Removed Common

Change-Id: I01ea8f07220375c2ad9bc0092281d4f27c642303
diff --git a/aos/byteorder.h b/aos/byteorder.h
new file mode 100644
index 0000000..4a0fd8c
--- /dev/null
+++ b/aos/byteorder.h
@@ -0,0 +1,201 @@
+#ifndef AOS_BYTEORDER_H_
+#define AOS_BYTEORDER_H_
+
+#ifndef __VXWORKS__
+#include <endian.h> // endian(3)
+#endif
+#include <string.h>
+#include <stdint.h>
+
+// Contains functions for converting between host and network byte order for
+// things other than 16/32 bit integers (those are provided by byteorder(3)).
+// Also gives a nice templated interface to these functions.
+
+namespace aos {
+namespace {
+
+template <typename int_type, int_type (*function)(int_type)>
+static inline void copier(const void *in, void *out) {
+  // Have confirmed by looking at the assembly code that this generates the same
+  // code as the (undefined by the c++ standard) way of using a union to do it.
+  // (which is pretty efficient)
+  int_type temp;
+  memcpy(&temp, in, sizeof(int_type));
+  temp = function(temp);
+  memcpy(out, &temp, sizeof(int_type));
+}
+template <typename int_type, typename T, int_type (*function)(int_type)>
+static inline T memcpier(T in) {
+  copier<int_type, function>(&in, &in);
+  return in;
+}
+
+// Needed because be64toh etc are macros (not that the manpage says
+// anything...).
+// These are used instead of ntohs etc because gcc didn't inline those.
+#ifdef __clang__
+// Apparently the macros use "register", and clang doesn't like that.
+#define register
+#endif
+static inline uint64_t _be64toh(uint64_t in) { return be64toh(in); }
+static inline uint64_t _htobe64(uint64_t in) { return htobe64(in); }
+static inline uint32_t _be32toh(uint32_t in) { return be32toh(in); }
+static inline uint32_t _htobe32(uint32_t in) { return htobe32(in); }
+static inline uint16_t _be16toh(uint16_t in) { return be16toh(in); }
+static inline uint16_t _htobe16(uint16_t in) { return htobe16(in); }
+#ifdef __clang__
+#undef register
+#endif
+
+template<int bytes, typename T> class do_ntoh {
+ public:
+  static inline T apply(T net);
+  static inline void copy(const char *in, T &net);
+};
+template<typename T> class do_ntoh<1, T> {
+ public:
+  static inline T apply(T net) { return net; }
+  static inline void copy(const char *in, T *host) { host[0] = in[0]; }
+};
+template<typename T> class do_ntoh<2, T> {
+ public:
+  static inline T apply(T net) { return memcpier<uint16_t, T, _be16toh>(net); }
+  static inline void copy(const char *in, T *host) {
+    copier<uint16_t, _be16toh>(in, host);
+  }
+};
+template<typename T> class do_ntoh<4, T> {
+ public:
+  static inline T apply(T net) { return memcpier<uint32_t, T, _be32toh>(net); }
+  static inline void copy(const char *in, T *host) {
+    copier<uint32_t, _be32toh>(in, host);
+  }
+};
+template<typename T> class do_ntoh<8, T> {
+ public:
+  static inline T apply(T net) { return memcpier<uint64_t, T, _be64toh>(net); }
+  static inline void copy(const char *in, T *host) {
+    copier<uint64_t, _be64toh>(in, host);
+  }
+};
+
+template <size_t Size>
+struct do_ntoh_int {
+  static inline void copy(const char *in, char *host);
+};
+template <>
+struct do_ntoh_int<1> {
+  static inline void copy(const char *in, char *host) { host[0] = in[0]; }
+};
+template <>
+struct do_ntoh_int<2> {
+  static inline void copy(const char *in, char *host) {
+    copier<uint16_t, _be16toh>(in, host);
+  }
+};
+template <>
+struct do_ntoh_int<4> {
+  static inline void copy(const char *in, char *host) {
+    copier<uint32_t, _be32toh>(in, host);
+  }
+};
+template <>
+struct do_ntoh_int<8> {
+  static inline void copy(const char *in, char *host) {
+    copier<uint64_t, _be64toh>(in, host);
+  }
+};
+
+template<int bytes, typename T> class do_hton {
+ public:
+  static inline T apply(T host);
+  static inline void copy(const T *host, char *out);
+};
+template<typename T> class do_hton<1, T> {
+ public:
+  static inline T apply(T host) { return host; }
+  static inline void copy(const T *host, char *out) { out[0] = host[0]; }
+};
+template<typename T> class do_hton<2, T> {
+ public:
+  static inline T apply(T host) { return memcpier<uint16_t, T, _htobe16>(host); }
+  static inline void copy(const T *host, char *out) {
+    copier<uint16_t, _htobe16>(host, out);
+  }
+};
+template<typename T> class do_hton<4, T> {
+ public:
+  static inline T apply(T host) { return memcpier<uint32_t, T, _htobe32>(host); }
+  static inline void copy(const T *host, char *out) {
+    copier<uint32_t, _htobe32>(host, out);
+  }
+};
+template<typename T> class do_hton<8, T> {
+ public:
+  static inline T apply(T host) { return memcpier<uint64_t, T, _htobe64>(host); }
+  static inline void copy(const T *host, char *out) {
+    copier<uint64_t, _htobe64>(host, out);
+  }
+};
+
+template <size_t Size>
+struct do_hton_int {
+  static inline void copy(const char *host, char *out);
+};
+template <>
+struct do_hton_int<1> {
+  static inline void copy(const char *host, char *out) { out[0] = host[0]; }
+};
+template <>
+struct do_hton_int<2> {
+  static inline void copy(const char *host, char *out) {
+    copier<uint16_t, _htobe16>(host, out);
+  }
+};
+template <>
+struct do_hton_int<4> {
+  static inline void copy(const char *host, char *out) {
+    copier<uint32_t, _htobe32>(host, out);
+  }
+};
+template <>
+struct do_hton_int<8> {
+  static inline void copy(const char *host, char *out) {
+    copier<uint64_t, _htobe64>(host, out);
+  }
+};
+
+}  // namespace
+
+// Converts T from network to host byte order.
+template <typename T>
+static inline T ntoh(T net) {
+  return do_ntoh<sizeof(net), T>::apply(net);
+}
+// Converts T from host to network byte order.
+template <typename T>
+static inline T hton(T host) {
+  return do_hton<sizeof(host), T>::apply(host);
+}
+
+template <typename T>
+static inline void to_host(const char *input, T *host) {
+  do_ntoh<sizeof(*host), T>::copy(input, host);
+}
+template <typename T>
+static inline void to_network(const T *host, char *output) {
+  do_hton<sizeof(*host), T>::copy(host, output);
+}
+
+template <size_t Size>
+static inline void to_host(const char *input, char *host) {
+  do_ntoh_int<Size>::copy(input, host);
+}
+template <size_t Size>
+static inline void to_network(const char *host, char *output) {
+  do_hton_int<Size>::copy(host, output);
+}
+
+} // namespace aos
+
+#endif