Rpc: introduce get_inflation_reward rpc call (#16278)

* feat: introduce get_inflation_reward rpc call

* fix: style suggestions

* fix: more style changes and match how other rpc functions are defined

* feat: get reward for a single epoch

* feat: default to the most recent epoch

* fix: don't factor out get_confirmed_block

* style: introduce from impl for RpcEncodingConfigWrapper

* style: bring commitment into variable

* feat: support multiple pubkeys for get_inflation_reward

* feat: add get_inflation_reward to rpc client

* feat: return rewards in order

* fix: rename pubkeys to addresses

* docs: introduce jsonrpc docs for get_inflation_reward

* style: early return in map (not sure which is more idiomatic)

* fix: call the rpc client function args addresses as well

* fix: style

* fix: filter out only addresses we care about

* style: make this more idiomatic

* fix: change rpc client epoch to optional and include some docs edits

* feat: filter out rent rewards in get_inflation_reward

* feat: add option epoch config param to get_inflation_reward

* feat: rpc client get_inflation_reward takes epoch instead of config and some filter staking and voting rewards

client/src/rpc_client.rs

@@ -5,10 +5,10 @@ use {
         mock_sender::{MockSender, Mocks},
         rpc_config::RpcAccountInfoConfig,
         rpc_config::{
-            RpcConfirmedBlockConfig, RpcConfirmedTransactionConfig,
+            RpcConfirmedBlockConfig, RpcConfirmedTransactionConfig, RpcEpochConfig,
             RpcGetConfirmedSignaturesForAddress2Config, RpcLargestAccountsConfig,
             RpcProgramAccountsConfig, RpcSendTransactionConfig, RpcSimulateTransactionConfig,
-            RpcStakeConfig, RpcTokenAccountsFilter,
+            RpcTokenAccountsFilter,
         },
         rpc_request::{RpcError, RpcRequest, RpcResponseErrorData, TokenAccountsFilter},
         rpc_response::*,
@@ -436,7 +436,7 @@ impl RpcClient {
             RpcRequest::GetStakeActivation,
             json!([
                 stake_account.to_string(),
-                RpcStakeConfig {
+                RpcEpochConfig {
                     epoch,
                     commitment: Some(self.commitment_config),
                 }
@@ -764,6 +764,27 @@ impl RpcClient {
         self.send(RpcRequest::GetInflationRate, Value::Null)
     }
 
+    pub fn get_inflation_reward(
+        &self,
+        addresses: &[Pubkey],
+        epoch: Option<Epoch>,
+    ) -> ClientResult<Vec<Option<RpcInflationReward>>> {
+        let addresses: Vec<_> = addresses
+            .iter()
+            .map(|address| address.to_string())
+            .collect();
+        self.send(
+            RpcRequest::GetInflationReward,
+            json!([
+                addresses,
+                RpcEpochConfig {
+                    epoch,
+                    commitment: Some(self.commitment_config),
+                }
+            ]),
+        )
+    }
+
     pub fn get_version(&self) -> ClientResult<RpcVersionInfo> {
         self.send(RpcRequest::GetVersion, Value::Null)
     }

client/src/rpc_config.rs

@@ -50,7 +50,7 @@ pub struct RpcLargestAccountsConfig {
 
 #[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
-pub struct RpcStakeConfig {
+pub struct RpcEpochConfig {
     pub epoch: Option<Epoch>,
     #[serde(flatten)]
     pub commitment: Option<CommitmentConfig>,
@@ -161,6 +161,12 @@ impl RpcConfirmedBlockConfig {
     }
 }
 
+impl From<RpcConfirmedBlockConfig> for RpcEncodingConfigWrapper<RpcConfirmedBlockConfig> {
+    fn from(config: RpcConfirmedBlockConfig) -> Self {
+        RpcEncodingConfigWrapper::Current(Some(config))
+    }
+}
+
 #[derive(Debug, Clone, Copy, Default, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct RpcConfirmedTransactionConfig {

client/src/rpc_request.rs

@@ -30,6 +30,7 @@ pub enum RpcRequest {
     GetIdentity,
     GetInflationGovernor,
     GetInflationRate,
+    GetInflationReward,
     GetLargestAccounts,
     GetLeaderSchedule,
     GetMaxRetransmitSlot,
@@ -91,6 +92,7 @@ impl fmt::Display for RpcRequest {
             RpcRequest::GetIdentity => "getIdentity",
             RpcRequest::GetInflationGovernor => "getInflationGovernor",
             RpcRequest::GetInflationRate => "getInflationRate",
+            RpcRequest::GetInflationReward => "getInflationReward",
             RpcRequest::GetLargestAccounts => "getLargestAccounts",
             RpcRequest::GetLeaderSchedule => "getLeaderSchedule",
             RpcRequest::GetMaxRetransmitSlot => "getMaxRetransmitSlot",

client/src/rpc_response.rs

@@ -362,6 +362,15 @@ pub struct RpcPerfSample {
     pub sample_period_secs: u16,
 }
 
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct RpcInflationReward {
+    pub epoch: Epoch,
+    pub effective_slot: Slot,
+    pub amount: u64,       // lamports
+    pub post_balance: u64, // lamports
+}
+
 impl From<ConfirmedTransactionStatusWithSignature> for RpcConfirmedTransactionStatusWithSignature {
     fn from(value: ConfirmedTransactionStatusWithSignature) -> Self {
         let ConfirmedTransactionStatusWithSignature {