Interface IBlockPolicy<T>

An interface to determine if consecutive Block<T>s are valid.

An implementation of this interface should perform all policy dependent checks, such as whether a Block<T> has the right difficulty, a Transaction<T> has the right signer, etc.

Namespace: Libplanet.Blockchain.Policies

Assembly: Libplanet.dll

Syntax

public interface IBlockPolicy<T>
    where T : IAction, new()

Type Parameters

Name	Description
T	An IAction type. It should match Block<T>'s type parameter.

Properties

BlockAction

An IAction to execute and be rendered for every block, if any.

Declaration

IAction BlockAction { get; }

Property Value

Type	Description
IAction

CanonicalChainComparer

A comparer to determine which branch is the canonical chain (i.e., best chain). The most greater one according to this comparer is considered to be the canon.

Declaration

IComparer<IBlockExcerpt> CanonicalChainComparer { get; }

Property Value

Type	Description
IComparer<IBlockExcerpt>

See Also

IBlockExcerpt

TotalDifficultyComparer

NativeTokens

A fixed set of Currency objects that are supported by the blockchain as first-class assets.

Declaration

IImmutableSet<Currency> NativeTokens { get; }

Property Value

Type	Description
IImmutableSet<Currency>

Methods

GetMaxBlockBytes(Int64)

Gets the maximum length of a Block<T> in bytes.

Declaration

long GetMaxBlockBytes(long index)

Parameters

Type	Name	Description
Int64	index	The Index of the Block<T> for which this constraint should apply.

Returns

Type	Description
Int64	The maximum length of a Block<T> in bytes to accept.

GetMaxTransactionsPerBlock(Int64)

Gets the maximum number of Transaction<T>s allowed for a valid Block<T>.

Declaration

int GetMaxTransactionsPerBlock(long index)

Parameters

Type	Name	Description
Int64	index	The Index of the Block<T> for which this constraint should apply.

Returns

Type	Description
Int32	The maximum number of Transaction<T>s allowed for a valid Block<T> can accept.

GetMaxTransactionsPerSignerPerBlock(Int64)

Gets the maximum number of Transaction<T>s allowed per signer for a valid Block<T>.

Declaration

int GetMaxTransactionsPerSignerPerBlock(long index)

Parameters

Type	Name	Description
Int64	index	The Index of the Block<T> for which this constraint should apply.

Returns

Type	Description
Int32	The maximum number of Transaction<T>s allowed per signer for a valid Block<T> can accept.

GetMinTransactionsPerBlock(Int64)

Gets the minimum number of Transaction<T>s allowed for a valid Block<T>.

Declaration

int GetMinTransactionsPerBlock(long index)

Parameters

Type	Name	Description
Int64	index	The Index of the Block<T> for which this constraint should apply.

Returns

Type	Description
Int32	The minimum number of Transaction<T>s allowed for a valid Block<T> can accept.

GetNextBlockDifficulty(BlockChain<T>)

Determines a right Difficulty for a new Block<T> to be mined right after the given blockChain.

Declaration

long GetNextBlockDifficulty(BlockChain<T> blockChain)

Parameters

Type	Name	Description
BlockChain<T>	blockChain	Consecutive Block<T>s to be followed by a new Block<T> to be mined.

Returns

Type	Description
Int64	A right Difficulty for a new Block<T> to be mined.

ValidateNextBlock(BlockChain<T>, Block<T>)

Checks if a Block<T> can be appended to the given BlockChain<T>.

Declaration

BlockPolicyViolationException ValidateNextBlock(BlockChain<T> blockChain, Block<T> nextBlock)

Parameters

Type	Name	Description
BlockChain<T>	blockChain	The target BlockChain<T> to append nextBlock.
Block<T>	nextBlock	The next block to append to blockChain.

Returns

Type	Description
BlockPolicyViolationException	A BlockPolicyViolationException with a description as to why given nextBlock is invalid, or null if nextBlock is valid.

Remarks

Note that ValidateNextBlockTx(BlockChain<T>, Transaction<T>) will be called separately from a BlockChain<T> when appending a Block<T>. Hence, to reduce redundancy, an implementation of this interface should not call ValidateNextBlockTx(BlockChain<T>, Transaction<T>).

ValidateNextBlockTx(BlockChain<T>, Transaction<T>)

Checks if a Transaction<T> can be included in a yet to be mined Block<T> that can be appended to the given BlockChain<T>.

Declaration

TxPolicyViolationException ValidateNextBlockTx(BlockChain<T> blockChain, Transaction<T> transaction)

Parameters

Type	Name	Description
BlockChain<T>	blockChain	The target BlockChain<T> to include given transaction.
Transaction<T>	transaction	The Transaction<T> to consider.

Returns

Type	Description
TxPolicyViolationException	A TxPolicyViolationException with a description as to why given transaction is invalid, or null if transaction is valid.

Remarks

This is used in two different cases:

• When selecting which Transaction<T> to include when mining a next Block<T>.
• When appending a Block<T> with transaction to a BlockChain<T>.

This is called separately from ValidateNextBlock(BlockChain<T>, Block<T>) from a BlockChain<T>.