blob: 241e3d59e5f9be9a063e49321b69473df33f8bdb [file] [log] [blame]
/*
* Copyright (C) 2016 The Android Open Source Project
*
* 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
*
* http://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 "event_log_list_builder.h"
#include <cinttypes>
#include <memory>
#include <string>
#include <android-base/logging.h>
#include <log/log.h>
namespace {
const size_t MAX_EVENT_PAYLOAD_SIZE = 512 - 1; // Leave room for final '\n'.
const size_t EVENT_TYPE_SIZE = 1; // Size in bytes of the event type marker.
} // namespace
EventLogListBuilder::EventLogListBuilder()
: payload_count_(0),
payload_size_(0),
payload_(std::make_unique<uint8_t[]>(MAX_EVENT_PAYLOAD_SIZE)) {
memset(payload_.get(), 0, MAX_EVENT_PAYLOAD_SIZE);
// Set up the top-level EventLog data type.
AppendByte(EVENT_TYPE_LIST);
// Skip over the byte prepresenting the number of items in the list. This
// value is set in Release().
payload_size_++;
}
bool EventLogListBuilder::Append(int value) {
DCHECK_NE(static_cast<uint8_t*>(nullptr), payload_.get());
if (!IsSpaceAvailable(sizeof(value) + EVENT_TYPE_SIZE)) {
return false;
}
AppendByte(EVENT_TYPE_INT);
AppendData(&value, sizeof(value));
payload_count_++;
return true;
}
bool EventLogListBuilder::Append(const std::string& value) {
DCHECK_NE(static_cast<uint8_t*>(nullptr), payload_.get());
int len = value.length();
if (!IsSpaceAvailable(sizeof(len) + len)) {
return false;
}
AppendByte(EVENT_TYPE_STRING);
AppendData(&len, sizeof(len));
AppendData(value.c_str(), len);
payload_count_++;
return true;
}
void EventLogListBuilder::Release(std::unique_ptr<uint8_t[]>* log,
size_t* size) {
// Finalize the log payload.
payload_[1] = payload_count_;
// Return the log payload.
*size = payload_size_;
*log = std::move(payload_);
}
void EventLogListBuilder::AppendData(const void* data, size_t size) {
DCHECK_LT(payload_size_ + size, MAX_EVENT_PAYLOAD_SIZE);
memcpy(&payload_[payload_size_], data, size);
payload_size_ += size;
}
void EventLogListBuilder::AppendByte(uint8_t byte) {
DCHECK_LT(payload_size_ + sizeof(byte), MAX_EVENT_PAYLOAD_SIZE);
payload_[payload_size_++] = byte;
}
bool EventLogListBuilder::IsSpaceAvailable(size_t value_size) {
size_t space_needed = value_size + EVENT_TYPE_SIZE;
if (payload_size_ + space_needed > MAX_EVENT_PAYLOAD_SIZE) {
size_t remaining = MAX_EVENT_PAYLOAD_SIZE - payload_size_;
LOG(WARNING) << "Not enough space for value. remain=" <<
remaining << "; needed=" << space_needed;
return false;
}
return true;
}