92 lines
3.1 KiB
C++
92 lines
3.1 KiB
C++
/***
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Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.
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File: ICompressionStream.hpp
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Date: 2021-7-14
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Author: Reece
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***/
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#pragma once
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namespace Aurora::Compression
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{
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struct ICompressionStream
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{
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/**
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* @brief Ingest n bytes from the input stream assigned to the compression object.
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* On error, returns {0, 0} or {bytesRead, 0}
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* If the stream buffer runs out of memory, {bytesRead, 0} is expected, and although
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* `GetAvailableProcessedBytes()` will still return some data, the decompressed data
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* or uncompressed stream will be dropped in part, and you should destroy from the stream object
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* @param dwBytesFromUnprocessedInputSource
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* @return
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*/
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virtual AuStreamReadWrittenPair_t Ingest(AuUInt32 dwBytesFromUnprocessedInputSource) = 0;
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/**
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* @brief Returns the available bytes for immediate release by ::Read (or ::ReadEx(..., false))
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* @return
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*/
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virtual AuUInt32 GetAvailableProcessedBytes() = 0;
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/**
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* @brief Returns the allocation overhead of the seekable stream buffer
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* @return
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*/
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virtual AuUInt32 GetInternalBufferSize() = 0;
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/**
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* @brief Reads 'minimumProcessed', optionally into the first buffer, until EOS or destination length.
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* If the destination is null and the length is a nonzero value, the stream seeks ahead
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* If the destination is null and the length is a zero, {0, GetAvailableProcessedBytes} is returned
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* @param destination
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* @param bIngestUntilEOS should continue to poll Ingest with an arbitrary page size to fulfill destination.length
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* @return Bytes read / written
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*/
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virtual AuStreamReadWrittenPair_t ReadEx(const Memory::MemoryViewWrite & /*opt*/ destination, bool bIngestUntilEOS = true) = 0;
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/**
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* @brief Reads 'minimumProcessed', optionally into the first buffer, from the internal stream buffer
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* @param dwOffset
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* @return Bytes written
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*/
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virtual AuUInt32 Read(const Memory::MemoryViewWrite & /*opt*/ destination) = 0;
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/**
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* @brief Seek processed ::Read/::ReadEx backwards
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* @param dwOffset
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* @return
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*/
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virtual bool GoBackByProcessedN (AuUInt32 dwOffset) = 0;
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/**
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* @brief Seek processed ::Read/::ReadEx forwards
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* @param dwOffset
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* @return
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*/
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virtual bool GoForwardByProcessedN(AuUInt32 dwOffset) = 0;
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/// Compression only
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virtual bool Flush() = 0;
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/// Compression only
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virtual bool Finish() = 0;
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/**
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* @brief
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* @return
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*/
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virtual AuOptional<int> GetLastError() = 0;
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/**
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* @brief
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* @return
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*/
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virtual AuOptional<AuString> GetLastErrorString() = 0;
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/**
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* @brief
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* @return
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*/
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virtual IO::IStreamReader *ToStreamReader() = 0;
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};
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} |