blob: 143dbf5edf2baec268505c1da1c40add6f566ede [file] [log] [blame]
// Copyright 2021 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/rpc_log_drain.h"
#include <limits>
#include <mutex>
#include <optional>
#include <string_view>
#include "pw_assert/check.h"
#include "pw_chrono/system_clock.h"
#include "pw_log/proto/log.pwpb.h"
#include "pw_result/result.h"
#include "pw_rpc/raw/server_reader_writer.h"
#include "pw_span/span.h"
#include "pw_status/status.h"
#include "pw_status/try.h"
namespace pw::log_rpc {
namespace {
// Creates an encoded drop message on the provided buffer and adds it to the
// bulk log entries. Resets the drop count when successfull.
void TryEncodeDropMessage(
ByteSpan encoded_drop_message_buffer,
std::string_view reason,
uint32_t& drop_count,
log::pwpb::LogEntries::MemoryEncoder& entries_encoder) {
// Encode drop count and reason, if any, in log proto.
log::pwpb::LogEntry::MemoryEncoder encoder(encoded_drop_message_buffer);
if (!reason.empty()) {
encoder.WriteMessage(as_bytes(span<const char>(reason))).IgnoreError();
}
encoder.WriteDropped(drop_count).IgnoreError();
if (!encoder.status().ok()) {
return;
}
// Add encoded drop messsage if fits in buffer.
ConstByteSpan drop_message(encoder);
if (drop_message.size() + RpcLogDrain::kLogEntriesEncodeFrameSize <
entries_encoder.ConservativeWriteLimit()) {
PW_CHECK_OK(entries_encoder.WriteBytes(
static_cast<uint32_t>(log::pwpb::LogEntries::Fields::kEntries),
drop_message));
drop_count = 0;
}
}
} // namespace
Status RpcLogDrain::Open(rpc::RawServerWriter& writer) {
if (!writer.active()) {
return Status::FailedPrecondition();
}
std::lock_guard lock(mutex_);
if (server_writer_.active()) {
return Status::AlreadyExists();
}
server_writer_ = std::move(writer);
// Set a callback to close the drain when RequestCompletion() is requested by
// the reader. This callback is only set and invoked if
// PW_RPC_REQUEST_COMPLETION_CALLBACK is enabled.
// TODO: b/274936558 - : Add unit tests to check that when this callback is
// invoked, the stream is closed gracefully without dropping logs.
server_writer_.set_on_completion_requested_if_enabled(
[this]() { Close().IgnoreError(); });
if (on_open_callback_ != nullptr) {
on_open_callback_();
}
return OkStatus();
}
Status RpcLogDrain::Flush(ByteSpan encoding_buffer) {
Status status;
SendLogs(std::numeric_limits<size_t>::max(), encoding_buffer, status);
return status;
}
std::optional<chrono::SystemClock::duration> RpcLogDrain::Trickle(
ByteSpan encoding_buffer) {
chrono::SystemClock::time_point now = chrono::SystemClock::now();
// Called before drain is ready to send more logs. Ignore this request and
// remind the caller how much longer they'll need to wait.
if (no_writes_until_ > now) {
return no_writes_until_ - now;
}
Status encoding_status;
if (SendLogs(max_bundles_per_trickle_, encoding_buffer, encoding_status) ==
LogDrainState::kCaughtUp) {
return std::nullopt;
}
no_writes_until_ = chrono::SystemClock::TimePointAfterAtLeast(trickle_delay_);
return trickle_delay_;
}
RpcLogDrain::LogDrainState RpcLogDrain::SendLogs(size_t max_num_bundles,
ByteSpan encoding_buffer,
Status& encoding_status_out) {
PW_CHECK_NOTNULL(multisink_);
LogDrainState log_sink_state = LogDrainState::kMoreEntriesRemaining;
std::lock_guard lock(mutex_);
size_t sent_bundle_count = 0;
while (sent_bundle_count < max_num_bundles &&
log_sink_state != LogDrainState::kCaughtUp) {
if (!server_writer_.active()) {
encoding_status_out = Status::Unavailable();
// No reason to keep polling this drain until the writer is opened.
return LogDrainState::kCaughtUp;
}
log::pwpb::LogEntries::MemoryEncoder encoder(encoding_buffer);
uint32_t packed_entry_count = 0;
log_sink_state = EncodeOutgoingPacket(encoder, packed_entry_count);
// Avoid sending empty packets.
if (encoder.size() == 0) {
continue;
}
encoder.WriteFirstEntrySequenceId(sequence_id_)
.IgnoreError(); // TODO: b/242598609 - Handle Status properly
sequence_id_ += packed_entry_count;
const Status status = server_writer_.Write(encoder);
sent_bundle_count++;
if (!status.ok() &&
error_handling_ == LogDrainErrorHandling::kCloseStreamOnWriterError) {
// Only update this drop count when writer errors are not ignored.
drop_count_writer_error_ += packed_entry_count;
server_writer_.Finish().IgnoreError();
encoding_status_out = Status::Aborted();
return log_sink_state;
}
}
return log_sink_state;
}
RpcLogDrain::LogDrainState RpcLogDrain::EncodeOutgoingPacket(
log::pwpb::LogEntries::MemoryEncoder& encoder,
uint32_t& packed_entry_count_out) {
const size_t total_buffer_size = encoder.ConservativeWriteLimit();
do {
// Peek entry and get drop count from multisink.
uint32_t drop_count = 0;
uint32_t ingress_drop_count = 0;
Result<multisink::MultiSink::Drain::PeekedEntry> possible_entry =
PeekEntry(log_entry_buffer_, drop_count, ingress_drop_count);
drop_count_ingress_error_ += ingress_drop_count;
// Check if the entry fits in the entry buffer.
if (possible_entry.status().IsResourceExhausted()) {
++drop_count_small_stack_buffer_;
continue;
}
// Check if there are any entries left.
if (possible_entry.status().IsOutOfRange()) {
// Stash multisink's reported drop count that will be reported later with
// any other drop counts.
drop_count_slow_drain_ += drop_count;
return LogDrainState::kCaughtUp; // There are no more entries.
}
// At this point all expected errors have been handled.
PW_CHECK_OK(possible_entry.status());
// Check if the entry passes any set filter rules.
if (filter_ != nullptr &&
filter_->ShouldDropLog(possible_entry.value().entry())) {
// Add the drop count from the multisink peek, stored in `drop_count`, to
// the total drop count. Then drop the entry without counting it towards
// the total drop count. Drops will be reported later all together.
drop_count_slow_drain_ += drop_count;
PW_CHECK_OK(PopEntry(possible_entry.value()));
continue;
}
// Check if the entry fits in the encoder buffer by itself.
const size_t encoded_entry_size =
possible_entry.value().entry().size() + kLogEntriesEncodeFrameSize;
if (encoded_entry_size + kLogEntriesEncodeFrameSize > total_buffer_size) {
// Entry is larger than the entire available buffer.
++drop_count_small_outbound_buffer_;
PW_CHECK_OK(PopEntry(possible_entry.value()));
continue;
}
// At this point, we have a valid entry that may fit in the encode buffer.
// Report any drop counts combined reusing the log_entry_buffer_ to encode a
// drop message.
drop_count_slow_drain_ += drop_count;
// Account for dropped entries too large for stack buffer, which PeekEntry()
// also reports.
drop_count_slow_drain_ -= drop_count_small_stack_buffer_;
bool log_entry_buffer_has_valid_entry = possible_entry.ok();
if (drop_count_slow_drain_ > 0) {
TryEncodeDropMessage(log_entry_buffer_,
std::string_view(kSlowDrainErrorMessage),
drop_count_slow_drain_,
encoder);
log_entry_buffer_has_valid_entry = false;
}
if (drop_count_ingress_error_ > 0) {
TryEncodeDropMessage(log_entry_buffer_,
std::string_view(kIngressErrorMessage),
drop_count_ingress_error_,
encoder);
log_entry_buffer_has_valid_entry = false;
}
if (drop_count_small_stack_buffer_ > 0) {
TryEncodeDropMessage(log_entry_buffer_,
std::string_view(kSmallStackBufferErrorMessage),
drop_count_small_stack_buffer_,
encoder);
log_entry_buffer_has_valid_entry = false;
}
if (drop_count_small_outbound_buffer_ > 0) {
TryEncodeDropMessage(log_entry_buffer_,
std::string_view(kSmallOutboundBufferErrorMessage),
drop_count_small_outbound_buffer_,
encoder);
log_entry_buffer_has_valid_entry = false;
}
if (drop_count_writer_error_ > 0) {
TryEncodeDropMessage(log_entry_buffer_,
std::string_view(kWriterErrorMessage),
drop_count_writer_error_,
encoder);
log_entry_buffer_has_valid_entry = false;
}
if (possible_entry.ok() && !log_entry_buffer_has_valid_entry) {
PW_CHECK_OK(PeekEntry(log_entry_buffer_, drop_count, ingress_drop_count)
.status());
}
// Check if the entry fits in the partially filled encoder buffer.
if (encoded_entry_size > encoder.ConservativeWriteLimit()) {
// Notify the caller there are more entries to send.
return LogDrainState::kMoreEntriesRemaining;
}
// Encode the entry and remove it from multisink.
PW_CHECK_OK(encoder.WriteBytes(
static_cast<uint32_t>(log::pwpb::LogEntries::Fields::kEntries),
possible_entry.value().entry()));
PW_CHECK_OK(PopEntry(possible_entry.value()));
++packed_entry_count_out;
} while (true);
}
Status RpcLogDrain::Close() {
std::lock_guard lock(mutex_);
return server_writer_.Finish();
}
} // namespace pw::log_rpc