bitmanipulation: add utils to read/write bigendian 64bit integers
Differential Revision: https://phab.mercurial-scm.org/D9845
--- a/mercurial/bitmanipulation.h Thu Mar 04 09:55:06 2021 +0100
+++ b/mercurial/bitmanipulation.h Mon Jan 18 10:43:12 2021 +0100
@@ -5,6 +5,18 @@
#include "compat.h"
+/* Reads a 64 bit integer from big-endian bytes. Assumes that the data is long
+ enough */
+static inline uint64_t getbe64(const char *c)
+{
+ const unsigned char *d = (const unsigned char *)c;
+
+ return ((((uint64_t)d[0]) << 56) | (((uint64_t)d[1]) << 48) |
+ (((uint64_t)d[2]) << 40) | (((uint64_t)d[3]) << 32) |
+ (((uint64_t)d[4]) << 24) | (((uint64_t)d[5]) << 16) |
+ (((uint64_t)d[6]) << 8) | (d[7]));
+}
+
static inline uint32_t getbe32(const char *c)
{
const unsigned char *d = (const unsigned char *)c;
@@ -27,6 +39,20 @@
return ((d[0] << 8) | (d[1]));
}
+/* Writes a 64 bit integer to bytes in a big-endian format.
+ Assumes that the buffer is long enough */
+static inline void putbe64(uint64_t x, char *c)
+{
+ c[0] = (x >> 56) & 0xff;
+ c[1] = (x >> 48) & 0xff;
+ c[2] = (x >> 40) & 0xff;
+ c[3] = (x >> 32) & 0xff;
+ c[4] = (x >> 24) & 0xff;
+ c[5] = (x >> 16) & 0xff;
+ c[6] = (x >> 8) & 0xff;
+ c[7] = (x)&0xff;
+}
+
static inline void putbe32(uint32_t x, char *c)
{
c[0] = (x >> 24) & 0xff;