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();
        }
    }
}

Parameters

Returns

ReadHandle A ReadHandle object you can use to check the status and monitor the progress of the read operations.

Description

Queues a set of read operations for a file opened with OpenFileAsync.

This function makes a copy of the ReadCommandArray struct passed as a parameter internally, so you do not need to maintain the array. Note: WebGL builds do not support using AsyncReadManager to open files from a remote web server; for example, from the path Application.streamingAssetsPath which maps to a URL on a remote web server.

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);
    }
}