37cd482db3
* [DEV-75] Removed fetchEntryByHash, which was no longer used. * [DEV-75] Removed a few functions in manager.go that weren't used by anything. * [DEV-75] checkConnectBlock will soon not accept a utxoViewpoint, so removed the call to view.Tip() so that it could be deleted. * [DEV-75] Got rid of tips in UtxoViewpoint. * [DEV-75] Added the full UTXO set to the virtual block. * [DEV-75] Implemented UTXO-wrangling when adding a new block. * [DEV-75] Added isCoinbase to utxoEntry creation. * [DEV-75] Added blockHeight to utxoEntry creation. * Implemented fetching the fullUTXOSet from the database. * [DEV-75] Simplified DAGState because almost all of the state in it was unnecessary. Also got rid of dbDAGState. * [DEV-75] Made the process around adding a new block, UTXO-wise, much safer. * [DEV-75] Implemented melding the virtual UTXO diff to the database. * [DEV-75] Fixed utxoSet loading from the wrong bucket. * [DEV-75] Began pruning utxoviewpoint.go. Replaced FetchUtxoEntry with a fullUTXOSet-based GetUTXOEntry. * [DEV-75] Removed fetchUtxos. * [DEV-75] Moved GetUTXOEntry into the virtual block. * [DEV-75] Updated IndexManager to not use utxoViewpoints. * [DEV-75] Fixed some bad login in restoreUTXO involving nodeDiffs. * [DEV-75] Got rid of the UTXO spend journal, which wasn't used anywhere. * [DEV-75] Moved some STXO-related validation logic out of connectToDAG and into checkConnectBlock. * [DEV-75] Renamed UtxoXxx to UTXOXxx. Removed a bunch of methods that were no longer used by anything. * [DEV-75] Another Utxo -> UTXO rename. * [DEV-75] Removed IsModified from UTXOView, which was not used anywhere. * [DEV-75] Renamed nodeDiff to provisionalNode. Added a bunch of comments. * [DEV-75] Removed the test for genesis in pastUTXO, since it can never happen. * [DEV-75] Wrote tests for errors in pastUTXO. * [DEV-75] Wrote tests for errors in restoreUTXO. * [DEV-75] Improved testErrorThroughPatching. * [DEV-75] Wrote tests for errors in verifyAndBuildUTXO. * [DEV-75] Used TipHashes instead of tips().hashes(), fixed comments in a few places, and brought back an error return that I erroneously removed. * [DEV-75] Removed UTXO set logs. * [DEV-75] Recreated add/remove/contains functions for utxoCollection. * [DEV-75] Changed newUTXOEntry to use an object initializer. * [DEV-75] Changed the UTXO bucket version to 1. * Added a comment that clarifies that the index is not initialized before initDAGState is called. * [DEV-75] Renamed GetVirtualBlock to VirtualBlock. * [DEV-75] Removed superfluous variables. * [DEV-75] Combined connectBlockToParents with updateParentsDiffs. * [DEV-75] Removed another superfluous variable. * [DEV-75] In pastUTXO, first fetch transactions from the database and only then add them. * [DEV-75] Reworded the comment for commit(). * [DEV-75] Made all the connectUTXO subfunctions not BlockDAG methods. * [DEV-75] Updated the comment for connectUTXO. * [DEV-75] Updated the comment explaining why we're creating provisionalNodes. * [DEV-75] Removed a couple of unnecessary calls to toProvisionalNode. * [DEV-75] Renamed connectUTXO to applyUTXOChanges. * [DEV-75] Replaced allProvisionalNodes with provisionalNodeSet, an object that holds provisionalNodes for this particular call to applyUTXOChanges. * [DEV-75] Changed createProvisionalNode to accept a boolean "withParents" instead of relying on the caller to supply the node's parents or an empty set. * [DEV-75] Made most applyUTXOChanges subfunctions be methods on provisionalNode. * [DEV-75] Fixed a couple of bad comments. * [DEV-75] Added descriptive error messages to callers of applyUTXOChanges. * [DEV-75] Fixed weird English. * [DEV-75] Replaced DAGState with a slice of DAG tip hashes. * [DEV-75] In createProvisionalNode, changed withParents to withRelatives to avoid certain kinds of attacks. * [DEV-75] Renamed createdProvisionalNode to newProvisionalNode. * [DEV-75] Added precalculating the amount of transactions inside a new block's blue set. * [DEV-75] Pruned unnecessary variable.
mempool
Package mempool provides a policy-enforced pool of unmined bitcoin transactions.
A key responsbility of the bitcoin network is mining user-generated transactions into blocks. In order to facilitate this, the mining process relies on having a readily-available source of transactions to include in a block that is being solved.
At a high level, this package satisfies that requirement by providing an in-memory pool of fully validated transactions that can also optionally be further filtered based upon a configurable policy.
One of the policy configuration options controls whether or not "standard" transactions are accepted. In essence, a "standard" transaction is one that satisfies a fairly strict set of requirements that are largely intended to help provide fair use of the system to all users. It is important to note that what is considered a "standard" transaction changes over time. For some insight, at the time of this writing, an example of some of the criteria that are required for a transaction to be considered standard are that it is of the most-recently supported version, finalized, does not exceed a specific size, and only consists of specific script forms.
Since this package does not deal with other bitcoin specifics such as network communication and transaction relay, it returns a list of transactions that were accepted which gives the caller a high level of flexibility in how they want to proceed. Typically, this will involve things such as relaying the transactions to other peers on the network and notifying the mining process that new transactions are available.
This package has intentionally been designed so it can be used as a standalone package for any projects needing the ability create an in-memory pool of bitcoin transactions that are not only valid by consensus rules, but also adhere to a configurable policy.
Feature Overview
The following is a quick overview of the major features. It is not intended to be an exhaustive list.
- Maintain a pool of fully validated transactions
- Reject non-fully-spent duplicate transactions
- Reject coinbase transactions
- Reject double spends (both from the chain and other transactions in pool)
- Reject invalid transactions according to the network consensus rules
- Full script execution and validation with signature cache support
- Individual transaction query support
- Orphan transaction support (transactions that spend from unknown outputs)
- Configurable limits (see transaction acceptance policy)
- Automatic addition of orphan transactions that are no longer orphans as new transactions are added to the pool
- Individual orphan transaction query support
- Configurable transaction acceptance policy
- Option to accept or reject standard transactions
- Option to accept or reject transactions based on priority calculations
- Rate limiting of low-fee and free transactions
- Non-zero fee threshold
- Max signature operations per transaction
- Max orphan transaction size
- Max number of orphan transactions allowed
- Additional metadata tracking for each transaction
- Timestamp when the transaction was added to the pool
- Most recent block height when the transaction was added to the pool
- The fee the transaction pays
- The starting priority for the transaction
- Manual control of transaction removal
- Recursive removal of all dependent transactions
Installation and Updating
$ go get -u github.com/daglabs/btcd/mempool
License
Package mempool is licensed under the copyfree ISC License.