nix-super/src/libstore/indirect-root-store.cc

45 lines
1.3 KiB
C++
Raw Normal View History

#include "indirect-root-store.hh"
namespace nix {
void IndirectRootStore::makeSymlink(const Path & link, const Path & target)
{
/* Create directories up to `gcRoot'. */
createDirs(dirOf(link));
/* Create the new symlink. */
Path tempLink = fmt("%1%.tmp-%2%-%3%", link, getpid(), rand());
createSymlink(target, tempLink);
/* Atomically replace the old one. */
renameFile(tempLink, link);
}
Path IndirectRootStore::addPermRoot(const StorePath & storePath, const Path & _gcRoot)
{
Path gcRoot(canonPath(_gcRoot));
if (isInStore(gcRoot))
throw Error(
"creating a garbage collector root (%1%) in the Nix store is forbidden "
"(are you running nix-build inside the store?)", gcRoot);
/* Register this root with the garbage collector, if it's
running. This should be superfluous since the caller should
have registered this root yet, but let's be on the safe
side. */
addTempRoot(storePath);
/* Don't clobber the link if it already exists and doesn't
point to the Nix store. */
if (pathExists(gcRoot) && (!isLink(gcRoot) || !isInStore(readLink(gcRoot))))
throw Error("cannot create symlink '%1%'; already exists", gcRoot);
makeSymlink(gcRoot, printStorePath(storePath));
addIndirectRoot(gcRoot);
return gcRoot;
}
}