Class Context

A state machine class of PBFT consensus algorithm. The state machine is responsible for proposing, validating, voting a block and committing the voted block to the blockchain. There are five states:

Default which is the initial state when the Start(BlockCommit, Boolean) is not called (i.e., round has not been started).
Propose, which is the state when the round has been started and waiting for the block proposal. If a validator is a proposer of the round, it will propose a block to the other validators and to itself.
PreVote, which is the state when a block proposal for a round has been received. While translating to this step, state machine votes for the block whether block is valid or not, and waiting for any +2/3 votes from other validators.
PreCommit, which is the state received any +2/3 votes in PreVote. While translating to this step, state machine votes for whether the block should be committed or not, and waiting for any +2/3 committing votes from other validators. If PreCommit receives +2/3 commit votes with NIL, starts new round Libplanet.Net.Consensus.Context.StartRound(System.Int32) and moves step to Propose.
EndCommit, which is the state represents committing vote has been received from other validators. Block will be committed to the blockchain and consensus for this height is stopped. (responsibility of next height handling is at Libplanet.Net.Consensus.Context.ConsensusContext).
In the above states, Propose, If receiving proposal fails in Libplanet.Net.Consensus.Context.TimeoutPropose(System.Int64), then step is moved to PreVote and vote NIL.
Similar to Propose, PreVote and PreCommit also wait for Libplanet.Net.Consensus.Context.TimeoutPreVote(System.Int64) or Libplanet.Net.Consensus.Context.TimeoutPreCommit(System.Int64) respectively, if +2/3 vote received but neither NIL nor Block is not +2/3. If still +2/3 vote is not received neither NIL nor Block after timeout runs out, then move to next step and vote NIL.

Validators are bonding/bonded nodes that participate in the consensus.

Inheritance

Object

Context

Implements

IDisposable

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Namespace: Libplanet.Net.Consensus

Assembly: Libplanet.Net.dll

Syntax

public class Context : IDisposable

Remarks

A Context represents a consensus of a single height and its multiple rounds.

Constructors

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Context(ConsensusContext, BlockChain, Int64, PrivateKey, ValidatorSet, ContextTimeoutOption)

Initializes a new instance of the Context class.

Declaration

public Context(ConsensusContext consensusContext, BlockChain blockChain, long height, PrivateKey privateKey, ValidatorSet validators, ContextTimeoutOption contextTimeoutOptions)

Parameters

Type	Name	Description
ConsensusContext	consensusContext	A command class for receiving ConsensusMsg from or broadcasts to other validators.
BlockChain	blockChain	A blockchain that will be committed, which will be voted by consensus, and used for proposing a block.
Int64	height	A target Height of the consensus state.
PrivateKey	privateKey	A private key for signing a block and message. Libplanet.Net.Consensus.Context.GetValue Libplanet.Net.Consensus.Context.ProcessGenericUponRules Libplanet.Net.Consensus.Context.MakeVote(System.Int32,System.Nullable{Libplanet.Blocks.BlockHash},Libplanet.Consensus.VoteFlag)
ValidatorSet	validators	The ValidatorSet for given `height`.
ContextTimeoutOption	contextTimeoutOptions	A ContextTimeoutOption for configuring a timeout for each Step.

Remarks

A Context represents a consensus of a single height and its multiple rounds.

Properties

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Height

A target height of this consensus state. This is also a block index now in consensus.

Declaration

public long Height { get; }

Property Value

Type	Description
Int64

Remarks

A Context represents a consensus of a single height and its multiple rounds.

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Round

A round represents of this consensus state.

Declaration

public int Round { get; }

Property Value

Type	Description
Int32

Remarks

A Context represents a consensus of a single height and its multiple rounds.

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Step

A step represents of this consensus state. See Context for more detail.

Declaration

public Step Step { get; }

Property Value

Type	Description
Step

Remarks

A Context represents a consensus of a single height and its multiple rounds.

Methods

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Dispose()

A state machine class of PBFT consensus algorithm. The state machine is responsible for proposing, validating, voting a block and committing the voted block to the blockchain. There are five states:

Default which is the initial state when the Start(BlockCommit, Boolean) is not called (i.e., round has not been started).
Propose, which is the state when the round has been started and waiting for the block proposal. If a validator is a proposer of the round, it will propose a block to the other validators and to itself.
PreVote, which is the state when a block proposal for a round has been received. While translating to this step, state machine votes for the block whether block is valid or not, and waiting for any +2/3 votes from other validators.
PreCommit, which is the state received any +2/3 votes in PreVote. While translating to this step, state machine votes for whether the block should be committed or not, and waiting for any +2/3 committing votes from other validators. If PreCommit receives +2/3 commit votes with NIL, starts new round Libplanet.Net.Consensus.Context.StartRound(System.Int32) and moves step to Propose.
EndCommit, which is the state represents committing vote has been received from other validators. Block will be committed to the blockchain and consensus for this height is stopped. (responsibility of next height handling is at Libplanet.Net.Consensus.Context.ConsensusContext).
In the above states, Propose, If receiving proposal fails in Libplanet.Net.Consensus.Context.TimeoutPropose(System.Int64), then step is moved to PreVote and vote NIL.
Similar to Propose, PreVote and PreCommit also wait for Libplanet.Net.Consensus.Context.TimeoutPreVote(System.Int64) or Libplanet.Net.Consensus.Context.TimeoutPreCommit(System.Int64) respectively, if +2/3 vote received but neither NIL nor Block is not +2/3. If still +2/3 vote is not received neither NIL nor Block after timeout runs out, then move to next step and vote NIL.

Validators are bonding/bonded nodes that participate in the consensus.

Declaration

public void Dispose()

Remarks

A Context represents a consensus of a single height and its multiple rounds.

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GetBlockCommit()

Returns a BlockCommit if the context is committed.

Declaration

public BlockCommit GetBlockCommit()

Returns

Type	Description
BlockCommit	Returns BlockCommit if the context is committed otherwise returns null.

Remarks

A Context represents a consensus of a single height and its multiple rounds.

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Start(BlockCommit, Boolean)

Starts round #0 of consensus for Height.

Declaration

public void Start(BlockCommit lastCommit = null, bool bootstrapping = false)

Parameters

Type	Name	Description
BlockCommit	lastCommit	A LastCommit from previous block.
Boolean	bootstrapping	A langword_csharp_bool flag indicating whether this Context should run as a bootstrapping Context or not.

Remarks

A Context represents a consensus of a single height and its multiple rounds.

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ToString()

Returns the summary of context in JSON-formatted string.

Declaration

public override string ToString()

Returns

Type	Description
String	Returns a JSON-formatted string of context state.

Overrides

Object.ToString()

Remarks

A Context represents a consensus of a single height and its multiple rounds.

Implements

System.IDisposable