Specialize transaction assets to i64

Proof-of-history is generic, but now that we're using it entirely
for tokens, we can specialize the type and start doing more interesting
things than just Eq and Serialize operations.

src/accountant.rs

@@ -31,7 +31,7 @@ pub struct Accountant {
     pub balances: HashMap<PublicKey, i64>,
     pub first_id: Hash,
     pub last_id: Hash,
-    pending: HashMap<Signature, Plan<i64>>,
+    pending: HashMap<Signature, Plan>,
     time_sources: HashSet<PublicKey>,
     last_time: DateTime<Utc>,
 }
@@ -84,7 +84,7 @@ impl Accountant {
         self.last_id
     }
 
-    fn is_deposit(allow_deposits: bool, from: &PublicKey, plan: &Plan<i64>) -> bool {
+    fn is_deposit(allow_deposits: bool, from: &PublicKey, plan: &Plan) -> bool {
         if let Plan::Action(Action::Pay(ref payment)) = *plan {
             allow_deposits && *from == payment.to
         } else {
@@ -92,7 +92,7 @@ impl Accountant {
         }
     }
 
-    pub fn process_transaction(self: &mut Self, tr: Transaction<i64>) -> Result<()> {
+    pub fn process_transaction(self: &mut Self, tr: Transaction) -> Result<()> {
         if !tr.verify() {
             return Err(AccountingError::InvalidTransfer);
         }
@@ -113,7 +113,7 @@ impl Accountant {
     }
 
     /// Commit funds to the 'to' party.
-    fn complete_transaction(self: &mut Self, plan: &Plan<i64>) {
+    fn complete_transaction(self: &mut Self, plan: &Plan) {
         if let Plan::Action(Action::Pay(ref payment)) = *plan {
             if self.balances.contains_key(&payment.to) {
                 if let Some(x) = self.balances.get_mut(&payment.to) {
@@ -127,7 +127,7 @@ impl Accountant {
 
     fn process_verified_transaction(
         self: &mut Self,
-        tr: &Transaction<i64>,
+        tr: &Transaction,
         allow_deposits: bool,
     ) -> Result<()> {
         if !reserve_signature(&mut self.historian.signatures, &tr.sig) {

src/accountant_skel.rs

@@ -19,7 +19,7 @@ pub struct AccountantSkel {
 
 #[derive(Serialize, Deserialize, Debug)]
 pub enum Request {
-    Transaction(Transaction<i64>),
+    Transaction(Transaction),
     GetBalance { key: PublicKey },
     GetEntries { last_id: Hash },
     GetId { is_last: bool },

src/accountant_stub.rs

@@ -26,7 +26,7 @@ impl AccountantStub {
         }
     }
 
-    pub fn transfer_signed(&self, tr: Transaction<i64>) -> io::Result<usize> {
+    pub fn transfer_signed(&self, tr: Transaction) -> io::Result<usize> {
         let req = Request::Transaction(tr);
         let data = serialize(&req).unwrap();
         self.socket.send_to(&data, &self.addr)

src/event.rs

@@ -7,7 +7,7 @@ use bincode::serialize;
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
 pub enum Event {
-    Transaction(Transaction<i64>),
+    Transaction(Transaction),
     Signature {
         from: PublicKey,
         tx_sig: Signature,

src/plan.rs

@@ -11,12 +11,12 @@ pub enum Condition {
 }
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
-pub enum Action<T> {
-    Pay(Payment<T>),
+pub enum Action {
+    Pay(Payment),
 }
 
-impl<T: Clone> Action<T> {
-    pub fn spendable(&self) -> T {
+impl Action {
+    pub fn spendable(&self) -> i64 {
         match *self {
             Action::Pay(ref payment) => payment.asset.clone(),
         }
@@ -24,22 +24,22 @@ impl<T: Clone> Action<T> {
 }
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
-pub struct Payment<T> {
-    pub asset: T,
+pub struct Payment {
+    pub asset: i64,
     pub to: PublicKey,
 }
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
-pub enum Plan<T> {
-    Action(Action<T>),
-    After(Condition, Box<Plan<T>>),
-    Race(Box<Plan<T>>, Box<Plan<T>>),
+pub enum Plan {
+    Action(Action),
+    After(Condition, Box<Plan>),
+    Race(Box<Plan>, Box<Plan>),
 }
 
-impl<T: Clone + Eq> Plan<T> {
-    pub fn verify(&self, spendable_assets: &T) -> bool {
+impl Plan {
+    pub fn verify(&self, spendable_assets: i64) -> bool {
         match *self {
-            Plan::Action(ref action) => action.spendable() == *spendable_assets,
+            Plan::Action(ref action) => action.spendable() == spendable_assets,
             Plan::Race(ref plan_a, ref plan_b) => {
                 plan_a.verify(spendable_assets) && plan_b.verify(spendable_assets)
             }

src/transaction.rs

@@ -1,23 +1,22 @@
 //! The `transaction` crate provides functionality for creating log transactions.
 
 use signature::{KeyPair, KeyPairUtil, PublicKey, Signature, SignatureUtil};
-use serde::Serialize;
 use bincode::serialize;
 use hash::Hash;
 use chrono::prelude::*;
 use plan::{Action, Condition, Payment, Plan};
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
-pub struct Transaction<T> {
+pub struct Transaction {
     pub from: PublicKey,
-    pub plan: Plan<T>,
-    pub asset: T,
+    pub plan: Plan,
+    pub asset: i64,
     pub last_id: Hash,
     pub sig: Signature,
 }
 
-impl<T: Serialize + Clone + Eq> Transaction<T> {
-    pub fn new(from_keypair: &KeyPair, to: PublicKey, asset: T, last_id: Hash) -> Self {
+impl Transaction {
+    pub fn new(from_keypair: &KeyPair, to: PublicKey, asset: i64, last_id: Hash) -> Self {
         let from = from_keypair.pubkey();
         let plan = Plan::Action(Action::Pay(Payment {
             asset: asset.clone(),
@@ -38,7 +37,7 @@ impl<T: Serialize + Clone + Eq> Transaction<T> {
         from_keypair: &KeyPair,
         to: PublicKey,
         dt: DateTime<Utc>,
-        asset: T,
+        asset: i64,
         last_id: Hash,
     ) -> Self {
         let from = from_keypair.pubkey();
@@ -79,7 +78,7 @@ impl<T: Serialize + Clone + Eq> Transaction<T> {
     }
 
     pub fn verify(&self) -> bool {
-        self.sig.verify(&self.from, &self.get_sign_data()) && self.plan.verify(&self.asset)
+        self.sig.verify(&self.from, &self.get_sign_data()) && self.plan.verify(self.asset)
     }
 }
 
@@ -87,14 +86,12 @@ impl<T: Serialize + Clone + Eq> Transaction<T> {
 mod tests {
     use super::*;
     use bincode::{deserialize, serialize};
-    use hash::hash;
 
     #[test]
     fn test_claim() {
         let keypair = KeyPair::new();
-        let asset = hash(b"hello, world");
         let zero = Hash::default();
-        let tr0 = Transaction::new(&keypair, keypair.pubkey(), asset, zero);
+        let tr0 = Transaction::new(&keypair, keypair.pubkey(), 42, zero);
         assert!(tr0.verify());
     }
 
@@ -104,8 +101,7 @@ mod tests {
         let keypair0 = KeyPair::new();
         let keypair1 = KeyPair::new();
         let pubkey1 = keypair1.pubkey();
-        let asset = hash(b"hello, world");
-        let tr0 = Transaction::new(&keypair0, pubkey1, asset, zero);
+        let tr0 = Transaction::new(&keypair0, pubkey1, 42, zero);
         assert!(tr0.verify());
     }
 
@@ -118,12 +114,12 @@ mod tests {
         let claim0 = Transaction {
             from: Default::default(),
             plan,
-            asset: 0u8,
+            asset: 0,
             last_id: Default::default(),
             sig: Default::default(),
         };
         let buf = serialize(&claim0).unwrap();
-        let claim1: Transaction<u8> = deserialize(&buf).unwrap();
+        let claim1: Transaction = deserialize(&buf).unwrap();
         assert_eq!(claim1, claim0);
     }
 
@@ -132,9 +128,9 @@ mod tests {
         let zero = Hash::default();
         let keypair = KeyPair::new();
         let pubkey = keypair.pubkey();
-        let mut tr = Transaction::new(&keypair, pubkey, hash(b"hello, world"), zero);
+        let mut tr = Transaction::new(&keypair, pubkey, 42, zero);
         tr.sign(&keypair);
-        tr.asset = hash(b"goodbye cruel world"); // <-- attack!
+        tr.asset = 1_000_000; // <-- attack!
         assert!(!tr.verify());
     }
 
@@ -145,8 +141,7 @@ mod tests {
         let thief_keypair = KeyPair::new();
         let pubkey1 = keypair1.pubkey();
         let zero = Hash::default();
-        let asset = hash(b"hello, world");
-        let mut tr = Transaction::new(&keypair0, pubkey1, asset, zero);
+        let mut tr = Transaction::new(&keypair0, pubkey1, 42, zero);
         tr.sign(&keypair0);
         if let Plan::Action(Action::Pay(ref mut payment)) = tr.plan {
             payment.to = thief_keypair.pubkey(); // <-- attack!