PLAIN encoding writer for a single Parquet column. More...

#include <column_writer.hpp>

Public Member Functions
	ColumnWriter (PhysicalType type, int32_t type_length=-1)
	Construct a writer for the given Parquet physical type.

void	write_bool (bool val)
	Write a single boolean value.

void	write_int32 (int32_t val)
	Write a single INT32 value (4 bytes little-endian).

void	write_int64 (int64_t val)
	Write a single INT64 value (8 bytes little-endian).

void	write_float (float val)
	Write a single FLOAT value (4 bytes little-endian, IEEE 754).

void	write_double (double val)
	Write a single DOUBLE value (8 bytes little-endian, IEEE 754).

void	write_byte_array (const std::string &val)
	Write a single BYTE_ARRAY value from a std::string.

void	write_byte_array (const uint8_t *data, size_t len)
	Write a single BYTE_ARRAY value from raw bytes.

void	write_fixed_len_byte_array (const uint8_t *data, size_t len)
	Write a single FIXED_LEN_BYTE_ARRAY value from raw bytes.

template<typename T >
void	write (const T &val)
	Write a single value, dispatching to the correct typed write method.

template<typename T >
void	write_batch (const T *values, size_t count)
	Write a batch of typed values.

void	write_batch (const std::string *values, size_t count)
	Write a batch of string values (BYTE_ARRAY).

const std::vector< uint8_t > &	data () const
	Returns a const reference to the encoded byte buffer.

size_t	encoded_size () const
	Returns the total encoded data size in bytes.

int64_t	num_values () const
	Returns the number of values written so far.

const ColumnStatistics &	statistics () const
	Returns a const reference to the column statistics.

void	reset ()
	Reset the writer for the next column chunk. Clears all data and statistics.

PhysicalType	type () const
	Returns the physical type this writer encodes.

Detailed Description

PLAIN encoding writer for a single Parquet column.

Encodes values into an internal byte buffer using the PLAIN encoding and simultaneously maintains ColumnStatistics. After all values have been written, call data() to retrieve the encoded buffer and statistics() for the accumulated column-chunk statistics.

Note: The writer does not enforce type safety at the column level – it is the caller's responsibility to use the correct write method for the configured PhysicalType.

See also: ColumnReader (the decoding counterpart); ColumnStatistics

Definition at line 66 of file column_writer.hpp.

Constructor & Destructor Documentation

◆ ColumnWriter()

signet::forge::ColumnWriter::ColumnWriter	(	PhysicalType	type,
		int32_t	type_length = `-1`
	)

inlineexplicit

Construct a writer for the given Parquet physical type.

Parameters

type	The physical type this writer will encode.
type_length	For FIXED_LEN_BYTE_ARRAY columns, the fixed byte length per value (from schema). Ignored for other types.

Definition at line 72 of file column_writer.hpp.

Member Function Documentation

◆ data()

const std::vector< uint8_t > & signet::forge::ColumnWriter::data ( ) const

inline

Returns a const reference to the encoded byte buffer.

Definition at line 257 of file column_writer.hpp.

◆ encoded_size()

size_t signet::forge::ColumnWriter::encoded_size ( ) const

inline

Returns the total encoded data size in bytes.

Definition at line 260 of file column_writer.hpp.

◆ num_values()

int64_t signet::forge::ColumnWriter::num_values ( ) const

inline

Returns the number of values written so far.

Definition at line 263 of file column_writer.hpp.

◆ reset()

void signet::forge::ColumnWriter::reset ( )

inline

Reset the writer for the next column chunk. Clears all data and statistics.

Definition at line 273 of file column_writer.hpp.

◆ statistics()

const ColumnStatistics & signet::forge::ColumnWriter::statistics ( ) const

inline

Returns a const reference to the column statistics.

Definition at line 268 of file column_writer.hpp.

◆ type()

PhysicalType signet::forge::ColumnWriter::type ( ) const

inline

Returns the physical type this writer encodes.

Definition at line 280 of file column_writer.hpp.

◆ write()

template<typename T >

void signet::forge::ColumnWriter::write ( const T & val )

inline

Write a single value, dispatching to the correct typed write method.

Template Parameters

T	Supported: `bool`, `int32_t`, `int64_t`, `float`, `double`, `std::string`.

Parameters

val	The value to encode.

Definition at line 212 of file column_writer.hpp.

◆ write_batch() [1/2]

void signet::forge::ColumnWriter::write_batch	(	const std::string *	values,
		size_t	count
	)

inline

Write a batch of string values (BYTE_ARRAY).

Parameters

values	Pointer to a contiguous array of `count` strings.
count	Number of strings to write.

Definition at line 248 of file column_writer.hpp.

◆ write_batch() [2/2]

template<typename T >

void signet::forge::ColumnWriter::write_batch	(	const T *	values,
		size_t	count
	)

inline

Write a batch of typed values.

Template Parameters

T	The value type (same constraints as write<T>()).

Parameters

values	Pointer to a contiguous array of `count` values.
count	Number of values to write.

Definition at line 239 of file column_writer.hpp.

◆ write_bool()

void signet::forge::ColumnWriter::write_bool ( bool val )

inline

Write a single boolean value.

PLAIN encoding: bit-packed, LSB first. Bit i of byte (i/8) is set if value[i] is true. N values produce ceil(N/8) bytes.

Parameters

val	The boolean to encode.

Definition at line 83 of file column_writer.hpp.

◆ write_byte_array() [1/2]

void signet::forge::ColumnWriter::write_byte_array ( const std::string & val )

inline

Write a single BYTE_ARRAY value from a std::string.

PLAIN encoding: 4-byte LE length prefix + raw bytes.

Parameters

val	The string whose bytes are encoded.

Definition at line 150 of file column_writer.hpp.

◆ write_byte_array() [2/2]

void signet::forge::ColumnWriter::write_byte_array	(	const uint8_t *	data,
		size_t	len
	)

inline

Write a single BYTE_ARRAY value from raw bytes.

PLAIN encoding: 4-byte LE length prefix + raw bytes.

Parameters

data	Pointer to the raw byte payload.
len	Number of bytes in the payload.

Definition at line 160 of file column_writer.hpp.

◆ write_double()

void signet::forge::ColumnWriter::write_double ( double val )

inline

Write a single DOUBLE value (8 bytes little-endian, IEEE 754).

Parameters

val	The double to encode.

Definition at line 136 of file column_writer.hpp.

◆ write_fixed_len_byte_array()

void signet::forge::ColumnWriter::write_fixed_len_byte_array	(	const uint8_t *	data,
		size_t	len
	)

inline

Write a single FIXED_LEN_BYTE_ARRAY value from raw bytes.

PLAIN encoding: raw bytes only (no length prefix – length is in the schema).

Precondition: len must exactly match the schema's type_length. Passing a different length produces a corrupt column chunk (no runtime check is performed here for performance – the caller must validate).

Parameters

data	Pointer to the raw byte payload.
len	Number of bytes (must match the schema's `type_length`).

Definition at line 187 of file column_writer.hpp.

◆ write_float()

void signet::forge::ColumnWriter::write_float ( float val )

inline

Write a single FLOAT value (4 bytes little-endian, IEEE 754).

Parameters

val	The float to encode.

Definition at line 125 of file column_writer.hpp.

◆ write_int32()

void signet::forge::ColumnWriter::write_int32 ( int32_t val )

inline

Write a single INT32 value (4 bytes little-endian).

Parameters

val	The 32-bit integer to encode.

Definition at line 103 of file column_writer.hpp.

◆ write_int64()

void signet::forge::ColumnWriter::write_int64 ( int64_t val )

inline

Write a single INT64 value (8 bytes little-endian).

Parameters

val	The 64-bit integer to encode.

Definition at line 114 of file column_writer.hpp.

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

include/signet/column_writer.hpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ColumnWriter()

Member Function Documentation

◆ data()

◆ encoded_size()

◆ num_values()

◆ reset()

◆ statistics()

◆ type()

◆ write()

◆ write_batch() [1/2]

◆ write_batch() [2/2]

◆ write_bool()

◆ write_byte_array() [1/2]

◆ write_byte_array() [2/2]

◆ write_double()

◆ write_fixed_len_byte_array()

◆ write_float()

◆ write_int32()

◆ write_int64()