BloomPool.sol

Overview

The BloomPool contract is a decentralized application built on the Ethereum blockchain. It's a lending platform that takes in deposits from both lenders and borrowers, with the main functionality driven by a state machine.

Key Features

• Commitment processing for both borrowers and lenders.

• Integration with external components like Whitelist, SwapFacility and BPSFeed.

• State transitions and time-bound operations.

• Handles swaps between two tokens using SwapFacility.

Libraries and Interfaces

• ERC20.sol: Used for handling operations related to ERC20 tokens.

• IBloomPool.sol: Interface to define methods for the BloomPool contract.

• ISwapRecipient.sol: Interface that defines methods for a contract that can receive tokens as a result of a swap operation.

• SafeTransferLib.sol: Used for safe token transfers, reverts transaction if the transfer fails.

• SafeCastLib.sol: Used for safe casting of integer types, prevents overflows.

• FixedPointMathLib.sol: Provides mathematical functions for fixed-point arithmetic.

• CommitmentsLib.sol: Provides functions to handle commitments of borrowers and lenders.

• IWhitelist.sol: Interface that defines methods for whitelist checking of an address.

• ISwapFacility.sol: Interface that defines methods for swapping tokens.

• IBPSFeed.sol: Interface that defines methods to get the Basis Point feed.

Core Parameters

The constructor of the contract sets the immutable state variables that determine the behavior of the contract:

• UNDERLYING_TOKEN: ERC20 token that is being deposited by lenders and borrowers.

• BILL_TOKEN: Token to be received as a result of swap operations.

• WHITELIST: Contract for checking if an address is whitelisted.

• SWAP_FACILITY: Contract for handling swap operations.

• TREASURY: Address of the treasury where the fees are sent.

• LENDER_RETURN_BPS_FEED: Contract for getting the Basis Point feed for lender returns.

• EMERGENCY_HANDLER: Address that can handle emergency situations.

• LEVERAGE_BPS: The leverage rate in Basis Points.

• MIN_BORROW_DEPOSIT: Minimum deposit required from a borrower.

• COMMIT_PHASE_END: Block timestamp marking the end of the commit phase.

• PRE_HOLD_SWAP_TIMEOUT_END: Block timestamp marking the end of pre-hold swap timeout.

• POOL_PHASE_END: Block timestamp marking the end of the pool phase.

• POOL_PHASE_DURATION: Duration of the pool phase.

• LENDER_RETURN_FEE: Fee that a lender must pay.

• BORROWER_RETURN_FEE: Fee that a borrower must pay.

Modifiers

• onlyState(State expectedState): Allows function execution only if the current state of the contract is the expected state.

• onlyAfterState(State lastInvalidState): Allows function execution only if the current state of the contract is after the last invalid state.

Functions

This section provides a brief overview of the key functions available in the contract:

• depositBorrower: Allows a whitelisted borrower to deposit a specified amount of the underlying token.

• depositLender: Allows a lender to deposit a specified amount of the underlying token.

• processBorrowerCommit: Processes the commitment of a borrower, splits the committed amount based on the leverage ratio, and returns the excluded amount to the borrower.

• processLenderCommit: Processes the commitment of a lender, splits the committed amount based on the leverage ratio, transfers the excluded amount back to the lender, and mints equivalent pool tokens.

• initiatePreHoldSwap: Initiates the swap operation from the underlying token to the bill token.

• initiatePostHoldSwap: Initiates the swap operation from the bill token back to the underlying token.

• completeSwap: Completes the swap operation, should be called by the ISwapFacility contract after a swap is successfully executed.

• emergencyHandlerCall: Allows the designated emergency handler to intervene and transfer assets from the pool in emergency situations.

Events

• BorrowerCommit: Emitted when a borrower commits some amount to the pool.

• LenderCommit: Emitted when a lender commits some amount to the pool.

• BorrowerCommitmentProcessed: Emitted when a borrower's commitment is processed.

• LenderCommitmentProcessed: Emitted when a lender's commitment is processed.

• ExplictStateTransition: Emitted when a state transition is triggered explicitly.

• SwapComplete: Emitted when a swap operation is successfully completed.

• EmergencyHandlerCall: Emitted when the emergency handler intervenes.

State Transitions

The contract maintains different states that it transitions through, governed by the time-bound phases and operations. The states include Commit, ReadyPreHoldSwap, PendingPreHoldSwap, Hold, ReadyPostHoldSwap, PendingPostHoldSwap, ReadyToWithdraw, and Emergency.