> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gains.trade/llms.txt
> Use this file to discover all available pages before exploring further.

# UpdatePositionSizeLifecycles

*This is an external library for position size updates lifecycles Used by GNSTrading and GNSTradingCallbacks facets*

## requestIncreasePositionSize

```solidity theme={null}
function requestIncreasePositionSize(struct IUpdatePositionSize.IncreasePositionSizeInput _input) external
```

*Initiate increase position size order, done in 2 steps because position size changes*

### Parameters

| Name    | Type                                                                                                                                                     | Description                                 |
| ------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- |
| \_input | [IUpdatePositionSize.IncreasePositionSizeInput](/developer/technical-reference/contracts/interfaces/types/iupdatepositionsize#increasepositionsizeinput) | request increase position size input struct |

## requestDecreasePositionSize

```solidity theme={null}
function requestDecreasePositionSize(struct IUpdatePositionSize.DecreasePositionSizeInput _input) external
```

*Initiate decrease position size order, done in 2 steps because position size changes*

### Parameters

| Name    | Type                                                                                                                                                     | Description                                 |
| ------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- |
| \_input | [IUpdatePositionSize.DecreasePositionSizeInput](/developer/technical-reference/contracts/interfaces/types/iupdatepositionsize#decreasepositionsizeinput) | request decrease position size input struct |

## executeIncreasePositionSizeMarket

```solidity theme={null}
function executeIncreasePositionSizeMarket(struct ITradingStorage.PendingOrder _order, struct ITradingCallbacks.AggregatorAnswer _answer) external
```

*Execute increase position size market callback*

### Parameters

| Name     | Type                                                                                                                               | Description                 |
| -------- | ---------------------------------------------------------------------------------------------------------------------------------- | --------------------------- |
| \_order  | [ITradingStorage.PendingOrder](/developer/technical-reference/contracts/interfaces/types/itradingstorage#pendingorder)             | corresponding pending order |
| \_answer | [ITradingCallbacks.AggregatorAnswer](/developer/technical-reference/contracts/interfaces/types/itradingcallbacks#aggregatoranswer) | price aggregator answer     |

## executeDecreasePositionSizeMarket

```solidity theme={null}
function executeDecreasePositionSizeMarket(struct ITradingStorage.PendingOrder _order, struct ITradingCallbacks.AggregatorAnswer _answer) external
```

*Execute decrease position size market callback*

### Parameters

| Name     | Type                                                                                                                               | Description                 |
| -------- | ---------------------------------------------------------------------------------------------------------------------------------- | --------------------------- |
| \_order  | [ITradingStorage.PendingOrder](/developer/technical-reference/contracts/interfaces/types/itradingstorage#pendingorder)             | corresponding pending order |
| \_answer | [ITradingCallbacks.AggregatorAnswer](/developer/technical-reference/contracts/interfaces/types/itradingcallbacks#aggregatoranswer) | price aggregator answer     |

## \_getMultiCollatDiamond

```solidity theme={null}
function _getMultiCollatDiamond() internal view returns (contract IGNSMultiCollatDiamond)
```

*Returns current address as multi-collateral diamond interface to call other facets functions.*

## \_baseValidateRequest

```solidity theme={null}
function _baseValidateRequest(address _trader, uint32 _index) internal view returns (struct ITradingStorage.Trade trade)
```

*Basic validation for increase/decrease position size request*

### Parameters

| Name     | Type    | Description    |
| -------- | ------- | -------------- |
| \_trader | address | trader address |
| \_index  | uint32  | trade index    |

## \_initiateRequest

```solidity theme={null}
function _initiateRequest(struct ITradingStorage.Trade _trade, bool _isIncrease, uint120 _collateralAmount, uint24 _leverage, uint256 _positionSizeCollateralDelta, uint64 _expectedPrice, uint16 _maxSlippageP) internal returns (struct ITradingStorage.Id orderId)
```

*Creates pending order, makes price aggregator request, and returns corresponding pending order id*

### Parameters

| Name                          | Type                                                                                                     | Description                                                                           |
| ----------------------------- | -------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
| \_trade                       | [ITradingStorage.Trade](/developer/technical-reference/contracts/interfaces/types/itradingstorage#trade) | trade to update                                                                       |
| \_isIncrease                  | bool                                                                                                     | whether is increase or decrease position size order                                   |
| \_collateralAmount            | uint120                                                                                                  | partial trade collateral amount (collateral precision)                                |
| \_leverage                    | uint24                                                                                                   | partial trade leverage (1e3)                                                          |
| \_positionSizeCollateralDelta | uint256                                                                                                  | position size delta in collateral tokens (collateral precision)                       |
| \_expectedPrice               | uint64                                                                                                   | reference price for max slippage check (1e10), only useful for increase position size |
| \_maxSlippageP                | uint16                                                                                                   | max slippage % (1e3), only useful for increase position size                          |

## \_validateBaseFulfillment

```solidity theme={null}
function _validateBaseFulfillment(struct ITradingStorage.Trade _trade, struct ITradingCallbacks.AggregatorAnswer _answer) internal pure returns (enum ITradingCallbacks.CancelReason)
```

*Basic validation for callbacks, returns corresponding cancel reason*

### Parameters

| Name     | Type                                                                                                                               | Description            |
| -------- | ---------------------------------------------------------------------------------------------------------------------------------- | ---------------------- |
| \_trade  | [ITradingStorage.Trade](/developer/technical-reference/contracts/interfaces/types/itradingstorage#trade)                           | trade struct           |
| \_answer | [ITradingCallbacks.AggregatorAnswer](/developer/technical-reference/contracts/interfaces/types/itradingcallbacks#aggregatoranswer) | price aggegator answer |