141 lines
4.0 KiB
C++

//
// Created by Kirill Zhukov on 20.04.2025.
//
#include "UDB.h"
namespace usub::core
{
UDB::UDB(const std::string& db_name, const std::string& shm_name,
utils::DatabaseSettings settings, bool create_new)
: db_name_(db_name),
shm_name_(shm_name),
shm_queue_capacity_(settings.shm_queue_capacity),
max_memtable_size_(settings.max_memtable_size),
shm_manager_(shm_name, sizeof(SharedCommandQueue), create_new),
version_manager_(db_name),
memtable_manager_(db_name + "_wal", settings.max_memtable_size, settings.estimated_element_size, this->version_manager_),
compactor_(this->version_manager_),
running_(true)
{
if (shm_manager_.needs_init())
{
new(shm_manager_.base_ptr()) SharedCommandQueue(shm_queue_capacity_);
}
command_queue_ = reinterpret_cast<SharedCommandQueue*>(shm_manager_.base_ptr());
recover_from_logs();
background_flush_thread_ = std::thread(&UDB::background_flush_worker, this);
compactor_.run();
}
UDB::~UDB()
{
running_ = false;
if (this->background_flush_thread_.joinable())
this->background_flush_thread_.join();
}
void UDB::recover_from_logs()
{
utils::RecoveryLog recovery_log(this->db_name_);
recovery_log.replay([this](const utils::Hash128& key, const std::string& value, bool is_tombstone)
{
if (!is_tombstone)
{
this->fast_cache_[key] = value;
this->memtable_manager_.put(key, value);
}
else
{
this->fast_cache_.erase(key);
this->memtable_manager_.remove(key);
}
});
std::cout << "[UDB] Recovery complete for database: " << this->db_name_ << "\n";
}
void UDB::run()
{
std::cout << "[UDB] Server for DB '" << this->db_name_ << "' started.\n";
while (this->running_)
{
Command* cmd = this->command_queue_->peek(0);
if (!cmd)
{
std::this_thread::sleep_for(std::chrono::milliseconds(1));
continue;
}
if (cmd->ready.load(std::memory_order_acquire) == 1)
{
process_command(*cmd);
this->command_queue_->pop();
}
else
{
std::this_thread::sleep_for(std::chrono::milliseconds(1));
}
}
}
void UDB::process_command(Command& cmd)
{
switch (cmd.op)
{
case OperationType::PUT:
{
std::cout << "PUT\n";
std::string value(cmd.value, cmd.value_size);
this->fast_cache_[cmd.key] = value;
this->memtable_manager_.put(cmd.key, value);
break;
}
case OperationType::DELETE:
{
std::cout << "DELETE\n";
fast_cache_.erase(cmd.key);
memtable_manager_.remove(cmd.key);
break;
}
case OperationType::FIND:
{
auto it = fast_cache_.find(cmd.key);
if (it != fast_cache_.end())
{
std::cout << "FIND\n";
std::string value = it->second;
cmd.response_size = static_cast<uint32_t>(value.size());
std::memcpy(cmd.response, value.data(), value.size());
}
else
{
cmd.response_size = 0;
}
cmd.response_ready.store(1, std::memory_order_release);
break;
}
default:
std::cout << "[UNKNOWN COMMAND]\n";
break;
}
}
void UDB::background_flush_worker()
{
while (running_)
{
memtable_manager_.flush_batch();
std::this_thread::sleep_for(std::chrono::milliseconds(10));
}
}
}