AsyncReadManager.Read

Parameters

Returns

ReadHandle Used to monitor the progress and status of the read command.

Description

Issues an asynchronous file read operation. Returns a ReadHandle.

You can set the assetName, typeId, and subsystem parameters to collect asset-specific metrics for this read operation. When you enable metrics collection with AsyncReadManagerMetrics.StartCollectingMetrics, Unity includes this information as part of the AsyncReadManagerMetrics, allowing you to analyze how different types of assets affect performance.

The AsyncReadManager copies the data referenced by Read; you can dispose or free the data immediately after calling Read.

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();
        }
    }
}