Module parquet::schema

Parquet schema definitions and methods to print and parse schema.

Example

use parquet::{
    basic::{LogicalType, Repetition, Type as PhysicalType},
    schema::{parser, printer, types::Type},
};
use std::rc::Rc;

// Create the following schema:
//
// message schema {
//   OPTIONAL BYTE_ARRAY a (UTF8);
//   REQUIRED INT32 b;
// }

let field_a = Type::primitive_type_builder("a", PhysicalType::BYTE_ARRAY)
    .with_logical_type(LogicalType::UTF8)
    .with_repetition(Repetition::OPTIONAL)
    .build()
    .unwrap();

let field_b = Type::primitive_type_builder("b", PhysicalType::INT32)
    .with_repetition(Repetition::REQUIRED)
    .build()
    .unwrap();

let schema = Type::group_type_builder("schema")
    .with_fields(&mut vec![Rc::new(field_a), Rc::new(field_b)])
    .build()
    .unwrap();

let mut buf = Vec::new();

// Print schema into buffer
printer::print_schema(&mut buf, &schema);

// Parse schema from the string
let string_schema = String::from_utf8(buf).unwrap();
let parsed_schema = parser::parse_message_type(&string_schema).unwrap();

assert_eq!(schema, parsed_schema);

Modules

parser	Parquet schema parser. Provides methods to parse and validate string message type into Parquet Type.
printer	Parquet schema printer. Provides methods to print Parquet file schema and list file metadata.
types	Contains structs and methods to build Parquet schema and schema descriptors.
visitor