(ITS#8420) lmdb Windows sizeof(off_t) == sizeof(int32_t)

Full_Name: Clayton Stangeland Version: lmdb master a04aad31c2 OS: Windows 7 64 bit URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (170.54.58.5)

This is an lmdb bug.

mdb_page_flush fails as database size nears 2 GB on Windows. The reason is off_t == int32_t on Windows. So the off_t pos variable becomes negative and this section of code in mdb_page_flush enters the error condition as ov.OffsetHigh is also negative:

ov.Offset = pos & 0xffffffff; ov.OffsetHigh = pos >> 16 >> 16; if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) { rc = ErrCode(); DPRINTF(("WriteFile: %d", rc)); return rc; }

Adding23dedefine off_t int64_t in an #ifdef _WIN32 region solves this.