DrawBuffer

The DrawBuffer provides historical lookups of Draws via a circular ring buffer. Historical Draws can be accessed on-chain using a Draw ID to calculate ring buffer storage slots. The Draw settings can be created by manager/owner and existing Draws can only be updated by the owner. Once a starting Draw has been added to the ring buffer, all following draws must have a sequential Draw ID.

A DrawBuffer stores a limited number of Draws before beginning to overwrite (managed via the cardinality) previous Draws. Mainnet DrawBuffer is updated directly from a DrawBeacon.

Write methods description

initialize()

Allows to initialize the contract during the deployment.

Parameters:

Name	Type	Description
_owner	address	Address of the owner of the DrawBuffer.
_cardinality	uint8	Draw ring buffer cardinality.

markDrawAsPaid()

Mark a draw as paid. It means that the winners of the draw were paid and the draw can not be paid again.

Parameters:

Name	Type	Description
_drawId	uint32	An ID of a draw that should be marked as paid.

pushDraw()

Push draw onto draws ring buffer history. Push new draw onto draws history via authorized manager or owner.

Parameters:

Name	Type	Description
_draw	IDrawBeacon.Draw	Draw information that was pushed.

setDraw()

Set existing draw in draws ring buffer with new parameters. Push new draw onto draws history via authorized manager or owner.

Parameters:

Name	Type	Description
_draw	IDrawBeacon.Draw	Draw to set.

Return:

Name	Type	Description
_drawId	uint32	Draw ID.

setPrizeDistributor()

Set a new PrizeDistributor contract address.

Parameters:

Name	Type	Description
_prizeDistributor	address	A new PrizeDistributor contract address

claimOwnership()

Allows the pendingOwner address to claim the owner role. This function is only callable by the pendingOwner.

renounceOwnership()

Leaves the contract without owner. It will not be possible to call the owner's functions anymore. Can only be called by the current owner. The method does not take any parameters. Renouncing ownership will leave the contract without an owner, thereby removing any functionality that is only available to the owner.

transferOwnership()

Transfers ownership of the contract to a _pendingOwner. Can only be called by the current owner.

Parameters:

Name	Type	Description
_newOwner	address	An account that will become the _pendingOwner.

setManager()

Allows the owner to give the manager role to an address. The manager role has access to the functions with the modified onlyManager or onlyManagerOrOwner.

Parameters:

Name	Type	Description
_newManager	address	An account that will become the new manager.

Read methods description

MAX_CARDINALITY()

Ring buffer max length.

getBufferCardinality()

Read a ring buffer cardinality.

getDraw()

Read a draw from the draws ring buffer. Read a draw using the draw.drawId to calculate position in the draws ring buffer.

Parameters:

Name	Type	Description
_drawId	uint32	The draw ID to retrieve the draw data from.

getDrawCount()

Gets the number of draws held in the draw ring buffer. If no draws have been pushed, it will return 0. If the ring buffer is full, it will return the cardinality. Otherwise, it will return the newest draw index + 1.

Return:

Name	Type	Description
_count	uint32	Number of draws held in the draw ring buffer.

getDraws()

Read multiple draws from the draws ring buffer. Read multiple draws using each draw.drawId to calculate position in the draws ring buffer.

Parameters:

Name	Type	Description
_drawIds	uint32[]	Array of draw IDs.

Return:

Name	Type	Description
_draws	IDrawBeacon.Draw[]	Array with the draw information of the requested draw IDs.

getNewestDraw()

Read newest draw from draws ring buffer. Uses the nextDrawIndex to calculate the most recently added draw.

getOldestDraw()

Read oldest draw from draws ring buffer. Finds the oldest draw by comparing and/or diffing totalDraws with the cardinality.

getPrizeDistributor()

Read a PrizeDistributor contract address.

owner()

Owner role that can be granted exclusive access to specific functions with the modifier onlyOwner.

manager()

Manager role that can be granted exclusive access to specific functions with the modifier onlyManager or onlyManagerOrOwner.

pendingOwner()

Address that can claim the owner role. It is used to transfer the owner.