1 files changed, 123 insertions, 0 deletions
diff --git a/src/util/byte_reverse.c b/src/util/byte_reverse.c
new file mode 100644
index 00000000..e96af14b
--- /dev/null
+++ b/src/util/byte_reverse.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2003-2012 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "byte_reverse.h"
+
+#include <glib.h>
+#include <assert.h>
+
+void
+reverse_bytes_16(uint16_t *dest, const uint16_t *src, const uint16_t *src_end)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+
+	while (src < src_end) {
+		const uint16_t x = *src++;
+		*dest++ = GUINT16_SWAP_LE_BE(x);
+	}
+}
+
+void
+reverse_bytes_32(uint32_t *dest, const uint32_t *src, const uint32_t *src_end)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+
+	while (src < src_end) {
+		const uint32_t x = *src++;
+		*dest++ = GUINT32_SWAP_LE_BE(x);
+	}
+}
+
+void
+reverse_bytes_64(uint64_t *dest, const uint64_t *src, const uint64_t *src_end)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+
+	while (src < src_end) {
+		const uint64_t x = *src++;
+		*dest++ = GUINT64_SWAP_LE_BE(x);
+	}
+}
+
+static void
+reverse_bytes_linear(uint8_t *dest, const uint8_t *src, size_t n)
+{
+	src += n;
+
+	while (n-- > 0)
+		*dest++ = *--src;
+}
+
+static void
+reverse_bytes_generic(uint8_t *dest,
+		      const uint8_t *src, const uint8_t *src_end,
+		      size_t frame_size)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+	assert(frame_size > 0);
+	assert((src_end - src) % frame_size == 0);
+
+	while (src < src_end) {
+		reverse_bytes_linear(dest, src, frame_size);
+		dest += frame_size;
+		src += frame_size;
+	}
+}
+
+void
+reverse_bytes(uint8_t *dest, const uint8_t *src, const uint8_t *src_end,
+	      size_t frame_size)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+	assert(frame_size > 0);
+	assert((src_end - src) % frame_size == 0);
+
+	switch (frame_size) {
+	case 2:
+		reverse_bytes_16((uint16_t *)dest,
+				 (const uint16_t *)src,
+				 (const uint16_t *)src_end);
+		break;
+
+	case 4:
+		reverse_bytes_32((uint32_t *)dest,
+				 (const uint32_t *)src,
+				 (const uint32_t *)src_end);
+		break;
+
+	case 8:
+		reverse_bytes_64((uint64_t *)dest,
+				 (const uint64_t *)src,
+				 (const uint64_t *)src_end);
+		break;
+
+	default:
+		reverse_bytes_generic(dest, src, src_end, frame_size);
+	}
+}