From c935fdb12fd5e0f9f5995422934b661f206e0db3 Mon Sep 17 00:00:00 2001
From: Greg Fitzgerald <garious@gmail.com>
Date: Thu, 1 Mar 2018 17:44:10 -0700
Subject: [PATCH] Move signature duplicate detection into the historian

---
 src/accountant.rs | 20 ++------------------
 src/historian.rs  | 12 +++++++++++-
 src/log.rs        | 18 ++++++++++++------
 3 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/src/accountant.rs b/src/accountant.rs
index ab2e3adc8f..627f214bad 100644
--- a/src/accountant.rs
+++ b/src/accountant.rs
@@ -11,7 +11,6 @@ use std::collections::HashMap;
 pub struct Accountant {
     pub historian: Historian<u64>,
     pub balances: HashMap<PublicKey, u64>,
-    pub signatures: HashMap<Signature, bool>,
     pub end_hash: Sha256Hash,
 }
 
@@ -21,19 +20,13 @@ impl Accountant {
         Accountant {
             historian: hist,
             balances: HashMap::new(),
-            signatures: HashMap::new(),
             end_hash: *start_hash,
         }
     }
 
     pub fn process_event(self: &mut Self, event: &Event<u64>) {
         match *event {
-            Event::Claim { key, data, sig } => {
-                if self.signatures.contains_key(&sig) {
-                    return;
-                }
-                self.signatures.insert(sig, true);
-
+            Event::Claim { key, data, .. } => {
                 if self.balances.contains_key(&key) {
                     if let Some(x) = self.balances.get_mut(&key) {
                         *x += data;
@@ -42,16 +35,7 @@ impl Accountant {
                     self.balances.insert(key, data);
                 }
             }
-            Event::Transaction {
-                from,
-                to,
-                data,
-                sig,
-            } => {
-                if self.signatures.contains_key(&sig) {
-                    return;
-                }
-                self.signatures.insert(sig, true);
+            Event::Transaction { from, to, data, .. } => {
                 if let Some(x) = self.balances.get_mut(&from) {
                     *x -= data;
                 }
diff --git a/src/historian.rs b/src/historian.rs
index 0226b6ac69..1a0441451c 100644
--- a/src/historian.rs
+++ b/src/historian.rs
@@ -6,9 +6,10 @@
 //! The resulting stream of entries represents ordered events in time.
 
 use std::thread::JoinHandle;
+use std::collections::HashMap;
 use std::sync::mpsc::{Receiver, SyncSender};
 use std::time::{Duration, SystemTime};
-use log::{hash, hash_event, verify_event, Entry, Event, Sha256Hash};
+use log::{get_signature, hash, hash_event, verify_event, Entry, Event, Sha256Hash, Signature};
 use serde::Serialize;
 use std::fmt::Debug;
 
@@ -45,6 +46,7 @@ fn log_event<T: Serialize + Clone + Debug>(
 fn log_events<T: Serialize + Clone + Debug>(
     receiver: &Receiver<Event<T>>,
     sender: &SyncSender<Entry<T>>,
+    signatures: &mut HashMap<Signature, bool>,
     num_hashes: &mut u64,
     end_hash: &mut Sha256Hash,
     epoch: SystemTime,
@@ -63,6 +65,12 @@ fn log_events<T: Serialize + Clone + Debug>(
         match receiver.try_recv() {
             Ok(event) => {
                 if verify_event(&event) {
+                    if let Some(sig) = get_signature(&event) {
+                        if signatures.contains_key(&sig) {
+                            continue;
+                        }
+                        signatures.insert(sig, true);
+                    }
                     log_event(sender, num_hashes, end_hash, event)?;
                 }
             }
@@ -94,11 +102,13 @@ pub fn create_logger<T: 'static + Serialize + Clone + Debug + Send>(
         let mut end_hash = start_hash;
         let mut num_hashes = 0;
         let mut num_ticks = 0;
+        let mut signatures = HashMap::new();
         let epoch = SystemTime::now();
         loop {
             if let Err(err) = log_events(
                 &receiver,
                 &sender,
+                &mut signatures,
                 &mut num_hashes,
                 &mut end_hash,
                 epoch,
diff --git a/src/log.rs b/src/log.rs
index 99d1eff75c..04a3b24823 100644
--- a/src/log.rs
+++ b/src/log.rs
@@ -101,18 +101,24 @@ pub fn hash(val: &[u8]) -> Sha256Hash {
 }
 
 /// Return the hash of the given hash extended with the given value.
-pub fn extend_and_hash(end_hash: &Sha256Hash, ty: u8, val: &[u8]) -> Sha256Hash {
+pub fn extend_and_hash(end_hash: &Sha256Hash, val: &[u8]) -> Sha256Hash {
     let mut hash_data = end_hash.to_vec();
-    hash_data.push(ty);
     hash_data.extend_from_slice(val);
     hash(&hash_data)
 }
 
-pub fn hash_event<T>(end_hash: &Sha256Hash, event: &Event<T>) -> Sha256Hash {
+pub fn get_signature<T>(event: &Event<T>) -> Option<Signature> {
     match *event {
-        Event::Tick => *end_hash,
-        Event::Claim { sig, .. } => extend_and_hash(end_hash, 2, &sig),
-        Event::Transaction { sig, .. } => extend_and_hash(end_hash, 3, &sig),
+        Event::Tick => None,
+        Event::Claim { sig, .. } => Some(sig),
+        Event::Transaction { sig, .. } => Some(sig),
+    }
+}
+
+pub fn hash_event<T>(end_hash: &Sha256Hash, event: &Event<T>) -> Sha256Hash {
+    match get_signature(event) {
+        None => *end_hash,
+        Some(sig) => extend_and_hash(end_hash, &sig),
     }
 }