add validator rewards pools (#4742)

* add validator rewards pools

* populate rewards syscall

programs/stake_api/Cargo.toml

@@ -11,6 +11,7 @@ edition = "2018"
 [dependencies]
 bincode = "1.1.4"
 log = "0.4.2"
+rand = "0.6.5"
 serde = "1.0.92"
 serde_derive = "1.0.92"
 solana-logger = { path = "../../logger", version = "0.16.0" }

programs/stake_api/src/lib.rs

@@ -1,3 +1,4 @@
+pub mod rewards_pools;
 pub mod stake_instruction;
 pub mod stake_state;
 

programs/stake_api/src/rewards_pools.rs

@@ -0,0 +1,67 @@
+//! rewards_pools
+//! * initialize genesis with rewards pools
+//! * keep track of rewards
+//! * own mining pools
+
+use crate::stake_state::StakeState;
+use rand::{thread_rng, Rng};
+use solana_sdk::account::Account;
+use solana_sdk::genesis_block::Builder;
+use solana_sdk::hash::{hash, Hash};
+use solana_sdk::pubkey::Pubkey;
+
+// base rewards pool ID
+const ID: [u8; 32] = [
+    6, 161, 216, 23, 186, 139, 91, 88, 83, 34, 32, 112, 237, 188, 184, 153, 69, 67, 238, 112, 93,
+    54, 133, 142, 145, 182, 214, 15, 0, 0, 0, 0,
+];
+
+solana_sdk::solana_name_id!(ID, "StakeRewards1111111111111111111111111111111");
+
+// to cut down on collisions for redemptions, we make multiple accounts
+pub const NUM_REWARDS_POOLS: usize = 256;
+
+pub fn genesis(mut builder: Builder) -> Builder {
+    let mut pubkey = id();
+
+    for _i in 0..NUM_REWARDS_POOLS {
+        builder = builder.rewards_pool(
+            pubkey,
+            Account::new_data(std::u64::MAX, &StakeState::RewardsPool, &crate::id()).unwrap(),
+        );
+        pubkey = Pubkey::new(hash(pubkey.as_ref()).as_ref());
+    }
+    builder
+}
+
+pub fn random_id() -> Pubkey {
+    let mut id = Hash::new(&ID);
+
+    for _i in 0..thread_rng().gen_range(0, NUM_REWARDS_POOLS) {
+        id = hash(id.as_ref());
+    }
+
+    Pubkey::new(id.as_ref())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use solana_sdk::genesis_block::Builder;
+
+    #[test]
+    fn test() {
+        let builder = Builder::new();
+
+        let genesis_block = genesis(builder).build();
+
+        for _i in 0..NUM_REWARDS_POOLS {
+            let id = random_id();
+            assert!(genesis_block
+                .rewards_pools
+                .iter()
+                .position(|x| x.0 == id)
+                .is_some());
+        }
+    }
+}

programs/stake_api/src/stake_state.rs

@@ -23,6 +23,7 @@ pub enum StakeState {
         /// the number of lamports each point is worth
         point_value: f64,
     },
+    RewardsPool,
 }
 
 impl Default for StakeState {