r/R/message.R

# 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

#' @title class arrow::ipc::Message
#'
#' @usage NULL
#' @format NULL
#' @docType class
#'
#' @section Methods:
#'
#' TODO
#'
#' @rdname arrow__ipc__Message
#' @name arrow__ipc__Message
`arrow::ipc::Message` <- R6Class("arrow::ipc::Message", inherit = `arrow::Object`,
  public = list(
    Equals = function(other){
      assert_that(inherits(other, "arrow::ipc::Message"))
      ipc___Message__Equals(self, other)
    },
    body_length = function() ipc___Message__body_length(self),
    Verify = function() ipc___Message__Verify(self)
  ),
  active = list(
    type = function() ipc___Message__type(self),
    metadata = function() shared_ptr(`arrow::Buffer`, ipc___Message__metadata(self)),
    body = function() shared_ptr(`arrow::Buffer`, ipc___Message__body(self))
  )
)

#' @export
`==.arrow::ipc::Message` <- function(x, y) x$Equals(y)

#' @title class arrow::ipc::MessageReader
#'
#' @usage NULL
#' @format NULL
#' @docType class
#'
#' @section Methods:
#'
#' TODO
#'
#' @rdname arrow__ipc__MessageReader
#' @name arrow__ipc__MessageReader
`arrow::ipc::MessageReader` <- R6Class("arrow::ipc::MessageReader", inherit = `arrow::Object`,
  public = list(
    ReadNextMessage = function() unique_ptr(`arrow::ipc::Message`, ipc___MessageReader__ReadNextMessage(self))
  )
)

#' Open a MessageReader that reads from a stream
#'
#' @param stream an InputStream
#'
#' @export
MessageReader <- function(stream) {
  UseMethod("MessageReader")
}

#' @export
MessageReader.default <- function(stream) {
  MessageReader(BufferReader(stream))
}

#' @export
`MessageReader.arrow::io::InputStream` <- function(stream) {
  unique_ptr(`arrow::ipc::MessageReader`, ipc___MessageReader__Open(stream))
}

#' Read a Message from a stream
#'
#' @param stream an InputStream
#'
#' @export
read_message <- function(stream) {
  UseMethod("read_message")
}

#' @export
read_message.default<- function(stream) {
  read_message(BufferReader(stream))
}

#' @export
`read_message.arrow::io::InputStream` <- function(stream) {
  unique_ptr(`arrow::ipc::Message`, ipc___ReadMessage(stream) )
}

#' @export
`read_message.arrow::ipc::MessageReader` <- function(stream) {
  stream$ReadNextMessage()
}