- Reputation Layer Contracts design
- Reputation Passport
- Passport factory
- Facts provider registry
The main idea behind our implementation is that the reputation passport is data storage owned by users, but all passports share the same contract that handles the logic. All the methods of the passport logic contract are executed in the context of the data of the passport contract through which they were called.
Currently implemented model:
╔═══════════════════╗
deploys ║ ║
┌─────passport────────────║ PassportFactory ║
│ ║ ║
│ ╚═══════════════════╝
│ │
│ uses registry to
│ bind it to passport
│ │
│ ▼
│ ╔═══════════════════════════════╗
│ ║ PassportLogicRegistry ║
│ ║ ┌─────────────────────────┐ ║
│ ║ │ versions mapping │──╬────────────────────┬─────────────────────┐
│ ║ └─────────────────────────┘ ║ │ │
│ ║ ┌─────────────────────────┐ ║ v0.1 v0.2
│ ┌────────╬─▶│ current passport logic │──╬───┐ │ │
│ │ ║ └─────────────────────────┘ ║ │ │ │
│ │ ╚═══════════════════════════════╝ │ ╔═══════════════════╗ ╔═══════════════════╗
│ gets current │ ║ ║ ║ ║
│ passport └──────║ PassportLogic ║ ║ PassportLogicV2 ║
│ logic ║ ║ ║ ║
│ │ ╚═══════════════════╝ ╚═══════════════════╝
│ │ ▲
│ ╔═══════╩══════╗ │
│ ║ Passport ║ delegate call │
├─▶║ (owner 1) ║─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┤
│ ╚═══════╦══════╝ │
│ │ │
│ │ │
│ ╔═══════╩══════╗ │
│ ║ Passport ║ delegate call │
├─▶║ (owner 2) ║─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘
│ ╚═══════╦══════╝ │
│ │
│ ... │
│ │
│ ╔══════════════╗ │
│ ║ Passport ║ delegate call
└─▶║ (owner N) ║─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘
╚══════════════╝
PassportLogic contract defines upgradable behavior of Passport contract, assuming that
each version will follow the storage structure of the previous one, but having the chance to add new behaviour and/or state variables.
Current PassportLogic implementation provides generic key-value storage structure. This is an initial set of mappings for
each type variable which could be accessed, modified or deleted by fact providers. Information can be saved to storage or as transaction data.
Data can be accessed by any person, but the facts can be modified or deleted only by the fact provider who has provided them. Currently supported set of methods is defined in
IPassportLogic.
Once the PassportLogic contract is created, it is registered in PassportLogicRegistry so that its logic
could be reused later in all the passports that use this registry. Passport owner might decide to use different registry if the logic which is maintained and developed by Monetha does not meet owner's requirementes.
PassportLogicRegistry contract contains versioned registry of passport logic.
It allows to add new versions of passport logic and set one of the available versions as current, which
will be used by all the passports. The registry simplifies the upgrade of the passport logic, leaving it be transparent,
and at the same time it does not restrict the passport owner in choosing a registry of passport logic.
Passport is a contract owned by the passport owner. It behaves like proxy that delegates
calls (using delegatecall) to current passport logic implementation which is currently set in the PassportLogicRegistry.
Given the passport uses delegatecall to resolve the requested behaviors, the upgradable passport logic contract's state
will be stored in the passport contract itself.
Passport owner is allowed to change the registry of passport logic, destroy passport or transfer ownership to the new owner (the ownership needs to be claimed).
PassportFactory contract allows anyone to deploy a new Reputation passport. To deploy a reputation passport one
should call the passport factory's createPassport() method. During this call the passport factory deploys a new passport
and binds it to the existing PassportLogicRegistry contract. It also emits PassportCreated(address indexed passport, address indexed owner)
event that allows you to get the address of the deployed passport.
After the passport contract is deployed, the same account who called the passport factory's createPassport() method should
additionally call the passport's claimOwnership() method to finalize the ownership transfer of the passport.
FactProviderRegistry contract behaves like a naming system for the known fact providers.
It associates various information (like name, passport address, website) with the fact provider address. factProviders mapping
should be used to get this information by the facts provider address:
struct FactProviderInfo {
bool initialized;
string name;
address reputation_passport;
string website;
}
mapping(address => FactProviderInfo) public factProviders;