Azure 函数上的 Blob 输出

Question

我有这个功能

 [FunctionName("Func")]
 public async Task Run(
         [TimerTrigger("1 1 8-23 * * 1-5")] TimerInfo timerInfo,
         [Blob("metrics/accepted.json", FileAccess.Read, Connection = "AzureWebJobsStorage")] string json,
         [Blob("metrics/accepted.json", FileAccess.Write, Connection = "AzureWebJobsStorage")] Stream outputFile,
         ILogger log
 )
 {
      string out = await doThing(json);
      if (out != "") {
         byte[] byteArray = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(resp));
          await outputFile.WriteAsync(byteArray, 0, byteArray.Length);
      }
}

添加断点后，文件填充流时被清空？ 有什么办法可以防止这种情况发生吗？

Answer 1

添加断点后，文件填充流时被清空？有什么办法可以防止这种情况发生吗？

您面临的问题，因为您尝试在同一个文件上读取和写入，这导致了并发问题，并且由于输出绑定覆盖了文件的内容，文件的数据被清空。

您需要将其写入不同的文件中。

这段代码对我有用。

Function1.cs

using System;
using System.IO;
using System.Reflection.Metadata;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;

namespace FunctionApp3
{
    public class Function1
    {
        [FunctionName("Function1")]
        public static async Task Run([TimerTrigger("0 */5 * * * *")] TimerInfo myTimer,
         [Blob("metrics/accepted.json", FileAccess.Read, Connection = "AzureWebJobsStorage")] Stream json,
         [Blob("metrics/accepted2.json", FileAccess.Write, Connection = "AzureWebJobsStorage")] Stream outputFile,
         ILogger log)

        {
            log.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");

            JsonModel jsonObject;
            using (var reader = new StreamReader(json))
            {
                var jsonContent = await reader.ReadToEndAsync();

                log.LogInformation($"content of accepted.json : {jsonContent}");

                jsonObject = JsonConvert.DeserializeObject<JsonModel>(jsonContent);
                jsonObject.Platform = "StackOverflow";

            }
            byte[] byteArray = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(jsonObject, Formatting.Indented));

            await outputFile.WriteAsync(byteArray,0,byteArray.Length);

        }

        public class JsonModel
        {
            public string FirstName { get; set; }
            public string LastName { get; set; }
            public string Platform { get; set; }
        }
    }
}

OUTPUT

:

accepted.json:

{
 "FirstName": "Vivek",
 "LastName": "Shandilya"
}

Functions:

        Function1: timerTrigger

For detailed output, run func with --verbose flag.
[2024-01-24T07:00:57.091Z] Executing 'Function1' (Reason='Timer fired at 2024-01-24T12:30:54.2878940+05:30', Id=56819861-b602-447c-82ea-5dab57849da1)
[2024-01-24T07:00:57.097Z] Trigger Details: UnscheduledInvocationReason: IsPastDue, OriginalSchedule: 2024-01-24T12:10:00.0000000+05:30
[2024-01-24T07:00:57.172Z] C# Timer trigger function executed at: 1/24/2024 12:30:57 PM
[2024-01-24T07:00:57.490Z] content of accepted.json : {
[2024-01-24T07:00:57.494Z]      "FirstName":"Vivek",
[2024-01-24T07:00:57.499Z]      "LastName":"Shandilya"
[2024-01-24T07:00:57.503Z] }
[2024-01-24T07:00:57.665Z] Host lock lease acquired by instance ID '000000000000000000000000AAE5F384'.
[2024-01-24T07:00:58.538Z] Executed 'Function1' (Succeeded, Id=56819861-b602-447c-82ea-5dab57849da1, Duration=4181ms)

accepted2.json：

{
  "FirstName": "Vivek",
  "LastName": "Shandilya",
  "Platform": "StackOverflow"
}