src: add BE support to StringBytes::Encode()

Versions of Node.js after v0.12 have relocated byte-swapping away from
the StringBytes::Encode function, thereby causing a nan test (which
accesses this function directly) to fail on big-endian machines.

This change re-introduces byte swapping in StringBytes::Encode,
done via a call to a function in util-inl. Another change in
NodeBuffer::StringSlice was necessary to avoid double byte swapping
in big-endian function calls to StringSlice.

PR-URL: https://github.com/nodejs/node/pull/3410
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Trevor Norris <trev.norris@gmail.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/util-inl.h b/src/util-inl.h
index 75bdb4784aa..669b7e75358 100644
--- a/src/util-inl.h
+++ b/src/util-inl.h
@@ -198,6 +198,20 @@ TypeName* Unwrap(v8::Local<v8::Object> object) {
   return static_cast<TypeName*>(pointer);
 }
 
+void SwapBytes(uint16_t* dst, const uint16_t* src, size_t buflen) {
+  for (size_t i = 0; i < buflen; i++) {
+    // __builtin_bswap16 generates more efficient code with
+    // g++ 4.8 on PowerPC and other big-endian archs
+#ifdef __GNUC__
+    dst[i] = __builtin_bswap16(src[i]);
+#else
+    dst[i] = (src[i] << 8) | (src[i] >> 8);
+#endif
+  }
+}
+
+
+
 }  // namespace node
 
 #endif  // SRC_UTIL_INL_H_