9、Function Calling过滤器

Function Calling 过滤器

SK 中提供了两个过滤器IFunctionInvocationFilter 和IAutoFuntionInvocationFilter 来实现错误处理、日志审计、功能增强。

IFunctionInvocationFilter：函数调用过滤器 - 每次调用KernelFunction时都会执行此过滤器。适用于：

• 权限验证：在函数调用之前验证用户权限，确保只有授权用户才能执行特定操作。
• 异常处理：捕获和处理函数执行过程中可能出现的异常，例如网络错误或 AI 模型故障。
• 结果重写：在函数执行前后修改或重写结果，例如缓存结果或应用 AI 负责性原则。
• 函数重试：在函数失败时自动重试，例如切换到备用 AI 模型。
• 日志记录：记录函数调用信息，例如函数名称、参数和结果，用于调试和监控。
• 敏感信息处理：在将提示发送给 AI 之前，识别和脱敏敏感信息，例如个人信息 (PII)。
• 语义缓存：缓存函数结果，避免重复调用相同的函数，提高效率。
• 内容安全：过滤或修改不适当的内容，例如色情或暴力内容。
• 文本摘要和翻译质量检查：在将文本发送给 AI 进行摘要或翻译之前，检查其质量和完整性。

IAutoFuntionInvocationFilter 自动函数调用过滤器——与IFunctionInvocationFilter类似，此过滤器在automatic function calling范围内运行，适用于：

• 自动函数调用过程中的控制：在自动函数调用过程中，根据特定条件终止或跳过函数调用，例如当获得期望的结果时。
• 提供额外的上下文信息：访问自动函数调用过程中的上下文信息，例如聊天历史、待执行函数列表和迭代计数器。
• 动态调整函数调用：根据上下文信息动态调整函数调用策略，例如选择不同的 AI 模型或参数

//准备工作
var chatCompletionService = kernel.GetRequiredService<IChatCompletionService>();

kernel.Plugins.Clear();
kernel.ImportPluginFromFunctions("HelperFunctions",
        [            
            kernel.CreateFunctionFromMethod(() => DateTime.UtcNow.ToString("R"), "GetCurrentDateTimeInUtc", "Retrieves the current date time in UTC."),
            kernel.CreateFunctionFromMethod((string cityName, string currentDateTimeInUtc) =>
                cityName switch
                {
                    "Boston" => "61 and rainy",
                    "London" => "55 and cloudy",
                    "Miami" => "80 and sunny",
                    "Paris" => "60 and rainy",
                    "Tokyo" => "50 and sunny",
                    "Sydney" => "75 and sunny",
                    "Tel Aviv" => "80 and sunny",
                    "Beijing" => throw new Exception("Weather data not available for Beijing."),
                    _ => "31 and snowing",
                }, "GetWeatherForCity", "Gets the current weather for the specified city and specified date time."),
        ]);

异常处理过滤器

private sealed class ExceptionHandleFilter : IFunctionInvocationFilter
{
    public async Task OnFunctionInvocationAsync(FunctionInvocationContext context, Func<FunctionInvocationContext, Task> next)
    {
        try
        {
            // Try to invoke function
            await next(context);
        }
        catch (Exception ex)
        {
            ex.Display();
            context.Result = new FunctionResult(context.Result, "Function invocation failed. Please check...");
        }
    }
}

kernel.FunctionInvocationFilters.Clear();
kernel.FunctionInvocationFilters.Add(new ExceptionHandleFilter());
OpenAIPromptExecutionSettings settings = new() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
var response = await kernel.InvokePromptAsync("What is the likely color of the sky in Beijing today?", new(settings));

response.Display();

提示：Weather data not available for Beijing.

审计过滤器

private sealed class FunctionCallsAuditFilter : IAutoFunctionInvocationFilter
{
    public async Task OnAutoFunctionInvocationAsync(AutoFunctionInvocationContext context, Func<AutoFunctionInvocationContext, Task> next)
    {
        context.Display();
        var chatHistory = context.ChatHistory;
        var functionCalls = FunctionCallContent.GetFunctionCalls(chatHistory.Last()).ToArray();
        if (functionCalls is { Length: > 0 })
        {
            foreach (var functionCall in functionCalls)
            {
                Console.WriteLine($"Request #{context.RequestSequenceIndex}. Function call: {functionCall.PluginName}.{functionCall.FunctionName}.");
            }
        }
        await next(context);
    }
}

kernel.AutoFunctionInvocationFilters.Clear();
kernel.AutoFunctionInvocationFilters.Add(new FunctionCallsAuditFilter());
OpenAIPromptExecutionSettings settings = new() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
var response =await kernel.InvokePromptAsync("What is the likely color of the sky in Boston today?", new(settings));

response.Display();

Request #0. Function call: HelperFunctions.GetCurrentDateTimeInUtc.


Request #1. Function call: HelperFunctions.GetWeatherForCity.

上下文增强过滤器

在用户请求中，添加额外上下文信息

kernel.Plugins.Clear();
kernel.ImportPluginFromFunctions("TodoPlugin",
        [            
            kernel.CreateFunctionFromMethod((Kernel kernel) =>{
                kernel.Data.Display();
                var userId = kernel.Data["CurrentUserId"];
                if (userId is "shengjie")
                {
                    return new List<string> { "Buy groceries", "Walk the dog", "Write a blog post" };
                }
                return [];
            }, "GetTodoList", " Gets the todo list."),
        ]);

private sealed class ContextEnhancementFilter : IFunctionInvocationFilter
{
    public async Task OnFunctionInvocationAsync(FunctionInvocationContext context, Func<FunctionInvocationContext, Task> next)
    {
        try
        {
            var currentUser = new { Name = "Shengjie", UserId ="shengjie", Phone ="1234567890", Email ="ysjxxx@live.com"};
            // context.Arguments.Add("CurrentUser", currentUser);
            context.Kernel.Data.Clear();
            context.Kernel.Data.TryAdd("CurrentUserId", currentUser.UserId);

            // Try to invoke function
            await next(context);
        }
        catch (Exception ex)
        {
            ex.Display();
            context.Result = new FunctionResult(context.Result, "Function invocation failed. Please check...");
        }
    }
}

kernel.AutoFunctionInvocationFilters.Clear();
kernel.FunctionInvocationFilters.Clear();
kernel.FunctionInvocationFilters.Add(new ContextEnhancementFilter());
OpenAIPromptExecutionSettings settings = new() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
var response =await kernel.InvokePromptAsync("What need I do next?", new(settings));

response.Display();

审批过滤器

using PolyglotKernel= Microsoft.DotNet.Interactive.Kernel;// 引入交互式的内核命名空间，以便用户输入

public class ApprovalFilter() : IFunctionInvocationFilter
{
    public async Task OnFunctionInvocationAsync(FunctionInvocationContext context, Func<FunctionInvocationContext, Task> next)
    {
        if (context.Function.PluginName == "DynamicsPlugin" && context.Function.Name == "create_order")
        {
            Console.WriteLine("System > The agent wants to create an approval, do you want to proceed? (Y/N)");

            var shouldProceed = await PolyglotKernel.GetInputAsync("Y/N");

            if (shouldProceed != "Y")
            {
                context.Result = new FunctionResult(context.Result, "The order creation was not approved by the user");
                return;
            }
        }

        await next(context);
    }
}

kernel.Plugins.Clear();
kernel.ImportPluginFromFunctions("DynamicsPlugin", 
[
   kernel.CreateFunctionFromMethod( (string userName, string skuId, int qty) =>
   {
       var orderId = Guid.NewGuid().ToString();
       Console.WriteLine("System > Creating order...");
       Console.WriteLine($"System > Order created! The order ID is {orderId}");
       return $"Order {orderId} created!";
   }, "create_order", "Create an order for a given SKU and quantity")
]);;

using Microsoft.SemanticKernel.Connectors.OpenAI;

kernel.FunctionInvocationFilters.Clear();
kernel.FunctionInvocationFilters.Add(new ApprovalFilter());

OpenAIPromptExecutionSettings settings = new() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
var response = await kernel.InvokePromptAsync("Please place an order for Jery. She would like to purchase one iPhone16.", new(settings));

response.Display();