libnexakotlin/org.nexa.libnexakotlin/Blockchain

Blockchain

class Blockchain(val chainSelector: ChainSelector, val name: String, val net: CnxnMgr, val genesisBlockHash: Hash256, var checkpointPriorBlockId: Hash256, var checkpointId: Hash256, var checkpointHeight: Long, var checkpointWork: BigInteger, val dbPrefix: String = "blkhdr_", var fullSync: Boolean = true)

Access and track a blockchain

Parameters

chainSelector

Specify which blockchain to track.

name

You may give this blockchain a name, for logging.

net

Provide an object that manages connections to blockchain data providers (full and electrum nodes).

genesisBlockHash

Specify the genesis block hash for this blockchain

checkpointPriorBlockId

Specify the block hash of the parent of your chosen checkpoint. Use Hash256() if you are using the genesis block as your checkpoint.

checkpointId

Specify the block hash for your chosen checkpoint. A checkpoint is a block that is known to be on the main chain. The blockchain will start headers sync from this point. Some blockchain implementations (BCH) cannot rewind prior to this point to access wallet data. You may use the genesis block as your checkpoint.

checkpointHeight

Specify the block height of this checkpoint?

checkpointWork

Specify the cumulative work (NOT THE BLOCK WORK) of all prior blocks including the checkpoint block. This information is available in block explorers, or via the full node getblock RPC call.

dbPrefix

Block headers are stored in a database. Specify a prefix for DB name here (default is "blkhdr_"). The full name will be dbPrefix_name.db.

Constructors

Blockchain

constructor(chainSelector: ChainSelector, name: String, net: CnxnMgr, genesisBlockHash: Hash256, checkpointPriorBlockId: Hash256, checkpointId: Hash256, checkpointHeight: Long, checkpointWork: BigInteger, dbPrefix: String = "blkhdr_", fullSync: Boolean = true)

Properties

attachedWallets

@Volatile

var attachedWallets: Int

bloomCapacityMultiplier

var bloomCapacityMultiplier: Int

Increase this to increase the interval of time before a bloom filter needs to be refreshed. Bloom filters are modified by full nodes to automatically include information "of interest" based on current "of interest" information. For example if a tx is interesting, then its outputs will be added into the bloom filter. But the existence of false positives (and because the wallet is likely interested in only a subset of the outputs) means that the bloom filter will slowly fill up with useless information. Setting this multiplier the N will make a bloom filter that is N times your current data size meet the bloomFalsePositiveRate.

bloomFalsePositiveRate

var bloomFalsePositiveRate: Double

Change this to increase privacy at the expense of bandwidth

chainSelector

val chainSelector: ChainSelector

changeCount

@Volatile

var changeCount: Int

wake up the blockchain header processing loop

checkpointHeight

var checkpointHeight: Long

checkpointId

var checkpointId: Hash256

checkpointPriorBlockId

var checkpointPriorBlockId: Hash256

checkpointWork

var checkpointWork: BigInteger

curHeight

val curHeight: Long

lateinit var db: BlockHeaderDatabase

val dbPrefix: String

var done: Boolean

var fillingGap: Int

var filterData: MutableMap<Int, Array<Any>>

fullSync

var fullSync: Boolean

genesisBlockHash

val genesisBlockHash: Hash256

isSynced

@Volatile

var isSynced: Boolean

lastFilterHandle

var lastFilterHandle: Int

LONG_DELAY_INTERVAL

var LONG_DELAY_INTERVAL: Int

MED_DELAY_INTERVAL

var MED_DELAY_INTERVAL: Int

name

val name: String

nearTip

@Volatile

var nearTip: iBlockHeader?

net

val net: CnxnMgr

onChange

val onChange: Callbacker<Blockchain>

installable callback for when some blockchain or connection state changes

processingThread

var processingThread: iThread?

req

val req: RequestMgr

tipTieBreaker

var tipTieBreaker: Int

unAttachedHdrs

var unAttachedHdrs: MutableMap<Hash256, MutableList<out iBlockHeader>>

uriScheme

val uriScheme: String

wakey

val wakey: iGate

Functions

ancestorAtHeight

fun ancestorAtHeight(hash: Hash256, height: Long): iBlockHeader

Return the ancestor of the passed block at the passed height, or the iBlockHeader of the passed hash is the height is larger. Throws RequestedPrehistoryHeader if you go back too far.

attachWallet

fun attachWallet()

Add a wallet to start accessing the blockchain The blockchain will stop updating if no wallets are attached

blockHeader

fun blockHeader(hash: ByteArray): iBlockHeader?

fun blockHeader(hash: Hash256): iBlockHeader?

Return the header corresponding to this hash.

fun blockHeader(height: Long): iBlockHeader

Return the main chain block header at this height.

chainSummary

fun chainSummary(tip: Hash256): BlockLocator

Takes a chain tip and produces a set of blocks that on that chain that allow someone to find the approximate fork location if they are on a different tip

coGetHeaderChain

fun coGetHeaderChain(height: Long, endAt: Hash256): MutableList<iBlockHeader>

deleteAllPersistentData

fun deleteAllPersistentData()

detachWallet

fun detachWallet(filterHandle: Int?)

remove a wallet from accessing this blockchain Right now its 1 wallet per chain, so stop this chain, but keep the DB around for a new wallet

earlyRequestTxInBlock

fun earlyRequestTxInBlock(blocks: Collection<Hash256>)

finalize

fun finalize()

findAnotherTip

fun findAnotherTip()

In rare cases of a tie where one block is invalid, this will kick the wallet over to a different block.

findClosestBefore

fun findClosestBefore(epochTime: Long): iBlockHeader?

Returns the header nearest to but before the passed epoch time. If the passed epoch time is later than the tip, the tip is returned.

findOrRewindTo

fun findOrRewindTo(height: Long): iBlockHeader

getBlockHeader

fun ~~getBlockHeader~~(height: Long): iBlockHeader

getHeaderChain

fun getHeaderChain(height: Long, hash: Hash256, endAt: Hash256, maxCount: Int = Int.MAX_VALUE): MutableList<iBlockHeader>

getHeaderFromCacheDbOrNet

fun getHeaderFromCacheDbOrNet(ha: Hash256): iBlockHeader?

fun getHeaderFromCacheDbOrNet(ha: ByteArray, loadFromNet: Boolean = true): iBlockHeader?

getTip

fun getTip(): iBlockHeader?

return the cached tip or recalculate it if it is null. Returns null if the tip cannot be determined

getTxInBlock

fun getTxInBlock(blockHash: Hash256): List<iTransaction>

headerGapFiller

fun headerGapFiller(hash: Hash256)

invHandler

fun invHandler(invLst: List<Inv>, source: P2pClient?)

isInMostWorkChain

fun isInMostWorkChain(height: Long, hash: Hash256): Boolean

return true if the passed block is on the most work chain

processBlockHeaders

fun processBlockHeaders(hdrs: MutableList<out iBlockHeader>, dbdao: BlockHeaderDatabase): Boolean

Attach these headers to existing chains in our DB and commit them. The passed hdrs list are expected to be in parent->child order

reacquireHeaders

fun reacquireHeaders(height: Long, endAt: Hash256)

Download and save some headers that aren't at the end of the blockchain

recalcTip

fun recalcTip(): iBlockHeader?

Rediscover the chain tip by looking at the block header database

rediscover

fun rediscover()

Erase all previous blockchain knowledge and re-download it

restart

fun restart()

Restart block processing after stop is called

run

fun run()

setFilterObjects

fun setFilterObjects(objects: Array<Any>, handle: Int?, onBloomInstalled: () -> Unit?): Int

tell all nodes, including future connections, that we are only interested in these things. a handle to this data is returned that can be used to update or delete the data. Pass null to create a new entry This blockchain will take data from all callers, and combine them into a single Bloom filter for installation into connected full nodes.

setTestDelayIntervals

fun setTestDelayIntervals()

start

fun start()

stop

fun stop()

Stop processing incoming blocks. You may call restart to resume processing

toString

open override fun toString(): String

updateBloomFilter

fun updateBloomFilter(onBloomInstalled: () -> Unit?)

Get all filter data connected wallets have offered us, and install it into all of our connections. Once all bloom filters are installed, call the passed callback.