"go tool vet -shadow=true" complained about the md5 package
being shadowed by variables called "md5".
Fix by using the Md5hex helper and dropping the md5 import.
...and convert all calls to syscall.{Fallocate,Openat}
to syscallcompat .
Both syscalls are not available on OSX. We emulate Openat and just
return EOPNOTSUPP for Fallocate.
We were growing the file block-by-block which was pretty
inefficient. We now coalesce all the grows into a single
Ftruncate. Also simplifies the code!
Simplistic benchmark: Before:
$ time truncate -s 1000M foo
real 0m0.568s
After:
$ time truncate -s 1000M foo
real 0m0.205s
