AuroraRuntime/Source/IO/AuIOAdapterCompression.cpp

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

    File: AuIOAdapterCompression.cpp
    Date: 2022-6-6
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include <Aurora/IO/IOExperimental.hpp>
#include "AuIOAdapterCompression.hpp"

namespace Aurora::IO
{
    CompressionStreamReader::CompressionStreamReader(const AuSPtr<Compression::ICompressionStream> &pCompressionStream) :
        pCompressionStream(pCompressionStream)
    {

    }

    CompressionSeekingReader::CompressionSeekingReader(const AuSPtr<Compression::ICompressionStream> &pCompressionStream)
        : pCompressionStream(pCompressionStream)
    {

    }

    EStreamError CompressionStreamReader::IsOpen()
    {
        return this->bErrored_ ? EStreamError::eErrorEndOfStream : EStreamError::eErrorNone;
    }

    EStreamError CompressionStreamReader::Read(const Memory::MemoryViewStreamWrite &parameters)
    {
        if (!this->pCompressionStream)
        {
            return EStreamError::eErrorStreamNotOpen;
        }

        auto pair = this->pCompressionStream->ReadEx(parameters, true);

        if (pair == AuStreamReadWrittenPair_t{})
        {
            this->bErrored_ = true;
            return EStreamError::eErrorEndOfStream;
        }

        parameters.outVariable = pair.second;
        return EStreamError::eErrorNone;
    }

    void CompressionStreamReader::Close()
    {
    }

    EStreamError CompressionSeekingReader::IsOpen()
    {
        return this->bErrored_ ?
               EStreamError::eErrorEndOfStream :
               EStreamError::eErrorNone;
    }

    EStreamError CompressionSeekingReader::ArbitraryRead(AuUInt offset, const Memory::MemoryViewStreamWrite &parameters)
    {
        if (this->uOffset != offset)
        {
            if (this->uOffset > offset)
            {
                if (!this->pCompressionStream->GoBackByProcessedN(this->uOffset - offset))
                {
                    SysPushErrorIO("Negative compression seek out of bounds");
                    return EStreamError::eErrorStreamInterrupted;
                }
            }
            else
            {
                if (!this->pCompressionStream->GoForwardByProcessedN(offset - this->uOffset))
                {
                    SysPushErrorIO("Positive compression seek out of bounds");
                    return EStreamError::eErrorStreamInterrupted;
                }
            }

            this->uOffset = offset;
        }

        auto pair = this->pCompressionStream->ReadEx(parameters, true);
        if (pair == AuStreamReadWrittenPair_t {})
        {
            this->bErrored_ = true;
            return EStreamError::eErrorEndOfStream;
        }

        this->uOffset += pair.second;
        parameters.outVariable = pair.second;
        return EStreamError::eErrorNone;
    }

    void CompressionSeekingReader::Close()
    {
    }

    AUKN_SYM AuSPtr<IStreamReader>   NewCompressionReadAdapter(const AuSPtr<Compression::ICompressionStream> &pCompresionStream)
    {
        return AuMakeShared<CompressionStreamReader>(pCompresionStream);
    }

    AUKN_SYM AuSPtr<ISeekingReader>  NewCompressionSeekingAdapter(const AuSPtr<Compression::ICompressionStream> &pCompresionStream)
    {
        return AuMakeShared<CompressionSeekingReader>(pCompresionStream);
    }
}