Documentation ¶
Overview ¶
Package xchain defines the types and interfaces used by the omni cross-chain protocol.
Index ¶
- Constants
- func AttestationRoot(attHeader AttestHeader, blockHeader BlockHeader, msgRoot common.Hash) (common.Hash, error)
- func BindFlags(flags *pflag.FlagSet, endpoints *RPCEndpoints)
- func DecodeXSubmit(txCallData []byte) (bindings.XSubmission, error)
- func EncodeXSubmit(sub bindings.XSubmission) ([]byte, error)
- func SubmissionToBinding(sub Submission) bindings.XSubmission
- type AttestHeader
- type Attestation
- type Block
- type BlockHeader
- type ChainVersion
- type ConfLevel
- type EmitCursor
- type EmitRef
- type Msg
- type MsgID
- type MsgTree
- type Provider
- type ProviderCallback
- type ProviderRequest
- type RPCEndpoints
- type Receipt
- type ShardID
- type SigTuple
- type Signature65
- type StreamID
- type Submission
- type SubmitCursor
- type Vote
Constants ¶
const ( DSTUnknown merkle.DomainSeparationTag = 0 DSTHeader merkle.DomainSeparationTag = 1 DSTMessage merkle.DomainSeparationTag = 2 )
const ( // ShardFinalized0 is the default finalized confirmation level shard. ShardFinalized0 = ShardID(ConfFinalized) // ShardLatest0 is the default latest confirmation level shard. ShardLatest0 = ShardID(ConfLatest) // ShardBroadcast0 is the default broadcast shard. It uses the finalized confirmation level. ShardBroadcast0 = ShardID(ConfFinalized) | 0x0100 )
const BroadcastChainID uint64 = 0
BroadcastChainID is the chain ID used by broadcast messages.
Variables ¶
This section is empty.
Functions ¶
func AttestationRoot ¶
func AttestationRoot(attHeader AttestHeader, blockHeader BlockHeader, msgRoot common.Hash) (common.Hash, error)
AttestationRoot returns the attestation root of the provided block submissionHeader and message root.
func BindFlags ¶
func BindFlags(flags *pflag.FlagSet, endpoints *RPCEndpoints)
BindFlags binds the xchain evm rpc flag.
func DecodeXSubmit ¶
func DecodeXSubmit(txCallData []byte) (bindings.XSubmission, error)
DecodeXSubmit decodes the xsubmit function call data.
func EncodeXSubmit ¶
func EncodeXSubmit(sub bindings.XSubmission) ([]byte, error)
EncodeXSubmit returns the abi encoding of the xsubmit function call.
func SubmissionToBinding ¶
func SubmissionToBinding(sub Submission) bindings.XSubmission
SubmissionToBinding converts a go xchain submission to a solidity binding submission.
Types ¶
type AttestHeader ¶
type AttestHeader struct { ConsensusChainID uint64 // Omni consensus chain ID this attestation/vote belangs to. Used for replay-protection. ChainVersion ChainVersion // ChainVersion defines a "version" of a chain being attested to ; either some fuzzy version or finalized. AttestOffset uint64 // Monotonically increasing offset of this vote per chain version. 1-indexed. }
AttestHeader uniquely identifies an attestation that require quorum vote. This is used to determine duplicate votes.
type Attestation ¶
type Attestation struct { AttestHeader // AttestHeader uniquely identifies the attestation. BlockHeader // BlockHeader identifies the cross-chain Block ValidatorSetID uint64 // Validator set that approved this attestation. MsgRoot common.Hash // Merkle root of all messages in the cross-chain Block Signatures []SigTuple // Validator signatures and public keys }
Attestation containing quorum votes by the validator set of a cross-chain Block.
func (Attestation) AttestationRoot ¶
func (a Attestation) AttestationRoot() ([32]byte, error)
type Block ¶
type Block struct { BlockHeader Msgs []Msg // All cross-chain messages sent/emittted in the block Receipts []Receipt // Receipts of all submitted cross-chain messages applied in the block ParentHash common.Hash // ParentHash is the hash of the parent block. Timestamp time.Time // Timestamp of the source chain block }
Block is a deterministic representation of the omni cross-chain properties of a source chain EVM block.
func (Block) ShouldAttest ¶
ShouldAttest returns true if the xblock should be attested by the omni consensus chain validators. All "non-empty" xblocks should be attested to. Every Nth block based on the chain's attest interval should be attested to. Attested blocks are assigned an incremented AttestOffset.
type BlockHeader ¶
type BlockHeader struct { ChainID uint64 // Source chain ID as per https://chainlist.org BlockHeight uint64 // Height of the source-chain block BlockHash common.Hash // Hash of the source-chain block }
BlockHeader uniquely identifies a cross chain block.
type ChainVersion ¶
type ChainVersion struct { ID uint64 // Source chain ID as per https://chainlist.org/ ConfLevel ConfLevel // ConfLevel defines the block "version"; either some fuzzy version or finalized. }
ChainVersion defines a version of a source chain; either some draft (fuzzy) version or finalized.
func NewChainVersion ¶
func NewChainVersion(chainID uint64, confLevel ConfLevel) ChainVersion
type ConfLevel ¶
type ConfLevel byte
ConfLevel defines a xblock confirmation level. This is similar to a "version"; with ConfFinalized being the final version and fuzzy conf levels being drafts.
const ( ConfUnknown ConfLevel = 0 // unknown ConfLatest ConfLevel = 1 // latest ConfFinalized ConfLevel = 4 // final )
ConfLevel values MUST never change as they are persisted on-chain.
func FuzzyConfLevels ¶
func FuzzyConfLevels() []ConfLevel
FuzzyConfLevels returns a list of all fuzzy confirmation levels.
func (ConfLevel) IsFinalized ¶
IsFinalized returns true if this confirmation level is ConfFinalized.
type EmitCursor ¶
type EmitCursor struct { StreamID // Stream ID of the Stream this cursor belongs to MsgOffset uint64 // Latest emitted Msg offset of the Stream }
EmitCursor is a cursor that tracks the progress of a cross-chain stream on source portal contracts.
type EmitRef ¶
type EmitRef struct { // Height specifies an absolute height to query; if non-nil. Height *uint64 // ConfLevel specifies a relative-to-head block to query; if non-nil. ConfLevel *ConfLevel }
EmitRef specifies which block to query for emit cursors.
func ConfEmitRef ¶
ConfEmitRef returns a EmitRef with the provided confirmation level.
func HeightEmitRef ¶
HeightEmitRef returns a EmitRef with the provided confirmation level.
func LatestEmitRef ¶
func LatestEmitRef() EmitRef
LatestEmitRef returns a EmitRef with the latest confirmation level.
type Msg ¶
type Msg struct { MsgID // Unique ID of the message SourceMsgSender common.Address // Sender on source chain, set to msg.Sender DestAddress common.Address // Target/To address to "call" on destination chain Data []byte // Data to provide to "call" on destination chain DestGasLimit uint64 // Gas limit to use for "call" on destination chain TxHash common.Hash // Hash of the source chain transaction that emitted the message Fees *big.Int // Fees paid for the xcall }
Msg is a cross-chain message.
type MsgID ¶
type MsgID struct { StreamID // Unique ID of the Stream this message belongs to StreamOffset uint64 // Monotonically incremented offset of Msg in the Stream (1-indexed) }
MsgID uniquely identifies a cross-chain message.
type MsgTree ¶
type MsgTree struct {
// contains filtered or unexported fields
}
MsgTree is a merkle tree of all the messages in a cross-chain block. It is used as a leaf when calculating the AttestationRoot. Its proofs are used to submit messages to destination chains.
func NewMsgTree ¶
NewMsgTree returns the merkle root of the provided messages to be submitted.
type Provider ¶
type Provider interface { // StreamAsync starts a goroutine that streams xblocks forever from the provided source chain and height (inclusive). // // It returns immediately. It only returns an error if the chainID in invalid. // This is the async version of StreamBlocks. // It retries forever (with backoff) on all fetch and callback errors. StreamAsync(ctx context.Context, req ProviderRequest, callback ProviderCallback) error // StreamBlocks is the synchronous fail-fast version of Subscribe. It streams // xblocks as they become available but returns on the first callback error. // This is useful for workers that need to reset on application errors. StreamBlocks(ctx context.Context, req ProviderRequest, callback ProviderCallback) error // GetBlock returns the block for the given chain and height, or false if not available (not finalized yet), // or an error. The AttestOffset field is populated with the provided offset (if required). GetBlock(ctx context.Context, req ProviderRequest) (Block, bool, error) // GetSubmittedCursor returns the submitted cursor for the provided stream, // or false if not available, or an error. // Calls the destination chain portal InXStreamOffset method. // Note this is only supported for EVM chains, no the consensus chain. GetSubmittedCursor(ctx context.Context, stream StreamID) (SubmitCursor, bool, error) // GetEmittedCursor returns the emitted cursor for the provided stream, // or false if not available, or an error. // Calls the source chain portal OutXStreamOffset method. // // Note that the AttestOffset field is not populated for emit cursors, since it isn't stored on-chain // but tracked off-chain. GetEmittedCursor(ctx context.Context, ref EmitRef, stream StreamID) (EmitCursor, bool, error) // ChainVersionHeight returns the height for the provided chain version. ChainVersionHeight(ctx context.Context, chainVer ChainVersion) (uint64, error) // GetSubmission returns the submission for the provided chain and tx hash, or an error. GetSubmission(ctx context.Context, chainID uint64, txHash common.Hash) (Submission, error) }
Provider abstracts fetching cross chain data from any supported chain. This is basically a cross-chain data client for all supported chains.
type ProviderCallback ¶
ProviderCallback is the callback function signature that will be called with every finalized.
type ProviderRequest ¶
type ProviderRequest struct { ChainID uint64 // Source chain ID to query for xblocks. Height uint64 // Height to query (from inclusive). ConfLevel ConfLevel // Confirmation level to ensure }
ProviderRequest is the request struct for fetching cross-chain blocks. When used in streaming context, the Height defines the starting point (inclusive).
func (ProviderRequest) ChainVersion ¶
func (r ProviderRequest) ChainVersion() ChainVersion
type RPCEndpoints ¶
func (RPCEndpoints) ByNameOrID ¶
func (e RPCEndpoints) ByNameOrID(name string, chainID uint64) (string, error)
func (RPCEndpoints) Keys ¶
func (e RPCEndpoints) Keys() []string
type Receipt ¶
type Receipt struct { MsgID // Unique ID of the cross chain message that was applied. GasUsed uint64 // Gas used during message "call" Success bool // Result, true for success, false for revert Error []byte // Error message if the message failed RelayerAddress common.Address // Address of relayer that submitted the message TxHash common.Hash // Hash of the relayer submission transaction }
Receipt is a cross-chain message receipt, the result of applying the Msg on the destination chain.
type ShardID ¶
type ShardID uint64
func (ShardID) ConfLevel ¶
ConfLevel returns confirmation level encoded in the last 8 bits of the shardID.
type SigTuple ¶
type SigTuple struct { ValidatorAddress common.Address // Validator Ethereum address Signature Signature65 // Validator signature over XBlockRoot; Ethereum 65 bytes [R || S || V] format. }
SigTuple is a validator signature and address.
type Signature65 ¶
type Signature65 [65]byte
Signature65 is a 65 byte Ethereum signature [R || S || V] format.
type StreamID ¶
type StreamID struct { SourceChainID uint64 // Source chain ID as per https://chainlist.org/ DestChainID uint64 // Destination chain ID as per https://chainlist.org/ ShardID ShardID // ShardID identifies a sequence of xmsgs (and maps to ConfLevel). }
StreamID uniquely identifies a cross-chain stream. A stream is a logical representation of a cross-chain connection between two chains.
func (StreamID) ChainVersion ¶
func (s StreamID) ChainVersion() ChainVersion
type Submission ¶
type Submission struct { AttestationRoot common.Hash // Attestation merkle root of the cross-chain Block ValidatorSetID uint64 // Validator set that approved the attestation. AttHeader AttestHeader // AttestHeader identifies the attestation this submission belongs to. BlockHeader BlockHeader // BlockHeader identifies the cross-chain Block Msgs []Msg // Messages to be submitted Proof [][32]byte // Merkle multi proofs of the messages ProofFlags []bool // Flags indicating whether the proof is a left or right proof Signatures []SigTuple // Validator signatures and public keys DestChainID uint64 // Destination chain ID, for internal use only }
Submission is a cross-chain submission of a set of messages and their proofs.
func SubmissionFromBinding ¶
func SubmissionFromBinding(sub bindings.XSubmission, destChainID uint64) Submission
type SubmitCursor ¶
type SubmitCursor struct { StreamID // Stream ID of the Stream this cursor belongs to MsgOffset uint64 // Latest submitted Msg offset of the Stream AttestOffset uint64 // Latest submitted cross chain attest offset }
SubmitCursor is a cursor that tracks the progress of a cross-chain stream on destination portal contracts.
type Vote ¶
type Vote struct { AttestHeader // AttestHeader identifies the attestation this vote should be included in. BlockHeader // BlockHeader identifies the cross-chain Block being voted for. MsgRoot common.Hash // Merkle root of all messages in the cross-chain Block Signature SigTuple // Validator signature and public key }
Vote by a validator for a cross-chain Block.