Mercurial > hg
view mercurial/bitmanipulation.h @ 31209:dd2364f5180a
localrepo: handle rename with hardlinks properly
In "aftertrans", we rename "journal.*" to "undo.*". We expect "journal.*"
files to disappear after renaming.
However, if "journal.foo" and "undo.foo" refer to a same file (hardlink),
rename may be a no-op, leaving both files on disk, according to Linux
manpage [1]:
If oldpath and newpath are existing hard links referring to the same
file, then rename() does nothing, and returns a suc‐ cess status.
The POSIX specification [2] is not very clear about what to do.
To be safe, remove "undo.*" before the rename so "journal.*" cannot be left
on disk.
[1]: http://man7.org/linux/man-pages/man2/rename.2.html
[2]: http://pubs.opengroup.org/onlinepubs/9699919799/
author | Jun Wu <quark@fb.com> |
---|---|
date | Thu, 02 Mar 2017 21:49:30 -0800 |
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