Add block time placeholder to getConfirmedBlock (#10989)

(cherry picked from commit 491f5ae61a)

Co-authored-by: Michael Vines <mvines@gmail.com>

docs/src/apps/jsonrpc-api.md

@@ -307,6 +307,7 @@ The result field will be an object with the following fields:
   * `rewards: <array>` - an array of JSON objects containing:
     * `pubkey: <string>` - The public key, as base-58 encoded string, of the account that received the reward
     * `lamports: <i64>`- number of reward lamports credited or debited by the account, as a i64
+  * `blockTime: <i64 | null>` - estimated production time, as Unix timestamp (seconds since the Unix epoch). null if not available
 
 #### Example:
 

ledger/src/blockstore.rs

@@ -1649,6 +1649,7 @@ impl Blockstore {
                         slot_transaction_iterator,
                     ),
                     rewards,
+                    block_time: None, // See https://github.com/solana-labs/solana/issues/10089
                 };
                 return Ok(block);
             }
@@ -5334,6 +5335,7 @@ pub mod tests {
             blockhash: blockhash.to_string(),
             previous_blockhash: Hash::default().to_string(),
             rewards: vec![],
+            block_time: None,
         };
         // The previous_blockhash of `expected_block` is default because its parent slot is a
         // root, but empty of entries. This is special handling for snapshot root slots.
@@ -5355,6 +5357,7 @@ pub mod tests {
             blockhash: blockhash.to_string(),
             previous_blockhash: blockhash.to_string(),
             rewards: vec![],
+            block_time: None,
         };
         assert_eq!(confirmed_block, expected_block);
 

transaction-status/src/lib.rs

@@ -2,7 +2,7 @@
 extern crate serde_derive;
 
 use solana_sdk::{
-    clock::Slot,
+    clock::{Slot, UnixTimestamp},
     commitment_config::CommitmentConfig,
     message::MessageHeader,
     transaction::{Result, Transaction, TransactionError},
@@ -91,6 +91,7 @@ pub struct ConfirmedBlock {
     pub parent_slot: Slot,
     pub transactions: Vec<TransactionWithStatusMeta>,
     pub rewards: Rewards,
+    pub block_time: Option<UnixTimestamp>,
 }
 
 #[derive(Debug, PartialEq, Serialize, Deserialize)]