Time chunk configuration

common/src/borrow.rs

@@ -56,7 +56,7 @@ impl BorrowPosition {
             collateral_asset_deposit: 0.into(),
             borrow_asset_principal: 0.into(),
             // Start from current (not next) snapshot to avoid the possibility
-            // of borrowing "for free". e.g. if ChainTime units are epochs (12
+            // of borrowing "for free". e.g. if TimeChunk units are epochs (12
             // hours), this prevents someone from getting 11 hours of free
             // borrowing if they create the borrow 1 hour into the epoch.
             borrow_asset_fees: Accumulator::new(current_snapshot_index),

common/src/lib.rs

@@ -1,7 +1,6 @@
 pub mod accumulator;
 pub mod asset;
 pub mod borrow;
-pub mod chain_time;
 pub mod event;
 pub mod fee;
 pub mod interest_rate_strategy;
@@ -11,6 +10,7 @@ pub mod oracle;
 pub mod snapshot;
 pub mod static_yield;
 pub mod supply;
+pub mod time_chunk;
 pub mod util;
 pub mod withdrawal_queue;
 

common/src/market/configuration.rs

@@ -8,13 +8,15 @@ use crate::{
     fee::{Fee, TimeBasedFee},
     interest_rate_strategy::InterestRateStrategy,
     number::Decimal,
+    time_chunk::TimeChunkConfiguration,
 };
 
 use super::{AssetConversion, AssetValuation, BalanceOracleConfiguration, PricePair, YieldWeights};
 
 #[derive(Clone, Debug)]
 #[near(serializers = [json, borsh])]
 pub struct MarketConfiguration {
+    pub time_chunk_configuration: TimeChunkConfiguration,
     pub borrow_asset: FungibleAsset<BorrowAsset>,
     pub collateral_asset: FungibleAsset<CollateralAsset>,
     pub balance_oracle: BalanceOracleConfiguration,

common/src/market/impl.rs

@@ -8,7 +8,6 @@ use near_sdk::{
 use crate::{
     asset::BorrowAssetAmount,
     borrow::{BorrowPosition, LinkedBorrowPosition, LinkedBorrowPositionMut},
-    chain_time::ChainTime,
     event::MarketEvent,
     market::MarketConfiguration,
     number::Decimal,
@@ -89,18 +88,18 @@ impl Market {
     }
 
     fn snapshot_with_yield_distribution(&mut self, yield_distribution: BorrowAssetAmount) -> u32 {
-        let chain_time = ChainTime::now();
+        let time_chunk = self.configuration.time_chunk_configuration.now();
 
         if let Some((last_index, old_snapshot)) =
             self.snapshots.len().checked_sub(1).and_then(|last_index| {
                 self.snapshots
                     .get(last_index)
-                    .filter(|s| s.chain_time == chain_time)
+                    .filter(|s| s.time_chunk == time_chunk)
                     .map(|s| (last_index, s))
             })
         {
             let new_snapshot = Snapshot {
-                chain_time,
+                time_chunk,
                 timestamp_ms: old_snapshot.timestamp_ms,
                 deposited: self.borrow_asset_deposited,
                 borrowed: self.borrow_asset_borrowed,
@@ -115,7 +114,7 @@ impl Market {
         } else {
             let index = self.snapshots.len();
             let new_snapshot = Snapshot {
-                chain_time,
+                time_chunk,
                 timestamp_ms: env::block_timestamp_ms().into(),
                 deposited: self.borrow_asset_deposited,
                 borrowed: self.borrow_asset_borrowed,

common/src/snapshot.rs

@@ -1,11 +1,11 @@
 use near_sdk::{json_types::U64, near};
 
-use crate::{asset::BorrowAssetAmount, chain_time::ChainTime};
+use crate::{asset::BorrowAssetAmount, time_chunk::TimeChunk};
 
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 #[near(serializers = [borsh, json])]
 pub struct Snapshot {
-    pub chain_time: ChainTime,
+    pub time_chunk: TimeChunk,
     pub timestamp_ms: U64,
     pub deposited: BorrowAssetAmount,
     pub borrowed: BorrowAssetAmount,

common/src/time_chunk.rs

@@ -0,0 +1,28 @@
+use near_sdk::{env, json_types::U64, near};
+
+/// Configure a method of determining the current time chunk.
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[near(serializers = [json, borsh])]
+pub enum TimeChunkConfiguration {
+    BlockHeight { divisor: U64 },
+    EpochHeight { divisor: U64 },
+    BlockTimestampMs { divisor: U64 },
+}
+
+impl TimeChunkConfiguration {
+    pub fn now(&self) -> TimeChunk {
+        let (time, U64(mut divisor)) = match self {
+            Self::BlockHeight { divisor } => (env::block_height(), divisor),
+            Self::EpochHeight { divisor } => (env::epoch_height(), divisor),
+            Self::BlockTimestampMs { divisor } => (env::block_timestamp_ms(), divisor),
+        };
+        if divisor == 0 {
+            divisor = 1;
+        }
+        TimeChunk(U64(time / divisor))
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[near(serializers = [borsh, json])]
+pub struct TimeChunk(pub U64);

test-utils/examples/generate_testnet_configuration.rs

@@ -12,12 +12,16 @@ use templar_common::{
     market::{BalanceOracleConfiguration, MarketConfiguration, YieldWeights},
     number::Decimal,
     oracle::pyth::PriceIdentifier,
+    time_chunk::TimeChunkConfiguration,
 };
 
 pub fn main() {
     println!(
         "{{\"configuration\":{}}}",
         serde_json::to_string(&MarketConfiguration {
+            time_chunk_configuration: TimeChunkConfiguration::BlockTimestampMs {
+                divisor: (1000u64 * 60 * 10).into(), // every 10 minutes
+            },
             borrow_asset: FungibleAsset::nep141("usdt.fakes.testnet".parse().unwrap()),
             collateral_asset: FungibleAsset::nep141("wrap.testnet".parse().unwrap()),
             balance_oracle: BalanceOracleConfiguration {

test-utils/src/lib.rs

@@ -709,7 +709,7 @@ impl TestController {
 
         println!("Market snapshots:");
         for (i, snapshot) in snapshots.iter().enumerate() {
-            println!("\t{i}: {}", snapshot.chain_time);
+            println!("\t{i}: {}", snapshot.time_chunk.0 .0);
             println!("\t\tTimestamp:\t{}", snapshot.timestamp_ms.0);
             println!("\t\tDeposited:\t{}", snapshot.deposited.as_u128());
             println!("\t\tBorrowed:\t{}", snapshot.borrowed.as_u128());
@@ -745,6 +745,9 @@ pub fn market_configuration(
     yield_weights: YieldWeights,
 ) -> MarketConfiguration {
     MarketConfiguration {
+        time_chunk_configuration: templar_common::time_chunk::TimeChunkConfiguration::BlockHeight {
+            divisor: U64(1),
+        },
         borrow_asset: FungibleAsset::nep141(borrow_asset_id),
         collateral_asset: FungibleAsset::nep141(collateral_asset_id),
         balance_oracle: BalanceOracleConfiguration {