Merge pull request #100 from pyth-network/guibescos/remove-mentions-of-get-current-price

Remove mentions of get_current_price

Author: guibescos

README.md

@@ -7,7 +7,7 @@ Key features of this SDK include:
 * Get the current price of over [50 products](https://pyth.network/markets/), including cryptocurrencies,
   US equities, forex and more.
 * Combine listed products to create new price feeds, e.g., for baskets of tokens or non-USD quote currencies.
-* Consume prices in Solana programs, CosmWasm smart contracts, or off-chain applications.
+* Consume prices in Solana programs or off-chain applications.
 
 Please see the [pyth.network documentation](https://docs.pyth.network/) for more information about pyth.network.
 
@@ -18,7 +18,6 @@ This repository is divided into several crates focused on specific use cases:
 1. [Pyth SDK](pyth-sdk) provides common data types and interfaces for that are shared across different blockchains.
 2. [Pyth SDK Solana](pyth-sdk-solana) provides an interface for reading Pyth price feeds in Solana programs.
    This crate may also be used in off-chain applications that read prices from the Solana blockchain.
-3. [Pyth SDK CosmWasm](pyth-sdk-cw) provides an interface for reading Pyth price feeds in on-chain CosmWasm contracts.
 
 Please see the documentation for the relevant crate to get started using Pyth Network.
 

pyth-sdk-solana/README.md

@@ -26,7 +26,7 @@ Applications can obtain the content of these accounts in two different ways:
 * On-chain programs should pass these accounts to the instructions that require price feeds.
 * Off-chain programs can access these accounts using the Solana RPC client (as in the [eth price example program](examples/eth_price.rs)).
 
-The pyth.network website can be used to identify the public keys of the various Pyth Network accounts (e.g., [Crypto.BTC/USD accounts](https://pyth.network/markets/#Crypto.BTC/USD)).
+The [pyth.network](https://pyth.network/developers/price-feed-ids#solana-mainnet-beta) website can be used to identify the public keys of each price feed's price account (e.g. Crypto.BTC/USD).
 
 ### On-chain
 
@@ -37,15 +37,19 @@ The `load_price_feed_from_account_info` function will construct a `PriceFeed` st
 ```rust
 use pyth_sdk_solana::{load_price_feed_from_account_info, PriceFeed};
 
+const STALENESS_THRESHOLD : u64 = 60; // staleness threshold in seconds
 let price_account_info: AccountInfo = ...;
 let price_feed: PriceFeed = load_price_feed_from_account_info( &price_account_info ).unwrap();
-let current_price: Price = price_feed.get_current_price().unwrap();
-println!("price: ({} +- {}) x 10^{}", current_price.price, current_price.conf, current_price.expo);
+let current_timestamp = Clock::get()?.unix_timestamp;
+let current_price: Price = price_feed.get_price_no_older_than(current_timestamp, STALENESS_THRESHOLD).unwrap();
+msg!("price: ({} +- {}) x 10^{}", current_price.price, current_price.conf, current_price.expo);
 ```
 
 The `PriceFeed` object returned by `load_price_feed_from_account_info` contains all currently-available pricing information about the product.
 This struct also has some useful functions for manipulating and combining prices; see the [common SDK documentation](../pyth-sdk) for more details.
 
+The function `get_price_no_older_than` takes in an `age` in seconds. If the current on-chain aggregate is older than `current_timestamp - age`, `get_price_no_older_than` will return `None`.
+
 Note that your application should also validate the address of the passed-in price account before using it.
 Otherwise, an attacker could pass in a different account and set the price to an arbitrary value.
 
@@ -58,10 +62,16 @@ The `load_price_feed_from_account` function will construct a `PriceFeed` struct
 ```rust
 use pyth_sdk_solana::{load_price_feed_from_account, PriceFeed};
 
+const STALENESS_THRESHOLD : u64 = 60; // staleness threshold in seconds
+let current_time = SystemTime::now()
+    .duration_since(UNIX_EPOCH)
+    .unwrap()
+    .as_secs() as i64;
+
 let price_key: Pubkey = ...;
-let mut price_account: Account = ...;
+let mut price_account: Account = clnt.get_account(&price_key).unwrap();
 let price_feed: PriceFeed = load_price_feed_from_account( &price_key, &mut price_account ).unwrap();
-let current_price: Price = price_feed.get_current_price().unwrap();
+let current_price: Price = price_feed.get_price_no_older_than(current_time, STALENESS_THRESHOLD).unwrap();
 println!("price: ({} +- {}) x 10^{}", current_price.price, current_price.conf, current_price.expo);
 ```
 

pyth-sdk-solana/src/state.rs

@@ -220,16 +220,14 @@ unsafe impl Pod for ProductAccount {
 #[repr(C)]
 pub struct PriceInfo {
     /// the current price.
-    /// For the aggregate price use price.get_current_price() whenever possible. It has more checks
-    /// to make sure price is valid.
+    /// For the aggregate price use `get_price_no_older_than()` whenever possible. Accessing fields
+    /// directly might expose you to stale or invalid prices.
     pub price:    i64,
     /// confidence interval around the price.
-    /// For the aggregate confidence use price.get_current_price() whenever possible. It has more
-    /// checks to make sure price is valid.
+    /// For the aggregate confidence use `get_price_no_older_than()` whenever possible. Accessing
+    /// fields directly might expose you to stale or invalid prices.
     pub conf:     u64,
-    /// status of price (Trading is valid).
-    /// For the aggregate status use price.get_current_status() whenever possible.
-    /// Price data can sometimes go stale and the function handles the status in such cases.
+    /// status of price (Trading is valid)
     pub status:   PriceStatus,
     /// notification of any corporate action
     pub corp_act: CorpAction,

pyth-sdk/README.md

@@ -1,7 +1,7 @@
 # Pyth Network Common Rust SDK
 
 This crate contains Pyth Network data structures that are shared across all Rust-based consumers of Pyth Network data.
-This crate is typically used in combination with a platform-specific crate such as [pyth-sdk-solana](../pyth-sdk-solana) or [pyth-sdk-cw](../pyth-sdk-cw).
+This crate is typically used in combination with a platform-specific crate such as [pyth-sdk-solana](../pyth-sdk-solana).
 
 ## Usage
 
@@ -19,7 +19,9 @@ Once you have a `PriceFeed`, you can call one of the methods below to get the pr
 Get the current price of the product from its `PriceFeed`:
 
 ```rust
-let current_price: Price = price_feed.get_current_price().ok_or(StdError::not_found("Current price is not available"))?;
+const STALENESS_THRESHOLD : u64 = 60; // staleness threshold in seconds
+let current_timestamp = ...;
+let current_price: Price = price_feed.get_price_no_older_than(current_timestamp, STALENESS_THRESHOLD).ok_or(StdError::not_found("Current price is not available"))?;
 println!("price: ({} +- {}) x 10^{}", current_price.price, current_price.conf, current_price.expo);
 ```
 
@@ -35,7 +37,9 @@ Please see the [consumer best practices guide](https://docs.pyth.network/consume
 The EMA price can be retrieved as follows:
 
 ```rust
-let ema_price: Price = price_feed.get_ema_price().ok_or(StdError::not_found("EMA price is not available"))?;
+const STALENESS_THRESHOLD : u64 = 60; // staleness threshold in seconds
+let current_timestamp = ...;
+let ema_price: Price = price_feed.get_ema_price_no_older_than(current_timestamp, STALENESS_THRESHOLD).ok_or(StdError::not_found("EMA price is not available"))?;
 println!("price: ({} +- {}) x 10^{}", ema_price.price, ema_price.conf, ema_price.expo);
 ```