r/man/FileFormat.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/dataset.R
\name{FileFormat}
\alias{FileFormat}
\alias{ParquetFileFormat}
\alias{IpcFileFormat}
\alias{CsvFileFormat}
\title{Dataset file formats}
\description{
A \code{FileFormat} holds information about how to read and parse the files
included in a \code{Dataset}. There are subclasses corresponding to the supported
file formats (\code{ParquetFileFormat} and \code{IpcFileFormat}).
}
\section{Factory}{

\code{FileFormat$create()} takes the following arguments:
\itemize{
\item \code{format}: A string identifier of the file format. Currently supported values:
\itemize{
\item "parquet"
\item "ipc"/"arrow"/"feather", all aliases for each other; for Feather, note that
only version 2 files are supported
\item "csv"/"text", aliases for the same thing (because comma is the default
delimiter for text files
\item "tsv", equivalent to passing \verb{format = "text", delimiter = "\\t"}
}
\item \code{...}: Additional format-specific options

`format = "parquet"``:
\itemize{
\item \code{use_buffered_stream}: Read files through buffered input streams rather than
loading entire row groups at once. This may be enabled
to reduce memory overhead. Disabled by default.
\item \code{buffer_size}: Size of buffered stream, if enabled. Default is 8KB.
\item \code{dict_columns}: Names of columns which should be read as dictionaries.
}

\code{format = "text"}: see \link{CsvReadOptions}. Note that you can specify them either
with the Arrow C++ library naming ("delimiter", "quoting", etc.) or the
\code{readr}-style naming used in \code{\link[=read_csv_arrow]{read_csv_arrow()}} ("delim", "quote", etc.)
}

It returns the appropriate subclass of \code{FileFormat} (e.g. \code{ParquetFileFormat})
}