Merge branch 'ielashi/error_message' into 'master'

chore: make payload exceeded error message more readable

When a canister creates a request that exceeds the payload, the error message currently:
1. Displays both the local subnet limit and the remote subnet limit, even though only the local subnet limit is relevant.
2. Doesn't display the payload size.

This change addresses both of the above faults. 

See merge request dfinity-lab/public/ic!13664

rs/system_api/src/request_in_prep.rs

@@ -67,8 +67,8 @@ impl RequestInPrep {
             let max_size_local_subnet = max_size_remote_subnet * multiplier_max_size_local_subnet;
             if method_name_len as u64 > max_size_local_subnet.get() {
                 return Err(HypervisorError::ContractViolation(format!(
-                    "RequestInPrep: size of method_name {} exceeded the allowed limit local-subnet {} remote-subnet {}",
-                    callee_size, max_size_local_subnet, max_size_remote_subnet
+                    "Size of method_name {} exceeds the allowed limit local-subnet {}",
+                    callee_size, max_size_local_subnet
                 )));
             }
             let method_name = valid_subslice(
@@ -126,8 +126,11 @@ impl RequestInPrep {
             self.max_size_remote_subnet * self.multiplier_max_size_local_subnet;
         if size as u64 > max_size_local_subnet.get() - current_size as u64 {
             Err(HypervisorError::ContractViolation(format!(
-                "RequestInPrep: current_size {} exceeded the allowed limit local-subnet {} remote-subnet {}",
-                current_size, max_size_local_subnet, self.max_size_remote_subnet
+                "Request to {}:{} has a payload size of {}, which exceeds the allowed local-subnet limit of {}",
+                self.callee,
+                self.method_name,
+                current_size + size as usize,
+                max_size_local_subnet
             )))
         } else {
             let data = valid_subslice("ic0.call_data_append", src, size, heap)?;
@@ -174,7 +177,9 @@ pub(crate) fn into_request(
         let max_size_local_subnet = max_size_remote_subnet * multiplier_max_size_local_subnet;
         if payload_size > max_size_local_subnet.get() {
             return Err(HypervisorError::ContractViolation(format!(
-                "RequestInPrep: size of message {} exceeded the allowed remote-subnet limit {}",
+                "Request to {}:{} has a payload size of {}, which exceeds the allowed remote-subnet limit of {}",
+                destination_canister,
+                method_name,
                 payload_size, max_size_remote_subnet
             )));
         }