Add misc logging

token-lending/program/Cargo.toml

@@ -21,6 +21,9 @@ spl-token = { version = "3.2.0", features=["no-entrypoint"] }
 switchboard-program = "0.2.0"
 thiserror = "1.0"
 uint = "=0.9.0"
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "1.0"
 
 [dev-dependencies]
 assert_matches = "1.5.0"

token-lending/program/src/lib.rs

@@ -5,6 +5,7 @@
 pub mod entrypoint;
 pub mod error;
 pub mod instruction;
+pub mod logs;
 pub mod math;
 pub mod processor;
 pub mod pyth;
@@ -13,6 +14,9 @@ pub mod state;
 // Export current sdk types for downstream users building with a different sdk version
 pub use solana_program;
 
+#[macro_use]
+extern crate serde_derive;
+
 solana_program::declare_id!("So1endDq2YkqhipRh3WViPa8hdiSpxWy6z3Z6tMCpAo");
 
 /// Canonical null pubkey. Prints out as "nu11111111111111111111111111111111111111111"

token-lending/program/src/logs.rs

@@ -0,0 +1,114 @@
+#![allow(missing_docs)]
+use crate::math::Decimal;
+use solana_program::pubkey::Pubkey;
+use std::fmt;
+
+extern crate serde;
+extern crate serde_json;
+
+#[derive(Debug, Serialize)]
+pub enum LogEventType {
+    ObligationStateUpdate,
+    ProgramVersion,
+    PythError,
+    PythOraclePriceUpdate,
+    ReserveStateUpdate,
+    SwitchboardError,
+    SwitchboardV1OraclePriceUpdate,
+}
+
+impl fmt::Display for LogEventType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+fn pubkey_serialize<S>(x: &Pubkey, s: S) -> Result<S::Ok, S::Error>
+where
+    S: serde::ser::Serializer,
+{
+    s.serialize_str(&x.to_string())
+}
+
+#[macro_export]
+macro_rules! emit_log_event {
+    ($e:expr) => {
+        msg!("solend-event-log:");
+        msg!(&serde_json::to_string($e).unwrap());
+    };
+}
+
+#[derive(Serialize)]
+pub struct PythOraclePriceUpdate {
+    pub event_type: LogEventType,
+    #[serde(serialize_with = "pubkey_serialize")]
+    pub oracle_pubkey: Pubkey,
+    pub price: Decimal,
+    pub confidence: u64,
+    pub published_slot: u64,
+}
+
+#[derive(Serialize)]
+pub struct PythError {
+    pub event_type: LogEventType,
+    #[serde(serialize_with = "pubkey_serialize")]
+    pub oracle_pubkey: Pubkey,
+    pub error_message: String,
+}
+
+#[derive(Serialize)]
+pub struct SwitchboardV1OraclePriceUpdate {
+    pub event_type: LogEventType,
+    #[serde(serialize_with = "pubkey_serialize")]
+    pub oracle_pubkey: Pubkey,
+    pub price: Decimal,
+    pub published_slot: u64,
+}
+
+#[derive(Serialize)]
+pub struct SwitchboardError {
+    pub event_type: LogEventType,
+    #[serde(serialize_with = "pubkey_serialize")]
+    pub oracle_pubkey: Pubkey,
+    pub error_message: String,
+}
+
+#[derive(Serialize)]
+pub struct ProgramVersion {
+    pub event_type: LogEventType,
+    pub version: u8,
+}
+
+#[derive(Serialize)]
+pub struct ReserveStateUpdate {
+    pub event_type: LogEventType,
+    pub available_amount: u64,
+    pub borrowed_amount_wads: Decimal,
+    pub cumulative_borrow_rate_wads: Decimal,
+    pub collateral_mint_total_supply: u64,
+    pub collateral_exchange_rate: String,
+}
+
+// ObligationStateUpdate intentionally does not contain the obligation ID
+// to save on compute since it is contained in the transaction itself.
+#[derive(Serialize)]
+pub struct ObligationStateUpdate {
+    pub event_type: LogEventType,
+    pub allowed_borrow_value: Decimal,
+    pub unhealthy_borrow_value: Decimal,
+    pub deposits: Vec<DepositLog>,
+    pub borrows: Vec<BorrowLog>,
+}
+
+#[derive(Serialize)]
+pub struct DepositLog {
+    pub reserve_id_index: u8,
+    pub deposited_amount: u64,
+}
+
+#[derive(Serialize)]
+pub struct BorrowLog {
+    pub reserve_id_index: u8,
+    pub borrowed_amount_wads: Decimal,
+    pub cumulative_borrow_rate_wads: Decimal,
+}

token-lending/program/src/math/decimal.rs

@@ -22,11 +22,12 @@ use uint::construct_uint;
 
 // U192 with 192 bits consisting of 3 x 64-bit words
 construct_uint! {
+    #[derive(Serialize)]
     pub struct U192(3);
 }
 
 /// Large decimal values, precise to 18 digits
-#[derive(Clone, Copy, Debug, Default, PartialEq, PartialOrd, Eq, Ord)]
+#[derive(Clone, Copy, Debug, Default, PartialEq, PartialOrd, Eq, Ord, Serialize)]
 pub struct Decimal(pub U192);
 
 impl Decimal {