wroclaw-git-backups/nix
1
0
Fork 0
mirror of https://github.com/NixOS/nix synced 2025-07-07 01:51:47 +02:00
Code Activity

Implement caching of fetchurl/fetchTarball results

Browse source 
ETags are used to prevent redownloading unchanged files.
This commit is contained in:
Eelco Dolstra 2015-04-09 11:42:04 +02:00
parent 1711679ea5
commit 60340ce3e2
4 changed files with 152 additions and 29 deletions
Download patch file Download diff file Expand all files Collapse all files

11
src/nix-env/profiles.cc
View file

@ -116,16 +116,7 @@ void switchLink(Path link, Path target)
/* Hacky. */
if (dirOf(target) == dirOf(link)) target = baseNameOf(target);
Path tmp = canonPath(dirOf(link) + "/.new_" + baseNameOf(link));
createSymlink(target, tmp);
/* The rename() system call is supposed to be essentially atomic
on Unix. That is, if we have links `current -> X' and
`new_current -> Y', and we rename new_current to current, a
process accessing current will see X or Y, but never a
file-not-found or other error condition. This is sufficient to
atomically switch user environments. */
if (rename(tmp.c_str(), link.c_str()) != 0)
throw SysError(format("renaming ‘%1%’ to ‘%2%’") % tmp % link);
replaceSymlink(target, link);
}