forceValue() were called after a value is copied effectively forcing only one of the copies keeping another copy not evaluated.
This resulted in its evaluation of the same lazy value more than once (the number of hits is not big though)
Before:
$ command time nix-prefetch-url https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.17.6.tar.xz
1.19user 1.02system 0:41.96elapsed 5%CPU (0avgtext+0avgdata 182720maxresident)k
After:
1.38user 1.05system 0:39.73elapsed 6%CPU (0avgtext+0avgdata 16204maxresident)k
Note however that addToStore() can still take a lot of memory
(e.g. RemoteStore::addToStore() is constant space, but
LocalStore::addToStore() isn't; that's fixed by
c94b4fc7ee
though).
Fixes#1400.
For example, this allows you to do run nix-daemon as a non-privileged
user:
eelco$ NIX_STATE_DIR=~/my-nix/nix/var nix-daemon --store ~/my-nix/
The NIX_STATE_DIR is still needed because settings.nixDaemonSocketFile
is not derived from settings.storeUri (and we can't derive it from the
store's state directory because we don't want to open the store in the
parent process).
As proposed in #1634 the `nix search` command could use some
improvements. Initially 0413aeb35d added
some basic sorting behavior using `std::map`, a next step would be an
improvement of the output.
This patch includes the following changes:
* Use `$PAGER` for outputs with `RunPager` from `shared.hh`:
The same behavior is defined for `nix-env --query`, furthermore it
makes searching huge results way easier.
* Simplified result blocks:
The new output is heavily inspired by the output from `nox`, the first
line shows the attribute path and the derivaiton name
(`attribute path (derivation name)`) and the description in the second
line.
We have automated builds at https://hub.docker.com/r/nixos/nix/ now. The master
branch of the "docker" repository is available as "latest". Branches that match
the regular expression "^[0-9.]+$" are pushed to the tag that corresponds to
their branch name. Other branches are ignored.
Slightly nicer behavior when updates are somewhat far apart
(during a long linking step, perhaps) ensuring things
don't appear unresponsive.
If we wait the maximum amount for the update,
don't bother waiting another 50ms (for rate-limiting purposes)
and just check if we should quit.
This also ensures we'll notice the request to quit within 1s
if quit is signalled but there is not an udpate.
(I'm not sure if this happens or not)
