Mercurial > hg
view mercurial/bitmanipulation.h @ 31763:8a0c47982ade
test-revlog-raw: fix "genbits" implementation
The "genbits" implementation is actually incorrect. This patch fixes it. A
good "genbits" implementation should pass the below assertion:
n = 3 # or other number
l = list(genbits(n))
assert 2**(n*2) == len(set((l[i]<<n)+l[i+1] for i in range(len(l)-1)))
An assertion is added to make sure "genbits" won't work unexpectedly.
author | Jun Wu <quark@fb.com> |
---|---|
date | Sun, 02 Apr 2017 18:12:47 -0700 |
parents | 284d742e5611 |
children | b4356d1cf3e4 |
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#ifndef _HG_BITMANIPULATION_H_ #define _HG_BITMANIPULATION_H_ #include "compat.h" static inline uint32_t getbe32(const char *c) { const unsigned char *d = (const unsigned char *)c; return ((d[0] << 24) | (d[1] << 16) | (d[2] << 8) | (d[3])); } static inline int16_t getbeint16(const char *c) { const unsigned char *d = (const unsigned char *)c; return ((d[0] << 8) | (d[1])); } static inline uint16_t getbeuint16(const char *c) { const unsigned char *d = (const unsigned char *)c; return ((d[0] << 8) | (d[1])); } static inline void putbe32(uint32_t x, char *c) { c[0] = (x >> 24) & 0xff; c[1] = (x >> 16) & 0xff; c[2] = (x >> 8) & 0xff; c[3] = (x) & 0xff; } static inline double getbefloat64(const char *c) { const unsigned char *d = (const unsigned char *)c; double ret; int i; uint64_t t = 0; for (i = 0; i < 8; i++) { t = (t<<8) + d[i]; } memcpy(&ret, &t, sizeof(t)); return ret; } #endif