Add unique identifier for Price (#23)

* Add unique identifier for Price
* Update solana sdk to support new id
- Also makes a major version bump because it's breaking.

Co-authored-by: Ali Behjati <[email protected]>

Author: tompntn

pyth-sdk-solana/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyth-sdk-solana"
-version = "0.1.0"
+version = "0.2.0"
 authors = ["Pyth Data Foundation"]
 edition = "2018"
 license = "Apache-2.0"
@@ -19,7 +19,7 @@ num-derive = "0.3"
 num-traits = "0.2"
 thiserror = "1.0"
 serde = { version = "1.0.136", features = ["derive"] }
-pyth-sdk = { path = "../pyth-sdk", version = "0.1.0" }
+pyth-sdk = { path = "../pyth-sdk", version = "0.2.0" }
 
 [dev-dependencies]
 solana-client = "1.8.1"
@@ -30,4 +30,3 @@ crate-type = ["cdylib", "lib"]
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
-

pyth-sdk-solana/README.md

@@ -47,18 +47,31 @@ The examples below assume that the user has already obtained this account data.
 Each price feed (e.g: `Crypto.BTC/USD`) is stored in a Solana price account.
 You can find price accounts in the pyth.network website (e.g.: [Crypto.BTC/USD accounts](https://pyth.network/markets/#Crypto.BTC/USD)).  
 
-To read the price from a price account, this library provides a `load_price` method that translates the binary account data into a `Price` struct:
+The `Price` struct contains several useful functions for working with the price.
+Some of these functions are described below.
+For more detailed information, please see the crate documentation.
+
+#### On-chain
+
+To read the price from a price account on-chain, this library provides a `load_price_from_account_info` method that constructs `Price` struct from AccountInfo:
 
 ```rust
-use pyth_sdk_solana::{load_price, Price};
+use pyth_sdk_solana::{load_price_from_account_info, Price};
 
-let price_account_data: Vec<u8> = ...;
-let price: Price = load_price( &price_account_data ).unwrap();
+let price_account_info: AccountInfo = ...;
+let price: Price = load_price( &price_account_info ).unwrap();
 ```
 
-The `Price` struct contains several useful functions for working with the price.
-Some of these functions are described below.
-For more detailed information, please see the crate documentation.
+#### Off-chain
+To read the price from a price account off-chain in clients, this library provides a `load_price_from_account` method that constructs `Price` struct from Account:
+
+```rust
+use pyth_sdk_solana::{load_price_from_account, Price};
+
+let price_key: Pubkey = ...;
+let mut price_account: Account = ...;
+let price: Price = load_price_from_account( &price_key, &mut price_account ).unwrap();
+```
 
 ### Get the current price
 

pyth-sdk-solana/examples/eth_price.rs

@@ -1,6 +1,6 @@
 // example usage of reading pyth price from solana price account
 
-use pyth_sdk_solana::load_price;
+use pyth_sdk_solana::load_price_from_account;
 use solana_client::rpc_client::RpcClient;
 use solana_program::pubkey::Pubkey;
 use std::str::FromStr;
@@ -19,8 +19,8 @@ fn main() {
 
     loop {
         // get price data from key
-        let eth_price_data = clnt.get_account_data(&eth_price_key).unwrap();
-        let eth_price = load_price(&eth_price_data).unwrap();
+        let mut eth_price_account = clnt.get_account(&eth_price_key).unwrap();
+        let eth_price = load_price_from_account(&eth_price_key, &mut eth_price_account).unwrap();
 
         println!(".....ETH/USD.....");
         println!("status .......... {:?}", eth_price.status);

pyth-sdk-solana/examples/get_accounts.rs

@@ -70,7 +70,7 @@ fn main() {
                 loop {
                     let price_data = clnt.get_account_data(&px_pkey).unwrap();
                     let price_account = load_price_account(&price_data).unwrap();
-                    let price = price_account.to_price();
+                    let price = price_account.to_price(&px_pkey);
 
                     println!("  price_account .. {:?}", px_pkey);
 

pyth-sdk-solana/src/lib.rs

@@ -7,6 +7,14 @@ pub use self::error::PythError;
 mod error;
 pub mod state;
 
+use solana_program::{
+    account_info::{
+        Account,
+        AccountInfo,
+        IntoAccountInfo,
+    }, pubkey::Pubkey,
+};
+
 use state::load_price_account;
 
 pub use pyth_sdk::{
@@ -19,9 +27,18 @@ pub use pyth_sdk::{
 /// Maximum valid slot period before price is considered to be stale.
 pub const VALID_SLOT_PERIOD: u64 = 25;
 
-/// Loads Pyth Price from the raw byte value of a Solana account.
-pub fn load_price(data: &[u8]) -> Result<Price, PythError> {
-    let price_account = load_price_account(data)?;
+/// Loads Pyth Price from Price Account Info.
+pub fn load_price_from_account_info(price_account_info: &AccountInfo) -> Result<Price, PythError> {
+    let data = price_account_info.try_borrow_data().map_err(|_| PythError::InvalidAccountData)?;
+    let price_account = load_price_account(*data)?;
+
+    Ok(price_account.to_price(&price_account_info.key))
+}
 
-    Ok(price_account.to_price())
+/// Loads Pyth Price from Account when using Solana Client.
+///
+/// It is a helper function which constructs Account Info when reading Account in clients.
+pub fn load_price_from_account(price_key: &Pubkey, price_account: &mut impl Account) -> Result<Price, PythError> {
+    let price_account_info = (price_key, price_account).into_account_info();
+    load_price_from_account_info(&price_account_info)
 }

pyth-sdk-solana/src/state.rs

@@ -12,6 +12,7 @@ use bytemuck::{
     PodCastError,
     Zeroable,
 };
+use solana_program::pubkey::Pubkey;
 use std::mem::size_of;
 
 pub use pyth_sdk::{
@@ -333,7 +334,7 @@ unsafe impl Pod for PriceAccount {
 }
 
 impl PriceAccount {
-    pub fn to_price(&self) -> Price {
+    pub fn to_price(&self, price_key: &Pubkey) -> Price {
         #[allow(unused_mut)]
         let mut status = self.agg.status;
 
@@ -345,6 +346,7 @@ impl PriceAccount {
         }
 
         Price {
+            id: price_key.to_bytes(),
             price: self.agg.price,
             conf: self.agg.conf,
             status,

pyth-sdk-solana/test-contract/Cargo.toml

@@ -1,14 +1,14 @@
 [package]
 name = "test-contract"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2018"
 
 [features]
 test-bpf = []
 no-entrypoint = []
 
 [dependencies]
-pyth-sdk-solana = { path = "../", version = "0.1.0" }
+pyth-sdk-solana = { path = "../", version = "0.2.0" }
 solana-program = "1.8.1"
 bytemuck = "1.7.2"
 borsh = "0.9"

pyth-sdk-solana/test-contract/src/processor.rs

@@ -7,7 +7,7 @@ use solana_program::program_error::ProgramError;
 use solana_program::pubkey::Pubkey;
 
 use crate::instruction::PythClientInstruction;
-use pyth_sdk_solana::load_price;
+use pyth_sdk_solana::state::load_price_account;
 
 pub fn process_instruction(
     _program_id: &Pubkey,
@@ -44,7 +44,8 @@ pub fn process_instruction(
             price_account_data,
             expected_price_status,
         } => {
-            let price = load_price(&price_account_data[..])?;
+            let price_account = load_price_account(price_account_data.as_ref())?;
+            let price = price_account.to_price(&Pubkey::default());
 
             if price.status == expected_price_status {
                 Ok(())

pyth-sdk/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyth-sdk"
-version = "0.1.0"
+version = "0.2.0"
 authors = ["Pyth Data Foundation"]
 edition = "2018"
 license = "Apache-2.0"

pyth-sdk/src/lib.rs

@@ -8,7 +8,11 @@ use schemars::JsonSchema;
 mod price_conf;
 pub use price_conf::PriceConf;
 
-/// Consists of 32 bytes and it is currently based on largest Public Key size on various blockchains.
+/// Unique identifier for a price.
+pub type PriceIdentifier = [u8; 32];
+
+/// Consists of 32 bytes and it is currently based on largest Public Key size on various
+/// blockchains.
 pub type ProductIdentifier = [u8; 32];
 
 /// Represents availability status of a price feed.
@@ -58,6 +62,8 @@ impl Default for PriceStatus {
 )]
 #[repr(C)]
 pub struct Price {
+    /// Unique identifier for this price.
+    pub id:                 PriceIdentifier,
     /// The current price.
     pub price:              i64,
     /// Confidence interval around the price.