Expose arrow::csv::TableReader, functions csv_table_reader() + csv_re…

…ad()

r/DESCRIPTION

@@ -55,6 +55,7 @@ Collate:
     'array.R'
     'buffer.R'
     'compute.R'
+    'csv.R'
     'dictionary.R'
     'feather.R'
     'io.R'

r/NAMESPACE

@@ -39,6 +39,19 @@ S3method(buffer,default)
 S3method(buffer,integer)
 S3method(buffer,numeric)
 S3method(buffer,raw)
+S3method(buffer_reader,"arrow::Buffer")
+S3method(buffer_reader,default)
+S3method(csv_table_reader,"arrow::csv::TableReader")
+S3method(csv_table_reader,"arrow::io::InputStream")
+S3method(csv_table_reader,character)
+S3method(csv_table_reader,default)
+S3method(csv_table_reader,fs_path)
+S3method(feather_table_reader,"arrow::io::RandomAccessFile")
+S3method(feather_table_reader,"arrow::ipc::feather::TableReader")
+S3method(feather_table_reader,character)
+S3method(feather_table_reader,default)
+S3method(feather_table_reader,fs_path)
+S3method(feather_table_writer,"arrow::io::OutputStream")
 S3method(length,"arrow::Array")
 S3method(names,"arrow::RecordBatch")
 S3method(print,"arrow-enum")
@@ -92,6 +105,11 @@ export(boolean)
 export(buffer)
 export(cast_options)
 export(chunked_array)
+export(csv_convert_options)
+export(csv_parse_options)
+export(csv_read)
+export(csv_read_options)
+export(csv_table_reader)
 export(date32)
 export(date64)
 export(decimal)
@@ -141,6 +159,7 @@ importFrom(glue,glue)
 importFrom(purrr,map)
 importFrom(purrr,map2)
 importFrom(purrr,map_int)
+importFrom(rlang,abort)
 importFrom(rlang,dots_n)
 importFrom(rlang,list2)
 importFrom(rlang,warn)

r/R/csv.R

@@ -0,0 +1,136 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+#' @include R6.R
+
+`arrow::csv::TableReader` <- R6Class("arrow::csv::TableReader", inherit = `arrow::Object`,
+  public = list(
+    Read = function() shared_ptr(`arrow::Table`, csv___TableReader__Read(self))
+  )
+)
+
+`arrow::csv::ReadOptions` <- R6Class("arrow::csv::ReadOptions", inherit = `arrow::Object`)
+`arrow::csv::ParseOptions` <- R6Class("arrow::csv::ParseOptions", inherit = `arrow::Object`)
+`arrow::csv::ConvertOptions` <- R6Class("arrow::csv::ConvertOptions", inherit = `arrow::Object`)
+
+#' read options for the csv reader
+#'
+#' @param use_threads Whether to use the global CPU thread pool
+#' @param block_size Block size we request from the IO layer; also determines the size of chunks when use_threads is `TRUE`
+#'
+#' @export
+csv_read_options <- function(use_threads = TRUE, block_size = 1048576L) {
+  shared_ptr(`arrow::csv::ReadOptions`, csv___ReadOptions__initialize(
+    list(
+      use_threads = use_threads,
+      block_size = block_size
+    )
+  ))
+}
+
+#' Parsing options
+#'
+#' @param delimiter Field delimiter
+#' @param quoting Whether quoting is used
+#' @param quote_char Quoting character (if `quoting` is `TRUE`)
+#' @param double_quote Whether a quote inside a value is double-quoted
+#' @param escaping Whether escaping is used
+#' @param escape_char Escaping character (if `escaping` is `TRUE`)
+#' @param newlines_in_values Whether values are allowed to contain CR (`0x0d``) and LF (`0x0a``) characters
+#' @param ignore_empty_lines Whether empty lines are ignored.  If false, an empty line represents
+#' @param header_rows Number of header rows to skip (including the first row containing column names)
+#'
+#' @export
+csv_parse_options <- function(delimiter = ",", quoting = TRUE, quote_char = '"', double_quote = TRUE, escaping = FALSE, escape_char = '\\', newlines_in_values = FALSE, ignore_empty_lines = TRUE, header_rows = 1L){
+  shared_ptr(`arrow::csv::ParseOptions`, csv___ParseOptions__initialize(
+    list(
+      delimiter = delimiter,
+      quoting = quoting,
+      quote_char = quote_char,
+      double_quote = double_quote,
+      escaping = escaping,
+      escape_char = escape_char,
+      newlines_in_values = newlines_in_values,
+      ignore_empty_lines = ignore_empty_lines,
+      header_rows = header_rows
+    )
+  ))
+}
+
+#' Conversion Options for the csv reader
+#'
+#' @param check_utf8 Whether to check UTF8 validity of string columns
+#'
+#' @export
+csv_convert_options <- function(check_utf8 = TRUE){
+  shared_ptr(`arrow::csv::ConvertOptions`, csv___ConvertOptions__initialize(
+    list(
+      check_utf8 = check_utf8
+    )
+  ))
+}
+
+#' CSV table reader
+#'
+#' @param file file
+#' @param read_options, see [csv_read_options()]
+#' @param parse_options, see [csv_parse_options()]
+#' @param convert_options, see [csv_convert_options()]
+#' @param ... additional parameters.
+#'
+#' @export
+csv_table_reader <- function(file, read_options = csv_read_options(), parse_options = csv_parse_options(), convert_options = csv_convert_options(), ...){
+  UseMethod("csv_table_reader")
+}
+
+#' @importFrom rlang abort
+#' @export
+csv_table_reader.default <- function(file, read_options = csv_read_options(), parse_options = csv_parse_options(), convert_options = csv_convert_options(), ...) {
+  abort("unsupported")
+}
+
+#' @export
+`csv_table_reader.character` <- function(file, read_options = csv_read_options(), parse_options = csv_parse_options(), convert_options = csv_convert_options(), ...){
+  csv_table_reader(fs::path_abs(file), read_options = read_options, parse_options = parse_options, convert_options = convert_options, ...)
+}
+
+#' @export
+`csv_table_reader.fs_path` <- function(file, read_options = csv_read_options(), parse_options = csv_parse_options(), convert_options = csv_convert_options(), mmap = TRUE, ...){
+  stream <- if (isTRUE(mmap)) mmap_open(file) else file_open(file)
+  csv_table_reader(stream, read_options = read_options, parse_options = parse_options, convert_options = convert_options, ...)
+}
+
+#' @export
+`csv_table_reader.arrow::io::InputStream` <- function(file, read_options = csv_read_options(), parse_options = csv_parse_options(), convert_options = csv_convert_options(), ...){
+  shared_ptr(`arrow::csv::TableReader`, csv___TableReader__Make(file, read_options, parse_options, convert_options))
+}
+
+#' @export
+`csv_table_reader.arrow::csv::TableReader` <- function(file, read_options = csv_read_options(), parse_options = csv_parse_options(), convert_options = csv_convert_options(), ...){
+  file
+}
+
+#' Read csv file into an arrow::Table
+#'
+#' Use arrow::csv::TableReader from [csv_table_reader()]
+#'
+#' @param ... Used to construct an arrow::csv::TableReader
+#' @export
+csv_read <- function(...) {
+  csv_table_reader(...)$Read()
+}
+