perf(account): reduce memory footprint (#17)

.gitignore

@@ -2,5 +2,9 @@
 
 .idea/
 
+# Profiling Tools
+heaptrack*.zst
+!docs/**/heaptrack*.zst
+
 flamegraph.svg
 profile.json

Cargo.toml

@@ -24,6 +24,11 @@ tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
 criterion = { version = "0.5.1", features = ["html_reports"] }
 test-log = { version = "0.2.16", features = ["trace"] }
 
+[profile.perf]
+# Profile for memory profiling
+inherits = "release"
+debug = true
+
 [[bench]]
 name = "bench_main"
 harness = false

Makefile.toml

@@ -0,0 +1,45 @@
+[env]
+BENCHES_DATA_DIR = "${CARGO_MAKE_WORKING_DIRECTORY}/benches/data"
+BUILD_PROFILE_PERF = "perf"
+
+# ------------------------------------------------------
+# Group: Memory Profiling
+# ------------------------------------------------------
+[tasks.build-perf]
+description = "Build the perf release to profile against"
+command = "cargo"
+args = ["build", "--profile", "${BUILD_PROFILE_PERF}"]
+
+[tasks.heaptrack]
+description = "Run heaptrack"
+dependencies = ["build-perf"]
+script = '''
+SIZE="${1:-10K}"
+TAG="${2:-$(date +"%Y-%m-%d_%H-%M-%S")}"
+
+if [ -z "${SIZE}" ] || [ -z "${TAG}" ]; then
+  echo "ERROR: Invalid or missing argument"
+  echo
+  echo "Usage:   cargo make mem-perf <SIZE> <TAG>"
+  echo "Example: cargo make mem-perf 1K optimized"
+  echo
+  exit 1
+fi
+
+SAMPLE_FILE="${BENCHES_DATA_DIR}/activities_${SIZE}.csv"
+if [ ! -f "$SAMPLE_FILE" ]; then
+  echo "ERROR: File '${SAMPLE_FILE}' does not exist."
+  echo
+  echo "Available sample files in '${DATA_DIR}':"
+  for file in ${BENCHES_DATA_DIR}/activities_*.csv; do
+    echo "• $(basename "$file")"
+  done
+  echo
+  exit 1
+fi
+
+OUTPUT_FILE="${CARGO_MAKE_WORKING_DIRECTORY}/heaptrack.${CARGO_MAKE_CRATE_NAME}.${SIZE}.${TAG}"
+BINARY="${CARGO_MAKE_CRATE_TARGET_DIRECTORY}/${BUILD_PROFILE_PERF}/${CARGO_MAKE_CRATE_NAME}"
+
+heaptrack --output "${OUTPUT_FILE}" "${BINARY}" "${SAMPLE_FILE}"
+'''

src/account.rs

@@ -6,7 +6,7 @@ use crate::ClientID;
 use rust_decimal::Decimal;
 use rust_decimal_macros::dec;
 use std::collections::hash_map::Entry;
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 
 /// An abstraction over the balances of a client.
 ///
@@ -56,10 +56,10 @@ pub struct Account {
     locked: bool,
 
     #[serde(skip)]
-    dispute_cases: HashMap<TransactionID, Decimal>,
+    dispute_cases: HashSet<TransactionID>,
 
     #[serde(skip)]
-    transaction_record: HashMap<TransactionID, Transaction>,
+    transaction_record: HashMap<TransactionID, Decimal>,
 }
 
 impl Account {
@@ -70,7 +70,7 @@ impl Account {
             total: dec!(0.0),
             available: dec!(0.0),
             locked: false,
-            dispute_cases: HashMap::new(),
+            dispute_cases: HashSet::new(),
             transaction_record: HashMap::new(),
         }
     }
@@ -152,43 +152,40 @@ impl Account {
     }
 
     fn initiate_dispute(&mut self, transaction_id: TransactionID) -> AccountActivityResult<()> {
-        match self.dispute_cases.entry(transaction_id) {
-            Entry::Occupied(_) => Err(FailedDisputeCase("transaction already disputed".into())),
-            Entry::Vacant(entry) => {
-                match self.transaction_record.get(&transaction_id) {
-                    None => Ok(()),
-                    Some(transaction) => {
-                        entry.insert(transaction.amount());
-                        self.hold(transaction.amount())
-                    }
+        match self.dispute_cases.contains(&transaction_id) {
+            true => Err(FailedDisputeCase("transaction already disputed".into())),
+            false => match self.transaction_record.get(&transaction_id) {
+                None => Ok(()),
+                Some(&amount) => {
+                    self.dispute_cases.insert(transaction_id);
+                    self.hold(amount)
                 }
             }
         }
     }
 
     fn resolve_dispute(&mut self, transaction_id: &TransactionID) -> AccountActivityResult<()> {
-        match self.dispute_cases.remove(transaction_id) {
-            None => Ok(()),
-            Some(amount) => self.release(amount),
+        if let Some(&amount) = self.transaction_record.get(transaction_id) {
+            self.release(amount)?;
+            self.dispute_cases.remove(transaction_id);
         }
+        Ok(())
     }
 
     fn issue_chargeback(&mut self, transaction_id: &TransactionID) -> AccountActivityResult<()> {
-        match self.dispute_cases.remove(transaction_id) {
-            None => Ok(()),
-            Some(amount) => {
-                self.charge(amount)?;
-                self.lock();
-                Ok(())
-            }
+        if let Some(&amount) = self.transaction_record.get(transaction_id) {
+            self.charge(amount)?;
+            self.dispute_cases.remove(transaction_id);
+            self.lock();
         }
+        Ok(())
     }
 
     fn record_transaction(&mut self, transaction: Transaction) -> AccountActivityResult<()> {
         match self.transaction_record.entry(transaction.id()) {
             Entry::Occupied(_) => Err(FailedTransaction("transaction already recorded".into())),
             Entry::Vacant(entry) => {
-                entry.insert(transaction);
+                entry.insert(transaction.amount());
                 Ok(())
             }
         }
@@ -227,7 +224,7 @@ pub mod test_utils {
     use crate::ClientID;
     use rust_decimal::Decimal;
     use rust_decimal_macros::dec;
-    use std::collections::HashMap;
+    use std::collections::{HashMap, HashSet};
 
     pub enum LockStatus {
         Locked,
@@ -251,7 +248,7 @@ pub mod test_utils {
                     LockStatus::Locked => true,
                     LockStatus::Unlocked => false,
                 },
-                dispute_cases: HashMap::new(),
+                dispute_cases: HashSet::new(),
                 transaction_record: HashMap::new(),
             }
         }