system/ByteOrder: new library for byte ordering / endianess

Replacing GLib macros.

1 files changed, 183 insertions, 0 deletions

diff --git a/src/system/ByteOrder.hxx b/src/system/ByteOrder.hxx
new file mode 100644
index 000000000..a070cd5d0
--- /dev/null
+++ b/src/system/ByteOrder.hxx
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2011-2013 Max Kellermann <max@duempel.org>,
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef BYTE_ORDER_HXX
+#define BYTE_ORDER_HXX
+
+#include <stdint.h>
+
+#if defined(__i386__) || defined(__x86_64__) || defined(__ARMEL__)
+#define IS_LITTLE_ENDIAN true
+#define IS_BIG_ENDIAN false
+#else
+#define IS_LITTLE_ENDIAN true
+#define IS_BIG_ENDIAN false;
+#endif
+
+static inline constexpr bool
+IsLittleEndian()
+{
+	return IS_LITTLE_ENDIAN;
+}
+
+static inline constexpr bool
+IsBigEndian()
+{
+	return IS_BIG_ENDIAN;
+}
+
+static inline constexpr uint16_t
+ByteSwap16(uint16_t value)
+{
+  return (value >> 8) | (value << 8);
+}
+
+static inline constexpr uint32_t
+ByteSwap32(uint32_t value)
+{
+  return (value >> 24) | ((value >> 8) & 0x0000ff00) |
+    ((value << 8) & 0x00ff0000) | (value << 24);
+}
+
+static inline constexpr uint64_t
+ByteSwap64(uint64_t value)
+{
+  return uint64_t(ByteSwap32(uint32_t(value >> 32)))
+    | (uint64_t(ByteSwap32(value)) << 32);
+}
+
+/**
+ * Converts a 16bit value from big endian to the system's byte order
+ */
+static inline constexpr uint16_t
+FromBE16(uint16_t value)
+{
+	return IsBigEndian() ? value : ByteSwap16(value);
+}
+
+/**
+ * Converts a 32bit value from big endian to the system's byte order
+ */
+static inline constexpr uint32_t
+FromBE32(uint32_t value)
+{
+	return IsBigEndian() ? value : ByteSwap32(value);
+}
+
+/**
+ * Converts a 64bit value from big endian to the system's byte order
+ */
+static inline constexpr uint64_t
+FromBE64(uint64_t value)
+{
+	return IsBigEndian() ? value : ByteSwap64(value);
+}
+
+/**
+ * Converts a 16bit value from little endian to the system's byte order
+ */
+static inline constexpr uint16_t
+FromLE16(uint16_t value)
+{
+	return IsLittleEndian() ? value : ByteSwap16(value);
+}
+
+/**
+ * Converts a 32bit value from little endian to the system's byte order
+ */
+static inline constexpr uint32_t
+FromLE32(uint32_t value)
+{
+	return IsLittleEndian() ? value : ByteSwap32(value);
+}
+
+/**
+ * Converts a 64bit value from little endian to the system's byte order
+ */
+static inline constexpr uint64_t
+FromLE64(uint64_t value)
+{
+	return IsLittleEndian() ? value : ByteSwap64(value);
+}
+
+/**
+ * Converts a 16bit value from the system's byte order to big endian
+ */
+static inline constexpr uint16_t
+ToBE16(uint16_t value)
+{
+	return IsBigEndian() ? value : ByteSwap16(value);
+}
+
+/**
+ * Converts a 32bit value from the system's byte order to big endian
+ */
+static inline constexpr uint32_t
+ToBE32(uint32_t value)
+{
+	return IsBigEndian() ? value : ByteSwap32(value);
+}
+
+/**
+ * Converts a 64bit value from the system's byte order to big endian
+ */
+static inline constexpr uint64_t
+ToBE64(uint64_t value)
+{
+	return IsBigEndian() ? value : ByteSwap64(value);
+}
+
+/**
+ * Converts a 16bit value from the system's byte order to little endian
+ */
+static inline constexpr uint16_t
+ToLE16(uint16_t value)
+{
+	return IsLittleEndian() ? value : ByteSwap16(value);
+}
+
+/**
+ * Converts a 32bit value from the system's byte order to little endian
+ */
+static inline constexpr uint32_t
+ToLE32(uint32_t value)
+{
+	return IsLittleEndian() ? value : ByteSwap32(value);
+}
+
+/**
+ * Converts a 64bit value from the system's byte order to little endian
+ */
+static inline constexpr uint64_t
+ToLE64(uint64_t value)
+{
+	return IsLittleEndian() ? value : ByteSwap64(value);
+}
+
+#endif