Commit graph

7 commits

Author SHA1 Message Date
Eelco Dolstra 759947bf72 StorePath: Rewrite in C++
On nix-env -qa -f '<nixpkgs>', this reduces maximum RSS by 20970 KiB
and runtime by 0.8%. This is mostly because we're not parsing the hash
part as a hash anymore (just validating that it consists of base-32
characters).

Also, replace storePathToHash() by StorePath::hashPart().
2020-06-16 14:28:41 +02:00
Eelco Dolstra 367577d9a6 Fix macOS build 2020-03-30 17:00:40 +02:00
Eelco Dolstra bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00
John Ericson fef9f5653b Remove mentions of libformat, it no longer exists 2019-01-05 14:31:29 -05:00
Jude Taylor 60f4b25d7d make inclusion conditional 2016-08-14 19:10:38 -07:00
Jude Taylor 596e4a5693 remove old traces of resolve-system-dependencies 2016-08-13 15:27:49 -07:00
Jude Taylor 2df9a972fc resolve-system-dependencies: implement in C++ 2016-08-13 11:36:22 -07:00