigOpCostPerTx is the cumulative maximum cost of all the signature
	// operations in a single transaction we will relay or mine.  It is a
	// fraction of the max signature operations for a block.
	MaxSigOpCostPerTx int

	// MinRelayTxFee defines the minimum transaction fee in BTC/kB to be
	// considered a non-zero fee.
	MinRelayTxFee btcutil.Amount
}

Policy houses the policy (configuration parameters) which is used to control the mempool.

type RuleError

type RuleError struct {
	Err error
}

RuleError identifies a rule violation. It is used to indicate that processing of a transaction failed due to one of the many validation rules. The caller can use type assertions to determine if a failure was specifically due to a rule violation and use the Err field to access the underlying error, which will be either a TxRuleError or a blockchain.RuleError.

func (RuleError) Error

func (e RuleError) Error() string

Error satisfies the error interface and prints human-readable errors.

type TxDesc

type TxDesc struct {
	mining.TxDesc

	// StartingPriority is the priority of the transaction when it was added
	// to the pool.
	StartingPriority float64
}

TxDesc is a descriptor containing a transaction in the mempool along with additional metadata.

type TxPool

type TxPool struct {
	// contains filtered or unexported fields
}

TxPool is used as a source of transactions that need to be mined into blocks and relayed to other peers. It is safe for concurrent access from multiple peers.

func New

func New(cfg *Config) *TxPool

New returns a new memory pool for validating and storing standalone transactions until they are mined into a block.

func (*TxPool) Count

func (mp *TxPool) Count() int

Count returns the number of transactions in the main pool. It does not include the orphan pool.

This function is safe for concurrent access.

func (*TxPool) FetchTransaction

func (mp *TxPool) FetchTransaction(txHash *chainhash.Hash) (*btcutil.Tx, error)

FetchTransaction returns the requested transaction from the transaction pool. This only fetches from the main transaction pool and does not include orphans.

This function is safe for concurrent access.

func (*TxPool) HaveTransaction

func (mp *TxPool) HaveTransaction(hash *chainhash.Hash) bool

HaveTransaction returns whether or not the passed transaction already exists in the main pool or in the orphan pool.

This function is safe for concurrent access.

func (*TxPool) IsOrphanInPool

func (mp *TxPool) IsOrphanInPool(hash *chainhash.Hash) bool

IsOrphanInPool returns whether or not the passed transaction already exists in the orphan pool.

This function is safe for concurrent access.

func (*TxPool) IsTransactionInPool

func (mp *TxPool) IsTransactionInPool(hash *chainhash.Hash) bool

IsTransactionInPool returns whether or not the passed transaction already exists in the main pool.

This function is safe for concurrent access.

func (*TxPool) LastUpdated

func (mp *TxPool) LastUpdated() time.Time

LastUpdated returns the last time a transaction was added to or removed from the main pool. It does not include the orphan pool.

This function is safe for concurrent access.

func (*TxPool) MaybeAcceptTransaction

func (mp *TxPool) MaybeAcceptTransaction(tx *btcutil.Tx, isNew, rateLimit bool) ([]*chainhash.Hash, error)

MaybeAcceptTransaction is the main workhorse for handling insertion of new free-standing transactions into a memory pool. It includes functionality such as rejecting duplicate transactions, ensuring transactions follow all rules, detecting orphan transactions, and insertion into the memory pool.

If the transaction is an orphan (missing parent transactions), the transaction is NOT added to the orphan pool, but each unknown referenced parent is returned. Use ProcessTransaction instead if new orphans should be added to the orphan pool.

This function is safe for concurrent access.

func (*TxPool) MiningDescs

func (mp *TxPool) MiningDescs() []*mining.TxDesc

MiningDescs returns a slice of mining descriptors for all the transactions in the pool.

This is part of the mining.TxSource interface implementation and is safe for concurrent access as required by the interface contract.

func (*TxPool) ProcessOrphans

func (mp *TxPool) ProcessOrphans(hash *chainhash.Hash) []*btcutil.Tx

ProcessOrphans determines if there are any orphans which depend on the passed transaction hash (it is possible that they are no longer orphans) and potentially accepts them to the memory pool. It repeats the process for the newly accepted transactions (to detect further orphans which may no longer be orphans) until there are no more.

It returns a slice of transactions added to the mempool. A nil slice means no transactions were moved from the orphan pool to the mempool.

This function is safe for concurrent access.

func (*TxPool) ProcessTransaction

func (mp *TxPool) ProcessTransaction(tx *btcutil.Tx, allowOrphan, rateLimit bool) ([]*btcutil.Tx, error)

ProcessTransaction is the main workhorse for handling insertion of new free-standing transactions into the memory pool. It includes functionality such as rejecting duplicate transactions, ensuring transactions follow all rules, orphan transaction handling, and insertion into the memory pool.

It returns a slice of transactions added to the mempool. When the error is nil, the list will include the passed transaction itself along with any additional orphan transaactions that were added as a result of the passed one being accepted.

This function is safe for concurrent access.

func (*TxPool) RawMempoolVerbose

func (mp *TxPool) RawMempoolVerbose() map[string]*btcjson.GetRawMempoolVerboseResult

RawMempoolVerbose returns all of the entries in the mempool as a fully populated btcjson result.

This function is safe for concurrent access.

func (*TxPool) RemoveDoubleSpends

func (mp *TxPool) RemoveDoubleSpends(tx *btcutil.Tx)

RemoveDoubleSpends removes all transactions which spend outputs spent by the passed transaction from the memory pool. Removing those transactions then leads to removing all transactions which rely on them, recursively. This is necessary when a block is connected to the main chain because the block may contain transactions which were previously unknown to the memory pool.

This function is safe for concurrent access.

func (*TxPool) RemoveOrphan

func (mp *TxPool) RemoveOrphan(txHash *chainhash.Hash)

RemoveOrphan removes the passed orphan transaction from the orphan pool and previous orphan index.

This function is safe for concurrent access.

func (*TxPool) RemoveTransaction

func (mp *TxPool) RemoveTransaction(tx *btcutil.Tx, removeRedeemers bool)

RemoveTransaction removes the passed transaction from the mempool. When the removeRedeemers flag is set, any transactions that redeem outputs from the removed transaction will also be removed recursively from the mempool, as they would otherwise become orphans.

This function is safe for concurrent access.

func (*TxPool) TxDescs

func (mp *TxPool) TxDescs() []*TxDesc

TxDescs returns a slice of descriptors for all the transactions in the pool. The descriptors are to be treated as read only.

This function is safe for concurrent access.

func (*TxPool) TxHashes

func (mp *TxPool) TxHashes() []*chainhash.Hash

TxHashes returns a slice of hashes for all of the transactions in the memory pool.

This function is safe for concurrent access.

type TxRuleError

type TxRuleError struct {
	RejectCode  wire.RejectCode // The code to send with reject messages
	Description string          // Human readable description of the issue
}

TxRuleError identifies a rule violation. It is used to indicate that processing of a transaction failed due to one of the many validation rules. The caller can use type assertions to determine if a failure was specifically due to a rule violation and access the ErrorCode field to ascertain the specific reason for the rule violation.

func (TxRuleError) Error

func (e TxRuleError) Error() string

Error satisfies the error interface and prints human-readable errors.