Documentation ¶
Index ¶
- Variables
- func SortTestBlocks(blocks []*TestBlock)
- type Block
- type Consensus
- type Factory
- type OracleBlock
- type TestBlock
- type Topological
- func (ts *Topological) Add(blk Block) error
- func (ts *Topological) Decided(blk Block) bool
- func (ts *Topological) Finalized() bool
- func (ts *Topological) HealthCheck() (interface{}, error)
- func (ts *Topological) Initialize(ctx *snow.ConsensusContext, params snowball.Parameters, rootID ids.ID, ...) error
- func (ts *Topological) IsPreferred(blk Block) bool
- func (ts *Topological) NumProcessing() int
- func (ts *Topological) Parameters() snowball.Parameters
- func (ts *Topological) Preference() ids.ID
- func (ts *Topological) Processing(blkID ids.ID) bool
- func (ts *Topological) RecordPoll(voteBag ids.Bag) error
- type TopologicalFactory
Constants ¶
This section is empty.
Variables ¶
var ErrNotOracle = errors.New("block isn't an oracle")
Functions ¶
func SortTestBlocks ¶ added in v0.8.0
func SortTestBlocks(blocks []*TestBlock)
SortTestBlocks sorts the array of blocks by height
Types ¶
type Block ¶
type Block interface { choices.Decidable // Parent returns the ID of this block's parent. Parent() ids.ID // Verify that the state transition this block would make if accepted is // valid. If the state transition is invalid, a non-nil error should be // returned. // // It is guaranteed that the Parent has been successfully verified. Verify() error // Bytes returns the binary representation of this block. // // This is used for sending blocks to peers. The bytes should be able to be // parsed into the same block on another node. Bytes() []byte // Height returns the height of this block in the chain. Height() uint64 // Time this block was proposed at. This value should be consistent across // all nodes. If this block hasn't been successfully verified, any value can // be returned. If this block is the last accepted block, the timestamp must // be returned correctly. Otherwise, accepted blocks can return any value. Timestamp() time.Time }
Block is a possible decision that dictates the next canonical block.
Blocks are guaranteed to be Verified, Accepted, and Rejected in topological order. Specifically, if Verify is called, then the parent has already been verified. If Accept is called, then the parent has already been accepted. If Reject is called, the parent has already been accepted or rejected.
If the status of the block is Unknown, ID is assumed to be able to be called. If the status of the block is Accepted or Rejected; Parent, Verify, Accept, and Reject will never be called.
type Consensus ¶
type Consensus interface { // Takes in the context, snowball parameters, and the last accepted block. Initialize( ctx *snow.ConsensusContext, params snowball.Parameters, lastAcceptedID ids.ID, lastAcceptedHeight uint64, ) error // Returns the parameters that describe this snowman instance Parameters() snowball.Parameters // Returns the number of blocks processing NumProcessing() int // Adds a new decision. Assumes the dependency has already been added. // Returns if a critical error has occurred. Add(Block) error // Decided returns true if the block has been decided. Decided(Block) bool // Processing returns true if the block ID is currently processing. Processing(ids.ID) bool // IsPreferred returns true if the block is currently on the preferred // chain. IsPreferred(Block) bool // Returns the ID of the tail of the strongly preferred sequence of // decisions. Preference() ids.ID // RecordPoll collects the results of a network poll. Assumes all decisions // have been previously added. Returns if a critical error has occurred. RecordPoll(ids.Bag) error // Finalized returns true if all decisions that have been added have been // finalized. Note, it is possible that after returning finalized, a new // decision may be added such that this instance is no longer finalized. Finalized() bool // HealthCheck returns information about the consensus health. HealthCheck() (interface{}, error) }
Consensus represents a general snowman instance that can be used directly to process a series of dependent operations.
type Factory ¶
type Factory interface {
New() Consensus
}
Factory returns new instances of Consensus
type OracleBlock ¶ added in v1.6.0
type OracleBlock interface { Block // Options returns the possible children of this block in the order this // validator prefers the blocks. Options() ([2]Block, error) }
OracleBlock is a block that only has two valid children. The children should be returned in preferential order.
This ordering does not need to be deterministically created from the chain state.
type TestBlock ¶ added in v0.8.0
type TestBlock struct { choices.TestDecidable ParentV ids.ID HeightV uint64 TimestampV time.Time VerifyV error BytesV []byte }
TestBlock is a useful test block
type Topological ¶
type Topological struct { metrics.Latency metrics.Polls metrics.Height // contains filtered or unexported fields }
Topological implements the Snowman interface by using a tree tracking the strongly preferred branch. This tree structure amortizes network polls to vote on more than just the next block.
func (*Topological) Add ¶
func (ts *Topological) Add(blk Block) error
func (*Topological) Decided ¶ added in v1.7.5
func (ts *Topological) Decided(blk Block) bool
func (*Topological) Finalized ¶
func (ts *Topological) Finalized() bool
func (*Topological) HealthCheck ¶ added in v1.2.2
func (ts *Topological) HealthCheck() (interface{}, error)
HealthCheck returns information about the consensus health.
func (*Topological) Initialize ¶
func (ts *Topological) Initialize(ctx *snow.ConsensusContext, params snowball.Parameters, rootID ids.ID, rootHeight uint64) error
func (*Topological) IsPreferred ¶ added in v1.2.1
func (ts *Topological) IsPreferred(blk Block) bool
func (*Topological) NumProcessing ¶ added in v1.2.0
func (ts *Topological) NumProcessing() int
func (*Topological) Parameters ¶
func (ts *Topological) Parameters() snowball.Parameters
func (*Topological) Preference ¶
func (ts *Topological) Preference() ids.ID
func (*Topological) Processing ¶ added in v1.7.5
func (ts *Topological) Processing(blkID ids.ID) bool
func (*Topological) RecordPoll ¶
func (ts *Topological) RecordPoll(voteBag ids.Bag) error
The votes bag contains at most K votes for blocks in the tree. If there is a vote for a block that isn't in the tree, the vote is dropped.
Votes are propagated transitively towards the genesis. All blocks in the tree that result in at least Alpha votes will record the poll on their children. Every other block will have an unsuccessful poll registered.
After collecting which blocks should be voted on, the polls are registered and blocks are accepted/rejected as needed. The tail is then updated to equal the leaf on the preferred branch.
To optimize the theoretical complexity of the vote propagation, a topological sort is done over the blocks that are reachable from the provided votes. During the sort, votes are pushed towards the genesis. To prevent interating over all blocks that had unsuccessful polls, we set a flag on the block to know that any future traversal through that block should register an unsuccessful poll on that block and every descendant block.
The complexity of this function is: - Runtime = 3 * |live set| + |votes| - Space = 2 * |live set| + |votes|
type TopologicalFactory ¶
type TopologicalFactory struct{}
TopologicalFactory implements Factory by returning a topological struct
func (TopologicalFactory) New ¶
func (TopologicalFactory) New() Consensus