Merge pull request #227 from phertyameen/feat/core/implementations

Add core contract systems: rate limiting, events, multisig, and escrow

Author: OthmanImam

contracts/common-utils/src/event_log.rs

@@ -0,0 +1,27 @@
+use soroban_sdk::{contracttype, Env, Vec, Map, Address};
+
+#[contracttype]
+#[derive(Clone)]
+pub struct Event {
+    pub id: u64,
+    pub event_type: u32,
+    pub caller: Address,
+    pub target: Address,
+    pub data: u32,
+    pub block: u64,
+}
+
+const EVENTS: symbol_short!("evts");
+const COUNTER: symbol_short!("cnt");
+
+pub fn log_event(e: &Env, evt: Event) {
+    let mut events: Vec<Event> =
+        e.storage().instance().get(&EVENTS).unwrap_or(Vec::new(e));
+
+    if events.len() >= 1000 {
+        events.remove(0);
+    }
+
+    events.push_back(evt);
+    e.storage().instance().set(&EVENTS, &events);
+}

contracts/common-utils/src/rate_limit.rs

@@ -0,0 +1,45 @@
+use soroban_sdk::{contracttype, Env, Address, Map};
+
+#[contracttype]
+#[derive(Clone)]
+pub struct RateLimit {
+    pub count: u32,
+    pub window_start: u64,
+}
+
+#[contracttype]
+pub struct Config {
+    pub limit: u32,
+    pub window: u64, // blocks
+}
+
+const RATE_LIMIT: symbol_short!("rl");
+const CONFIG: symbol_short!("cfg");
+
+pub fn check_rate_limit(e: &Env, addr: Address) {
+    let mut store: Map<Address, RateLimit> =
+        e.storage().instance().get(&RATE_LIMIT).unwrap_or(Map::new(e));
+
+    let cfg: Config = e.storage().instance().get(&CONFIG).unwrap();
+
+    let ledger = e.ledger().sequence();
+    let mut rl = store.get(addr.clone()).unwrap_or(RateLimit {
+        count: 0,
+        window_start: ledger,
+    });
+
+    // reset window
+    if ledger - rl.window_start > cfg.window {
+        rl.count = 0;
+        rl.window_start = ledger;
+    }
+
+    if rl.count >= cfg.limit {
+        panic!("RateLimitExceeded");
+    }
+
+    rl.count += 1;
+    store.set(addr, rl);
+
+    e.storage().instance().set(&RATE_LIMIT, &store);
+}

contracts/escrow/src/escrow.rs

@@ -0,0 +1,10 @@
+use soroban_sdk::{contracttype, Address};
+
+#[contracttype]
+#[derive(Clone)]
+pub struct Escrow {
+    pub buyer: Address,
+    pub seller: Address,
+    pub amount: i128,
+    pub released: bool,
+}

contracts/multi-sig/src/approval.rs

@@ -0,0 +1,11 @@
+use soroban_sdk::{contracttype, Address, Vec};
+
+#[contracttype]
+#[derive(Clone)]
+pub struct ApprovalRequest {
+    pub id: u64,
+    pub signers: Vec<Address>,
+    pub approvals: Vec<Address>,
+    pub threshold: u32,
+    pub deadline: u64,
+}