Check gas

packages/std/src/imports.rs

@@ -82,6 +82,8 @@ extern "C" {
 
     fn ed25519_sign(messages_ptr: u32, private_key_ptr: u32) -> u64;
 
+    fn check_gas() -> u64;
+
     fn gas_evaporate(evaporate: u32) -> u32;
 }
 
@@ -410,6 +412,15 @@ impl Api for ExternalApi {
         }
     }
 
+    fn check_gas(&self) -> StdResult<u64> {
+        let result = unsafe { check_gas() };
+        if result == 0 {
+            return Err(StdError::generic_err("check_gas error"));
+        }
+
+        Ok(result)
+    }
+
     fn gas_evaporate(&self, evaporate: u32) -> StdResult<()> {
         let result = unsafe { gas_evaporate(evaporate) };
         if result != 0 {

packages/std/src/testing/mock.rs

@@ -228,6 +228,10 @@ impl Api for MockApi {
         Ok(cosmwasm_crypto::ed25519_sign(message, private_key)?)
     }
 
+    fn check_gas(&self) -> StdResult<u64> {
+        Ok(0)
+    }
+
     fn gas_evaporate(&self, _evaporate: u32) -> StdResult<()> {
         Ok(())
     }

packages/std/src/traits.rs

@@ -213,10 +213,15 @@ pub trait Api {
     /// - private key: Raw ED25519 private key (32 bytes)
     fn ed25519_sign(&self, message: &[u8], private_key: &[u8]) -> Result<Vec<u8>, SigningError>;
 
+    /// Check Gas.
+    ///
+    /// This function will return the amount of gas currently used by the contract.
+    fn check_gas(&self) -> StdResult<u64>;
+
     /// Gas evaporation.
-    /// 
+    ///
     /// This function will burn a evaporate a precise and reproducible amount of sdk gas.
-    /// 
+    ///
     ///  - evaporate: Amount of SDK gas to evaporate.
     fn gas_evaporate(&self, evaporate: u32) -> StdResult<()>;
 }