PositionUtils

Utility library for position management operations

PositionUtils

The PositionUtils is a library contract that provides utility functions for position management across the Satoshi Perps protocol. It encapsulates common position-related logic for reuse across different contracts.

Contract Overview

The PositionUtils handles:

• Utility functions for fee calculations
• Helper functions for position operations
• Standardized implementations of common position logic

As a library, PositionUtils does not store state and is designed to be used by other contracts.

Key Functions

Fee Utilities

function shouldDeductFee(
    address _account,
    address _router,
    address[] memory _path,
    uint256 _amountIn,
    address _indexToken,
    bool _isLong
) external view returns (bool);

Determines whether a deposit fee should be charged to prevent zero-fee swaps.

Position Operations

function increasePosition(
    address _account,
    address _collateralToken,
    address _indexToken,
    uint256 _sizeDelta,
    bool _isLong,
    uint256 _price
) external;

Standard implementation for increasing a position with validation.

Usage in Other Contracts

The PositionUtils library is utilized by various contracts in the Satoshi Perps protocol:

1. BasePositionManager: Uses utility functions for position operations
2. PositionManager: Inherits position utility functions through BasePositionManager
3. PositionRouter: Uses fee utility functions to determine fee application

Implementation Details

Fee Deduction Logic

The shouldDeductFee function implements the following logic:

• If the path length is 1 (no swap), check if amountIn is greater than 0
• If it’s a long position with collateral token same as index token, no fee
• For all other cases, apply the fee

This logic helps prevent users from avoiding fees through complex transaction paths.

Integration Example

Here’s how the PositionUtils library is typically used in other contracts:

// In a position management contract
function increasePosition(/* parameters */) external {
    bool shouldChargeFee = PositionUtils.shouldDeductFee(
        msg.sender,
        router,
        path,
        amountIn,
        indexToken,
        isLong
    );
    
    if (shouldChargeFee) {
        // Apply fee logic
    }
    
    // Proceed with position increase
}

Benefits of Library Approach

Using a library for position utilities offers several advantages:

• Code Reusability: Common logic is defined once and reused across contracts
• Gas Efficiency: Library code is deployed once and shared by all contracts
• Consistency: Ensures uniform behavior across different contract implementations
• Maintainability: Changes to the utility functions need to be made in only one place

Library contracts like PositionUtils help maintain consistent behavior across the protocol and make the codebase more maintainable.