AuroraRuntime/Include/Aurora/IO/IStreamReader.inl

/***
    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: IStreamReader.inl
    Date: 2022-2-1
    Author: Reece
***/
#pragma once

namespace Aurora::IO
{
    inline EStreamError ReadAll(IStreamReader *that, Memory::ByteBuffer &buffer, AuOptional<bool> bBreakOnFirstMismatchLength)
    {
        static const int kBufferSize = 8192;
        
        EStreamError ret;
        ret = EStreamError::eErrorEndOfStream;

        if (buffer.HasStreamError())
        {
            return EStreamError::eErrorByteBuffer;
        }

        while (true)
        {
            AuUInt uBytesRead {};
            bool bDoublebreak {};

            auto next = buffer.GetNextLinearWrite();
            if (!next)
            {
                next = buffer.GetOrAllocateLinearWriteable(kBufferSize);
            }

            if (!next)
            {
                return EStreamError::eErrorOutOfMemory;
            }

            while ((ret = that->Read(Memory::MemoryViewStreamWrite(next, uBytesRead))) == EStreamError::eErrorNone)
            {
                if (uBytesRead == 0)
                {
                    bDoublebreak = true;
                    break;
                }

                buffer.Write(next.ptr, uBytesRead);

                if (bBreakOnFirstMismatchLength.value_or(true) &&
                    uBytesRead != next.length)
                {
                    bDoublebreak = true;
                    break;
                }
            }

            if (uBytesRead == 0 ||
                bDoublebreak)
            {
                break;
            }
        }

        if (buffer.HasStreamError())
        {
            return EStreamError::eErrorByteBuffer;
        }

        if (ret == EStreamError::eErrorEndOfStream)
        {
            return EStreamError::eErrorNone;
        }

        return ret;
    }
}