IUniassetStream

Uniasset.IUniassetStream abstracts a readable and seekable data source. Both ImageAsset.LoadIO(...) and AudioAsset.LoadIO(...) depend on it.

Definition

namespace Uniasset
{
    public interface IUniassetStream
    {
        int Read(Span<byte> buffer);
        long Seek(long offset, SeekOrigin origin);
    }
}

Methods

Read

int Read(Span<byte> buffer);

Reads data from the stream into the destination buffer.

Parameter	Type	Description
buffer	Span<byte>	Destination buffer

Returns the number of bytes actually read. Returning 0 means EOF.

Seek

long Seek(long offset, SeekOrigin origin);

Moves the read position.

Parameter	Type	Description
offset	long	Offset
origin	SeekOrigin	Origin of the offset

Returns the new absolute position.

SeekOrigin

namespace Uniasset
{
    public enum SeekOrigin
    {
        Begin = 0,
        Current = 1,
        End = 2
    }
}

Member	Value	Description
Begin	0	Offset from the start of the stream
Current	1	Offset from the current position
End	2	Offset from the end of the stream

Custom implementations

You can implement IUniassetStream for in-memory data, packaged resources, or any custom storage layer:

public class MemoryStreamAdapter : IUniassetStream
{
    private readonly byte[] _data;
    private int _position;

    public MemoryStreamAdapter(byte[] data)
    {
        _data = data;
    }

    public int Read(Span<byte> buffer)
    {
        int available = _data.Length - _position;
        int toRead = Math.Min(buffer.Length, available);
        _data.AsSpan(_position, toRead).CopyTo(buffer);
        _position += toRead;
        return toRead;
    }

    public long Seek(long offset, SeekOrigin origin)
    {
        _position = origin switch
        {
            SeekOrigin.Begin => (int)offset,
            SeekOrigin.Current => _position + (int)offset,
            SeekOrigin.End => _data.Length + (int)offset,
            _ => throw new ArgumentOutOfRangeException(nameof(origin))
        };
        return _position;
    }
}

Notes

• ImageAsset provides both LoadIO(IUniassetStream) and LoadIO(Stream).
• AudioAsset only provides LoadIO(IUniassetStream).
• Custom implementations must support both sequential reads and random access.