Rewarding Uploaders

The system smart contract that implements the "lottery" mechanism.

An operation can be initiated by any account, but the network will only accept one attempt every 28 days.

Pseudocode

# Iterate over all non-empty reward pools
for rewardPool in nonEmptyRewardPools:
    # Make lots
    lots = []
    for uploader in rewardPool.uploaders:
        # trafficAmount contains amount of uploaded traffic in megabytes
        # Each uploaded gigabyte equals to one lot
        numberOfLots = floor(uploader.trafficAmount / 1024)
        for i in range(numberOfLots):
            lots.append(uploader.account)

    # Shuffle
    shuffle(lots)

    # win factor is stored in pool settings
    winFactor = SystemSettings.uploaderRewardWinFactor

    # Number of winner is based on the win factor.
    # For example, if win factor if 100, then each 100th lot is a winner.
    numberOfWinners = floor(len(lots) / winFactor)

    # If number of lots is less than win factor then one winner gets all reward
    if numberOfWinners == 0:
        numberOfWinners = 1

    # Select winners
    winners = []
    for i in range(numberOfWinners):
        winners.append(lots[i*winFactor])

    # Reward pool is distributed equally among the winners
    singleReward = rewardPool.amount / len(winners)
    for winner in winners:
        addTokens(winner, singleReward)

    # reset reward pool (empty amount and uploaders)
    rewardPool.reset()

Description

• the smart contract finds all non-empty reward pools

• the following actions are performed for each found reward pool:

  • an array of lots is generated based on the list of candidates (uploaders) and the winFactor (winFactor)
  • the list of candidates is an array of public keys of nodes, which gave the traffic of the given broadcaster or pool since the previous launch of the Reward Uploaders smart contract. For each node, the list stores the number of traffic units given away
  • win ratio is an integer number stored in the system settings. It sets the ratio of the number of winners to the total number of lots
  • each Gbyte of traffic uploaded (1024 Mb) is equal to one lot
  • only candidates who have uploaded >= 1 Gb of traffic participate in the lottery

  • number of lots for one candidate is limited by formula:

    maxLots = accessPrice / trafficPrice where:

    • accessPrice - the content access price in stablecoins
    • trafficPrice - the price of 1 Gb of the traffic in stablecoins (it's calculated based on the current AceByte token market price)

  • the number of winners is determined based on the gaining coefficient (at the coefficient N every N-th element of the lots array is a winner)

  • if the number of lots is less than the odds of winning, then one winner is selected
  • the smart contract randomly chooses the necessary number of winners from the array of lots
  • the content of the reward pool is distributed equally among the winning lots
  • after the drawing the reward pool and the list of candidates will be reset to zero

Example

Suppose there is one reward pool that contains the following data at the time of launching the Reward Uploaders smart contract:

• rewards pool: 3 XAB
• list of candidates who gave >= 1 GB of traffic:
  • userA: uploaded 60 GB
  • userB: uploaded 70 GB
  • userC: uploaded 2 GB
  • userD: uploaded 85 GB

Let the win rate be 100, then:

• total number of lots: 60 + 70 + 2 + 85 = 217
• the number of winning lots: floor(217 / 2) = 2.
• winnings per lot: 3 / 2 = 1.5 XAB.

The Reward Uploaders smart contract randomly selects 2 of the 217 lots and awards 1.5 XAB to the owners of those lots. If both winning lots belong to the same owner, they receives 3 XAB.