HIP-122 restrict boosting from poc bucket

[michaeldjeffrey]

Reference: HIP-122

DataTransferAndPocAllocatedRewardBuckets and CalculatedPocRewardShares

Data Transfer rewards used to be calculated to fit within the MAX_DATA_TRANSFER_REWARDS_PERCENT from the total scheduled tokens for an epoch. This has been moved to the construction of DataTransferAndPocAllocatedRewardBuckets so boosted poc rewards can be carved out of the poc allocation as soon as possible.

After Data Transfer has been rewarded, the unallocated amount is rolled into the normal POC bucket with reward_shares.handle_unallocated_data_transfer(dc_unallocated_amount);.

Unallocated Data Transfer rewards are allowed to increase the POC rewards, but not service provider boosted rewards.
(In the case where boosted rewards do not exceed 10%, nothing extra needs to be done.)

CoveragePoints and HexPoints

To ensure we can do reward calculations with regard to the boosted poc pool, we store the points received from service provider boosting per hex separate from the points received by covering a hex.

Any time boosted points are used in code or comment they do not include base points from covering a hex.

Example:

An IndoorWifi radio with good SignalLevel receives 400 coverage points from a hex.
If that hex is boosted 10x, the radio receives 4,000 coverage points.
But they are stored { base: 400, boosted: 3,600 }, because the radio receives 3,600 additional points thanks to Service Provider Boosting.

hex_boosting.rs test file

Tests where boosting did not exceed 10% of rewards were untouched.

For the rest, I attempted to recreate the math that derives the expected rewards for radios.
For a sense of how expected rewards changed with few radios and few hexes, some examples.
(These tests include the 40% data transfer bucket as well)

test_poc_with_boosted_hexes

• 3 IndoorWifi radios
• 2 boosted hexes at 20x and 10x

	Old Expected Reward	New Expected Reward
20x boosted	31,729,243,786,356	19,223,263,075,722
10x boosted	15,864,621,893,178	16,295,862,607,338
No boost	1,586,462,189,317	13,661,202,185,792

The boosts contributed significantly less than before.

test_poc_with_multi_coverage_boosted_hexes

• 3 Indoor Wifi Radios
• 2 boosted hexes at 10x, 1 at 20x

	Old Expected Reward	New Expected Reward
1 at 20x boosted	23,990,403,838,464	14,455,028,799,291
2 at 10x boosted	23,990,403,838,464	24,479,397,430,217
No boost	1,199,520,191,923	10,245,901,639,344

Covering more hexes is much more valuable than a strong boosted hex.