Move SLOTS_PER_SEGMENT to genesis (#4992)

automerge

sdk/src/genesis_block.rs

@@ -8,7 +8,7 @@ use crate::poh_config::PohConfig;
 use crate::pubkey::Pubkey;
 use crate::signature::{Keypair, KeypairUtil};
 use crate::system_program;
-use crate::timing::{DEFAULT_SLOTS_PER_EPOCH, DEFAULT_TICKS_PER_SLOT};
+use crate::timing::{DEFAULT_SLOTS_PER_EPOCH, DEFAULT_SLOTS_PER_SEGMENT, DEFAULT_TICKS_PER_SLOT};
 use bincode::{deserialize, serialize};
 use memmap::Mmap;
 use std::fs::{File, OpenOptions};
@@ -24,6 +24,7 @@ pub struct GenesisBlock {
     pub stakers_slot_offset: u64,
     pub epoch_warmup: bool,
     pub ticks_per_slot: u64,
+    pub slots_per_segment: u64,
     pub poh_config: PohConfig,
     pub fee_calculator: FeeCalculator,
     pub inflation: Inflation,
@@ -54,6 +55,7 @@ impl Default for GenesisBlock {
             slots_per_epoch: DEFAULT_SLOTS_PER_EPOCH,
             stakers_slot_offset: DEFAULT_SLOTS_PER_EPOCH,
             ticks_per_slot: DEFAULT_TICKS_PER_SLOT,
+            slots_per_segment: DEFAULT_SLOTS_PER_SEGMENT,
             poh_config: PohConfig::default(),
             inflation: Inflation::default(),
             fee_calculator: FeeCalculator::default(),

sdk/src/syscall/current.rs

@@ -17,6 +17,7 @@ const ID: [u8; 32] = [
 #[derive(Serialize, Deserialize, Debug, Default, PartialEq)]
 pub struct Current {
     pub slot: Slot,
+    pub segment: Segment,
     pub epoch: Epoch,
     pub stakers_epoch: Epoch,
 }
@@ -34,11 +35,18 @@ impl Current {
     }
 }
 
-pub fn create_account(lamports: u64, slot: Slot, epoch: Epoch, stakers_epoch: Epoch) -> Account {
+pub fn create_account(
+    lamports: u64,
+    slot: Slot,
+    segment: Segment,
+    epoch: Epoch,
+    stakers_epoch: Epoch,
+) -> Account {
     Account::new_data(
         lamports,
         &Current {
             slot,
+            segment,
             epoch,
             stakers_epoch,
         },
@@ -49,6 +57,8 @@ pub fn create_account(lamports: u64, slot: Slot, epoch: Epoch, stakers_epoch: Ep
 
 use crate::account::KeyedAccount;
 use crate::instruction::InstructionError;
+use crate::timing::Segment;
+
 pub fn from_keyed_account(account: &KeyedAccount) -> Result<Current, InstructionError> {
     if !check_id(account.unsigned_key()) {
         return Err(InstructionError::InvalidArgument);
@@ -62,7 +72,7 @@ mod tests {
 
     #[test]
     fn test_create_account() {
-        let account = create_account(1, 0, 0, 0);
+        let account = create_account(1, 0, 0, 0, 0);
         let current = Current::from(&account).unwrap();
         assert_eq!(current, Current::default());
     }

sdk/src/timing.rs

@@ -13,6 +13,9 @@ pub const DEFAULT_TICKS_PER_SLOT: u64 = 4;
 // 1 Epoch = 400 * 8192 ms ~= 55 minutes
 pub const DEFAULT_SLOTS_PER_EPOCH: u64 = 8192;
 
+// Storage segment configuration
+pub const DEFAULT_SLOTS_PER_SEGMENT: u64 = 16;
+
 pub const NUM_CONSECUTIVE_LEADER_SLOTS: u64 = 4;
 
 /// The time window of recent block hash values that the bank will track the signatures
@@ -61,10 +64,17 @@ pub fn timestamp() -> u64 {
     duration_as_ms(&now)
 }
 
+pub fn get_segment_from_slot(slot: Slot, slots_per_segment: u64) -> Segment {
+    ((slot + (slots_per_segment - 1)) / slots_per_segment)
+}
+
 /// Slot is a unit of time given to a leader for encoding,
 ///  is some some number of Ticks long.  Use a u64 to count them.
 pub type Slot = u64;
 
+/// A segment is some number of slots stored by replicators
+pub type Segment = u64;
+
 /// Epoch is a unit of time a given leader schedule is honored,
 ///  some number of Slots.  Use a u64 to count them.
 pub type Epoch = u64;