From 456c5d26031203e9efa134fc76f41aba4a5c4199 Mon Sep 17 00:00:00 2001
From: Jeffrey Wong <jeffreyw@netflix.com>
Date: Wed, 19 Dec 2018 19:42:58 +0000
Subject: [PATCH] read parquet files

---
 r/R/read_parquet.R          | 10 ++++++++++
 r/src/parquetfilereader.cpp | 38 +++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 r/R/read_parquet.R
 create mode 100644 r/src/parquetfilereader.cpp

diff --git a/r/R/read_parquet.R b/r/R/read_parquet.R
new file mode 100644
index 0000000000000..b6f6fb59f16e0
--- /dev/null
+++ b/r/R/read_parquet.R
@@ -0,0 +1,10 @@
+#' Read parquet file from disk
+#' 
+#' @param files a vector of filenames
+#' @export
+read_parquet = function(files) {
+  tables = lapply(files, function(f) {
+    return (as_tibble(shared_ptr(`arrow::Table`, read_parquet_file(f))))
+  })
+  do.call('rbind', tables)
+}
diff --git a/r/src/parquetfilereader.cpp b/r/src/parquetfilereader.cpp
new file mode 100644
index 0000000000000..05b1252eb6358
--- /dev/null
+++ b/r/src/parquetfilereader.cpp
@@ -0,0 +1,38 @@
+// // 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 <arrow/api.h>
+#include <arrow/io/api.h>
+#include <parquet/arrow/reader.h>
+#include <parquet/arrow/writer.h>
+#include <parquet/exception.h>
+
+// [[Rcpp::export]]
+std::shared_ptr<arrow::Table> read_parquet_file(std::string filename) {
+  std::shared_ptr<arrow::io::ReadableFile> infile;
+  PARQUET_THROW_NOT_OK(arrow::io::ReadableFile::Open(
+      filename, arrow::default_memory_pool(), &infile));
+
+  std::unique_ptr<parquet::arrow::FileReader> reader;
+  PARQUET_THROW_NOT_OK(
+    parquet::arrow::OpenFile(infile, arrow::default_memory_pool(), &reader));
+  std::shared_ptr<arrow::Table> table;
+  PARQUET_THROW_NOT_OK(reader->ReadTable(&table));
+  
+  return table;
+}