Update

examples/swap/programs/swap/src/lib.rs

@@ -142,7 +142,6 @@ pub mod swap {
             )
         };
 
-        // Assert this trade is acceptable.
         apply_risk_checks_transitive(
             &ctx,
             DidSwap {
@@ -162,20 +161,14 @@ pub mod swap {
 }
 
 fn apply_risk_checks(ctx: &Context<Swap>, event: DidSwap) -> Result<()> {
-    //    msg!("event: {:?}", event);
     // todo
-    //
-    // TODO: check that the executed within some % from mid/fair.
-    //    emit!(event);
+    emit!(event);
     Ok(())
 }
 
 fn apply_risk_checks_transitive(ctx: &Context<SwapTransitive>, event: DidSwap) -> Result<()> {
-    //    msg!("event: {:?}", event);
     // todo
-    //
-    // TODO: check that the executed within some % from mid/fair.
-    //    emit!(event);
+    emit!(event);
     Ok(())
 }
 
@@ -374,6 +367,8 @@ fn coin_lots(market: &MarketState, size: u64) -> u64 {
     size.checked_div(market.coin_lot_size).unwrap()
 }
 
+// Market accounts are the accounts used to place orders against the dex minus
+// common accounts, i.e., program ids, sysvars, and the `pc_wallet`.
 #[derive(Accounts, Clone)]
 pub struct MarketAccounts<'info> {
     #[account(mut)]
@@ -402,6 +397,7 @@ pub struct MarketAccounts<'info> {
     // this is the vault for the B mint.
     #[account(mut)]
     pc_vault: AccountInfo<'info>,
+    // PDA owner of the DEX's token accounts for base + quote currencies.
     vault_signer: AccountInfo<'info>,
     // User wallets.
     #[account(mut)]

spl/src/dex.rs

@@ -1,13 +1,8 @@
 use anchor_lang::solana_program::account_info::AccountInfo;
 use anchor_lang::solana_program::entrypoint::ProgramResult;
-use anchor_lang::solana_program::instruction::AccountMeta;
-use anchor_lang::solana_program::program_error::ProgramError;
-use anchor_lang::{Accounts, AccountsExit, CpiContext, ToAccountInfos, ToAccountMetas};
+use anchor_lang::{Accounts, CpiContext, ToAccountInfos};
 use serum_dex::instruction::SelfTradeBehavior;
 use serum_dex::matching::{OrderType, Side};
-use serum_dex::state::MarketState;
-use solana_program::pubkey::Pubkey;
-use std::cell::RefMut;
 use std::num::NonZeroU64;
 
 pub use serum_dex;
@@ -117,63 +112,3 @@ pub struct SettleFunds<'info> {
     pub vault_signer: AccountInfo<'info>,
     pub token_program: AccountInfo<'info>,
 }
-
-pub struct Market<'info> {
-    acc_info: AccountInfo<'info>,
-}
-
-impl<'info> Market<'info> {
-    fn new(acc_info: AccountInfo<'info>) -> Market<'info> {
-        Self { acc_info }
-    }
-
-    pub fn load_mut(&self) -> Result<RefMut<MarketState>, ProgramError> {
-        MarketState::load(&self.acc_info, &ID).map_err(Into::into)
-    }
-}
-
-impl<'info> anchor_lang::Accounts<'info> for Market<'info> {
-    #[inline(never)]
-    fn try_accounts(
-        _program_id: &Pubkey,
-        accounts: &mut &[AccountInfo<'info>],
-    ) -> Result<Self, ProgramError> {
-        if accounts.is_empty() {
-            return Err(ProgramError::NotEnoughAccountKeys);
-        }
-        let account = &accounts[0];
-        *accounts = &accounts[1..];
-        let l = Market::new(account.clone());
-        if l.acc_info.owner != &ID {
-            return Err(ProgramError::Custom(1)); // todo: proper error
-        }
-        Ok(l)
-    }
-}
-
-impl<'info> ToAccountMetas for Market<'info> {
-    #[inline(never)]
-    fn to_account_metas(&self, is_signer: Option<bool>) -> Vec<AccountMeta> {
-        let is_signer = is_signer.unwrap_or(self.acc_info.is_signer);
-        let meta = match self.acc_info.is_writable {
-            false => AccountMeta::new_readonly(*self.acc_info.key, is_signer),
-            true => AccountMeta::new(*self.acc_info.key, is_signer),
-        };
-        vec![meta]
-    }
-}
-
-impl<'info> ToAccountInfos<'info> for Market<'info> {
-    #[inline(never)]
-    fn to_account_infos(&self) -> Vec<AccountInfo<'info>> {
-        vec![self.acc_info.clone()]
-    }
-}
-
-impl<'info> AccountsExit<'info> for Market<'info> {
-    #[inline(never)]
-    fn exit(&self, _program_id: &Pubkey) -> ProgramResult {
-        // no-op
-        Ok(())
-    }
-}

spl/src/token.rs

@@ -203,7 +203,8 @@ impl Deref for Mint {
     }
 }
 
-// Field parsers to save compute.
+// Field parsers to save compute. All account validation is assumed to be done
+// outside of these methods.
 pub mod accessor {
     use super::*;