Pkg/parquet/Reader

Reader

struct Reader

Methods

new

pub fn new(reader: ReadSeek, batch_size: int = 8192, projection_mask_indices: [int]? = nil): Reader throws IoError, ParquetError, ArrowError

[src]

pub fn new(
    reader: ReadSeek, batch_size: int = 8192, projection_mask_indices: [int]? = nil
): Reader throws IoError, ParquetError, ArrowError {
    let inner = try _Reader
        .new(_create_native_read_seek(reader), batch_size:, projection_mask_indices:);
    return Reader { inner };
}

Create a new Parquet reader from a given reader.

Create a new Parquet reader from a given reader.

use std.fs.File;
use parquet.Reader;

fn main() throws {
    let f = try File.open("data.parquet");
    let reader = try Reader.new(f);
}

next

pub fn next(self): Record? throws IoError, ParquetError, ArrowError

[src]

pub fn next(self): Record? throws IoError, ParquetError, ArrowError {
    return try self.inner.next().map(|record| record as Record);
}

Get the next record from the Parquet file.

Get the next record from the Parquet file.

The each batch is a RecordBatch type, batch size is determined by the batch_size parameter. If there is no more record, it will return nil.

use std.fs.File;
use parquet.Reader;

fn main() throws {
    let f = try File.open("data.parquet");
    let reader = try Reader.new(f, batch_size: 1000);
    let record = try reader.next();
}

scan

pub fn scan<T>(self): T? throws IoError, ParquetError, ArrowError

[src]

pub fn scan<T>(self): T? throws IoError, ParquetError, ArrowError {
    return try self.inner.scan::<T>();
}

Get the next record and deserialize it.

Get the next record and deserialize it.