From 2a00a1669eb8ca7612b1f6c7eb94eae9ea69dced Mon Sep 17 00:00:00 2001
From: Julien Le Dem <julien@dremio.com>
Date: Mon, 8 Aug 2016 11:23:16 -0700
Subject: [PATCH] autodetect endianness

---
 cpp/src/arrow/ipc/metadata-internal.cc | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/cpp/src/arrow/ipc/metadata-internal.cc b/cpp/src/arrow/ipc/metadata-internal.cc
index 7c7dc6ba10f02..a38b05610f755 100644
--- a/cpp/src/arrow/ipc/metadata-internal.cc
+++ b/cpp/src/arrow/ipc/metadata-internal.cc
@@ -262,11 +262,21 @@ Status MessageBuilder::SetSchema(const Schema* schema) {
   return Status::OK();
 }
 
+// will return the endianness of the system we are running on
+flatbuf::Endianness endianness(void) {
+  union {
+    uint32_t i;
+    char c[4];
+  } bint = {0x01020304};
+
+  return bint.c[0] == 1 ? flatbuf::Endianness_Big : flatbuf::Endianness_Little;
+}
+
 Status MessageBuilder::SetRecordBatch(int32_t length, int64_t body_length,
     const std::vector<flatbuf::FieldNode>& nodes,
     const std::vector<flatbuf::Buffer>& buffers) {
   header_type_ = flatbuf::MessageHeader_RecordBatch;
-  header_ = flatbuf::CreateRecordBatch(fbb_, length, flatbuf::Endianness_Little,
+  header_ = flatbuf::CreateRecordBatch(fbb_, length, endianness(),
                 fbb_.CreateVectorOfStructs(nodes),
                 fbb_.CreateVectorOfStructs(buffers))
                 .Union();