toolbox::base Namespace Reference

提供基础 C++ 工具和组件。 Provides fundamental C++ utilities and components. More...

Namespaces
namespace	detail

Classes
class	memory_pool_t
	固定大小内存池类/Fixed-size memory pool class More...
class	object_pool_t
class	PoolDeleter
class	thread_pool_singleton_t
	简单的线程池单例封装/A simple singleton wrapper around thread_pool_t More...
class	thread_pool_t

Functions
CPP_TOOLBOX_EXPORT auto	get_environment_variable (const std::string &name) -> std::string
	获取环境变量的值 (Retrieves the value of an environment variable)
CPP_TOOLBOX_EXPORT auto	set_environment_variable (const std::string &name, const std::string &value) -> bool
	设置或更新环境变量 (Sets or updates an environment variable)
CPP_TOOLBOX_EXPORT auto	remove_environment_variable (const std::string &name) -> bool
	从当前进程环境中删除环境变量 (Removes an environment variable from the current process environment)

Detailed Description

提供基础 C++ 工具和组件。 Provides fundamental C++ utilities and components.

工具箱库的基础命名空间 (Base namespace for toolbox library)

该命名空间包含了一系列用于 C++ 开发的核心基础功能，旨在提高开发效率和代码质量。 主要包括：

• 线程管理 (Thread Management): 提供易于使用的线程池 (ThreadPool, ThreadPoolSingleton)，用于高效管理并发任务。
• 资源管理 (Resource Management): 提供对象池 (ObjectPool) 和可能的内存池 (MemoryPool) 实现，以优化资源的分配和回收。
• 环境交互 (Environment Interaction): 可能包含与运行时环境交互的工具，例如环境变量的读取 (env.hpp)。

这些组件是构建更复杂应用程序的基础模块。

This namespace contains a collection of core fundamental functionalities for C++ development, aiming to improve development efficiency and code quality. Key components include:

• Thread Management: Provides easy-to-use thread pools (ThreadPool, ThreadPoolSingleton) for efficient management of concurrent tasks.
• Resource Management: Offers implementations for object pools (ObjectPool) and potentially memory pools (MemoryPool) to optimize resource allocation and recycling.
• Environment Interaction: May include utilities for interacting with the runtime environment, such as reading environment variables (env.hpp).

These components serve as foundational building blocks for constructing more complex applications.

示例 (Examples)

线程池使用示例 (ThreadPool Usage

Example)

#include <cpp-toolbox/base/thread_pool.hpp>
#include <iostream>
#include <vector>
#include <future>
#include <chrono>
#include <numeric>
 
int main() {
    // 创建一个拥有 4 个工作线程的线程池
    // Create a thread pool with 4 worker threads
    toolbox::base::ThreadPool pool(4);
 
    // 准备提交的任务
    // Prepare tasks to submit
    std::vector<std::future<int>> results;
 
    for (int i = 0; i < 8; ++i) {
        results.emplace_back(
            pool.enqueue([i] { // 提交 Lambda 函数作为任务 (Submit a lambda
function as a task) std::cout << "Processing task " << i << " on thread " <<
std::this_thread::get_id() << std::endl;
                std::this_thread::sleep_for(std::chrono::milliseconds(100));
// 模拟工作 (Simulate work) std::cout << "Finished task " << i << std::endl;
                return i * i; // 返回结果 (Return a result)
            })
        );
    }
 
    // 等待所有任务完成并获取结果
    // Wait for all tasks to complete and retrieve results
    int sum = 0;
    for (auto && result : results) {
        try {
            sum += result.get(); // 获取任务的返回值 (Get the return value of
the task) } catch (const std::exception& e) { std::cerr << "Exception caught:
" << e.what() << std::endl;
        }
    }
 
    std::cout << "All tasks finished. Sum of squares: " << sum << std::endl;
 
    // 线程池会在析构时自动停止并加入所有线程
    // The thread pool will automatically stop and join all threads upon
    // destruction
  return 0;
}

对象池使用示例 (ObjectPool Usage

Example)

#include <cpp-toolbox/base/object_pool.hpp>
#include <iostream>
#include <vector>
#include <memory> // for std::shared_ptr
 
struct MyObject {
    int id;
    MyObject() : id(-1) { std::cout << "MyObject Default constructing." <<
std::endl; } MyObject(int i) : id(i) { std::cout << "MyObject constructing
with id " << id << "." << std::endl; } ~MyObject() { std::cout << "MyObject
destructing with id " << id << "." << std::endl; }
 
    // 对象池可能会调用 reset 来重置状态 (Object pool might call reset to
    // reset state)
    void reset() {
       id = -1;
       std::cout << "MyObject resetting." << sstd::endl;
    }
};
 
int main() {
    // 创建一个 MyObject 对象池，初始大小为 2，最大可扩展到 10
    // Create an ObjectPool for MyObject, initial size 2, max size 10
    toolbox::base::ObjectPool<MyObject> pool(2, 10);
 
    std::vector<std::shared_ptr<MyObject>> objects;
 
    std::cout << "Acquiring objects..." << std::endl;
    for (int i = 0; i < 5; ++i) {
        // 从池中获取对象 (Acquire an object from the pool)
        // 使用 acquire 获取带有关联释放器的智能指针 (Use acquire to get a
smart pointer with associated releaser)
        // 或者如果 ObjectPool 提供构造函数参数传递，则使用 allocate
        // Or use allocate if the ObjectPool supports constructor argument
forwarding
        // auto obj = pool.allocate(i); // 假设 allocate 可以传递构造函数参数
        auto obj = pool.acquire(); // 使用 acquire 获取对象，然后手动设置
        if (obj) {
           obj->id = i; // 手动设置 ID (Manually set ID)
           std::cout << "Acquired object with id: " << obj->id << std::endl;
           objects.push_back(obj);
        } else {
           std::cerr << "Failed to acquire object " << i << " (Pool likely
reached max size)" << std::endl;
           break;
        }
    }
 
    std::cout << "\nUsing objects..." << std::endl;
    for (const auto& obj : objects) {
        std::cout << "Using object with id: " << obj->id << std::endl;
    }
 
    std::cout << "\nReleasing objects..." << std::endl;
    objects.clear(); // 当 shared_ptr 引用计数归零时，对象会自动释放回池中
                     // When the shared_ptr reference count drops to zero,
the object is automatically released back to the pool
 
    std::cout << "\nAcquiring again..." << std::endl;
    // 再次获取对象，应该会复用之前释放的对象
    // Acquire objects again, should reuse previously released objects
     auto reused_obj1 = pool.acquire();
     if(reused_obj1) std::cout << "Acquired reused object with id: " <<
reused_obj1->id << std::endl;
     // ID 应该是被 reset 后的值 (ID should be the reset value)
 
     auto reused_obj2 = pool.acquire();
     if(reused_obj2) std::cout << "Acquired reused object with id: " <<
reused_obj2->id << std::endl;
 
     std::cout << "\nExiting..." << std::endl;
     // 对象池析构时，会销毁其管理的所有对象
     // When the object pool is destructed, it destroys all the objects it
     // manages
     return 0;
}

< 用于 std::size_t/For std::size_t 用于 std::numeric_limits/For std::numeric_limits 用于 std::mutex/For std::mutex 用于 std::queue/For std::queue 用于 std::invalid_argument/For std::invalid_argument

Function Documentation

get_environment_variable()

CPP_TOOLBOX_EXPORT auto toolbox::base::get_environment_variable

(

const std::string &

name

)

-> std::string

获取环境变量的值 (Retrieves the value of an environment variable)

该函数查询系统环境变量并返回与指定名称关联的值。如果环境变量不存在，则返回空字符串。 (This function queries the system environment variables and returns the value associated with the specified name. If the environment variable does not exist, an empty string is returned.)

Parameters

name	要获取的环境变量名称，不能为空 (The name of the environment variable to retrieve. Must be non-empty)

Returns

环境变量的字符串值。如果变量未找到则返回空字符串 (The value of the environment variable as a string. Returns an empty string if not found)

// 获取 PATH 环境变量 (Get the PATH environment variable)
auto path = get_environment_variable("PATH");
// path 将包含 PATH 环境变量的值 (path will contain the PATH value)
 
// 获取不存在的变量 (Get a non-existent variable)
auto value = get_environment_variable("NON_EXISTENT_VAR");
// value 将是空字符串 (value will be empty)

remove_environment_variable()

CPP_TOOLBOX_EXPORT auto toolbox::base::remove_environment_variable

(

const std::string &

name

)

-> bool

从当前进程环境中删除环境变量 (Removes an environment variable from the current process environment)

该函数从当前进程的环境中删除指定的环境变量。更改会影响当前进程及其后创建的任何子进程。 (This function deletes the specified environment variable from the current process's environment. The change affects the current process and any child processes spawned after the change.)

Parameters

name	要删除的环境变量名称，不能为空 (The name of the environment variable to remove. Must be non-empty)

Returns

如果环境变量成功删除则返回true，否则返回false (True if successfully removed, false otherwise)

// 删除临时环境变量 (Remove a temporary environment variable)
bool removed = remove_environment_variable("TEMP_VAR");
// removed 如果变量存在并被删除将为true (removed will be true if existed and
removed)
 
// 尝试删除不存在的变量 (Try to remove non-existent variable)
bool result = remove_environment_variable("NON_EXISTENT_VAR");
// result 将为false (result will be false)
 
// 清理会话变量 (Clean up session variables)
remove_environment_variable("SESSION_ID");
remove_environment_variable("USER_TEMP");

set_environment_variable()

CPP_TOOLBOX_EXPORT auto toolbox::base::set_environment_variable	(	const std::string &	name,
		const std::string &	value
	)		-> bool

设置或更新环境变量 (Sets or updates an environment variable)

该函数创建或修改具有指定名称和值的环境变量。更改会影响当前进程及其后创建的任何子进程。 (This function creates or modifies an environment variable with the specified name and value. The change affects the current process and any child processes spawned after the change.)

Parameters

name	要设置的环境变量名称，不能为空 (The name of the environment variable to set. Must be non-empty)
value	要分配给环境变量的值 (The value to assign to the environment variable)

Returns

如果环境变量设置成功则返回true，否则返回false (True if successfully set, false otherwise)

// 设置新的环境变量 (Set a new environment variable)
bool success = set_environment_variable("MY_VAR", "12345");
// success 如果变量设置成功将为true (success will be true if set)
 
// 更新现有变量 (Update existing variable)
set_environment_variable("PATH", "/new/path:" +
                        get_environment_variable("PATH"));
 
// 设置临时变量 (Set temporary variable)
set_environment_variable("TEMP_DIR", "/tmp/workdir");