Rent tangential stuff (#5910)

* rename rent.rs to rent_calculator.rs

* add rent sysvar

* integrate rent_calculator with bank

* rent_calculator integration with genesis

* add test for rent sysvar

sdk/src/genesis_block.rs

@@ -7,7 +7,7 @@ use crate::hash::{hash, Hash};
 use crate::inflation::Inflation;
 use crate::poh_config::PohConfig;
 use crate::pubkey::Pubkey;
-use crate::rent::Rent;
+use crate::rent_calculator::RentCalculator;
 use crate::signature::{Keypair, KeypairUtil};
 use crate::system_program::{self, solana_system_program};
 use bincode::{deserialize, serialize};
@@ -28,8 +28,8 @@ pub struct GenesisBlock {
     pub slots_per_segment: u64,
     pub poh_config: PohConfig,
     pub fee_calculator: FeeCalculator,
+    pub rent_calculator: RentCalculator,
     pub inflation: Inflation,
-    pub rent: Rent,
 }
 
 // useful for basic tests
@@ -61,7 +61,7 @@ impl Default for GenesisBlock {
             poh_config: PohConfig::default(),
             inflation: Inflation::default(),
             fee_calculator: FeeCalculator::default(),
-            rent: Rent::default(),
+            rent_calculator: RentCalculator::default(),
         }
     }
 }
@@ -147,6 +147,10 @@ impl Builder {
         self.genesis_block.inflation = inflation;
         self
     }
+    pub fn rent_calculator(mut self, rent_calculator: RentCalculator) -> Self {
+        self.genesis_block.rent_calculator = rent_calculator;
+        self
+    }
 }
 
 impl GenesisBlock {

sdk/src/lib.rs

@@ -13,7 +13,7 @@ pub mod native_loader;
 pub mod packet;
 pub mod poh_config;
 pub mod pubkey;
-pub mod rent;
+pub mod rent_calculator;
 pub mod rpc_port;
 pub mod short_vec;
 pub mod system_instruction;

sdk/src/rent_calculator.rs

@@ -1,7 +1,7 @@
 //! configuration for network rent
 
 #[derive(Serialize, Deserialize, PartialEq, Clone, Copy, Debug)]
-pub struct Rent {
+pub struct RentCalculator {
     /// Rental rate
     pub lamports_per_byte_year: u64,
 
@@ -25,7 +25,7 @@ pub const DEFAULT_EXEMPTION_THRESHOLD: f64 = 2.0;
 /// default amount of rent to burn, as a fraction of std::u8::MAX
 pub const DEFAULT_BURN_PERCENT: u8 = ((50usize * std::u8::MAX as usize) / 100usize) as u8;
 
-impl Default for Rent {
+impl Default for RentCalculator {
     fn default() -> Self {
         Self {
             lamports_per_byte_year: DEFAULT_LAMPORTS_PER_BYTE_YEAR,
@@ -35,7 +35,7 @@ impl Default for Rent {
     }
 }
 
-impl Rent {
+impl RentCalculator {
     /// minimum balance due for a given size Account::data.len()
     pub fn minimum_balance(&self, data_len: usize) -> u64 {
         let bytes = data_len as u64;
@@ -66,17 +66,17 @@ mod tests {
 
     #[test]
     fn test_due() {
-        let rent = Rent::default();
+        let rent_calculator = RentCalculator::default();
 
         assert_eq!(
-            rent.due(0, 1, 1.0),
+            rent_calculator.due(0, 1, 1.0),
             (
                 DEFAULT_LAMPORTS_PER_BYTE_YEAR,
                 DEFAULT_LAMPORTS_PER_BYTE_YEAR == 0
             )
         );
         assert_eq!(
-            rent.due(
+            rent_calculator.due(
                 DEFAULT_LAMPORTS_PER_BYTE_YEAR * DEFAULT_EXEMPTION_THRESHOLD as u64,
                 1,
                 1.0
@@ -94,21 +94,21 @@ mod tests {
     //        const SLOTS_PER_YEAR: f64 =
     //            SECONDS_PER_YEAR / (DEFAULT_TICKS_PER_SLOT as f64 / DEFAULT_TICKS_PER_SECOND as f64);
     //
-    //        let rent = Rent::default();
+    //        let rent_calculator = RentCalculator::default();
     //
     //        eprintln();
     //        // lamports charged per byte per slot at $1/MByear, rent per slot is zero
     //        eprintln(
-    //            "{} lamports per byte-slot, rent.due(): {}",
+    //            "{} lamports per byte-slot, rent_calculator.due(): {}",
     //            (1.0 / SLOTS_PER_YEAR) * DEFAULT_LAMPORTS_PER_BYTE_YEAR as f64,
-    //            rent.due(0, 1, 1.0 / SLOTS_PER_YEAR).0,
+    //            rent_calculator.due(0, 1, 1.0 / SLOTS_PER_YEAR).0,
     //        );
     //        // lamports charged per byte per _epoch_ starts to have some significant digits
     //        eprintln(
-    //            "{} lamports per byte-epoch, rent.due(): {}",
+    //            "{} lamports per byte-epoch, rent_calculator.due(): {}",
     //            (1.0 / SLOTS_PER_YEAR)
     //                * (DEFAULT_LAMPORTS_PER_BYTE_YEAR * DEFAULT_SLOTS_PER_EPOCH) as f64,
-    //            rent.due(
+    //            rent_calculator.due(
     //                0,
     //                1,
     //                (1.0 / SLOTS_PER_YEAR) * DEFAULT_SLOTS_PER_EPOCH as f64
@@ -119,7 +119,7 @@ mod tests {
     //        eprintln(
     //            "stake_history: {}kB == {} lamports per epoch",
     //            crate::sysvar::stake_history::StakeHistory::size_of() / 1024,
-    //            rent.due(
+    //            rent_calculator.due(
     //                0,
     //                crate::sysvar::stake_history::StakeHistory::size_of(),
     //                (1.0 / SLOTS_PER_YEAR) * DEFAULT_SLOTS_PER_EPOCH as f64

sdk/src/sysvar/mod.rs

@@ -4,6 +4,7 @@ use crate::pubkey::Pubkey;
 
 pub mod clock;
 pub mod fees;
+pub mod rent;
 pub mod rewards;
 pub mod slot_hashes;
 pub mod stake_history;

sdk/src/sysvar/rent.rs

@@ -0,0 +1,63 @@
+//! This account contains the current cluster rent
+//!
+use crate::account::Account;
+use crate::account_info::AccountInfo;
+use crate::rent_calculator::RentCalculator;
+use crate::sysvar;
+use bincode::serialized_size;
+
+///  rent account pubkey
+const ID: [u8; 32] = [
+    6, 167, 213, 23, 25, 44, 92, 81, 33, 140, 201, 76, 61, 74, 241, 127, 88, 218, 238, 8, 155, 161,
+    253, 68, 227, 219, 217, 138, 0, 0, 0, 0,
+];
+
+crate::solana_name_id!(ID, "SysvarRent111111111111111111111111111111111");
+
+#[repr(C)]
+#[derive(Serialize, Deserialize, Debug, Default)]
+pub struct Rent {
+    pub rent_calculator: RentCalculator,
+}
+
+impl Rent {
+    pub fn from_account(account: &Account) -> Option<Self> {
+        account.deserialize_data().ok()
+    }
+    pub fn to_account(&self, account: &mut Account) -> Option<()> {
+        account.serialize_data(self).ok()
+    }
+    pub fn from_account_info(account: &AccountInfo) -> Option<Self> {
+        account.deserialize_data().ok()
+    }
+    pub fn to_account_info(&self, account: &mut AccountInfo) -> Option<()> {
+        account.serialize_data(self).ok()
+    }
+    pub fn size_of() -> usize {
+        serialized_size(&Rent::default()).unwrap() as usize
+    }
+}
+
+pub fn create_account(lamports: u64, rent_calculator: &RentCalculator) -> Account {
+    Account::new_data(
+        lamports,
+        &Rent {
+            rent_calculator: *rent_calculator,
+        },
+        &sysvar::id(),
+    )
+    .unwrap()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_fees_create_account() {
+        let lamports = 42;
+        let account = create_account(lamports, &RentCalculator::default());
+        let rent = Rent::from_account(&account).unwrap();
+        assert_eq!(rent.rent_calculator, RentCalculator::default());
+    }
+}