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yourpart3/src/performance_utils.h

135 lines
3.7 KiB
C++

#pragma once
#include <string_view>
#include <chrono>
#include <memory>
#include <vector>
#include <unordered_map>
namespace PerformanceUtils {
// C++23: std::expected-like error handling
template<typename T, typename E>
class Expected {
private:
union {
T value_;
E error_;
};
bool has_value_;
public:
Expected(T&& value) : value_(std::move(value)), has_value_(true) {}
Expected(const E& error) : error_(error), has_value_(false) {}
bool has_value() const noexcept { return has_value_; }
const T& value() const { return value_; }
const E& error() const { return error_; }
T&& move_value() { return std::move(value_); }
};
// C++23: std::optional with better performance
template<typename T>
class FastOptional {
private:
alignas(T) char storage_[sizeof(T)];
bool has_value_;
public:
FastOptional() : has_value_(false) {}
template<typename... Args>
FastOptional(Args&&... args) : has_value_(true) {
new(storage_) T(std::forward<Args>(args)...);
}
~FastOptional() {
if (has_value_) {
reinterpret_cast<T*>(storage_)->~T();
}
}
bool has_value() const noexcept { return has_value_; }
T& value() { return *reinterpret_cast<T*>(storage_); }
const T& value() const { return *reinterpret_cast<const T*>(storage_); }
};
// String interning for better memory usage
class StringInterner {
private:
std::unordered_map<std::string_view, std::string> interned_strings_;
public:
std::string_view intern(std::string_view str) {
auto it = interned_strings_.find(str);
if (it != interned_strings_.end()) {
return it->second;
}
auto [new_it, inserted] = interned_strings_.emplace(str, std::string(str));
return new_it->second;
}
};
// Performance timer
class Timer {
private:
std::chrono::high_resolution_clock::time_point start_;
public:
Timer() : start_(std::chrono::high_resolution_clock::now()) {}
auto elapsed() const {
return std::chrono::high_resolution_clock::now() - start_;
}
auto elapsed_ms() const {
return std::chrono::duration_cast<std::chrono::milliseconds>(elapsed()).count();
}
};
// Memory pool for frequent allocations
template<typename T>
class MemoryPool {
private:
std::vector<std::unique_ptr<T[]>> blocks_;
std::vector<T*> free_list_;
size_t block_size_;
size_t current_block_;
size_t current_index_;
public:
MemoryPool(size_t block_size = 1024)
: block_size_(block_size), current_block_(0), current_index_(0) {
allocate_block();
}
T* allocate() {
if (!free_list_.empty()) {
T* ptr = free_list_.back();
free_list_.pop_back();
return ptr;
}
if (current_index_ >= block_size_) {
allocate_block();
}
return &blocks_[current_block_][current_index_++];
}
void deallocate(T* ptr) {
free_list_.push_back(ptr);
}
private:
void allocate_block() {
blocks_.emplace_back(std::make_unique<T[]>(block_size_));
current_block_ = blocks_.size() - 1;
current_index_ = 0;
}
};
}