From: antirez <antirez@gmail.com>
Date: Wed, 9 Mar 2011 15:24:18 +0000 (+0100)
Subject: endianess conversion API, to be applied to specially encoded data types for arch... 
X-Git-Url: https://git.saurik.com/redis.git/commitdiff_plain/e12cb14308ab2719b506762e662ab179f31aceb9

endianess conversion API, to be applied to specially encoded data types for arch agnostic encoding.
---

diff --git a/src/endian.c b/src/endian.c
new file mode 100644
index 00000000..aff2425a
--- /dev/null
+++ b/src/endian.c
@@ -0,0 +1,63 @@
+/* Toggle the 16 bit unsigned integer pointed by *p from little endian to
+ * big endian */
+void memrev16(void *p) {
+    unsigned char *x = p, t;
+
+    t = x[0];
+    x[0] = x[1];
+    x[1] = t;
+}
+
+/* Toggle the 32 bit unsigned integer pointed by *p from little endian to
+ * big endian */
+void memrev32(void *p) {
+    unsigned char *x = p, t;
+
+    t = x[0];
+    x[0] = x[3];
+    x[3] = t;
+    t = x[1];
+    x[1] = x[2];
+    x[2] = t;
+}
+
+/* Toggle the 64 bit unsigned integer pointed by *p from little endian to
+ * big endian */
+void memrev64(void *p) {
+    unsigned char *x = p, t;
+
+    t = x[0];
+    x[0] = x[7];
+    x[7] = t;
+    t = x[1];
+    x[1] = x[6];
+    x[6] = t;
+    t = x[2];
+    x[2] = x[5];
+    x[5] = t;
+    t = x[3];
+    x[3] = x[4];
+    x[4] = t;
+}
+
+#ifdef TESTMAIN
+#include <stdio.h>
+
+int main(void) {
+    char buf[32];
+
+    sprintf(buf,"ciaoroma");
+    memrev16(buf);
+    printf("%s\n", buf);
+
+    sprintf(buf,"ciaoroma");
+    memrev32(buf);
+    printf("%s\n", buf);
+
+    sprintf(buf,"ciaoroma");
+    memrev64(buf);
+    printf("%s\n", buf);
+
+    return 0;
+}
+#endif
diff --git a/src/endian.h b/src/endian.h
new file mode 100644
index 00000000..ea295ee5
--- /dev/null
+++ b/src/endian.h
@@ -0,0 +1,8 @@
+#ifndef __ENDIAN_H
+#define __ENDIAN_H
+
+void memrev16(void *p);
+void memrev32(void *p);
+void memrev64(void *p);
+
+#endif