AuroraRuntime/Include/Aurora/Memory/ByteBuffer.hpp

604 lines
22 KiB
C++

/***
Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.
File: ByteBuffer.hpp
Date: 2021-8-5
Author: Reece
***/
#pragma once
#include <Aurora/Locale/ECodePage.hpp>
namespace Aurora::Memory
{
enum class EStringType
{
eStringTerminated,
eStringByte,
eStringWord,
eStringDword,
eStringQword
};
static const auto kBufferPageSize = 512;
//static const auto kBufferBasePower = 8;
static const auto kBufferInitialPower = 9;// -kBufferBasePower; // 4-bit integer
/***
* A bytebuffer object represents a "page" aligned (optionally) resizable buffer **or** a ring buffer.
* Trivial linear serialization use cases will follow the linear fast paths, not those of a ring buffer.
*
* Ring buffers are used to wrap streams when the consumer may expect arbitrary stream seeks of an otherwise
* limited consume-once stream
*
* EG (old):
* -> Peeking a header in a datagram, or tcp stream; where instead of freeing the datagram or double
* buffering the network stack when required, a ring buffer is used to prevent reallocation on each frame
* -> Peeking, or seeking back after, compression read. A compression api could be fed on-known-input-available
* or on-demand, writing to its write head pointer, while never running out of space so long as the
* decompressed ring read head continues moving
*
* EG (2022):
* -> AuProtocol ProtocolPiece buffers
* -> AuCompression internal buffer
* -> A socket's output stream / space for user-write and overlapped submission
* -> ...
*
* Deprecates INetworkStream, fixes allocation issues around compression backends
* Superseeds abuse of AuList<AuUInt8> for binary blobs alongside other fixed u8 arrays
*/
struct ByteBuffer
{
///////////////////////////////////////////////////////////////////////
// Stable ByteBuffer ABI Header; length and read/write head pointers //
///////////////////////////////////////////////////////////////////////
/// Internal capacity to mitigate trivial reallocs
AuUInt allocSize;
/// Abstract size
AuUInt length;
/// Buffer pointer
AuUInt8 *base {};
/// Stream pointer
AuUInt8 *readPtr {};
/// Stream pointer
AuUInt8 *writePtr {};
///////////////////////////////////////////////////////////////////////
// Stable ByteBuffer ABI Header; u32 flags //
///////////////////////////////////////////////////////////////////////
/// Is ring buffer?
AuUInt8 flagCircular : 1 {};
/// Should resize linear buffer to accommodate additional writes
AuUInt8 flagExpandable : 1 {};
AuUInt8 flagReadError : 1 {};
AuUInt8 flagWriteError : 1 {};
AuUInt8 flagNoFree : 1 {};
AuUInt8 flagAlwaysExpandable : 1 {}; // it's a long story from how we got from string views to std::vector<std::uint8_t>s to current day AuByteBuffer.
// anyway long story short, if you want a buffered api to write into us linearly and grow, enable me.
// if you just want ::Write and similar functions to work keem me false and enable flagExpandable.
// flagExpandable is for when the default constructor is called. i'm for apis that use us as an interface to grow.
// TODO: flag: allow circular overrun to allow for 100% access of the buffer from either read head
// - implicit padding
AuUInt8 scaleSize {};//
///////////////////////////////////////////////////////////////////////
/**
* @brief Move constructor
* @param buffer
*/
inline ByteBuffer(ByteBuffer &&buffer)
{
this->base = buffer.base;
this->length = buffer.length;
this->allocSize = buffer.length;
this->writePtr = this->base + (buffer.writePtr - buffer.base);
this->readPtr = this->base + (buffer.readPtr - buffer.base);
this->flagCircular = buffer.flagCircular;
this->flagExpandable = buffer.flagExpandable;
this->scaleSize = buffer.scaleSize;
this->flagReadError = buffer.flagReadError;
this->flagWriteError = buffer.flagWriteError;
buffer.base = {};
buffer.length = {};
buffer.allocSize = {};
buffer.writePtr = {};
buffer.readPtr = {};
buffer.flagCircular = {};
buffer.flagExpandable = {};
buffer.flagAlwaysExpandable = {};
buffer.scaleSize = {};
}
/**
* @brief Copy with possible preserve pointers
* @param buffer
* @param preservePointers
*/
inline ByteBuffer(const ByteBuffer &buffer, bool preservePointers = true)
{
if (buffer.length)
{
this->base = ZAlloc<AuUInt8 *>(buffer.length);
}
this->scaleSize = buffer.scaleSize;
this->flagCircular = buffer.flagCircular;
this->flagExpandable = buffer.flagExpandable;
this->flagAlwaysExpandable = buffer.flagAlwaysExpandable;
if (!this->base)
{
Reset();
return;
}
this->length = buffer.length;
this->allocSize = buffer.length;
if (preservePointers)
{
this->writePtr = this->base + (buffer.writePtr - buffer.base);
this->readPtr = this->base + (buffer.readPtr - buffer.base);
}
else
{
this->writePtr = this->base;
this->readPtr = this->base;
}
AuMemcpy(this->base, buffer.base, this->length);
}
/**
* @brief Copy pointer range into a new ring or byte buffer
* @param in
* @param length
* @param circular
* @param expandable
*/
inline ByteBuffer(const void *in, AuUInt length, bool circular = false, bool expandable = false) : flagCircular(circular), flagExpandable(expandable), flagReadError(0), flagWriteError(0)
{
this->scaleSize = kBufferInitialPower;
this->base = length ? ZAlloc<AuUInt8 *>(length) : nullptr;
if (!this->base)
{
Reset();
return;
}
if (!in)
{
Reset();
return;
}
this->length = length;
this->allocSize = length;
this->readPtr = this->base;
this->writePtr = this->readPtr + this->length;
AuMemcpy(this->base, in, this->length);
}
inline ByteBuffer(const AuList<AuUInt8> &vector, bool circular = false, bool expandable = false) : flagCircular(circular), flagExpandable(expandable), flagReadError(0), flagWriteError(0)
{
this->scaleSize = kBufferInitialPower;
this->base = vector.size() ? ZAlloc<AuUInt8 *>(vector.size()) : nullptr;
if (!this->base)
{
Reset();
return;
}
this->length = vector.size();
this->allocSize = vector.size();
this->readPtr = this->base;
this->writePtr = this->readPtr + this->length;
AuMemcpy(this->base, vector.data(), this->length);
}
inline ByteBuffer(AuUInt length, bool circular = false, bool expandable = false) : flagCircular(circular), flagExpandable(expandable), flagReadError(0), flagWriteError(0)
{
this->scaleSize = kBufferInitialPower;
if (!length)
{
Reset();
return;
}
this->base = ZAlloc<AuUInt8 *>(length);
if (!this->base)
{
Reset();
return;
}
this->length = length;
this->allocSize = length;
this->readPtr = this->base;
this->writePtr = this->base;
}
inline ByteBuffer(AuUInt length, AuUInt alignment, bool circular = false, bool expandable = false) : flagCircular(circular), flagExpandable(expandable), flagReadError(0), flagWriteError(0)
{
if (!length)
{
Reset();
return;
}
this->scaleSize = kBufferInitialPower;
this->base = ZAlloc<AuUInt8 *>(length, alignment);
if (!this->base)
{
Reset();
return;
}
this->length = length;
this->allocSize = length;
this->readPtr = this->base;
this->writePtr = this->base;
}
template<typename T>
ByteBuffer(T *base, T *end, bool circular = false, bool expandable = false) : flagCircular(circular), flagExpandable(expandable), flagReadError(0), flagWriteError(0)
{
if (!base)
{
Reset();
return;
}
if (!end)
{
Reset();
return;
}
auto length = static_cast<AuUInt>(end - base) * sizeof(T);
this->base = length ? ZAlloc<AuUInt8 *>(length) : nullptr;
this->scaleSize = kBufferInitialPower;
if (!this->base)
{
Reset();
return;
}
this->length = length;
this->allocSize = length;
this->readPtr = this->base;
this->writePtr = this->base + length;
AuMemcpy(this->base, base, length);
}
/**
* @brief Default constructor, allocates an auto-expanding linear bytebuffer
*/
inline ByteBuffer() : flagCircular(0), flagExpandable(true), flagReadError(0), flagWriteError(0)
{
this->base = {};
this->length = {};
this->allocSize = {};
this->readPtr = {};
this->writePtr = {};
this->scaleSize = kBufferInitialPower;
}
inline ~ByteBuffer()
{
if (this->base)
{
Free(this->base);
}
}
inline void ResetPositions()
{
this->flagReadError = 0;
this->flagWriteError = 0;
this->readPtr = base;
this->writePtr = base;
}
// utils: Iterator
/**
* @brief base of the bytebuffer
* @return
*/
inline auline AuUInt8 * data() const;
/**
* @brief size of the byte array as requested by the caller (actual allocation may differ, ::allocSize)
* @return
*/
inline auline AuUInt size() const;
/**
* @brief linear read begin
* @warning writers should use ::GetLinearWriteable(uDesiredLength) or ::GetOrAllocateLinearWriteable(...)
* @return
*/
inline auline const AuUInt8 * begin();
inline auline const AuUInt8 * cbegin() const;
/**
* @brief linear read end
* @warning writers should use ::GetLinearWriteable(uDesiredLength) or ::GetOrAllocateLinearWriteable(...)
* @return
*/
inline auline const AuUInt8 * end();
inline auline const AuUInt8 * cend() const;
inline auline bool empty() const;
inline void clear();
inline void resize(AuUInt size);
inline void reserve(AuUInt size);
// utils: Utils to alternative types
inline auline AuList<AuUInt8> ToVector() const;
inline AuUInt32 GetAllocationPower() const;
inline operator MemoryViewRead() const;
inline operator MemoryViewWrite();
// utils: Internal buffer comparison
inline bool operator ==(const AuList<AuUInt8> &) const;
inline bool operator ==(const MemoryViewRead &) const;
inline bool operator ==(const ByteBuffer &) const;
// utils: Move assignment
inline ByteBuffer &operator =(ByteBuffer &&);
inline ByteBuffer &operator =(const ByteBuffer &buffer);
// utils: &byteArray[n]
/**
* @brief read u8 relative to the read head
* @param idx
* @return
*/
inline AuUInt8 &operator [](AuUInt idx) const;
// utils: if (byteArray) -> if (byteArray->IsValid())
inline operator bool() const;
inline AuList<AuUInt8> RemainingBytesToVector(bool endAtWrite = true) const;
// ... utils are mostly const functions that provide language intrinsics, access, and container-like compatibility
// ByteBuffer specific utils can be found under Utilities
// Seek / Position
inline auline bool ReaderTryGoForward(AuUInt32 offset);
inline auline bool ReaderTryGoBack(AuUInt32 offset);
inline auline bool WriterTryGoForward(AuUInt32 offset);
inline auline AuUInt RemainingWrite(bool endAtRead = true) const;
inline auline AuUInt RemainingBytes(bool endAtWrite = true) const;
inline auline bool Skip(AuUInt count);
inline auline AuUInt GetReadOffset() const;
inline auline AuUInt GetWriteOffset() const;
inline auline void ResetReadPointer();
inline auline MemoryViewRead GetNextLinearRead();
inline auline MemoryViewWrite GetNextLinearWrite();
inline auline bool CanWrite(AuUInt length);
inline auline bool CanRead(AuUInt length);
/**
* @brief Returns a linear amount of memory for exactly length of linear bytes
* @param length
* @return
*/
inline auline MemoryViewRead GetLinearReadableForExactly(AuUInt length)
{
return GetLinearReadable(length);
}
inline auline MemoryViewWrite GetLinearWriteableForExactly(AuUInt length)
{
return GetLinearWriteable(length);
}
/**
* @brief Returns a linear amount of memory of at least length
* @param length
* @return
*/
inline auline MemoryViewRead GetLinearReadableForAtleast(AuUInt length);
inline auline MemoryViewWrite GetLinearWriteableForAtleast(AuUInt length);
/**
* @brief Returns a linear amount of memory capped to length
* @param length
* @return
*/
inline auline MemoryViewRead GetLinearReadableForNoMore(AuUInt length);
inline auline MemoryViewWrite GetLinearWriteableForNoMore(AuUInt length);
/// legacy: ForExactly variant
inline auline MemoryViewRead GetLinearReadable(AuUInt length);
/// legacy: ForExactly variant
inline auline MemoryViewWrite GetLinearWriteable(AuUInt length);
/**
* @brief Long story short, AuList<AuUInt8> ~= std::vector<AuUInt8>:
* AuByteBuffer should be (was) a drag and drop replacement for trash code that uses lists as bytebuffers. This is opposed to ye old std::string contains anything buffers.
* Either way, to the point, AuByteBuffer's default constructor is to allow for expandability on Write. GetOrAllocateLinearWriteable is used by certain parse APIs to
* expand ONCE into a buffer that is uninitialized. Should the caller setup the AuByteBuffer, preallocate a runway, etc, etc, GetOrAllocateLinearWriteable will run on
* the memory - the read/write heads of the already setup buffer.
* Otherwise, the default constructor shall allow this to ALLOCATE ONCE given a buffer in an uninitialized/!IsValid()/!refByteBuffer state.
* @param length
* @return
*/
inline auline MemoryViewWrite GetOrAllocateLinearWriteable(AuUInt length);
// Memory operations
inline auline bool Allocate(AuUInt length, bool fast = true);
inline auline bool Allocate(AuUInt length, AuUInt alignment, bool fast = true);
inline auline bool SetBuffer(MemoryViewRead readView, bool bMoveWriteHeadForReaders = true);
/**
* @brief Releases excess memory (like, shrink to fit in c++)
* @return
*/
inline auline void GC();
/**
* @brief Releases all resources and resets the bytebuffer without an allocation
*/
inline void Reset();
/**
* @brief Expands the underlying buffer allocation to at least length.
* Does nothing on failure. Programs can try to allocate in real time
* and handle the write error flag condition from there. To pull the
* real buffer size, see member field allocSize.
* @param length
*/
inline void Reserve(AuUInt length);
/**
* @brief Is allocated or dummy object?
* @return
*/
inline auline bool IsEmpty() const;
/**
* @brief Is an error flag set?
* @return
*/
inline auline bool HasStreamError() const;
/**
* @brief Returns true so long as
* 1) an error has not occured or,
* 1) the relevant error flag was reset; and
* 2) there is a valid underlying buffer
*
* @return
*/
inline auline bool IsValid() const;
/**
* @brief Allocate at least length bytes, without adjusting the relative read/write head offsets
* @param length
* @return
*/
inline auline bool Resize(AuUInt length);
// Basic Read Write
inline auline AuUInt Write(const void *buffer, AuUInt requestLength);
inline auline AuUInt Read(void *out, AuUInt requestedLength, bool peek = false);
inline auline AuUInt Write(const MemoryViewRead &read)
{
return Write(read.ptr, read.length);
}
inline auline AuUInt Read(const MemoryViewWrite &write)
{
return Read(write.ptr, write.length);
}
// String API
inline bool WriteString(std::string_view string, EStringType type = EStringType::eStringDword, Locale::ECodePage codepage = Locale::ECodePage::eUTF8);
inline bool ReadString(AuString &string, EStringType type = EStringType::eStringDword, Locale::ECodePage codepage = Locale::ECodePage::eUTF8);
// Copy, concat, etc
inline AuUInt WriteFromEx(ByteBuffer &buffer,
AuUInt uLength);
inline bool WriteFrom(ByteBuffer &buffer);
// Utilities
inline bool Trim(AuUInt tail);
inline bool Pad(AuUInt16 aPowOf2, AuUInt8 magicCharacter = '\x00');
inline bool Fill(AuUInt length, AuUInt8 magicCharacter = '\x00');
// Templated read/write for **PODs**
// (yes, there's some support for non-primitive classes this early into the abstraction.)
// (AuString and some other containers may work, but really, we need a typed bytebuffer.)
template<typename T>
T Read();
// Panics if flagReadError is true by the end of deserialization
template<typename T>
T ReadChecked();
template<typename T>
bool Write(const T &in);
template<typename T>
bool Read(T &out);
template<typename T>
bool WriteTagged(const T &in);
template<typename T>
bool ReadTagged(T &out);
//
inline AuUInt calcDifferenceBetweenHeadsUnsigned(AuUInt8 *pHeadPointer, AuUInt8 *pSubtrahend)
{
if (pHeadPointer > pSubtrahend)
{
return pHeadPointer - pSubtrahend;
}
else
{
return (pSubtrahend - this->base) + ((this->base + this->length) - pHeadPointer);
}
}
inline AuSInt calcDifferenceBetweenHeadsSigned(AuUInt8 *pHeadPointer, AuUInt8 *pSubtrahend)
{
if (pHeadPointer > pSubtrahend)
{
return pHeadPointer - pSubtrahend;
}
else
{
return -(pSubtrahend - this->base);
}
}
};
static ByteBuffer NewResizableBuffer(AuUInt32 length = 0)
{
return ByteBuffer(length, false, true);
}
static ByteBuffer NewRingBuffer(AuUInt32 length = 1024 * 5)
{
return ByteBuffer(length, true, false);
}
struct SharedByteBuffer : ByteBuffer
{
AuSPtr<void> memory;
inline SharedByteBuffer(AuSPtr<MemoryViewWrite> pReadView) : ByteBuffer()
{
this->allocSize = 0;
this->base = (AuUInt8 *)pReadView->ptr;
this->length = pReadView->length;
this->readPtr = this->base;
this->writePtr = this->base + this->length;
this->flagNoFree = true;
this->memory = pReadView;
}
inline SharedByteBuffer(AuSPtr<void> pRAIIParentOwner, MemoryViewWrite view) : ByteBuffer()
{
this->allocSize = 0;
this->base = (AuUInt8 *)view.ptr;
this->length = view.length;
this->readPtr = this->base;
this->writePtr = this->base + this->length;
this->flagNoFree = true;
this->memory = pRAIIParentOwner;
}
};
}