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+# 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.
+
+#' Write Arrow IPC stream format
+#'
+#' Apache Arrow defines two formats for [serializing data for interprocess
+#' communication
+#' (IPC)](https://arrow.apache.org/docs/format/Columnar.html#serialization-and-interprocess-communication-ipc):
+#' a "stream" format and a "file" format, known as Feather. `write_ipc_stream()`
+#' and [write_feather()] write those formats, respectively.
+#'
+#' `write_arrow()`, a wrapper around `write_ipc_stream()` and `write_feather()`
+#' with some nonstandard behavior, is deprecated. You should explicitly choose
+#' the function that will write the desired IPC format (stream or file) since
+#' either can be written to a file or `OutputStream`.
+#'
+#' @inheritParams write_feather
+#' @param ... extra parameters passed to `write_feather()`.
+#'
+#' @return `x`, invisibly.
+#' @seealso [write_feather()] for writing IPC files. [write_to_raw()] to
+#' serialize data to a buffer.
+#' [RecordBatchWriter] for a lower-level interface.
+#' @export
+#' @examplesIf arrow_available()
+#' tf <- tempfile()
+#' on.exit(unlink(tf))
+#' write_ipc_stream(mtcars, tf)
+write_ipc_stream <- function(x, sink, ...) {
+ x_out <- x # So we can return the data we got
+ if (is.data.frame(x)) {
+ x <- Table$create(x)
+ }
+ assert_that(is_writable_table(x))
+ if (!inherits(sink, "OutputStream")) {
+ sink <- make_output_stream(sink)
+ on.exit(sink$close())
+ }
+
+ writer <- RecordBatchStreamWriter$create(sink, x$schema)
+ writer$write(x)
+ writer$close()
+ invisible(x_out)
+}
+
+#' Write Arrow data to a raw vector
+#'
+#' [write_ipc_stream()] and [write_feather()] write data to a sink and return
+#' the data (`data.frame`, `RecordBatch`, or `Table`) they were given.
+#' This function wraps those so that you can serialize data to a buffer and
+#' access that buffer as a `raw` vector in R.
+#' @inheritParams write_feather
+#' @param format one of `c("stream", "file")`, indicating the IPC format to use
+#' @return A `raw` vector containing the bytes of the IPC serialized data.
+#' @examplesIf arrow_available()
+#' # The default format is "stream"
+#' mtcars_raw <- write_to_raw(mtcars)
+#' @export
+write_to_raw <- function(x, format = c("stream", "file")) {
+ sink <- BufferOutputStream$create()
+ if (match.arg(format) == "stream") {
+ write_ipc_stream(x, sink)
+ } else {
+ write_feather(x, sink)
+ }
+ as.raw(buffer(sink))
+}
+
+#' Read Arrow IPC stream format
+#'
+#' Apache Arrow defines two formats for [serializing data for interprocess
+#' communication
+#' (IPC)](https://arrow.apache.org/docs/format/Columnar.html#serialization-and-interprocess-communication-ipc):
+#' a "stream" format and a "file" format, known as Feather. `read_ipc_stream()`
+#' and [read_feather()] read those formats, respectively.
+#'
+#' `read_arrow()`, a wrapper around `read_ipc_stream()` and `read_feather()`,
+#' is deprecated. You should explicitly choose
+#' the function that will read the desired IPC format (stream or file) since
+#' a file or `InputStream` may contain either.
+#'
+#' @param file A character file name or URI, `raw` vector, an Arrow input stream,
+#' or a `FileSystem` with path (`SubTreeFileSystem`).
+#' If a file name or URI, an Arrow [InputStream] will be opened and
+#' closed when finished. If an input stream is provided, it will be left
+#' open.
+#' @param as_data_frame Should the function return a `data.frame` (default) or
+#' an Arrow [Table]?
+#' @param ... extra parameters passed to `read_feather()`.
+#'
+#' @return A `data.frame` if `as_data_frame` is `TRUE` (the default), or an
+#' Arrow [Table] otherwise
+#' @seealso [read_feather()] for writing IPC files. [RecordBatchReader] for a
+#' lower-level interface.
+#' @export
+read_ipc_stream <- function(file, as_data_frame = TRUE, ...) {
+ if (!inherits(file, "InputStream")) {
+ file <- make_readable_file(file)
+ on.exit(file$close())
+ }
+
+ # TODO: this could take col_select, like the other readers
+ # https://issues.apache.org/jira/browse/ARROW-6830
+ out <- RecordBatchStreamReader$create(file)$read_table()
+ if (as_data_frame) {
+ out <- as.data.frame(out)
+ }
+ out
+}