Karma police: a reputation system on ethereum

README.md

Karma police: a simple reputation system on top of ethereum

Tired of the alcoins mania? Here is a coin that you cannot exhange or lose. It aims to be a reputation system. Every n=42 days m=1000000 karma units are issued. So it's a disinflationary unit.

Users of this system can votes ("+1") for others if they do a great contribution. A user with 1% of the total amount of karma will "distribute" 1% of the new m units. These new karma units are equally distributed between all users that have received a vote from him.

Persistent storage usage

Global informations

[0] ; total amount of karma
[1] ; number of checkouts
[2] ; last checkout timestamp

Karma units before checkouts

[-1] ; Total amount of karma units before checkout 1
[-2] ; Total amount of karma units before checkout 2
...

Votes

@location = addr * 10000 * 10000;
[location - 1] ; karma of addr
[location - 2] ; lastCheckoutIndex

[location + checkoutIndex * 10000 - 1] ; personnal amount of karma units before checkoutIndex
[location + checkoutIndex * 10000]     ; number of votes
[location + checkoutIndex * 10000 + 1] ; vote n°1
[location + checkoutIndex * 10000 + 2] ; vote n°2

karma.lisp

{
  [2] (timestamp)
}
{
  ; Contract parameters
  [daysBetweenCheckouts] 42
  [newKarmaUnitsByCheckout] 1000000

  ; Global infos
  [globalAmountOfKarma] @@0
  [lastCheckoutIndex] @@1
  [lastCheckoutTimestamp] @@2

  ; If needed, update last checkout informations
  (when (> (+ @lastCheckoutTimestamp (* @daysBetweenCheckouts 24 60 60)) (timestamp)) {
    [lastCheckoutIndex] (+ @lastCheckoutIndex 1)
    [lastCheckoutTimestamp] (timestamp)
    [[1]] @lastCheckoutIndex
    [[2]] @lastCheckoutTimestamp
    [[(- @lastCheckoutIndex)]] @globalAmountOfKarma})

  ; Caller user infos
  [location] (* (caller) 10000 10000)
  [myKarma] @@(- @location 1)
  [lastCheckoutDistributed] @@(- @location 2)

  ; If this user hasn't call this contract since the last checkout, we need to distribute new karma units earned in previous periods
  (for [checkoutIndex] (+ @lastCheckoutDistributed 1) (<= @checkoutIndex @lastCheckoutIndex) [checkoutIndex] (+ @checkoutIndex 1) {
    [checkoutLoc] (+ @location (* 10000 @checkoutIndex))
    [nbVotes] @@@checkoutLoc
    [karmaBeforeCheckout] @@(- @checkoutLoc 1)
    [totalKarmaBeforeCheckout] @@(- @checkoutIndex)
    [newUnitsByVote] (+ (/ (* @karmaBeforeCheckout @newKarmaUnitsByCheckout) @totalKarmaBeforeCheckout @nbVotes) 1)
    (for ()  (< @m @nbVotes) [m] (+ @m 1) {
      [receiverAddress] @@(+ @location (* 10000 @checkoutIndex) @m)
      [receiverLoc] (* @receiverAddress 10000 10000)
      [receiverCurrentKarma] @@(- @receiverLoc 1)
      [[(- (+ @receiverLoc (* @checkoutIndex 10000)) 1)]] @receiverCurrentKarma ; Backup current karma
      [[(- @receiverLoc 1)]] (+ @receiverCurrentKarma @newUnitsByVote)
      [[0]] (+ @globalAmountOfKarma @newUnitsByVote)})}) ; Increment receiver karma

  ; And now it's time to register the new votes for the current period!
  [votesLoc] (+ @location (* 10000 @lastCheckoutIndex))
  [nbVotes] @@@votesLoc
  [nbNewVotes] (/ (calldatasize) 32)
  [[@votesLoc]] (+ @nbVotes @nbNewVotes)
  (for () (< @i @nbNewVotes) [i] (+ @i 1)
    [[(+ @votesLoc @nbVotes @i 1)]] (calldataload (* @i 32)))
}