Query all Delegator Distribution Rewards (#3433)

PENDING.md

@@ -22,6 +22,8 @@ FEATURES
 * Gaia REST API
 
 * Gaia CLI  (`gaiacli`)
+  * [\#3429](https://github.com/cosmos/cosmos-sdk/issues/3429) Support querying
+  for all delegator distribution rewards.
 
 * Gaia
   - [\#3397](https://github.com/cosmos/cosmos-sdk/pull/3397) Implement genesis file sanitization to avoid failures at chain init.

docs/gaia/gaiacli.md

@@ -685,6 +685,14 @@ To check current rewards for a delegation (were they to be withdrawn), run:
 gaiacli query distr rewards <delegator_address> <validator_address>
 ```
 
+#### Query all delegator rewards
+
+To check all current rewards for a delegation (were they to be withdrawn), run:
+
+```bash
+gaiacli query distr rewards <delegator_address>
+```
+
 ### Multisig transactions
 
 Multisig transactions require signatures of multiple private keys. Thus, generating and signing

x/distribution/client/cli/query.go

@@ -154,8 +154,8 @@ func GetCmdQueryValidatorSlashes(queryRoute string, cdc *codec.Codec) *cobra.Com
 func GetCmdQueryDelegatorRewards(queryRoute string, cdc *codec.Codec) *cobra.Command {
 	return &cobra.Command{
 		Use:   "rewards [delegator] [validator]",
-		Args:  cobra.ExactArgs(2),
-		Short: "Query distribution delegator rewards",
+		Args:  cobra.RangeArgs(1, 2),
+		Short: "Query all distribution delegator rewards or rewards from a particular validator",
 		RunE: func(cmd *cobra.Command, args []string) error {
 			cliCtx := context.NewCLIContext().WithCodec(cdc)
 
@@ -164,26 +164,39 @@ func GetCmdQueryDelegatorRewards(queryRoute string, cdc *codec.Codec) *cobra.Com
 				return err
 			}
 
-			validatorAddr, err := sdk.ValAddressFromBech32(args[1])
-			if err != nil {
-				return err
+			var (
+				route  string
+				params distr.QueryDelegationRewardsParams
+				result sdk.DecCoins
+			)
+
+			if len(args) == 1 {
+				// query for all rewards
+				params = distr.NewQueryDelegationRewardsParams(delegatorAddr, nil)
+				route = fmt.Sprintf("custom/%s/all_delegation_rewards", queryRoute)
+			} else {
+				// query for rewards from a particular validator
+				validatorAddr, err := sdk.ValAddressFromBech32(args[1])
+				if err != nil {
+					return err
+				}
+
+				params = distr.NewQueryDelegationRewardsParams(delegatorAddr, validatorAddr)
+				route = fmt.Sprintf("custom/%s/delegation_rewards", queryRoute)
 			}
 
-			params := distr.NewQueryDelegationRewardsParams(delegatorAddr, validatorAddr)
 			bz, err := cdc.MarshalJSON(params)
 			if err != nil {
 				return err
 			}
 
-			route := fmt.Sprintf("custom/%s/delegation_rewards", queryRoute)
-			res, err := cliCtx.QueryWithData(route, bz)
+			resp, err := cliCtx.QueryWithData(route, bz)
 			if err != nil {
 				return err
 			}
 
-			var coins sdk.DecCoins
-			cdc.MustUnmarshalJSON(res, &coins)
-			return cliCtx.PrintOutput(coins)
+			cdc.MustUnmarshalJSON(resp, &result)
+			return cliCtx.PrintOutput(result)
 		},
 	}
 }

x/distribution/keeper/querier.go

@@ -12,11 +12,12 @@ import (
 
 // nolint
 const (
-	QueryParams              = "params"
-	QueryOutstandingRewards  = "outstanding_rewards"
-	QueryValidatorCommission = "validator_commission"
-	QueryValidatorSlashes    = "validator_slashes"
-	QueryDelegationRewards   = "delegation_rewards"
+	QueryParams               = "params"
+	QueryOutstandingRewards   = "outstanding_rewards"
+	QueryValidatorCommission  = "validator_commission"
+	QueryValidatorSlashes     = "validator_slashes"
+	QueryDelegationRewards    = "delegation_rewards"
+	QueryAllDelegationRewards = "all_delegation_rewards"
 
 	ParamCommunityTax        = "community_tax"
 	ParamBaseProposerReward  = "base_proposer_reward"
@@ -29,14 +30,22 @@ func NewQuerier(k Keeper) sdk.Querier {
 		switch path[0] {
 		case QueryParams:
 			return queryParams(ctx, path[1:], req, k)
+
 		case QueryOutstandingRewards:
 			return queryOutstandingRewards(ctx, path[1:], req, k)
+
 		case QueryValidatorCommission:
 			return queryValidatorCommission(ctx, path[1:], req, k)
+
 		case QueryValidatorSlashes:
 			return queryValidatorSlashes(ctx, path[1:], req, k)
+
 		case QueryDelegationRewards:
 			return queryDelegationRewards(ctx, path[1:], req, k)
+
+		case QueryAllDelegationRewards:
+			return queryAllDelegationRewards(ctx, path[1:], req, k)
+
 		default:
 			return nil, sdk.ErrUnknownRequest("unknown distr query endpoint")
 		}
@@ -158,20 +167,57 @@ func NewQueryDelegationRewardsParams(delegatorAddr sdk.AccAddress, validatorAddr
 	}
 }
 
-func queryDelegationRewards(ctx sdk.Context, path []string, req abci.RequestQuery, k Keeper) ([]byte, sdk.Error) {
+func queryDelegationRewards(ctx sdk.Context, _ []string, req abci.RequestQuery, k Keeper) ([]byte, sdk.Error) {
 	var params QueryDelegationRewardsParams
 	err := k.cdc.UnmarshalJSON(req.Data, &params)
 	if err != nil {
 		return nil, sdk.ErrUnknownRequest(sdk.AppendMsgToErr("incorrectly formatted request data", err.Error()))
 	}
+
+	// cache-wrap context as to not persist state changes during querying
 	ctx, _ = ctx.CacheContext()
+
 	val := k.stakingKeeper.Validator(ctx, params.ValidatorAddr)
 	del := k.stakingKeeper.Delegation(ctx, params.DelegatorAddr, params.ValidatorAddr)
 	endingPeriod := k.incrementValidatorPeriod(ctx, val)
 	rewards := k.calculateDelegationRewards(ctx, val, del, endingPeriod)
+
 	bz, err := codec.MarshalJSONIndent(k.cdc, rewards)
 	if err != nil {
 		return nil, sdk.ErrInternal(sdk.AppendMsgToErr("could not marshal result to JSON", err.Error()))
 	}
+
+	return bz, nil
+}
+
+func queryAllDelegationRewards(ctx sdk.Context, _ []string, req abci.RequestQuery, k Keeper) ([]byte, sdk.Error) {
+	var params QueryDelegationRewardsParams
+	err := k.cdc.UnmarshalJSON(req.Data, &params)
+	if err != nil {
+		return nil, sdk.ErrUnknownRequest(sdk.AppendMsgToErr("incorrectly formatted request data", err.Error()))
+	}
+
+	// cache-wrap context as to not persist state changes during querying
+	ctx, _ = ctx.CacheContext()
+
+	var totalRewards sdk.DecCoins
+
+	k.stakingKeeper.IterateDelegations(
+		ctx, params.DelegatorAddr,
+		func(_ int64, del sdk.Delegation) (stop bool) {
+			val := k.stakingKeeper.Validator(ctx, del.GetValidatorAddr())
+			endingPeriod := k.incrementValidatorPeriod(ctx, val)
+			rewards := k.calculateDelegationRewards(ctx, val, del, endingPeriod)
+
+			totalRewards = totalRewards.Plus(rewards)
+			return false
+		},
+	)
+
+	bz, err := codec.MarshalJSONIndent(k.cdc, totalRewards)
+	if err != nil {
+		return nil, sdk.ErrInternal(sdk.AppendMsgToErr("could not marshal result to JSON", err.Error()))
+	}
+
 	return bz, nil
 }