Implementing Market Balance (#524)

* Implementing market balance

* Lint fix

* Adding requested changes

* Update blockchain/state_manager/src/lib.rs

Co-authored-by: Purple Hair Rust Bard <AshantiMutinta@gmail.com>

* Update blockchain/state_manager/src/lib.rs

Co-authored-by: Purple Hair Rust Bard <AshantiMutinta@gmail.com>

* Update blockchain/state_manager/src/lib.rs

Co-authored-by: Purple Hair Rust Bard <AshantiMutinta@gmail.com>

* Update lib.rs

Co-authored-by: Purple Hair Rust Bard <AshantiMutinta@gmail.com>

blockchain/state_manager/src/lib.rs

@@ -4,7 +4,10 @@
 mod errors;
 pub mod utils;
 pub use self::errors::*;
-use actor::{init, miner, power, ActorState, INIT_ACTOR_ADDR, STORAGE_POWER_ACTOR_ADDR};
+use actor::{
+    init, market, miner, power, ActorState, BalanceTable, INIT_ACTOR_ADDR,
+    STORAGE_MARKET_ACTOR_ADDR, STORAGE_POWER_ACTOR_ADDR,
+};
 use address::{Address, BLSPublicKey, Payload, BLS_PUB_LEN};
 use async_log::span;
 use async_std::sync::RwLock;
@@ -26,6 +29,13 @@ use std::sync::Arc;
 /// Intermediary for retrieving state objects and updating actor states
 pub type CidPair = (Cid, Cid);
 
+#[allow(dead_code)]
+#[derive(Default)]
+pub struct MarketBalance {
+    escrow: BigUint,
+    locked: BigUint,
+}
+
 pub struct StateManager<DB> {
     bs: Arc<DB>,
     cache: RwLock<HashMap<TipsetKeys, CidPair>>,
@@ -234,4 +244,31 @@ where
             )),
         }
     }
+
+    pub fn lookup_id(&self, addr: &Address, ts: &Tipset) -> Result<Address, Error> {
+        let state_tree = StateTree::new_from_root(self.bs.as_ref(), ts.parent_state())?;
+        state_tree.lookup_id(addr).map_err(Error::State)
+    }
+
+    pub fn market_balance(&mut self, addr: &Address, ts: &Tipset) -> Result<MarketBalance, Error> {
+        let market_state: market::State =
+            self.load_actor_state(&*STORAGE_MARKET_ACTOR_ADDR, ts.parent_state())?;
+
+        let new_addr = self.lookup_id(addr, ts)?;
+
+        let out = MarketBalance {
+            escrow: {
+                let et = BalanceTable::from_root(self.bs.as_ref(), &market_state.escrow_table)
+                    .map_err(|_x| Error::State("Failed to build Escrow Table".to_string()))?;
+                et.get(&new_addr).unwrap_or_default()
+            },
+            locked: {
+                let lt = BalanceTable::from_root(self.bs.as_ref(), &market_state.locked_table)
+                    .map_err(|_x| Error::State("Failed to build Locked Table".to_string()))?;
+                lt.get(&new_addr).unwrap_or_default()
+            },
+        };
+
+        Ok(out)
+    }
 }