#include <nlohmann/json.hpp>
#include <regex>
#include <absl/strings/ascii.h>
#include <absl/strings/match.h>
#include <absl/strings/str_split.h>
#include <glog/logging.h>
#include <sys/time.h>
#include "libexpr/eval-inline.hh"
#include "libexpr/primops.hh"
#include "libstore/download.hh"
#include "libstore/pathlocks.hh"
#include "libstore/store-api.hh"
using namespace std::string_literals;
namespace nix {
struct HgInfo {
Path storePath;
std::string branch;
std::string rev;
uint64_t revCount = 0;
};
std::regex commitHashRegex("^[0-9a-fA-F]{40}$");
HgInfo exportMercurial(ref<Store> store, const std::string& uri,
std::string rev, const std::string& name) {
if (evalSettings.pureEval && rev == "")
throw Error(
"in pure evaluation mode, 'fetchMercurial' requires a Mercurial "
"revision");
if (rev == "" && absl::StartsWith(uri, "/") && pathExists(uri + "/.hg")) {
bool clean = runProgram("hg", true,
{"status", "-R", uri, "--modified", "--added",
"--removed"}) == "";
if (!clean) {
/* This is an unclean working tree. So copy all tracked
files. */
DLOG(INFO) << "copying unclean Mercurial working tree '" << uri << "'";
HgInfo hgInfo;
hgInfo.rev = "0000000000000000000000000000000000000000";
hgInfo.branch = absl::StripTrailingAsciiWhitespace(
runProgram("hg", true, {"branch", "-R", uri}));
std::set<std::string> files = absl::StrSplit(
runProgram("hg", true,
{"status", "-R", uri, "--clean", "--modified", "--added",
"--no-status", "--print0"}),
absl::ByChar('\0'), absl::SkipEmpty());
PathFilter filter = [&](const Path& p) -> bool {
assert(absl::StartsWith(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() && absl::StartsWith(*i, prefix);
}
return files.count(file);
};
hgInfo.storePath =
store->addToStore("source", uri, true, htSHA256, filter);
return hgInfo;
}
}
if (rev == "") {
rev = "default";
}
Path cacheDir = fmt("%s/nix/hg/%s", getCacheDir(),
hashString(htSHA256, uri).to_string(Base32, false));
Path stampFile = fmt("%s/.hg/%s.stamp", cacheDir,
hashString(htSHA512, rev).to_string(Base32, false));
/* If we haven't pulled this repo less than ‘tarball-ttl’ seconds,
do so now. */
time_t now = time(0);
struct stat st;
if (stat(stampFile.c_str(), &st) != 0 ||
(uint64_t)st.st_mtime + settings.tarballTtl <= (uint64_t)now) {
/* Except that if this is a commit hash that we already have,
we don't have to pull again. */
if (!(std::regex_match(rev, commitHashRegex) && pathExists(cacheDir) &&
runProgram(RunOptions("hg", {"log", "-R", cacheDir, "-r", rev,
"--template", "1"})
.killStderr(true))
.second == "1")) {
DLOG(INFO) << "fetching Mercurial repository '" << uri << "'";
if (pathExists(cacheDir)) {
try {
runProgram("hg", true, {"pull", "-R", cacheDir, "--", uri});
} catch (ExecError& e) {
std::string transJournal = cacheDir + "/.hg/store/journal";
/* hg throws "abandoned transaction" error only if this file exists */
if (pathExists(transJournal)) {
runProgram("hg", true, {"recover", "-R", cacheDir});
runProgram("hg", true, {"pull", "-R", cacheDir, "--", uri});
} else {
throw ExecError(e.status,
fmt("'hg pull' %s", statusToString(e.status)));
}
}
} else {
createDirs(dirOf(cacheDir));
runProgram("hg", true, {"clone", "--noupdate", "--", uri, cacheDir});
}
}
writeFile(stampFile, "");
}
std::vector<std::string> tokens =
absl::StrSplit(runProgram("hg", true,
{"log", "-R", cacheDir, "-r", rev, "--template",
"{node} {rev} {branch}"}),
absl::ByAnyChar(" \t\n\r"), absl::SkipEmpty());
assert(tokens.size() == 3);
HgInfo hgInfo;
hgInfo.rev = tokens[0];
hgInfo.revCount = std::stoull(tokens[1]);
hgInfo.branch = tokens[2];
std::string storeLinkName =
hashString(htSHA512, name + std::string("\0"s) + hgInfo.rev)
.to_string(Base32, false);
Path storeLink = fmt("%s/.hg/%s.link", cacheDir, storeLinkName);
try {
auto json = nlohmann::json::parse(readFile(storeLink));
assert(json["name"] == name && json["rev"] == hgInfo.rev);
hgInfo.storePath = json["storePath"];
if (store->isValidPath(hgInfo.storePath)) {
DLOG(INFO) << "using cached Mercurial store path '" << hgInfo.storePath
<< "'";
return hgInfo;
}
} catch (SysError& e) {
if (e.errNo != ENOENT) {
throw;
}
}
Path tmpDir = createTempDir();
AutoDelete delTmpDir(tmpDir, true);
runProgram("hg", true, {"archive", "-R", cacheDir, "-r", rev, tmpDir});
deletePath(tmpDir + "/.hg_archival.txt");
hgInfo.storePath = store->addToStore(name, tmpDir);
nlohmann::json json;
json["storePath"] = hgInfo.storePath;
json["uri"] = uri;
json["name"] = name;
json["branch"] = hgInfo.branch;
json["rev"] = hgInfo.rev;
json["revCount"] = hgInfo.revCount;
writeFile(storeLink, json.dump());
return hgInfo;
}
static void prim_fetchMercurial(EvalState& state, const Pos& pos, Value** args,
Value& v) {
std::string url;
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_iter : *args[0]->attrs) {
auto& attr = attr_iter.second;
std::string n(attr.name);
if (n == "url")
url =
state.coerceToString(*attr.pos, *attr.value, context, false, false);
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 'fetchMercurial', 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 hgInfo = exportMercurial(state.store, url, rev, name);
state.mkAttrs(v, 8);
mkString(*state.allocAttr(v, state.sOutPath), hgInfo.storePath,
PathSet({hgInfo.storePath}));
mkString(*state.allocAttr(v, state.symbols.Create("branch")), hgInfo.branch);
mkString(*state.allocAttr(v, state.symbols.Create("rev")), hgInfo.rev);
mkString(*state.allocAttr(v, state.symbols.Create("shortRev")),
std::string(hgInfo.rev, 0, 12));
mkInt(*state.allocAttr(v, state.symbols.Create("revCount")), hgInfo.revCount);
if (state.allowedPaths) {
state.allowedPaths->insert(state.store->toRealPath(hgInfo.storePath));
}
}
static RegisterPrimOp r("fetchMercurial", 1, prim_fetchMercurial);
} // namespace nix
