AsyncReadManager.Read

参数

返回值

ReadHandle 用于监控读取命令的进度和状态。

描述

发出异步文件读取操作。返回一个 ReadHandle。

您可以设置assetName、typeId 和subsystem 参数来收集此读取操作的特定于资产的指标。当您使用AsyncReadManagerMetrics.StartCollectingMetrics启用指标收集时，Unity 会将此信息作为AsyncReadManagerMetrics的一部分包含在内，允许您分析不同类型的资产如何影响性能。

AsyncReadManager 复制Read引用的数据；您可以在调用Read后立即处理或释放数据。

using System.IO;
using Unity.Collections;
using Unity.IO.LowLevel.Unsafe;
using Unity.Collections.LowLevel.Unsafe;
using UnityEngine;

class AsyncReadSample : MonoBehaviour
{
    private ReadHandle readHandle;
    NativeArray<ReadCommand> cmds;
    string assetName = "myfile";
    ulong typeID = 114; // from ClassIDReference
    AssetLoadingSubsystem subsystem = AssetLoadingSubsystem.Scripts;

    public unsafe void Start()
    {
        string filePath = Path.Combine(Application.streamingAssetsPath, "myfile.bin");
        cmds = new NativeArray<ReadCommand>(1, Allocator.Persistent);
        ReadCommand cmd;
        cmd.Offset = 0;
        cmd.Size = 1024;
        cmd.Buffer = (byte*)UnsafeUtility.Malloc(cmd.Size, 16, Allocator.Persistent);
        cmds[0] = cmd;
        readHandle = AsyncReadManager.Read(filePath, (ReadCommand*)cmds.GetUnsafePtr(), 1, assetName, typeID, subsystem);
    }

    public unsafe void Update()
    {
        if (readHandle.IsValid() && readHandle.Status != ReadStatus.InProgress)
        {
            Debug.LogFormat("Read {0}", readHandle.Status == ReadStatus.Complete ? "Successful" : "Failed");
            readHandle.Dispose();
            UnsafeUtility.Free(cmds[0].Buffer, Allocator.Persistent);
            cmds.Dispose();
        }
    }
}

参数

返回值

ReadHandle 一个ReadHandle 对象，您可以使用它来检查状态并监控读取操作的进度。

描述

为使用OpenFileAsync打开的文件排队一组读取操作。

此函数在内部复制作为参数传递的ReadCommandArray 结构体，因此您无需维护该数组。注意：WebGL 构建不支持使用AsyncReadManager从远程 Web 服务器打开文件；例如，从路径Application.streamingAssetsPath映射到远程 Web 服务器上的 URL。

using System.IO;
using Unity.Collections;
using Unity.IO.LowLevel.Unsafe;
using Unity.Collections.LowLevel.Unsafe;
using UnityEngine;
using Unity.Jobs;

class AsyncReadSample : MonoBehaviour
{
    static string TestFilename = Path.Combine(Application.streamingAssetsPath, "myfile.bin");

    public unsafe void Start()
    {
        ReadCommand cmd;
        cmd.Offset = 0;
        cmd.Size = 1024;
        cmd.Buffer = (byte*)UnsafeUtility.Malloc(cmd.Size, 16, Allocator.Persistent);

        FileHandle fileHandle = AsyncReadManager.OpenFileAsync(TestFilename);

        ReadCommandArray readCmdArray;
        readCmdArray.ReadCommands = &cmd;
        readCmdArray.CommandCount = 1;

        ReadHandle readHandle = AsyncReadManager.Read(fileHandle, readCmdArray);

        JobHandle closeJob = fileHandle.Close(readHandle.JobHandle);

        closeJob.Complete();

        // ... Use the data read into the buffer

        readHandle.Dispose();

        for (int i = 0; i < readCmdArray.CommandCount; i++)
            UnsafeUtility.Free(readCmdArray.ReadCommands[i].Buffer, Allocator.Persistent);
    }
}