Add additional documentation

coins/monero/wallet/src/decoys.rs

@@ -94,7 +94,8 @@ async fn select_n(
     let mut candidates = Vec::with_capacity(remaining);
     while candidates.len() != remaining {
       // Use a gamma distribution, as Monero does
-      // TODO: Cite these constants
+      // https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c45
+      //   /src/wallet/wallet2.cpp#L142-L143
       let mut age = Gamma::<f64>::new(19.28, 1.0 / 1.61).unwrap().sample(rng).exp();
       #[allow(clippy::cast_precision_loss)]
       if age > TIP_APPLICATION {

coins/monero/wallet/src/extra.rs

@@ -226,7 +226,9 @@ impl Extra {
   }
 
   /// The payment ID embedded within this extra.
-  // TODO: Monero distinguishes encrypted/unencrypted payment ID retrieval
+  // Monero finds the first nonce field and reads the payment ID from it:
+  // https://github.com/monero-project/monero/blob/ac02af92867590ca80b2779a7bbeafa99ff94dcb/
+  //   src/wallet/wallet2.cpp#L2709-L2752
   pub fn payment_id(&self) -> Option<PaymentId> {
     for field in &self.0 {
       if let ExtraField::Nonce(data) = field {

coins/monero/wallet/src/output.rs

@@ -301,7 +301,7 @@ impl WalletOutput {
 
   /// The payment ID included with this output.
   ///
-  /// This field may be `Some` even if wallet would not return a payment ID. This will happen if
+  /// This field may be `Some` even if wallet2 would not return a payment ID. This will happen if
   /// the scanned output belongs to the subaddress which spent Monero within the transaction which
   /// created the output. If multiple subaddresses spent Monero within this transactions, the key
   /// image with the highest index is determined to be the subaddress considered as the one

coins/monero/wallet/src/scan.rs

@@ -336,8 +336,8 @@ impl InternalScanner {
     }
 
     // If the block's version is >= 12, drop all unencrypted payment IDs
-    // TODO: Cite rule
-    // TODO: What if TX extra had multiple payment IDs embedded?
+    // https://github.com/monero-project/monero/blob/ac02af92867590ca80b2779a7bbeafa99ff94dcb/
+    //   src/wallet/wallet2.cpp#L2739-L2744
     if block.header.hardfork_version >= 12 {
       for output in &mut res.0 {
         if matches!(output.metadata.payment_id, Some(PaymentId::Unencrypted(_))) {
@@ -354,8 +354,10 @@ impl InternalScanner {
 ///
 /// When an output is successfully scanned, the output key MUST be checked against the local
 /// database for lack of prior observation. If it was prior observed, that output is an instance
-/// of the burning bug (TODO: cite) and MAY be unspendable. Only the prior received output(s) or
-/// the newly received output will be spendable (as spending one will burn all of them).
+/// of the
+/// [burning bug](https://web.getmonero.org/2018/09/25/a-post-mortum-of-the-burning-bug.html) and
+/// MAY be unspendable. Only the prior received output(s) or the newly received output will be
+/// spendable (as spending one will burn all of them).
 ///
 /// Once checked, the output key MUST be saved to the local database so future checks can be
 /// performed.

coins/monero/wallet/src/send/mod.rs

@@ -238,7 +238,6 @@ impl SignableTransaction {
       Err(SendError::NoInputs)?;
     }
     for input in &self.inputs {
-      // TODO: Add a function for the ring length
       if input.decoys().len() !=
         match self.rct_type {
           RctType::ClsagBulletproof => 11,
@@ -317,11 +316,14 @@ impl SignableTransaction {
       })?;
     }
 
-    // The actual limit is half the block size, and for the minimum block size of 300k, that'd be
-    // 150k
-    // wallet2 will only create transactions up to 100k bytes however
-    // TODO: Cite
-    const MAX_TX_SIZE: usize = 100_000;
+    // The limit is half the no-penalty block size
+    // https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
+    //   /src/wallet/wallet2.cpp#L110766-L11085
+    // https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
+    //   /src/cryptonote_config.h#L61
+    // https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454
+    //   /src/cryptonote_config.h#L64
+    const MAX_TX_SIZE: usize = (300_000 / 2) - 600;
     if weight >= MAX_TX_SIZE {
       Err(SendError::TooLargeTransaction)?;
     }