duckdb::IndexPointer Class Reference

Inheritance diagram for duckdb::IndexPointer:

Public Member Functions
	IndexPointer ()
	Constructs an empty IndexPointer.
	IndexPointer (const uint32_t buffer_id, const uint32_t offset)
	Constructs an in-memory IndexPointer with a buffer ID and an offset.
idx_t	Get () const
	Get data (all 64 bits)
void	Set (const idx_t data_p)
	Set data (all 64 bits)
bool	HasMetadata () const
	Returns false, if the metadata is empty.
uint8_t	GetMetadata () const
	Get metadata (Bits 56-63)
void	SetMetadata (const uint8_t metadata)
	Set metadata (Bits 56-63)
idx_t	GetOffset () const
	Get the offset (Bits 32-55)
idx_t	GetBufferId () const
	Get the buffer ID (Bits 0-31)
void	Clear ()
	Resets the IndexPointer.
void	IncreaseBufferId (const idx_t summand)
	Adds an idx_t to a buffer ID, the rightmost 32 bits of data (Bits 0-31) contain the buffer ID.
bool	operator== (const IndexPointer &ptr) const
	Comparison operator.

Static Public Attributes
static constexpr idx_t	SHIFT_OFFSET = 32
	Bit-shifting.
static constexpr idx_t	SHIFT_METADATA = 56
static constexpr idx_t	AND_OFFSET = 0x0000000000FFFFFF
	AND operations.
static constexpr idx_t	AND_BUFFER_ID = 0x00000000FFFFFFFF
static constexpr idx_t	AND_METADATA = 0xFF00000000000000

Private Attributes
idx_t	data

Constructor & Destructor Documentation

IndexPointer() [1/2]

duckdb::IndexPointer::IndexPointer ( )

inline

Constructs an empty IndexPointer.

: data(0) {};

IndexPointer() [2/2]

duckdb::IndexPointer::IndexPointer ( const uint32_t  buffer_id, const uint32_t  offset  )

inline

Constructs an in-memory IndexPointer with a buffer ID and an offset.

                                                                  : data(0) {
        auto shifted_offset = UnsafeNumericCast<idx_t>(offset) << SHIFT_OFFSET;
        data += shifted_offset;
        data += buffer_id;
    };

Member Function Documentation

Get()

idx_t duckdb::IndexPointer::Get ( ) const

inline

Get data (all 64 bits)

                             {
        return data;
    }

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Set()

void duckdb::IndexPointer::Set ( const idx_t  data_p )

inline

Set data (all 64 bits)

                                        {
        data = data_p;
    }

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HasMetadata()

bool duckdb::IndexPointer::HasMetadata ( ) const

inline

Returns false, if the metadata is empty.

                                    {
        return data & AND_METADATA;
    }

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GetMetadata()

uint8_t duckdb::IndexPointer::GetMetadata ( ) const

inline

Get metadata (Bits 56-63)

                                       {
        return data >> SHIFT_METADATA;
    }

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SetMetadata()

void duckdb::IndexPointer::SetMetadata ( const uint8_t  metadata )

inline

Set metadata (Bits 56-63)

                                                    {
        data &= ~AND_METADATA;
        data |= UnsafeNumericCast<idx_t>(metadata) << SHIFT_METADATA;
    }

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GetOffset()

idx_t duckdb::IndexPointer::GetOffset ( ) const

inline

Get the offset (Bits 32-55)

                                   {
        auto offset = data >> SHIFT_OFFSET;
        return offset & AND_OFFSET;
    }

GetBufferId()

idx_t duckdb::IndexPointer::GetBufferId ( ) const

inline

Get the buffer ID (Bits 0-31)

                                     {
        return data & AND_BUFFER_ID;
    }

Clear()

void duckdb::IndexPointer::Clear ( )

inline

Resets the IndexPointer.

                        {
        data = 0;
    }

IncreaseBufferId()

void duckdb::IndexPointer::IncreaseBufferId ( const idx_t  summand )

inline

Adds an idx_t to a buffer ID, the rightmost 32 bits of data (Bits 0-31) contain the buffer ID.

                                                      {
        data += summand;
    }

operator==()

bool duckdb::IndexPointer::operator== ( const IndexPointer &  ptr ) const

inline

Comparison operator.

                                                          {
        return data == ptr.data;
    }

Member Data Documentation

data

idx_t duckdb::IndexPointer::data

private

Data holds all the information contained in an IndexPointer (64-bit value) Bit layout: MSB LSB 63 56 55 32 31 0 +---------—+-----------------------—+---------------------------------—+ | Metadata | Offset | Buffer ID | | 8 bits | 24 bits | 32 bits | +---------—+-----------------------—+---------------------------------—+ NOTE: we do not use bit fields because when using bit fields Windows compiles the IndexPointer class into 16 bytes instead of the intended 8 bytes, doubling the space requirements https://learn.microsoft.com/en-us/cpp/cpp/cpp-bit-fields?view=msvc-170

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The documentation for this class was generated from the following file:

• external/duckdb/duckdb.hpp