make last_log_id an Option<LogId> #68
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| @@ -31,8 +31,8 @@ impl<'a, D: AppData, R: AppDataResponse, N: RaftNetwork<D>, S: RaftStorage<D, R> | |||
| &mut self, | |||
| mut members: BTreeSet<NodeId>, | |||
| ) -> Result<(), InitializeError> { | |||
| if self.core.last_log_id.index != 0 || self.core.current_term != 0 { | |||
| tracing::error!({self.core.last_log_id.index, self.core.current_term}, "rejecting init_with_config request as last_log_index or current_term is 0"); | |||
| if self.core.last_log_id.unwrap().index != 0 || self.core.current_term != 0 { | |||
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Before this PR, the zero value of last_log_id is (0,0).
Since now on, the zero value of it should be None.
Thus here to check if the state is uninitialized by checking if last_log_id is None.
unwrap() is not safe and should be avoided.
| if self.core.last_log_id.index != 0 || self.core.current_term != 0 { | ||
| tracing::error!({self.core.last_log_id.index, self.core.current_term}, "rejecting init_with_config request as last_log_index or current_term is 0"); | ||
| if self.core.last_log_id.unwrap().index != 0 || self.core.current_term != 0 { | ||
| tracing::error!({"{} {}", self.core.last_log_id.unwrap(), self.core.current_term}, "rejecting init_with_config request as last_log_index or current_term is 0"); |
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Why do we need the format literal string? 🤔
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tracing seems not allow to do expression like unwrap() or unwrap_or_else(), it needs manually format, so I did it.
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The compiler is not smart enough 🤔
These syntaxes just compile smoothly:
let x = Some(1);
tracing::debug!(x=%x.unwrap(), "message: x: Display");
tracing::debug!(x=?x.unwrap(), "message: x: Debug");
tracing::debug!({ x=%x.unwrap() }, "message");| @@ -181,7 +184,7 @@ impl<'a, D: AppData, R: AppDataResponse, N: RaftNetwork<D>, S: RaftStorage<D, R> | |||
| ChangeMembershipError::LearnerIsLagging { | |||
| node_id: *new_node, | |||
| matched: node.matched, | |||
| distance: self.core.last_log_id.index.saturating_sub(node.matched.index), | |||
| distance: self.core.last_log_id.unwrap().index.saturating_sub(node.matched.index), | |||
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Here using unwrap_or_else() would be better.
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in my humble opinion, here using unwrap() is equal to assert!, it is the right way to do here?
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it means that we can only do this action when it is initialized.
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In theory, it is legal to change membership with an empty, uninitialized state.
Although in this codebase it hardly will.
| @@ -217,7 +220,7 @@ impl<'a, D: AppData, R: AppDataResponse, N: RaftNetwork<D>, S: RaftStorage<D, R> | |||
|
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| // Caveat: membership must be updated before commit check is done with the new config. | |||
| self.core.effective_membership = EffectiveMembership { | |||
| log_id: self.core.last_log_id, | |||
| log_id: self.core.last_log_id.expect("raft core last_log_id is uninitialized"), | |||
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Here it's better to use the log_id of the returned entry in res.
There is another issue that updating the effective_membership at line 222 should be placed after checking res, e.g. at line 242
| @@ -26,7 +26,7 @@ impl<D: AppData, R: AppDataResponse, N: RaftNetwork<D>, S: RaftStorage<D, R>> Ra | |||
| &mut self, | |||
| msg: AppendEntriesRequest<D>, | |||
| ) -> RaftResult<AppendEntriesResponse> { | |||
| tracing::debug!(%self.last_log_id, %self.last_applied, msg=%msg.summary(), "handle_append_entries_request"); | |||
| tracing::debug!({"{} {} {}", self.last_log_id.unwrap(), self.last_applied, msg.summary()}, "handle_append_entries_request"); | |||
this pr fix #49 .
make struct
RaftCore'slast_log_idintoOption<LogId>to express an uninitialized state.