From ea39c98d419a816029299b99f70455798e66f6b7 Mon Sep 17 00:00:00 2001 From: Christian Theune Date: Tue, 19 May 2015 20:03:36 +0200 Subject: Implement alternative to lazy generations: * only the last generation can be lazy * depend on the '--lazy-generation' flag to be set --- src/nix-env/profiles.cc | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'src/nix-env/profiles.cc') diff --git a/src/nix-env/profiles.cc b/src/nix-env/profiles.cc index 1691dc099f4c..f2caa9868209 100644 --- a/src/nix-env/profiles.cc +++ b/src/nix-env/profiles.cc @@ -74,7 +74,7 @@ static void makeName(const Path & profile, unsigned int num, } -Path createGeneration(Path profile, Path outPath) +Path createGeneration(Path profile, Path outPath, bool lazy) { /* The new generation number should be higher than old the previous ones. */ @@ -83,13 +83,16 @@ Path createGeneration(Path profile, Path outPath) unsigned int num; if (gens.size() > 0) { - /* Check existing generations whether they represent an - environment we already materialized before. In that case: - avoid cluttering the system with additional symlinks. */ - for (auto & gen : gens) { - if (readLink(gen.path) == outPath) { - return gen.path; - } + Generation last = gens.back(); + + if (lazy && readLink(last.path) == outPath) { + /* If lazy generations are enabled then we only create a + new generation symlink if it differs from the last one. + + This helps keeping gratuitous installs/rebuilds from piling + up uncontrolled numbers of generations, cluttering up the + UI like grub. */ + return last.path; } num = gens.back().number; -- cgit 1.4.1