signet::forge::Schema Class Reference

Immutable schema description for a Parquet file. More...

#include <schema.hpp>

Public Member Functions
	Schema ()=default
	Default-construct an empty schema.
	Schema (std::string name, std::vector< ColumnDescriptor > columns)
	Construct a schema directly from a name and column list.
const std::string &	name () const
	Root schema name (e.g. "tick_data").
size_t	num_columns () const
	Number of columns in this schema.
const ColumnDescriptor &	column (size_t index) const
	Access a column descriptor by index.
const std::vector< ColumnDescriptor > &	columns () const
	All column descriptors (ordered).
std::optional< size_t >	find_column (const std::string &col_name) const
	Find a column index by name.
bool	operator== (const Schema &other) const
	Equality — schemas match if they have the same name and identical columns (name, physical_type, logical_type, repetition, type_length).
bool	operator!= (const Schema &other) const
	Inequality operator.

Static Public Member Functions
template<typename... Cols>
static Schema	build (std::string name, Cols &&... cols)
	Build a Schema from typed Column<T> descriptors (variadic factory).
static SchemaBuilder	builder (std::string name)
	Create a SchemaBuilder for fluent column construction.

Detailed Description

Immutable schema description for a Parquet file.

A Schema has a root name and an ordered list of ColumnDescriptor entries. Create one via the variadic Schema::build() factory or the fluent Schema::builder() API.

See also

Column, SchemaBuilder, ColumnDescriptor

Definition at line 192 of file schema.hpp.

Constructor & Destructor Documentation

Schema() [1/2]

signet::forge::Schema::Schema ( )

default

Default-construct an empty schema.

Schema() [2/2]

signet::forge::Schema::Schema ( std::string  name, std::vector< ColumnDescriptor >  columns  )

inline

Construct a schema directly from a name and column list.

Parameters

name	Root schema name.
columns	Ordered column descriptors.

Definition at line 200 of file schema.hpp.

Member Function Documentation

build()

template<typename... Cols>

static Schema signet::forge::Schema::build ( std::string  name, Cols &&...  cols  )

inlinestatic

Build a Schema from typed Column<T> descriptors (variadic factory).

auto s = Schema::build("tick_data",
    Column<int64_t>{"timestamp", LogicalType::TIMESTAMP_NS},
    Column<double>{"price"},
    Column<std::string>{"symbol"});

Template Parameters

Cols	Pack of Column<T> types.

Parameters

name	Schema root name.
cols	One or more Column<T> objects.

Returns

An immutable Schema.

Definition at line 217 of file schema.hpp.

builder()

static SchemaBuilder signet::forge::Schema::builder ( std::string  name )

inlinestatic

Create a SchemaBuilder for fluent column construction.

Parameters

name	Root schema name.

Returns

A SchemaBuilder instance.

See also

SchemaBuilder

Definition at line 228 of file schema.hpp.

column()

const ColumnDescriptor & signet::forge::Schema::column ( size_t  index ) const

inline

Access a column descriptor by index.

Parameters

index

Zero-based column index.

Returns

Const reference to the ColumnDescriptor.

Exceptions

std::out_of_range

if index >= num_columns().

Definition at line 244 of file schema.hpp.

columns()

const std::vector< ColumnDescriptor > & signet::forge::Schema::columns ( ) const

inline

All column descriptors (ordered).

Definition at line 254 of file schema.hpp.

find_column()

std::optional< size_t > signet::forge::Schema::find_column ( const std::string &  col_name ) const

inline

Find a column index by name.

Parameters

col_name

Column name to search for.

Returns

The zero-based index, or std::nullopt if not found.

Definition at line 261 of file schema.hpp.

name()

const std::string & signet::forge::Schema::name ( ) const

inline

Root schema name (e.g. "tick_data").

Definition at line 235 of file schema.hpp.

num_columns()

size_t signet::forge::Schema::num_columns ( ) const

inline

Number of columns in this schema.

Definition at line 238 of file schema.hpp.

operator!=()

bool signet::forge::Schema::operator!= ( const Schema &  other ) const

inline

Inequality operator.

Definition at line 291 of file schema.hpp.

operator==()

bool signet::forge::Schema::operator== ( const Schema &  other ) const

inline

Equality — schemas match if they have the same name and identical columns (name, physical_type, logical_type, repetition, type_length).

Definition at line 272 of file schema.hpp.

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

• include/signet/schema.hpp