Factory

Overview

The Factory contract is a generalized deployment mechanism for creating upgradeable proxy instances of pre-approved implementations. It tracks multiple implementation versions, proposal workflows, blacklisting for security, and ownership-based access control.

It conforms to the IFactory interface and supports deploying any IFactoryEntity compliant contracts via TransparentUpgradeableProxy, using initialize() for configuration.

Key Capabilities

• Versioned deployment: track multiple logic contract versions, each deployable by index.
• Proposal system: allow anyone to propose implementations, with owner approval required.
• Blacklist mechanism: prevent deployment of insecure or deprecated versions.
• Deterministic deployments: uses create2 salt to ensure predictable addresses.
• Entity tracking: keeps a registry of all deployed entities.

Storage Structure

The contract uses a deterministic storage layout via:

bytes32 _factoryStorageSlot = SlotLibrary.getSlot("Factory", name_, version_);

Storage fields (in FactoryStorage) include:

Field	Description
entities	Set of all deployed proxy instances
implementations	Approved logic contract addresses
proposals	Pending implementation proposals
isBlacklisted	Mapping from version -> is blacklisted

Initialization

function initialize(bytes calldata data) external initializer

• Accepts encoded owner address.
• Sets initial admin and emits Initialized.

Entity Deployment

function create(uint256 version, address owner, bytes calldata initParams) external returns (address instance)

Deploys a new TransparentUpgradeableProxy:

• Uses implementation from implementations.at(version).
• Rejects if version is out of bounds or blacklisted.
• Uses salt = keccak256(version, owner, initParams, currentEntityCount) for deterministic deployment.
• Calls initialize(initParams) on the new proxy.

Emits:

event Created(address instance, uint256 version, address owner, bytes initParams);

Implementation Management

Propose New Implementation

function proposeImplementation(address implementation) external

• Fails if already in implementations or proposals.
• Adds to proposals.
• Emits ProposeImplementation(implementation).
• Permissionless function.

Accept Proposed Implementation

function acceptProposedImplementation(address implementation) external onlyOwner

• Only callable by owner.
• Fails if not proposed.
• Moves from proposals to implementations.
• Emits AcceptProposedImplementation(implementation).

Blacklisting

function setBlacklistStatus(uint256 version, bool flag) external onlyOwner

• Blocks deployments using a specific version.
• Enforces that version index exists.
• Emits SetBlacklistStatus(version, flag).

View Functions

Function	Returns
entities()	Total number of deployed entities
entityAt(index)	Deployed entity at index
isEntity(address)	Checks if address is a deployed entity
implementations()	Total implementation count
implementationAt(index)	Implementation at index
proposals()	Total proposals pending approval
proposalAt(index)	Proposal at index
isBlacklisted(version)	Whether a version is blocked from deployment

Access Control

• Uses OwnableUpgradeable.
• Only owner can accept implementations and blacklist versions.

Security Considerations

• Immutable logic whitelist: only approved contracts can be deployed.
• Blacklisting: emergency response for vulnerabilities.
• Replay protection: deployment salt ensures unique addresses.
• Decentralized proposals: anyone can propose implementations, but only owner can accept.