Merge #4370

4370: Contract level messages r=alsrdn a=alsrdn

Contract level messages are a facility that enable a smart contract to emit a message while executing, which eventually gets sent on the event stream and is visible from outside the network.

This PR introduces 2 new FFIs that allow contracts to manage message topics and emit messages.
Messages are sent out through `DeployProcessed` SSE events.

Co-authored-by: Alexandru Sardan <alexandru@casperlabs.io>
Co-authored-by: Joe Sacher <321623+sacherjj@users.noreply.github.com>
Co-authored-by: Luca B <93586856+bradjohnl@users.noreply.github.com>

execution_engine/src/engine_state/execution_result.rs

@@ -4,6 +4,7 @@ use std::collections::VecDeque;
 
 use casper_types::{
     bytesrepr::FromBytes,
+    contract_messages::Messages,
     execution::{Effects, ExecutionResultV2 as TypesExecutionResult, Transform, TransformKind},
     CLTyped, CLValue, Gas, Key, Motes, StoredValue, TransferAddr,
 };
@@ -25,6 +26,8 @@ pub enum ExecutionResult {
         cost: Gas,
         /// Execution effects.
         effects: Effects,
+        /// Messages emitted during execution.
+        messages: Messages,
     },
     /// Execution was finished successfully
     Success {
@@ -34,6 +37,8 @@ pub enum ExecutionResult {
         cost: Gas,
         /// Execution effects.
         effects: Effects,
+        /// Messages emitted during execution.
+        messages: Messages,
     },
 }
 
@@ -60,6 +65,7 @@ impl ExecutionResult {
             transfers: Vec::default(),
             cost: Gas::default(),
             effects: Effects::new(),
+            messages: Vec::default(),
         }
     }
 
@@ -127,19 +133,25 @@ impl ExecutionResult {
                 error,
                 transfers,
                 effects,
+                messages,
                 ..
             } => ExecutionResult::Failure {
                 error,
                 transfers,
                 cost,
                 effects,
+                messages,
             },
             ExecutionResult::Success {
-                transfers, effects, ..
+                transfers,
+                effects,
+                messages,
+                ..
             } => ExecutionResult::Success {
                 transfers,
                 cost,
                 effects,
+                messages,
             },
         }
     }
@@ -154,17 +166,25 @@ impl ExecutionResult {
                 error,
                 cost,
                 effects,
+                messages,
                 ..
             } => ExecutionResult::Failure {
                 error,
                 transfers,
                 cost,
                 effects,
+                messages,
             },
-            ExecutionResult::Success { cost, effects, .. } => ExecutionResult::Success {
+            ExecutionResult::Success {
+                cost,
+                effects,
+                messages,
+                ..
+            } => ExecutionResult::Success {
                 transfers,
                 cost,
                 effects,
+                messages,
             },
         }
     }
@@ -180,20 +200,24 @@ impl ExecutionResult {
                 transfers,
                 cost,
                 effects: _,
+                messages,
             } => ExecutionResult::Failure {
                 error,
                 transfers,
                 cost,
                 effects,
+                messages,
             },
             ExecutionResult::Success {
                 transfers,
                 cost,
                 effects: _,
+                messages,
             } => ExecutionResult::Success {
                 transfers,
                 cost,
                 effects,
+                messages,
             },
         }
     }
@@ -291,6 +315,7 @@ impl ExecutionResult {
             effects,
             transfers,
             cost: gas_cost,
+            messages: Vec::default(),
         })
     }
 
@@ -305,28 +330,44 @@ impl ExecutionResult {
     }
 }
 
-impl From<ExecutionResult> for TypesExecutionResult {
+/// A versioned execution result and the messages produced by that execution.
+pub struct ExecutionResultAndMessages {
+    /// Execution result
+    pub execution_result: TypesExecutionResult,
+    /// Messages emitted during execution
+    pub messages: Messages,
+}
+
+impl From<ExecutionResult> for ExecutionResultAndMessages {
     fn from(execution_result: ExecutionResult) -> Self {
         match execution_result {
             ExecutionResult::Success {
                 transfers,
                 cost,
                 effects,
-            } => TypesExecutionResult::Success {
-                effects,
-                transfers,
-                cost: cost.value(),
+                messages,
+            } => ExecutionResultAndMessages {
+                execution_result: TypesExecutionResult::Success {
+                    effects,
+                    transfers,
+                    cost: cost.value(),
+                },
+                messages,
             },
             ExecutionResult::Failure {
                 error,
                 transfers,
                 cost,
                 effects,
-            } => TypesExecutionResult::Failure {
-                effects,
-                transfers,
-                cost: cost.value(),
-                error_message: error.to_string(),
+                messages,
+            } => ExecutionResultAndMessages {
+                execution_result: TypesExecutionResult::Failure {
+                    effects,
+                    transfers,
+                    cost: cost.value(),
+                    error_message: error.to_string(),
+                },
+                messages,
             },
         }
     }
@@ -422,9 +463,11 @@ impl ExecutionResultBuilder {
         let mut transfers = self.transfers();
         let cost = self.total_cost();
 
-        let mut all_effects = match self.payment_execution_result {
+        let (mut all_effects, mut all_messages) = match self.payment_execution_result {
             Some(result @ ExecutionResult::Failure { .. }) => return Ok(result),
-            Some(ExecutionResult::Success { effects, .. }) => effects,
+            Some(ExecutionResult::Success {
+                effects, messages, ..
+            }) => (effects, messages),
             None => return Err(ExecutionResultBuilderError::MissingPaymentExecutionResult),
         };
 
@@ -436,11 +479,18 @@ impl ExecutionResultBuilder {
                 transfers: session_transfers,
                 effects: _,
                 cost: _,
+                messages,
             }) => {
                 error = Some(session_error);
                 transfers = session_transfers;
+                all_messages.extend(messages);
+            }
+            Some(ExecutionResult::Success {
+                effects, messages, ..
+            }) => {
+                all_effects.append(effects);
+                all_messages.extend(messages);
             }
-            Some(ExecutionResult::Success { effects, .. }) => all_effects.append(effects),
             None => return Err(ExecutionResultBuilderError::MissingSessionExecutionResult),
         };
 
@@ -451,7 +501,12 @@ impl ExecutionResultBuilder {
                     error::Error::Finalization,
                 ));
             }
-            Some(ExecutionResult::Success { effects, .. }) => all_effects.append(effects),
+            Some(ExecutionResult::Success {
+                effects, messages, ..
+            }) => {
+                all_effects.append(effects);
+                all_messages.extend(messages);
+            }
             None => return Err(ExecutionResultBuilderError::MissingFinalizeExecutionResult),
         }
 
@@ -460,12 +515,14 @@ impl ExecutionResultBuilder {
                 transfers,
                 cost,
                 effects: all_effects,
+                messages: all_messages,
             }),
             Some(error) => Ok(ExecutionResult::Failure {
                 error,
                 transfers,
                 cost,
                 effects: all_effects,
+                messages: all_messages,
             }),
         }
     }

execution_engine/src/engine_state/genesis.rs

@@ -17,7 +17,7 @@ use serde::{Deserialize, Serialize};
 
 use casper_storage::global_state::state::StateProvider;
 use casper_types::{
-    addressable_entity::{ActionThresholds, NamedKeys},
+    addressable_entity::{ActionThresholds, MessageTopics, NamedKeys},
     execution::Effects,
     package::{EntityVersions, Groups, PackageKind, PackageStatus},
     system::{
@@ -1152,6 +1152,7 @@ where
             main_purse,
             associated_keys,
             ActionThresholds::default(),
+            MessageTopics::default(),
         );
 
         let access_key = self

execution_engine/src/engine_state/mod.rs

@@ -47,7 +47,7 @@ use casper_storage::{
 
 use casper_types::{
     account::{Account, AccountHash},
-    addressable_entity::{AssociatedKeys, NamedKeys},
+    addressable_entity::{AssociatedKeys, MessageTopics, NamedKeys},
     bytesrepr::ToBytes,
     execution::Effects,
     package::{EntityVersions, Groups, PackageKind, PackageKindTag, PackageStatus},
@@ -822,6 +822,7 @@ where
             account.main_purse(),
             associated_keys,
             account.action_thresholds().clone().into(),
+            MessageTopics::default(),
         );
 
         let access_key = generator.new_uref(AccessRights::READ_ADD_WRITE);
@@ -2630,11 +2631,13 @@ fn log_execution_result(preamble: &'static str, result: &ExecutionResult) {
             transfers,
             cost,
             effects,
+            messages,
         } => {
             debug!(
                 %cost,
                 transfer_count = %transfers.len(),
                 transforms_count = %effects.len(),
+                messages_count = %messages.len(),
                 "{}: execution success",
                 preamble
             );
@@ -2644,12 +2647,14 @@ fn log_execution_result(preamble: &'static str, result: &ExecutionResult) {
             transfers,
             cost,
             effects,
+            messages,
         } => {
             debug!(
                 %error,
                 %cost,
                 transfer_count = %transfers.len(),
                 transforms_count = %effects.len(),
+                messages_count = %messages.len(),
                 "{}: execution failure",
                 preamble
             );
@@ -2664,6 +2669,7 @@ fn should_charge_for_errors_in_wasm(execution_result: &ExecutionResult) -> bool
             transfers: _,
             cost: _,
             effects: _,
+            messages: _,
         } => match error {
             Error::Exec(err) => match err {
                 ExecError::WasmPreprocessing(_) | ExecError::UnsupportedWasmStart => true,
@@ -2718,7 +2724,9 @@ fn should_charge_for_errors_in_wasm(execution_result: &ExecutionResult) -> bool
                 | ExecError::UnexpectedKeyVariant(_)
                 | ExecError::InvalidPackageKind(_)
                 | ExecError::Transform(_)
-                | ExecError::InvalidEntryPointType => false,
+                | ExecError::InvalidEntryPointType
+                | ExecError::InvalidMessageTopicOperation
+                | ExecError::InvalidUtf8Encoding(_) => false,
                 ExecError::DisabledUnrestrictedTransfers => false,
             },
             Error::WasmPreprocessing(_) => true,

execution_engine/src/engine_state/upgrade.rs

@@ -5,7 +5,7 @@ use thiserror::Error;
 
 use casper_storage::global_state::state::StateProvider;
 use casper_types::{
-    addressable_entity::{ActionThresholds, AssociatedKeys, NamedKeys, Weight},
+    addressable_entity::{ActionThresholds, AssociatedKeys, MessageTopics, NamedKeys, Weight},
     bytesrepr::{self, ToBytes},
     execution::Effects,
     package::{EntityVersions, Groups, PackageKind, PackageKindTag, PackageStatus},
@@ -151,6 +151,7 @@ where
             URef::default(),
             AssociatedKeys::default(),
             ActionThresholds::default(),
+            MessageTopics::default(),
         );
 
         let byte_code_key =
@@ -297,6 +298,7 @@ where
             main_purse,
             associated_keys,
             ActionThresholds::default(),
+            MessageTopics::default(),
         );
 
         let access_key = address_generator.new_uref(AccessRights::READ_ADD_WRITE);