lix/src/libexpr/primops/fetchMercurial.cc
Eelco Dolstra 272b58220d
Enforce use of immutable flakes in pure mode
... plus a temporary hack to allow impure flakes at top-level for the
default installation source.
2019-02-12 21:07:48 +01:00

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#include "primops.hh"
#include "eval-inline.hh"
#include "download.hh"
#include "store-api.hh"
#include "pathlocks.hh"
#include <sys/time.h>
#include <regex>
#include <nlohmann/json.hpp>
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 (rev == "" && hasPrefix(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. */
printTalkative("copying unclean Mercurial working tree '%s'", uri);
HgInfo hgInfo;
hgInfo.rev = "0000000000000000000000000000000000000000";
hgInfo.branch = chomp(runProgram("hg", true, { "branch", "-R", uri }));
auto files = tokenizeString<std::set<std::string>>(
runProgram("hg", true, { "status", "-R", uri, "--clean", "--modified", "--added", "--no-status", "--print0" }), "\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);
};
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 ||
st.st_mtime + settings.tarballTtl <= 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"))
{
Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching Mercurial repository '%s'", uri));
if (pathExists(cacheDir)) {
try {
runProgram("hg", true, { "pull", "-R", cacheDir, "--", uri });
}
catch (ExecError & e){
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("program hg '%1%' ", statusToString(e.status)));
}
}
} else {
createDirs(dirOf(cacheDir));
runProgram("hg", true, { "clone", "--noupdate", "--", uri, cacheDir });
}
}
writeFile(stampFile, "");
}
auto tokens = tokenizeString<std::vector<std::string>>(
runProgram("hg", true, { "log", "-R", cacheDir, "-r", rev, "--template", "{node} {rev} {branch}" }));
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)) {
printTalkative("using cached Mercurial store path '%s'", 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 : *args[0]->attrs) {
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);
if (evalSettings.pureEval && rev == "")
throw Error("in pure evaluation mode, 'fetchMercurial' requires a Mercurial revision");
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);
v.attrs->sort();
if (state.allowedPaths)
state.allowedPaths->insert(hgInfo.storePath);
}
static RegisterPrimOp r("fetchMercurial", 1, prim_fetchMercurial);
}