Support Git repos in the Nix path

E.g.

  $ nix-build -I nixpkgs=git://github.com/NixOS/nixpkgs '<nixpkgs>' -A hello

This is not extremely useful yet because you can't specify a
branch/revision.
This commit is contained in:
Eelco Dolstra 2016-04-29 21:04:40 +02:00
parent 38539b943a
commit d8bf0d4859
5 changed files with 71 additions and 37 deletions

View file

@ -520,9 +520,10 @@ formal
#include <fcntl.h>
#include <unistd.h>
#include <eval.hh>
#include <download.hh>
#include <store-api.hh>
#include "eval.hh"
#include "download.hh"
#include "store-api.hh"
#include "primops/fetchgit.hh"
namespace nix {
@ -657,6 +658,10 @@ std::pair<bool, std::string> EvalState::resolveSearchPathElem(const SearchPathEl
if (isUri(elem.second)) {
try {
if (hasPrefix(elem.second, "git://") || hasSuffix(elem.second, ".git"))
// FIXME: support specifying revision/branch
res = { true, exportGit(store, elem.second, "master") };
else
res = { true, makeDownloader()->downloadCached(store, elem.second, true) };
} catch (DownloadError & e) {
printMsg(lvlError, format("warning: Nix search path entry %1% cannot be downloaded, ignoring") % elem.second);

View file

@ -5,6 +5,43 @@
namespace nix {
Path exportGit(ref<Store> store, const std::string & uri, const std::string & rev)
{
if (!isUri(uri))
throw EvalError(format("%s is not a valid URI") % uri);
Path cacheDir = getCacheDir() + "/nix/git";
if (!pathExists(cacheDir)) {
createDirs(cacheDir);
runProgram("git", true, { "init", "--bare", cacheDir });
}
Activity act(*logger, lvlInfo, format("fetching Git repository %s") % uri);
std::string localRef = "pid-" + std::to_string(getpid());
Path localRefFile = cacheDir + "/refs/heads/" + localRef;
runProgram("git", true, { "-C", cacheDir, "fetch", uri, rev + ":" + localRef });
std::string commitHash = chomp(readFile(localRefFile));
unlink(localRefFile.c_str());
debug(format("got revision %s") % commitHash);
// FIXME: should pipe this, or find some better way to extract a
// revision.
auto tar = runProgram("git", true, { "-C", cacheDir, "archive", commitHash });
Path tmpDir = createTempDir();
AutoDelete delTmpDir(tmpDir, true);
runProgram("tar", true, { "x", "-C", tmpDir }, tar);
return store->addToStore("git-export", tmpDir);
}
static void prim_fetchgit(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
// FIXME: cut&paste from fetch().
@ -35,39 +72,7 @@ static void prim_fetchgit(EvalState & state, const Pos & pos, Value * * args, Va
} else
url = state.forceStringNoCtx(*args[0], pos);
if (!isUri(url))
throw EvalError(format("%s is not a valid URI, at %s") % url % pos);
Path cacheDir = getCacheDir() + "/nix/git";
if (!pathExists(cacheDir)) {
createDirs(cacheDir);
runProgram("git", true, { "init", "--bare", cacheDir });
}
Activity act(*logger, lvlInfo, format("fetching Git repository %s") % url);
std::string localRef = "pid-" + std::to_string(getpid());
Path localRefFile = cacheDir + "/refs/heads/" + localRef;
runProgram("git", true, { "-C", cacheDir, "fetch", url, rev + ":" + localRef });
std::string commitHash = chomp(readFile(localRefFile));
unlink(localRefFile.c_str());
debug(format("got revision %s") % commitHash);
// FIXME: should pipe this, or find some better way to extract a
// revision.
auto tar = runProgram("git", true, { "-C", cacheDir, "archive", commitHash });
Path tmpDir = createTempDir();
AutoDelete delTmpDir(tmpDir, true);
runProgram("tar", true, { "x", "-C", tmpDir }, tar);
Path storePath = state.store->addToStore("git-export", tmpDir);
Path storePath = exportGit(state.store, url, rev);
mkString(v, storePath, PathSet({storePath}));
}

View file

@ -0,0 +1,14 @@
#pragma once
#include <string>
#include "ref.hh"
namespace nix {
class Store;
Path exportGit(ref<Store> store,
const std::string & uri, const std::string & rev);
}

View file

@ -1082,6 +1082,12 @@ bool statusOk(int status)
}
bool hasPrefix(const string & s, const string & suffix)
{
return s.compare(0, suffix.size(), suffix) == 0;
}
bool hasSuffix(const string & s, const string & suffix)
{
return s.size() >= suffix.size() && string(s, s.size() - suffix.size()) == suffix;

View file

@ -333,6 +333,10 @@ template<class N> bool string2Float(const string & s, N & n)
}
/* Return true iff `s' starts with `prefix'. */
bool hasPrefix(const string & s, const string & prefix);
/* Return true iff `s' ends in `suffix'. */
bool hasSuffix(const string & s, const string & suffix);