chore: Make CallContext::time required

Author: alin-at-dfinity

rs/protobuf/def/state/canister_state_bits/v1/canister_state_bits.proto

@@ -30,7 +30,7 @@ message CallContext {
   bool responded = 5;
   state.queues.v1.Funds available_funds = 6;
   bool deleted = 8;
-  optional uint64 time_nanos = 9;
+  uint64 time_nanos = 9;
   uint64 instructions_executed = 10;
 }
 

rs/protobuf/src/gen/state/state.canister_state_bits.v1.rs

@@ -7,8 +7,8 @@ pub struct CallContext {
     pub available_funds: ::core::option::Option<super::super::queues::v1::Funds>,
     #[prost(bool, tag = "8")]
     pub deleted: bool,
-    #[prost(uint64, optional, tag = "9")]
-    pub time_nanos: ::core::option::Option<u64>,
+    #[prost(uint64, tag = "9")]
+    pub time_nanos: u64,
     #[prost(uint64, tag = "10")]
     pub instructions_executed: u64,
     #[prost(oneof = "call_context::CallOrigin", tags = "1, 2, 3, 4, 7")]

rs/replicated_state/src/canister_state/system_state/call_context_manager.rs

@@ -40,10 +40,8 @@ pub struct CallContext {
     /// Cycles that were sent in the request that created the `CallContext`.
     available_cycles: Cycles,
 
-    /// Point in time at which the `CallContext` was created. This field is only
-    /// optional to accommodate contexts that were created before this field was
-    /// added.
-    time: Option<Time>,
+    /// Point in time at which the `CallContext` was created.
+    time: Time,
 
     /// The total number of instructions executed in the given call context.
     /// This value is used for the `ic0.performance_counter` type 1.
@@ -63,7 +61,7 @@ impl CallContext {
             responded,
             deleted,
             available_cycles,
-            time: Some(time),
+            time,
             instructions_executed: NumInstructions::default(),
         }
     }
@@ -113,7 +111,7 @@ impl CallContext {
     }
 
     /// The point in time at which the call context was created.
-    pub fn time(&self) -> Option<Time> {
+    pub fn time(&self) -> Time {
         self.time
     }
 
@@ -132,7 +130,7 @@ impl From<&CallContext> for pb::CallContext {
             responded: item.responded,
             deleted: item.deleted,
             available_funds: Some((&funds).into()),
-            time_nanos: item.time.map(|t| t.as_nanos_since_unix_epoch()),
+            time_nanos: item.time.as_nanos_since_unix_epoch(),
             instructions_executed: item.instructions_executed.get(),
         }
     }
@@ -149,7 +147,7 @@ impl TryFrom<pb::CallContext> for CallContext {
             responded: value.responded,
             deleted: value.deleted,
             available_cycles: funds.cycles(),
-            time: value.time_nanos.map(Time::from_nanos_since_unix_epoch),
+            time: Time::from_nanos_since_unix_epoch(value.time_nanos),
             instructions_executed: value.instructions_executed.into(),
         })
     }
@@ -335,7 +333,7 @@ impl CallContextManager {
                 responded: false,
                 deleted: false,
                 available_cycles: cycles,
-                time: Some(time),
+                time,
                 instructions_executed: NumInstructions::default(),
             },
         );
@@ -581,15 +579,10 @@ impl CallContextManager {
         // context that isn't old enough.
         self.call_contexts
             .iter()
-            .take_while(|(_, call_context)| match call_context.time() {
-                Some(context_time) => context_time + age <= current_time,
-                None => true,
-            })
+            .take_while(|(_, call_context)| call_context.time() + age <= current_time)
             .filter_map(|(_, call_context)| {
-                if let Some(time) = call_context.time() {
-                    if !call_context.is_deleted() {
-                        return Some((call_context.call_origin(), time));
-                    }
+                if !call_context.is_deleted() {
+                    return Some((call_context.call_origin(), call_context.time()));
                 }
                 None
             })

rs/test_utilities/src/state.rs

@@ -306,7 +306,7 @@ impl CanisterStateBuilder {
             let call_context_id = call_context_manager.new_call_context(
                 call_context.call_origin().clone(),
                 call_context.available_cycles(),
-                call_context.time().unwrap(),
+                call_context.time(),
             );
 
             let call_context_in_call_context_manager = call_context_manager