Move net/base/sys_byteorder.h to base/sys_byteorder.h

base/sys_byteorder.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This is a convenience header to pull in the platform-specific
+// headers that define functions for byte-order conversion,
+// particularly: ntohs(), htons(), ntohl(), htonl(). Prefer including
+// this file instead of directly writing the #if / #else, since it
+// avoids duplicating the platform-specific selections.
+// This header also provides ntohll() and htonll() for byte-order conversion
+// for 64-bit integers.
+
+#ifndef BASE_SYS_BYTEORDER_H_
+#define BASE_SYS_BYTEORDER_H_
+
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+#include <winsock2.h>
+#else
+#include <arpa/inet.h>
+#endif
+
+// Include headers to provide bswap for all platforms.
+#if defined(COMPILER_MSVC)
+#include <stdlib.h>
+#elif defined(OS_MACOSX)
+#include <libkern/OSByteOrder.h>
+#elif defined(OS_OPENBSD)
+#include <sys/endian.h>
+#else
+#include <byteswap.h>
+#endif
+
+
+namespace base {
+
+inline uint64_t ByteSwap(uint64_t x) {
+#if defined(COMPILER_MSVC)
+  return _byteswap_uint64(x);
+#elif defined(OS_MACOSX)
+  return OSSwapInt64(x);
+#elif defined(OS_OPENBSD)
+  return swap64(x);
+#else
+  return bswap_64(x);
+#endif
+}
+
+inline uint64_t ntohll(uint64_t x) {

[brettw, 2011/12/25 00:16:01]

Can these have documentation? I've never heard of this function. Personally, I
would have called this NetworkEndianToHost or something. If we think this is
more clear because the people using this are more used to ntohll, that's OK, but
we should at least have a description of what it's for for the majority of us
that don't.

[Ilya Sherman, 2011/12/26 08:05:26]

Added some documentation.  I'd prefer to keep this name for consistency with
ntohs and ntohl.  Or, we could add wrappers for the 16-bit and 32-bit versions
of the function... but I'm not sure that it's worth the code churn.

+#if defined(ARCH_CPU_LITTLE_ENDIAN)
+  return ByteSwap(x);
+#else
+  return x;
+#endif
+}
+
+inline uint64_t htonll(uint64_t x) {
+#if defined(ARCH_CPU_LITTLE_ENDIAN)
+  return ByteSwap(x);
+#else
+  return x;
+#endif
+}
+
+}  // namespace base
+
+
+#endif  // BASE_SYS_BYTEORDER_H_