mirror of https://github.com/poanetwork/gecko.git
42 lines
1.4 KiB
Go
42 lines
1.4 KiB
Go
// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
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// See the file LICENSE for licensing terms.
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package snowman
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import (
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"github.com/ava-labs/gecko/snow/choices"
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)
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// Block is a possible decision that dictates the next canonical block.
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//
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// Blocks are guaranteed to be Verified, Accepted, and Rejected in topological
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// order. Specifically, if Verify is called, then the parent has already been
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// verified. If Accept is called, then the parent has already been accepted. If
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// Reject is called, the parent has already been accepted or rejected.
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//
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// If the status of the block is Unknown, ID is assumed to be able to be called.
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// If the status of the block is Accepted or Rejected; Parent, Verify, Accept,
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// and Reject will never be called.
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type Block interface {
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choices.Decidable
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// Parent returns the block that this block points to.
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//
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// If the parent block is not known, a Block should be returned with the
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// status Unknown.
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Parent() Block
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// Verify that the state transition this block would make if accepted is
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// valid. If the state transition is invalid, a non-nil error should be
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// returned.
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//
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// It is guaranteed that the Parent has been successfully verified.
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Verify() error
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// Bytes returns the binary representation of this block.
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//
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// This is used for sending blocks to peers. The bytes should be able to be
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// parsed into the same block on another node.
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Bytes() []byte
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}
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