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Improve constness in several method bodies

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This commit is contained in:
Tyler Neely 2022-08-29 13:43:27 +00:00
parent 325aae34d2
commit a410864855
1 changed files with 35 additions and 33 deletions

68
src/io/rsm/raft.hpp
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@ -243,7 +243,7 @@ class Raft {
last_cron = now;
}
Duration receive_timeout = RandomTimeout(kMinimumReceiveTimeout, kMaximumReceiveTimeout);
const Duration receive_timeout = RandomTimeout(kMinimumReceiveTimeout, kMaximumReceiveTimeout);
auto request_result =
io_.template ReceiveWithTimeout<ReadRequest<ReadOperation>, AppendRequest<WriteOperation>, AppendResponse,
@ -294,8 +294,8 @@ class Raft {
// [3, 2, 1] 2 (3 / 2) => 1
// [4, 3, 2, 1] 2 (4 / 2) => 2
// [5, 4, 3, 2, 1] 3 (5 / 2) => 2
size_t majority_index = confirmed_log_sizes.size() / 2;
LogSize new_committed_log_size = confirmed_log_sizes[majority_index];
const size_t majority_index = confirmed_log_sizes.size() / 2;
const LogSize new_committed_log_size = confirmed_log_sizes[majority_index];
// We never go backwards in history.
MG_ASSERT(state_.committed_log_size <= new_committed_log_size,
@ -312,13 +312,13 @@ class Raft {
for (; state_.applied_size < state_.committed_log_size; state_.applied_size++) {
const LogIndex apply_index = state_.applied_size;
const auto &write_request = state_.log[apply_index].second;
WriteResponseValue write_return = replicated_state_.Apply(write_request);
const WriteResponseValue write_return = replicated_state_.Apply(write_request);
if (leader.pending_client_requests.contains(apply_index)) {
PendingClientRequest client_request = std::move(leader.pending_client_requests.at(apply_index));
const PendingClientRequest client_request = std::move(leader.pending_client_requests.at(apply_index));
leader.pending_client_requests.erase(apply_index);
WriteResponse<WriteResponseValue> resp{
const WriteResponse<WriteResponseValue> resp{
.success = true,
.write_return = std::move(write_return),
.raft_index = apply_index,
@ -337,12 +337,12 @@ class Raft {
for (auto &[address, follower] : followers) {
const LogSize follower_log_size = follower.confirmed_log_size;
std::vector<std::pair<Term, WriteOperation>> entries;
const auto missing = state_.log.size() - follower_log_size;
const auto batch_size = std::min(missing, kMaximumAppendBatchSize);
const auto start_index = follower_log_size;
const auto end_index = start_index + batch_size;
auto missing = state_.log.size() - follower_log_size;
auto batch_size = std::min(missing, kMaximumAppendBatchSize);
auto start_index = follower_log_size;
auto end_index = start_index + batch_size;
std::vector<std::pair<Term, WriteOperation>> entries;
entries.insert(entries.begin(), state_.log.begin() + start_index, state_.log.begin() + end_index);
@ -371,7 +371,7 @@ class Raft {
Duration RandomTimeout(Duration min, Duration max) {
std::uniform_int_distribution time_distrib(min.count(), max.count());
auto rand_micros = io_.Rand(time_distrib);
const auto rand_micros = io_.Rand(time_distrib);
return Duration{rand_micros};
}
@ -379,7 +379,7 @@ class Raft {
Duration RandomTimeout(int min_micros, int max_micros) {
std::uniform_int_distribution time_distrib(min_micros, max_micros);
int rand_micros = io_.Rand(time_distrib);
const int rand_micros = io_.Rand(time_distrib);
return std::chrono::microseconds{rand_micros};
}
@ -399,7 +399,7 @@ class Raft {
return 0;
}
auto &[term, data] = state_.log.at(state_.committed_log_size - 1);
const auto &[term, data] = state_.log.at(state_.committed_log_size - 1);
return term;
}
@ -415,16 +415,14 @@ class Raft {
template <typename... Ts>
void Log(Ts &&...args) {
const Time now = io_.Now();
auto micros = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
const auto micros = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
const Term term = state_.term;
const std::string role_string = std::visit([&](const auto &role) { return role.ToString(); }, role_);
std::ostringstream out;
out << '\t' << (int)micros << "\t" << term << "\t" << io_.GetAddress().last_known_port;
std::string role_string = std::visit([&](const auto &role) { return role.ToString(); }, role_);
out << role_string;
(out << ... << args);
@ -587,6 +585,7 @@ class Raft {
.leader_address = from_address,
};
}
if (term_dominates) {
Log("received a vote from an inferior candidate. Becoming Candidate");
state_.term = std::max(state_.term, req.term) + 1;
@ -717,7 +716,7 @@ class Raft {
Log("applying batch of ", req.entries.size(), " entries to our log starting at index ",
req.batch_start_log_index);
auto resize_length = req.batch_start_log_index;
const auto resize_length = req.batch_start_log_index;
MG_ASSERT(resize_length >= state_.committed_log_size,
"Applied history from Leader which goes back in time from our commit_index");
@ -797,7 +796,7 @@ class Raft {
ReadResponseValue read_return = replicated_state_.Read(read_operation);
ReadResponse<ReadResponseValue> resp{
const ReadResponse<ReadResponseValue> resp{
.success = true,
.read_return = std::move(read_return),
.retry_leader = std::nullopt,
@ -811,9 +810,9 @@ class Raft {
// Candidates should respond with a failure, similar to the Candidate + WriteRequest failure below
std::optional<Role> Handle(Candidate &, ReadRequest<ReadOperation> &&, RequestId request_id, Address from_address) {
Log("received ReadOperation - not redirecting because no Leader is known");
auto res = ReadResponse<ReadResponseValue>{};
res.success = false;
const ReadResponse<ReadResponseValue> res{
.success = false,
};
io_.Send(from_address, request_id, res);
@ -825,11 +824,12 @@ class Raft {
// Followers should respond with a redirection, similar to the Follower + WriteRequest response below
std::optional<Role> Handle(Follower &follower, ReadRequest<ReadOperation> &&, RequestId request_id,
Address from_address) {
auto res = ReadResponse<ReadResponseValue>{};
res.success = false;
Log("redirecting client to known Leader with port ", follower.leader_address.last_known_port);
res.retry_leader = follower.leader_address;
const ReadResponse<ReadResponseValue> res{
.success = false,
.retry_leader = follower.leader_address,
};
io_.Send(from_address, request_id, res);
@ -843,11 +843,12 @@ class Raft {
// about the most recent leader it has heard from.
std::optional<Role> Handle(Follower &follower, WriteRequest<WriteOperation> &&, RequestId request_id,
Address from_address) {
auto res = WriteResponse<WriteResponseValue>{};
res.success = false;
Log("redirecting client to known Leader with port ", follower.leader_address.last_known_port);
res.retry_leader = follower.leader_address;
const WriteResponse<WriteResponseValue> res{
.success = false,
.retry_leader = follower.leader_address,
};
io_.Send(from_address, request_id, res);
@ -856,9 +857,10 @@ class Raft {
std::optional<Role> Handle(Candidate &, WriteRequest<WriteOperation> &&, RequestId request_id, Address from_address) {
Log("received WriteRequest - not redirecting because no Leader is known");
auto res = WriteResponse<WriteResponseValue>{};
res.success = false;
const WriteResponse<WriteResponseValue> res{
.success = false,
};
io_.Send(from_address, request_id, res);