BTCRelay¶

Calls¶

initialize¶

One time function to initialize the BTC-Relay with the first block

# Arguments

block_header - Bitcoin block header.
block_height - starting Bitcoin block height of the submitted block header.

## Complexity - O(1)

Attributes¶

Name	Type
block_header	`BlockHeader`
block_height	`u32`

Python¶

call = substrate.compose_call(
    'BTCRelay', 'initialize', {
    'block_header': {
        'hash': {
            'content': '[u8; 32]',
        },
        'hash_prev_block': {
            'content': '[u8; 32]',
        },
        'merkle_root': {
            'content': '[u8; 32]',
        },
        'nonce': 'u32',
        'target': 'scale_info::186',
        'timestamp': 'u32',
        'version': 'i32',
    },
    'block_height': 'u32',
}
)

store_block_header¶

Stores a single new block header

# Arguments

block_header - Bitcoin block header.

## Complexity - O(F) where F is the number of forks

Attributes¶

Name	Type
block_header	`BlockHeader`
fork_bound	`u32`

Python¶

call = substrate.compose_call(
    'BTCRelay', 'store_block_header', {
    'block_header': {
        'hash': {
            'content': '[u8; 32]',
        },
        'hash_prev_block': {
            'content': '[u8; 32]',
        },
        'merkle_root': {
            'content': '[u8; 32]',
        },
        'nonce': 'u32',
        'target': 'scale_info::186',
        'timestamp': 'u32',
        'version': 'i32',
    },
    'fork_bound': 'u32',
}
)

Events¶

ChainReorg¶

Attributes¶

Name	Type	Composition
new_chain_tip_hash	`H256Le`	`{'content': '[u8; 32]'}`
new_chain_tip_height	`u32`	`u32`
fork_depth	`u32`	`u32`

ForkAheadOfMainChain¶

Attributes¶

Name	Type	Composition
main_chain_height	`u32`	`u32`
fork_height	`u32`	`u32`
fork_id	`u32`	`u32`

Initialized¶

Attributes¶

Name	Type	Composition
block_height	`u32`	`u32`
block_hash	`H256Le`	`{'content': '[u8; 32]'}`
relayer_id	`T::AccountId`	`AccountId`

StoreForkHeader¶

Attributes¶

Name	Type	Composition
chain_id	`u32`	`u32`
fork_height	`u32`	`u32`
block_hash	`H256Le`	`{'content': '[u8; 32]'}`
relayer_id	`T::AccountId`	`AccountId`

StoreMainChainHeader¶

Attributes¶

Name	Type	Composition
block_height	`u32`	`u32`
block_hash	`H256Le`	`{'content': '[u8; 32]'}`
relayer_id	`T::AccountId`	`AccountId`

Storage functions¶

BestBlock¶

Store the current blockchain tip

Python¶

result = substrate.query(
    'BTCRelay', 'BestBlock', []
)

Return value¶

{'content': '[u8; 32]'}

BestBlockHeight¶

Store the height of the best block

Python¶

result = substrate.query(
    'BTCRelay', 'BestBlockHeight', []
)

Return value¶

'u32'

BlockHeaders¶

Store Bitcoin block headers

Python¶

result = substrate.query(
    'BTCRelay', 'BlockHeaders', [{'content': '[u8; 32]'}]
)

Return value¶

{
    'block_header': {
        'hash': {'content': '[u8; 32]'},
        'hash_prev_block': {'content': '[u8; 32]'},
        'merkle_root': {'content': '[u8; 32]'},
        'nonce': 'u32',
        'target': 'scale_info::186',
        'timestamp': 'u32',
        'version': 'i32',
    },
    'block_height': 'u32',
    'chain_id': 'u32',
    'para_height': 'u32',
}

ChainCounter¶

Increment-only counter used to track new BlockChain entries

Python¶

result = substrate.query(
    'BTCRelay', 'ChainCounter', []
)

Return value¶

'u32'

Chains¶

Priority queue of BlockChain elements, ordered by the maximum height (descending). The first index into this mapping (0) is considered to be the longest chain. The value of the entry is the index into ChainsIndex to retrieve the BlockChain.

Python¶

result = substrate.query(
    'BTCRelay', 'Chains', ['u32']
)

Return value¶

'u32'

ChainsHashes¶

Stores a mapping from (chain_index, block_height) to block hash

Python¶

result = substrate.query(
    'BTCRelay', 'ChainsHashes', ['u32', 'u32']
)

Return value¶

{'content': '[u8; 32]'}

ChainsIndex¶

Auxiliary mapping of chains ids to BlockChain entries. The first index into this mapping (0) is considered to be the Bitcoin main chain.

Python¶

result = substrate.query(
    'BTCRelay', 'ChainsIndex', ['u32']
)

Return value¶

{'chain_id': 'u32', 'max_height': 'u32', 'start_height': 'u32'}

DisableDifficultyCheck¶

Whether the module should perform difficulty checks.

Python¶

result = substrate.query(
    'BTCRelay', 'DisableDifficultyCheck', []
)

Return value¶

'bool'

DisableInclusionCheck¶

Whether the module should perform inclusion checks.

Python¶

result = substrate.query(
    'BTCRelay', 'DisableInclusionCheck', []
)

Return value¶

'bool'

StableBitcoinConfirmations¶

Global security parameter k for stable Bitcoin transactions

Python¶

result = substrate.query(
    'BTCRelay', 'StableBitcoinConfirmations', []
)

Return value¶

'u32'

StableParachainConfirmations¶

Global security parameter k for stable Parachain transactions

Python¶

result = substrate.query(
    'BTCRelay', 'StableParachainConfirmations', []
)

Return value¶

'u32'

StartBlockHeight¶

BTC height when the relay was initialized

Python¶

result = substrate.query(
    'BTCRelay', 'StartBlockHeight', []
)

Return value¶

'u32'

Constants¶

ParachainBlocksPerBitcoinBlock¶

Value¶

Python¶

constant = substrate.get_constant('BTCRelay', 'ParachainBlocksPerBitcoinBlock')

Errors¶

AlreadyInitialized¶

Already initialized

AlreadyReported¶

Error code already reported

ArithmeticOverflow¶

Arithmetic overflow

ArithmeticUnderflow¶

Arithmetic underflow

BitcoinConfirmations¶

Transaction has less confirmations of Bitcoin blocks than required

BlockHeightOverflow¶

Overflow of block height

BlockNotFound¶

Block header not found for given hash

BoundExceeded¶

Weight bound exceeded

ChainCounterOverflow¶

Overflow of chain counter

ChainsUnderflow¶

Underflow of stored blockchains counter

DiffTargetHeader¶

Incorrect difficulty target specified in block header

DuplicateBlock¶

Block already stored

EndOfFile¶

EndOfFile reached while parsing

ForkIdNotFound¶

Blockchain with requested ID not found

InvalidBlockVersion¶

Invalid block header version

InvalidBtcAddress¶

Specified invalid Bitcoin address

InvalidBtcHash¶

User supplied an invalid address

InvalidChainID¶

Invalid chain ID

InvalidCoinbasePosition¶

Coinbase tx must be the first transaction in the block

InvalidCompact¶

Invalid compact value in header

InvalidHeaderSize¶

Invalid block header size

InvalidMerkleProof¶

Invalid merkle proof

InvalidOpReturn¶

Incorrect identifier in OP_RETURN field

InvalidOpReturnTransaction¶

Transaction does meet the requirements to be a valid op-return payment

InvalidOutputFormat¶

Incorrect transaction output format

InvalidPayment¶

Incorrect recipient Bitcoin address

InvalidPaymentAmount¶

Invalid payment amount

InvalidScript¶

User supplied an invalid script

InvalidStartHeight¶

Start height must be start of difficulty period

InvalidTransaction¶

Transaction does meet the requirements to be considered valid

InvalidTxVersion¶

Invalid transaction version

InvalidTxid¶

Transaction hash does not match given txid

LowDiff¶

PoW hash does not meet difficulty target of header

MalformedHeader¶

Format of the header is invalid

MalformedMerkleProof¶

Merkle proof is malformed

MalformedOpReturnOutput¶

Format of the OP_RETURN transaction output is invalid

MalformedP2PKHOutput¶

MalformedP2SHOutput¶

MalformedTransaction¶

Transaction has incorrect format

MalformedTxid¶

Malformed transaction identifier

MalformedWitnessOutput¶

Format of the BIP141 witness transaction output is invalid

MissingBlockHeight¶

Missing the block at this height

OngoingFork¶

Current fork ongoing

ParachainConfirmations¶

Transaction has less confirmations of Parachain blocks than required

PrevBlock¶

Previous block hash not found

Shutdown¶

BTC Parachain has shut down

TryIntoIntError¶

TryInto failed on integer

UnauthorizedRelayer¶

Unauthorized staked relayer

UnknownErrorcode¶

Error code not applicable to blocks

UnsupportedInputFormat¶

UnsupportedOutputFormat¶

WrongForkBound¶

Wrong fork bound, should be higher