API Reference

WitnetRandomness contract

IWitnetRandomness interface

Functions defined within the IWitnetRandomness interface:

Function

Description

estimateRandomizeFee(uint256)

Returns amount of wei required to be paid as a fee when requesting randomization with a transaction gas price as the one given.

getRandomizeData(uint256)

Retrieves data of a randomization request that got successfully posted to the WRB within a given block. Returns zero values if no randomness request was actually posted within a given block.

getRandomnessAfter(uint256)

Retrieves the randomness generated upon solving a request that was posted within a given block, if any, or to the first request posted after that block, otherwise. Should the intended request happen to be finalized with errors on the Witnet oracle network side, this function will recursively try to return randomness from the next non-faulty randomization request found in storage, if any. Fails if: (a) no randomize() was not called in either the given block, or afterwards; (b) a request posted in/after given block does exist, but no result has been provided yet; or (c), all requests in/after the given block were solved with errors.

getRandomnessNextBlock(uint256)

Tells what is the number of the next block in which a randomization request was posted after the given one.

getRandomnessPrevBlock(uint256)

Gets previous block in which a randomness request was posted before the given one.

isRandomized(uint256)

Returns true only when the randomness request that got posted within given block was already reported back from the Witnet oracle, either successfully or with an error of any kind.

latestRandomizeBlock()

Returns latest block in which a randomness request got sucessfully posted to the WRB.

random(uint32,uint256,uint256)

Generates a pseudo-random number uniformly distributed within the range [0 .. _range), by using the given _nonce value and the randomness returned by getRandomnessAfter(_block). Fails under the same conditions as getRandomnessAfter(uint256) does.

random(uint32,uint256,bytes32)

Generates a pseudo-random number uniformly distributed within the range [0 .. _range), by using the given _nonce value and the given _seed as a source of entropy.

randomize() payable

Requests the Witnet oracle to generate an EVM-agnostic and trustless source of randomness. Only one randomness request per block will be actually posted to the WRB. Should there already be a posted request within current block, it will try to upgrade Witnet fee of current's block randomness request according to current gas price. In both cases, all unused funds shall be transfered back to the tx sender.

upgradeRandomizeFee(uint256) payable

Increases Witnet fee related to a pending-to-be-solved randomness request, as much as it may be required in proportion to how much bigger the current tx.gasprice is with respect the highest gas price that was paid in either previous fee upgrades, or when the given randomness request was posted. All unused funds shall be transferred back to the msg.sender.

witnetRandomnessRequest()

Clonable base contract

Public functions inherited from the Clonable abstract pattern:

Function

Description

cloned()

Tells whether this contract is a clone of another (i.e. self())

clone()

Deploys and returns the address of a minimal proxy clone that replicates contract behaviour while using its own EVM storage.

cloneDeterministic(bytes32)

Deploys and returns the address of a minimal proxy clone that replicates contract behaviour while using its own EVM storage. This function uses the CREATE2 opcode and a _salt to deterministically deploy the clone. Using the same _salt multiple times will revert, since no contract can be deployed more than once at the same address.

self()

Returns the address of the underlying logic implementation contract.

UsingWitnet base contract

Public function inherited from the UsingWitnet abstract contract:

Function

Description

witnet()

WitnetRequestRandomness contract

IWitnetRequest interface

Functions defined within the IWitnetRequest interface:

Function

Description

bytecode()

hash()

Returns the SHA256 hash of the bytecode().

WitnetRequestMalleableBase base contract

Public and restricted functions inherited from the WitnetRequestMalleableBase abstract contract:

Function

Description

setWitnessingCollateral(uint64)

setWitnessingFees(uint64,uint64)

setWitnessingQuorum(uint8,uint8)

template()

Returns bytecode of the immutable RAD (Retrieve-Attest-Delivery) script's bytecode. Encoded using Protocol Buffers.

totalWitnessingCollateral()

Returns total amount of nanowits that witnessing nodes will need to collateralize all together.

totalWitnessingFee()

Returns total amount of nanowits that will have to be paid in total for this request to be solved.

witnessingParams()

Returns witnessing parameters of current Witnet Data Request.

Clonable base contract

Public functions inherited from the Clonable abstract pattern:

Function

Description

cloned()

Tells whether this contract is a clone of another (i.e. self())

clone()

Deploys and returns the address of a minimal proxy clone that replicates contract behaviour while using its own EVM storage.

cloneDeterministic(bytes32)

Deploys and returns the address of a minimal proxy clone that replicates contract behaviour while using its own EVM storage. This function uses the CREATE2 opcode and a _salt to deterministically deploy the clone. Using the same _salt multiple times will revert, since no contract can be deployed more than once at the same address.

self()

Returns the address of the underlying logic implementation contract.

Ownable base contract

Public function inherited from the Ownable abstract pattern:

Function

Description

owner()

Tells who the current owner of this contract is. Owner may only modify the witnessing parameters of the contained Witnet Data Request, not the actual RAD (Retrieval-Attest-Deliver) script to be executed by Witnet nodes when solving the Data Request. Ownership can only be transferred by current owner. Ownership of this Data Request can only be gained by cloning the WitnetRandomness contract.

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