Support channel:<channel-name> URIs

For convenience, you can now say

  $ nix-env -f channel:nixos-16.03 -iA hello

instead of

  $ nix-env -f https://nixos.org/channels/nixos-16.03/nixexprs.tar.xz -iA hello

Similarly,

  $ nix-shell -I channel:nixpkgs-unstable -p hello
  $ nix-build channel:nixos-15.09 -A hello

Abstracting over the NixOS/Nixpkgs channels location also allows us to
use a more efficient transport (e.g. Git) in the future.
This commit is contained in:
Eelco Dolstra 2016-04-14 16:27:48 +02:00
parent 363f37d084
commit c045630522

View file

@ -18,6 +18,14 @@ double getTime()
return tv.tv_sec + (tv.tv_usec / 1000000.0);
}
std::string resolveUri(const std::string & uri)
{
if (uri.compare(0, 8, "channel:") == 0)
return "https://nixos.org/channels/" + std::string(uri, 8) + "/nixexprs.tar.xz";
else
return uri;
}
struct CurlDownloader : public Downloader
{
CURL * curl;
@ -197,7 +205,7 @@ struct CurlDownloader : public Downloader
DownloadResult download(string url, const DownloadOptions & options) override
{
DownloadResult res;
if (fetch(url, options)) {
if (fetch(resolveUri(url), options)) {
res.cached = false;
res.data = data;
} else
@ -207,15 +215,15 @@ struct CurlDownloader : public Downloader
}
};
ref<Downloader> makeDownloader()
{
return make_ref<CurlDownloader>();
}
Path Downloader::downloadCached(ref<Store> store, const string & url, bool unpack)
Path Downloader::downloadCached(ref<Store> store, const string & url_, bool unpack)
{
auto url = resolveUri(url_);
Path cacheDir = getEnv("XDG_CACHE_HOME", getEnv("HOME", "") + "/.cache") + "/nix/tarballs";
createDirs(cacheDir);
@ -300,10 +308,11 @@ Path Downloader::downloadCached(ref<Store> store, const string & url, bool unpac
bool isUri(const string & s)
{
if (s.compare(0, 8, "channel:") == 0) return true;
size_t pos = s.find("://");
if (pos == string::npos) return false;
string scheme(s, 0, pos);
return scheme == "http" || scheme == "https" || scheme == "file";
return scheme == "http" || scheme == "https" || scheme == "file" || scheme == "channel";
}