blob: ada547049f29c8bf05d73675c2a67a24ea3b9dee [file] [log] [blame]
// Copyright 2020 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
#include "pw_log_rpc/logs_rpc.h"
#include "pw_log/log.h"
#include "pw_log_proto/log.pwpb.h"
#include "pw_status/try.h"
namespace pw::log_rpc {
namespace {
Result<ConstByteSpan> GenerateDroppedEntryMessage(ByteSpan encode_buffer,
size_t dropped_entries) {
pw::protobuf::NestedEncoder nested_encoder(encode_buffer);
pw::log::LogEntry::Encoder encoder(&nested_encoder);
encoder.WriteDropped(dropped_entries);
return nested_encoder.Encode();
}
} // namespace
void Logs::Get(ServerContext&, ConstByteSpan, rpc::RawServerWriter& writer) {
response_writer_ = std::move(writer);
}
Status Logs::Flush() {
// If the response writer was not initialized or has since been closed,
// ignore the flush operation.
if (!response_writer_.open()) {
return Status::Ok();
}
// If previous calls to flush resulted in dropped entries, generate a
// dropped entry message and write it before further log messages.
if (dropped_entries_ > 0) {
ByteSpan payload = response_writer_.PayloadBuffer();
Result dropped_log = GenerateDroppedEntryMessage(payload, dropped_entries_);
PW_TRY(dropped_log.status());
PW_TRY(response_writer_.Write(dropped_log.value()));
dropped_entries_ = 0;
}
// Write logs to the response writer. An important limitation of this
// implementation is that if this RPC call fails, the logs are lost -
// a subsequent call to the RPC will produce a drop count message.
ByteSpan payload = response_writer_.PayloadBuffer();
Result possible_logs = log_queue_.PopMultiple(payload);
PW_TRY(possible_logs.status());
if (possible_logs.value().entry_count == 0) {
return Status::Ok();
}
Status status = response_writer_.Write(possible_logs.value().entries);
if (!status.ok()) {
// On a failure to send logs, track the dropped entries.
dropped_entries_ = possible_logs.value().entry_count;
return status;
}
return Status::Ok();
}
} // namespace pw::log_rpc