Introduce estimate_retention_cost() for TTL bump calculation

beam-contract/src/lib.rs

@@ -101,6 +101,23 @@ impl BeamOracleContract {
         PriceOracleContractBase::expires(e, asset)
     }
 
+    // Estimates amount of fee tokens required to extend the asset retention config for a given time
+    //
+    // # Arguments
+    //
+    // * `period` - Desired retention period extension (in seconds)
+    //
+    // # Returns
+    //
+    // Fee asset and estimated amount required for the fee bump
+    //
+    // # Panics
+    //
+    // Panics if the asset is not supported or if retention config is malformed/missing
+    pub fn estimate_retention_cost(e: &Env, period: u64) -> (Address, i128) {
+        PriceOracleContractBase::estimate_retention_cost(e, period)
+    }
+
     // Extends asset expiration date by a given amount of tokens.
     //
     // # Arguments
@@ -109,11 +126,15 @@ impl BeamOracleContract {
     // * `asset` - Quoted asset
     // * `amount` - Amount of tokens to burn for extending the expiration date
     //
+    // # Returns
+    //
+    // Current asset expiration timestamp (in seconds)
+    //
     // # Panics
     //
     // Panics if asset is not supported or if retention config is malformed/missing
-    pub fn extend_asset_ttl(e: &Env, sponsor: Address, asset: Asset, amount: i128) {
-        PriceOracleContractBase::extend_asset_ttl(e, sponsor, asset, amount, 0);
+    pub fn extend_asset_ttl(e: &Env, sponsor: Address, asset: Asset, amount: i128) -> u64 {
+        PriceOracleContractBase::extend_asset_ttl(e, sponsor, asset, amount, 0)
     }
 
     // Return fee token address daily price feed retainer fee amount

beam-contract/src/tests/contract_tests.rs

@@ -4,7 +4,7 @@ extern crate std;
 use crate::{BeamOracleContract, BeamOracleContractClient};
 use oracle::testutils::register_token;
 use oracle::types::{Asset, FeeConfig};
-use oracle::{assets, init_contract_with_admin};
+use oracle::{assets, init_contract_with_admin, timestamps};
 use soroban_sdk::{testutils::Address as _, Address, Vec};
 use test_case::test_case;
 
@@ -87,9 +87,18 @@ fn check_extending_asset_ttl() {
     let sponsor = Address::generate(&env);
     fee_token_client.mint(&sponsor, &10_000_000);
 
-    //check the extending
-    client.extend_asset_ttl(&sponsor, &new_asset, &1_000_000);
-    assert_eq!(client.expires(&new_asset), Some(87_300));
+    //estimate bump cost for 1 day
+    let day = 24 * 60 * 60u64;
+    let amount = client.estimate_retention_cost(&day);
+    assert_eq!(amount.0, fee_token_client.address);
+    assert_eq!(amount.1, 1_000_000);
+
+    //check bump
+    let current_expiration = client.expires(&new_asset).unwrap();
+    assert_eq!(current_expiration, 0);
+    let ttl = client.extend_asset_ttl(&sponsor, &new_asset, &amount.1);
+    assert_eq!(ttl, client.expires(&new_asset).unwrap());
+    assert_eq!(ttl, timestamps::ledger_timestamp(&env) / 1000 + day);
 
     //check that expiration records length matches assets length
     env.as_contract(&client.address, || {

oracle/src/assets.rs

@@ -7,6 +7,7 @@ const ASSET_LIMIT: u32 = 256;
 //storage keys
 const ASSETS_KEY: &str = "assets";
 const EXPIRATION_KEY: &str = "expiration";
+const DAY: i128 = 86400000;
 
 fn get_expiration_timestamp(e: &Env, initial_expiration_period: u32) -> u64 {
     if initial_expiration_period > 0 {
@@ -88,7 +89,7 @@ pub fn extend_ttl(
     asset: Asset,
     amount: i128,
     initial_expiration_period: u32,
-) {
+) -> u64 {
     //check if the amount is valid
     if amount <= 0 {
         e.panic_with_error(Error::InvalidAmount);
@@ -100,24 +101,14 @@ pub fn extend_ttl(
     }
     let asset_index = asset_index.unwrap();
     //load required fee amount from retention config
-    let (xrf, fee) = match settings::get_fee_config(e) {
-        FeeConfig::Some(fee_data) => {
-            if fee_data.1 <= 0 {
-                e.panic_with_error(Error::InvalidConfig);
-            }
-            fee_data
-        }
-        FeeConfig::None => {
-            e.panic_with_error(Error::InvalidConfig);
-        }
-    };
-    //burn corresponding amount of fee tokens
-    TokenClient::new(&e, &xrf).burn(&sponsor, &amount);
+    let (xrf, fee) = load_fee_settings(e);
     //calculate extension period
-    let bump = amount * 86400000 / fee; // in milliseconds
+    let bump = amount * DAY / fee; // in milliseconds
     if bump <= 0 {
         e.panic_with_error(Error::InvalidAmount);
     }
+    //burn corresponding amount of fee tokens
+    TokenClient::new(&e, &xrf).burn(&sponsor, &amount);
     //load expiration info
     let mut expiration = load_expiration_records(e);
     let now = timestamps::ledger_timestamp(&e);
@@ -133,7 +124,32 @@ pub fn extend_ttl(
     //write into the vector that holds expiration dates for all symbols
     expiration.set(asset_index, asset_expiration);
     //update expiration records in instance storage
-    set_expirations_records(e, &expiration)
+    set_expirations_records(e, &expiration);
+    //return current asset TTL
+    asset_expiration
+}
+
+// Estimate amount of fee tokens required to bump the retention for a given time (in milliseconds)
+pub fn estimate_retention_cost(e: &Env, bump: u64) -> (Address, i128) {
+    //load daily retention cost from config
+    let (xrf, fee) = load_fee_settings(e);
+    let amount = bump as i128 * fee / DAY;
+    (xrf, amount)
+}
+
+// Load current asset retention fee settings
+fn load_fee_settings(e: &Env) -> (Address, i128) {
+    match settings::get_fee_config(e) {
+        FeeConfig::Some(fee_data) => {
+            if fee_data.1 <= 0 {
+                e.panic_with_error(Error::InvalidConfig);
+            }
+            fee_data
+        }
+        FeeConfig::None => {
+            e.panic_with_error(Error::InvalidConfig);
+        }
+    }
 }
 
 // Load expiration data for all assets

oracle/src/price_oracle.rs

@@ -96,7 +96,7 @@ impl PriceOracleContractBase {
     //
     // # Returns
     //
-    // Asset expiration timestamp (in seconds) or None if asset is not supported
+    // Asset expiration timestamp (in seconds) or None if asset is expired
     //
     // # Panics
     //
@@ -108,6 +108,23 @@ impl PriceOracleContractBase {
         }
     }
 
+    // Estimates amount of fee tokens required to extend the asset retention config for a given time
+    //
+    // # Arguments
+    //
+    // * `period` - Desired retention period extension (in seconds)
+    //
+    // # Returns
+    //
+    // Fee asset and estimated amount required for the fee bump
+    //
+    // # Panics
+    //
+    // Panics if the asset is not supported or if retention config is malformed/missing
+    pub fn estimate_retention_cost(e: &Env, period: u64) -> (Address, i128) {
+        assets::estimate_retention_cost(e, period * 1000)
+    }
+
     // Extends the asset expiration date by a given amount of tokens.
     //
     // # Arguments
@@ -117,6 +134,10 @@ impl PriceOracleContractBase {
     // * `amount` - Amount of tokens to burn for extending the expiration date
     // * `initial_expiration_period` - Initial expiration period for new assets (in days)
     //
+    // # Returns
+    //
+    // Current asset expiration timestamp (in seconds)
+    //
     // # Panics
     //
     // Panics if the asset is not supported or if retention config is malformed/missing
@@ -126,10 +147,11 @@ impl PriceOracleContractBase {
         asset: Asset,
         amount: i128,
         initial_expiration_period: u32,
-    ) {
+    ) -> u64 {
         //check sponsor authorization
         sponsor.require_auth();
-        assets::extend_ttl(e, sponsor, asset, amount, initial_expiration_period);
+        //extend and return current TTL
+        assets::extend_ttl(e, sponsor, asset, amount, initial_expiration_period) / 1000
     }
 
     // Return the fee token address daily price feed retainer fee amount

pulse-contract/src/lib.rs

@@ -99,6 +99,23 @@ impl PulseOracleContract {
         PriceOracleContractBase::expires(e, asset)
     }
 
+    // Estimates amount of fee tokens required to extend the asset retention config for a given time
+    //
+    // # Arguments
+    //
+    // * `period` - Desired retention period extension (in seconds)
+    //
+    // # Returns
+    //
+    // Fee asset and estimated amount required for the fee bump
+    //
+    // # Panics
+    //
+    // Panics if the asset is not supported or if retention config is malformed/missing
+    pub fn estimate_retention_cost(e: &Env, period: u64) -> (Address, i128) {
+        PriceOracleContractBase::estimate_retention_cost(e, period)
+    }
+
     // Extends the asset expiration date by a given amount of tokens.
     //
     // # Arguments
@@ -107,17 +124,21 @@ impl PulseOracleContract {
     // * `asset` - Quoted asset
     // * `amount` - Amount of tokens to burn for extending the expiration date
     //
+    // # Returns
+    //
+    // Current asset expiration timestamp (in seconds)
+    //
     // # Panics
     //
     // Panics if the asset is not supported or if retention config is malformed/missing
-    pub fn extend_asset_ttl(e: &Env, sponsor: Address, asset: Asset, amount: i128) {
+    pub fn extend_asset_ttl(e: &Env, sponsor: Address, asset: Asset, amount: i128) -> u64 {
         PriceOracleContractBase::extend_asset_ttl(
             e,
             sponsor,
             asset,
             amount,
             INITIAL_EXPIRATION_PERIOD,
-        );
+        )
     }
 
     // Return the fee token address daily price feed retainer fee amount

pulse-contract/src/tests/contract_interface_tests.rs

@@ -197,10 +197,16 @@ fn extend_asset_ttl_test() {
     let asset = &init_data.assets.first_unchecked();
     let initial_expiration = client.expires(&asset).unwrap();
 
-    //extend TTL by 10 day (864000 seconds)
-    client.extend_asset_ttl(&sponsor, &asset, &10_000_000);
+    //estimate bump cost for 10 day (864000 seconds)
+    let ten_days = 10 * 24 * 60 * 60u64;
+    let amount = client.estimate_retention_cost(&ten_days);
+    assert_eq!(amount.0, fee_token.address);
+    assert_eq!(amount.1, 10_000_000);
+
+    //extend TTL
+    let ttl = client.extend_asset_ttl(&sponsor, &asset, &amount.1);
+    assert_eq!(ttl, client.expires(&asset).unwrap());
 
     //verify new expiration
-    let new_expiration = client.expires(&asset).unwrap();
-    assert_eq!(new_expiration, initial_expiration + 864000);
+    assert_eq!(ttl, initial_expiration + 864000);
 }