0g-chain/x/pricefeed/handler.go

package pricefeed

import (
	sdk "github.com/cosmos/cosmos-sdk/types"
	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
)

// NewHandler handles all pricefeed type messages
func NewHandler(k Keeper) sdk.Handler {
	return func(ctx sdk.Context, msg sdk.Msg) (*sdk.Result, error) {
		switch msg := msg.(type) {
		case MsgPostPrice:
			return HandleMsgPostPrice(ctx, k, msg)
		default:
			return nil, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "unrecognized %s message type: %T", ModuleName, msg)
		}
	}
}

// price feed questions:
// do proposers need to post the round in the message? If not, how do we determine the round?

// HandleMsgPostPrice handles prices posted by oracles
func HandleMsgPostPrice(
	ctx sdk.Context,
	k Keeper,
	msg MsgPostPrice) (*sdk.Result, error) {

	_, err := k.GetOracle(ctx, msg.MarketID, msg.From)
	if err != nil {
		return nil, err
	}
	_, err = k.SetPrice(ctx, msg.From, msg.MarketID, msg.Price, msg.Expiry)
	if err != nil {
		return nil, err
	}

	ctx.EventManager().EmitEvent(
		sdk.NewEvent(
			sdk.EventTypeMessage,
			sdk.NewAttribute(sdk.AttributeKeyModule, AttributeValueCategory),
			sdk.NewAttribute(sdk.AttributeKeySender, msg.From.String()),
		),
	)

	return &sdk.Result{Events: ctx.EventManager().Events()}, nil
}