adjustment calculation (#520)

app/app.go

@@ -20,6 +20,7 @@ import (
  tmos "github.com/cometbft/cometbft/libs/os"
  tmproto "github.com/cometbft/cometbft/proto/tendermint/types"
 
+ sdkmath "cosmossdk.io/math"
  "github.com/cosmos/cosmos-sdk/baseapp"
  "github.com/cosmos/cosmos-sdk/client"
  nodeservice "github.com/cosmos/cosmos-sdk/client/grpc/node"
@@ -128,14 +129,57 @@ type TerraApp struct {
 func (app *TerraApp) CheckTx(req abci.RequestCheckTx) abci.ResponseCheckTx {
  res := app.BaseApp.CheckTx(req)
 
+ // the ctx here is just for the logger, so it might be okay to remove it
+ // and the logging in the event parsing
  ctx := app.NewContext(true, tmproto.Header{})
 
- maxGas := app.BaseApp.GetConsensusParams(ctx).Block.MaxGas
+ // fetch consumed tax gas from events
+ taxGas := sdkmath.ZeroInt()
+ for _, event := range res.Events {
+ if event.Type == "tax2gas" {
+ for _, attr := range event.Attributes {
+ if attr.Key == "tax_gas" {
+ value, ok := sdkmath.NewIntFromString(attr.Value)
+ if !ok {
+ ctx.Logger().Error("failed to parse tax gas from events", "value", attr.Value)
+ continue
+ }
+
+ taxGas = taxGas.Add(value)
+ }
+ }
+ }
+ }
+
+ if taxGas.IsZero() {
+ return res
+ }
+
+ gasWanted := uint64(res.GasWanted)
+ gasUsed := uint64(res.GasUsed)
+ subTaxGas := taxGas.Uint64()
+
+ // check how many times the gas used fits into the gas wanted
+ // if it doesn't fit, we need to adjust the gas wanted
+ multiple := sdkmath.LegacyNewDec(res.GasWanted).Quo(sdkmath.LegacyNewDec(res.GasUsed).Add(taxGas.ToLegacyDec()))
+
+ // we have a multiplier, so we know approximately how often tax gas can be subtracted
+ // we should assume everything >= 0.9 should be subtracted. Using >= 1 would have issues with approximations
+ if multiple.GTE(sdkmath.LegacyNewDecWithPrec(9, 1)) {
+ // adjust gas wanted by the tax gas
+ subTaxGas = taxGas.ToLegacyDec().Mul(multiple).TruncateInt().Uint64()
+ }
+
+ if gasWanted > subTaxGas {
+ gasWanted -= subTaxGas
+ }
+
+ // maxGas := app.BaseApp.GetConsensusParams(ctx).Block.MaxGas
+ ctx.Logger().Info("CheckTx", "GasWanted", res.GasWanted, "GasUsed", res.GasUsed, "TaxGas", taxGas, "GasWantedAdjusted", gasWanted, "Multiple", multiple)
 
- // Adjust GasWanted if necessary
- if uint64(res.GasWanted) > uint64(maxGas) {
- // Set GasWanted to maxGasWanted to satisfy the mempool's check
- res.GasWanted = maxGas
+ // if the gas wanted is still higher than the gas used, we can adjust the gas wanted
+ if gasWanted >= gasUsed {
+ res.GasWanted = int64(gasWanted)
  }
 
  return res

x/tax2gas/post/post.go

@@ -109,6 +109,9 @@ func (tgd Tax2gasPostDecorator) PostHandle(ctx sdk.Context, tx sdk.Tx, simulate
  }
  }
 
+ // add the consumed tax gas to the transaction logs
+ ctx.EventManager().EmitEvent(sdk.NewEvent("tax2gas", sdk.NewAttribute("tax_gas", taxGas.String())))
+
  // Deduct the gas consumed amount spent on ante handler
  totalGasRemaining := sdkmath.NewInt(int64(totalGasConsumed - anteConsumedGas)).Add(taxGas)