diff options
Diffstat (limited to 'third_party/nix/src/libexpr/primops/fetchGit.cc')
| -rw-r--r-- | third_party/nix/src/libexpr/primops/fetchGit.cc | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/third_party/nix/src/libexpr/primops/fetchGit.cc b/third_party/nix/src/libexpr/primops/fetchGit.cc new file mode 100644 index 0000000000..90f600284b --- /dev/null +++ b/third_party/nix/src/libexpr/primops/fetchGit.cc @@ -0,0 +1,247 @@ +#include "primops.hh" +#include "eval-inline.hh" +#include "download.hh" +#include "store-api.hh" +#include "pathlocks.hh" +#include "hash.hh" + +#include <sys/time.h> + +#include <regex> + +#include <nlohmann/json.hpp> + +using namespace std::string_literals; + +namespace nix { + +struct GitInfo +{ + Path storePath; + std::string rev; + std::string shortRev; + uint64_t revCount = 0; +}; + +std::regex revRegex("^[0-9a-fA-F]{40}$"); + +GitInfo exportGit(ref<Store> store, const std::string & uri, + std::optional<std::string> ref, std::string rev, + const std::string & name) +{ + if (evalSettings.pureEval && rev == "") + throw Error("in pure evaluation mode, 'fetchGit' requires a Git revision"); + + if (!ref && rev == "" && hasPrefix(uri, "/") && pathExists(uri + "/.git")) { + + bool clean = true; + + try { + runProgram("git", true, { "-C", uri, "diff-index", "--quiet", "HEAD", "--" }); + } catch (ExecError & e) { + if (!WIFEXITED(e.status) || WEXITSTATUS(e.status) != 1) throw; + clean = false; + } + + if (!clean) { + + /* This is an unclean working tree. So copy all tracked + files. */ + + GitInfo gitInfo; + gitInfo.rev = "0000000000000000000000000000000000000000"; + gitInfo.shortRev = std::string(gitInfo.rev, 0, 7); + + auto files = tokenizeString<std::set<std::string>>( + runProgram("git", true, { "-C", uri, "ls-files", "-z" }), "\0"s); + + PathFilter filter = [&](const Path & p) -> bool { + assert(hasPrefix(p, uri)); + std::string file(p, uri.size() + 1); + + auto st = lstat(p); + + if (S_ISDIR(st.st_mode)) { + auto prefix = file + "/"; + auto i = files.lower_bound(prefix); + return i != files.end() && hasPrefix(*i, prefix); + } + + return files.count(file); + }; + + gitInfo.storePath = store->addToStore("source", uri, true, htSHA256, filter); + + return gitInfo; + } + + // clean working tree, but no ref or rev specified. Use 'HEAD'. + rev = chomp(runProgram("git", true, { "-C", uri, "rev-parse", "HEAD" })); + ref = "HEAD"s; + } + + if (!ref) ref = "HEAD"s; + + if (rev != "" && !std::regex_match(rev, revRegex)) + throw Error("invalid Git revision '%s'", rev); + + deletePath(getCacheDir() + "/nix/git"); + + Path cacheDir = getCacheDir() + "/nix/gitv2/" + hashString(htSHA256, uri).to_string(Base32, false); + + if (!pathExists(cacheDir)) { + createDirs(dirOf(cacheDir)); + runProgram("git", true, { "init", "--bare", cacheDir }); + } + + Path localRefFile; + if (ref->compare(0, 5, "refs/") == 0) + localRefFile = cacheDir + "/" + *ref; + else + localRefFile = cacheDir + "/refs/heads/" + *ref; + + bool doFetch; + time_t now = time(0); + /* If a rev was specified, we need to fetch if it's not in the + repo. */ + if (rev != "") { + try { + runProgram("git", true, { "-C", cacheDir, "cat-file", "-e", rev }); + doFetch = false; + } catch (ExecError & e) { + if (WIFEXITED(e.status)) { + doFetch = true; + } else { + throw; + } + } + } else { + /* If the local ref is older than ‘tarball-ttl’ seconds, do a + git fetch to update the local ref to the remote ref. */ + struct stat st; + doFetch = stat(localRefFile.c_str(), &st) != 0 || + (uint64_t) st.st_mtime + settings.tarballTtl <= (uint64_t) now; + } + if (doFetch) + { + Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching Git repository '%s'", uri)); + + // FIXME: git stderr messes up our progress indicator, so + // we're using --quiet for now. Should process its stderr. + runProgram("git", true, { "-C", cacheDir, "fetch", "--quiet", "--force", "--", uri, fmt("%s:%s", *ref, *ref) }); + + struct timeval times[2]; + times[0].tv_sec = now; + times[0].tv_usec = 0; + times[1].tv_sec = now; + times[1].tv_usec = 0; + + utimes(localRefFile.c_str(), times); + } + + // FIXME: check whether rev is an ancestor of ref. + GitInfo gitInfo; + gitInfo.rev = rev != "" ? rev : chomp(readFile(localRefFile)); + gitInfo.shortRev = std::string(gitInfo.rev, 0, 7); + + printTalkative("using revision %s of repo '%s'", gitInfo.rev, uri); + + std::string storeLinkName = hashString(htSHA512, name + std::string("\0"s) + gitInfo.rev).to_string(Base32, false); + Path storeLink = cacheDir + "/" + storeLinkName + ".link"; + PathLocks storeLinkLock({storeLink}, fmt("waiting for lock on '%1%'...", storeLink)); // FIXME: broken + + try { + auto json = nlohmann::json::parse(readFile(storeLink)); + + assert(json["name"] == name && json["rev"] == gitInfo.rev); + + gitInfo.storePath = json["storePath"]; + + if (store->isValidPath(gitInfo.storePath)) { + gitInfo.revCount = json["revCount"]; + return gitInfo; + } + + } catch (SysError & e) { + if (e.errNo != ENOENT) throw; + } + + // FIXME: should pipe this, or find some better way to extract a + // revision. + auto tar = runProgram("git", true, { "-C", cacheDir, "archive", gitInfo.rev }); + + Path tmpDir = createTempDir(); + AutoDelete delTmpDir(tmpDir, true); + + runProgram("tar", true, { "x", "-C", tmpDir }, tar); + + gitInfo.storePath = store->addToStore(name, tmpDir); + + gitInfo.revCount = std::stoull(runProgram("git", true, { "-C", cacheDir, "rev-list", "--count", gitInfo.rev })); + + nlohmann::json json; + json["storePath"] = gitInfo.storePath; + json["uri"] = uri; + json["name"] = name; + json["rev"] = gitInfo.rev; + json["revCount"] = gitInfo.revCount; + + writeFile(storeLink, json.dump()); + + return gitInfo; +} + +static void prim_fetchGit(EvalState & state, const Pos & pos, Value * * args, Value & v) +{ + std::string url; + std::optional<std::string> ref; + std::string rev; + std::string name = "source"; + PathSet context; + + state.forceValue(*args[0]); + + if (args[0]->type == tAttrs) { + + state.forceAttrs(*args[0], pos); + + for (auto & attr : *args[0]->attrs) { + string n(attr.name); + if (n == "url") + url = state.coerceToString(*attr.pos, *attr.value, context, false, false); + else if (n == "ref") + ref = state.forceStringNoCtx(*attr.value, *attr.pos); + else if (n == "rev") + rev = state.forceStringNoCtx(*attr.value, *attr.pos); + else if (n == "name") + name = state.forceStringNoCtx(*attr.value, *attr.pos); + else + throw EvalError("unsupported argument '%s' to 'fetchGit', at %s", attr.name, *attr.pos); + } + + if (url.empty()) + throw EvalError(format("'url' argument required, at %1%") % pos); + + } else + url = state.coerceToString(pos, *args[0], context, false, false); + + // FIXME: git externals probably can be used to bypass the URI + // whitelist. Ah well. + state.checkURI(url); + + auto gitInfo = exportGit(state.store, url, ref, rev, name); + + state.mkAttrs(v, 8); + mkString(*state.allocAttr(v, state.sOutPath), gitInfo.storePath, PathSet({gitInfo.storePath})); + mkString(*state.allocAttr(v, state.symbols.create("rev")), gitInfo.rev); + mkString(*state.allocAttr(v, state.symbols.create("shortRev")), gitInfo.shortRev); + mkInt(*state.allocAttr(v, state.symbols.create("revCount")), gitInfo.revCount); + v.attrs->sort(); + + if (state.allowedPaths) + state.allowedPaths->insert(state.store->toRealPath(gitInfo.storePath)); +} + +static RegisterPrimOp r("fetchGit", 1, prim_fetchGit); + +} |