Commit graph

13 commits

Author SHA1 Message Date
Eelco Dolstra 1511aa9f48 Allow remote builds without sending the derivation closure
Previously, to build a derivation remotely, we had to copy the entire
closure of the .drv file to the remote machine, even though we only
need the top-level derivation. This is very wasteful: the closure can
contain thousands of store paths, and in some Hydra use cases, include
source paths that are very large (e.g. Git/Mercurial checkouts).

So now there is a new operation, StoreAPI::buildDerivation(), that
performs a build from an in-memory representation of a derivation
(BasicDerivation) rather than from a on-disk .drv file. The only files
that need to be in the Nix store are the sources of the derivation
(drv.inputSrcs), and the needed output paths of the dependencies (as
described by drv.inputDrvs). "nix-store --serve" exposes this
interface.

Note that this is a privileged operation, because you can construct a
derivation that builds any store path whatsoever. Fixing this will
require changing the hashing scheme (i.e., the output paths should be
computed from the other fields in BasicDerivation, allowing them to be
verified without access to other derivations). However, this would be
quite nice because it would allow .drv-free building (e.g. "nix-env
-i" wouldn't have to write any .drv files to disk).

Fixes #173.
2015-07-17 17:57:40 +02:00
Eelco Dolstra b64988bb35 Allow substitutes for builds that have preferLocalBuild set
Not substituting builds with "preferLocalBuild = true" was a bad idea,
because it didn't take the cost of dependencies into account. For
instance, if we can't substitute a fetchgit call, then we have to
download/build git and all its dependencies.

Partially reverts 5558652709 and adds a
new derivation attribute "allowSubstitutes" to specify whether a
derivation may be substituted.
2015-06-04 16:30:22 +02:00
Eelco Dolstra 7ccd946407 Don't set $preferLocalBuild and $requiredSystemFeatures in builders
With C++ std::map, doing a comparison like ‘map["foo"] == ...’ has the
side-effect of adding a mapping from "foo" to the empty string if
"foo" doesn't exist in the map.  So we ended up setting some
environment variables by accident.
2013-06-20 18:07:27 +00:00
Eelco Dolstra 5558652709 Don't substitute derivations that have preferLocalBuild set
In particular this means that "trivial" derivations such as writeText
are not substituted, reducing the number of GET requests to the binary
cache by about 200 on a typical NixOS configuration.
2013-06-20 19:26:31 +02:00
Eelco Dolstra 2754a07ead nix-store -q --roots: Respect the gc-keep-outputs/gc-keep-derivations settings
So if a path is not garbage solely because it's reachable from a root
due to the gc-keep-outputs or gc-keep-derivations settings, ‘nix-store
-q --roots’ now shows that root.
2012-12-20 18:41:44 +01:00
Eelco Dolstra b7fd2c2822 Use "#pragma once" to prevent repeated header file inclusion 2012-07-18 14:59:03 -04:00
Eelco Dolstra 93227ff65c * Eliminate all uses of the global variable ‘store’ from libstore.
This should also fix:

    nix-instantiate: ./../boost/shared_ptr.hpp:254: T* boost::shared_ptr<T>::operator->() const [with T = nix::StoreAPI]: Assertion `px != 0' failed.

  which was caused by hashDerivationModulo() calling the ‘store’
  object (during store upgrades) before openStore() assigned it.
2011-08-31 21:11:50 +00:00
Eelco Dolstra bdf089f463 * Before a build, show the disk space that the downloaded store paths
will approximately require.
2010-11-17 14:31:42 +00:00
Eelco Dolstra fdcaf37361 * Made `nix-store -qR --include-outputs' much faster if there are
multiple paths specified on the command line (from O(n * m) to O(n +
  m), where n is the number of arguments and m is the size of the
  closure).
2010-01-25 17:18:44 +00:00
Eelco Dolstra c4f98941ed * nix-env --dry-run: show the total size of the substituter
downloads.
2008-08-04 12:29:04 +00:00
Eelco Dolstra 03427e76f1 * querySubstitutablePathInfo: work properly when run via the daemon.
* --dry-run: print the paths that we don't know how to build/substitute.
2008-08-04 11:44:50 +00:00
Eelco Dolstra 75068e7d75 * Use a proper namespace.
* Optimise header file usage a bit.
* Compile the parser as C++.
2006-09-04 21:06:23 +00:00
Eelco Dolstra c8bfb11b34 * `nix-env (-i|-u) --dry-run' now shows exactly which missing paths
will be built or substituted.
2006-03-06 11:21:15 +00:00