nix-super/src/libexpr/flake/flakeref.cc

294 lines
9.1 KiB
C++

#include "flakeref.hh"
#include "store-api.hh"
#include "url.hh"
#include "url-parts.hh"
#include "fetchers.hh"
#include "registry.hh"
namespace nix {
#if 0
// 'dir' path elements cannot start with a '.'. We also reject
// potentially dangerous characters like ';'.
const static std::string subDirElemRegex = "(?:[a-zA-Z0-9_-]+[a-zA-Z0-9._-]*)";
const static std::string subDirRegex = subDirElemRegex + "(?:/" + subDirElemRegex + ")*";
#endif
std::string FlakeRef::to_string() const
{
std::map<std::string, std::string> extraQuery;
if (subdir != "")
extraQuery.insert_or_assign("dir", subdir);
return input.toURLString(extraQuery);
}
fetchers::Attrs FlakeRef::toAttrs() const
{
auto attrs = input.toAttrs();
if (subdir != "")
attrs.emplace("dir", subdir);
return attrs;
}
std::ostream & operator << (std::ostream & str, const FlakeRef & flakeRef)
{
str << flakeRef.to_string();
return str;
}
bool FlakeRef::operator ==(const FlakeRef & other) const
{
return input == other.input && subdir == other.subdir;
}
FlakeRef FlakeRef::resolve(ref<Store> store) const
{
auto [input2, extraAttrs] = lookupInRegistries(store, input);
return FlakeRef(std::move(input2), fetchers::maybeGetStrAttr(extraAttrs, "dir").value_or(subdir));
}
FlakeRef parseFlakeRef(
const std::string & url,
const std::optional<Path> & baseDir,
bool allowMissing,
bool isFlake)
{
auto [flakeRef, fragment] = parseFlakeRefWithFragment(url, baseDir, allowMissing, isFlake);
if (fragment != "")
throw Error("unexpected fragment '%s' in flake reference '%s'", fragment, url);
return flakeRef;
}
std::optional<FlakeRef> maybeParseFlakeRef(
const std::string & url, const std::optional<Path> & baseDir)
{
try {
return parseFlakeRef(url, baseDir);
} catch (Error &) {
return {};
}
}
std::pair<FlakeRef, std::string> parsePathFlakeRefWithFragment(
const std::string & url,
const std::optional<Path> & baseDir,
bool allowMissing,
bool isFlake)
{
std::string path = url;
std::string fragment = "";
std::map<std::string, std::string> query;
auto pathEnd = url.find_first_of("#?");
auto fragmentStart = pathEnd;
if (pathEnd != std::string::npos && url[pathEnd] == '?') {
fragmentStart = url.find("#");
}
if (pathEnd != std::string::npos) {
path = url.substr(0, pathEnd);
}
if (fragmentStart != std::string::npos) {
fragment = percentDecode(url.substr(fragmentStart+1));
}
if (pathEnd != std::string::npos && fragmentStart != std::string::npos) {
query = decodeQuery(url.substr(pathEnd+1, fragmentStart));
}
if (baseDir) {
/* Check if 'url' is a path (either absolute or relative
to 'baseDir'). If so, search upward to the root of the
repo (i.e. the directory containing .git). */
path = absPath(path, baseDir);
if (isFlake) {
if (!allowMissing && !pathExists(path + "/flake.nix")){
notice("path '%s' does not contain a 'flake.nix', searching up",path);
// Save device to detect filesystem boundary
dev_t device = lstat(path).st_dev;
bool found = false;
while (path != "/") {
if (pathExists(path + "/flake.nix")) {
found = true;
break;
} else if (pathExists(path + "/.git"))
throw Error("path '%s' is not part of a flake (neither it nor its parent directories contain a 'flake.nix' file)", path);
else {
if (lstat(path).st_dev != device)
throw Error("unable to find a flake before encountering filesystem boundary at '%s'", path);
}
path = dirOf(path);
}
if (!found)
throw BadURL("could not find a flake.nix file");
}
if (!S_ISDIR(lstat(path).st_mode))
throw BadURL("path '%s' is not a flake (because it's not a directory)", path);
if (!allowMissing && !pathExists(path + "/flake.nix"))
throw BadURL("path '%s' is not a flake (because it doesn't contain a 'flake.nix' file)", path);
auto flakeRoot = path;
std::string subdir;
while (flakeRoot != "/") {
if (pathExists(flakeRoot + "/.git")) {
auto base = std::string("git+file://") + flakeRoot;
auto parsedURL = ParsedURL{
.url = base, // FIXME
.base = base,
.scheme = "git+file",
.authority = "",
.path = flakeRoot,
.query = query,
};
if (subdir != "") {
if (parsedURL.query.count("dir"))
throw Error("flake URL '%s' has an inconsistent 'dir' parameter", url);
parsedURL.query.insert_or_assign("dir", subdir);
}
if (pathExists(flakeRoot + "/.git/shallow"))
parsedURL.query.insert_or_assign("shallow", "1");
return std::make_pair(
FlakeRef(fetchers::Input::fromURL(parsedURL), getOr(parsedURL.query, "dir", "")),
fragment);
}
subdir = std::string(baseNameOf(flakeRoot)) + (subdir.empty() ? "" : "/" + subdir);
flakeRoot = dirOf(flakeRoot);
}
}
} else {
if (!hasPrefix(path, "/"))
throw BadURL("flake reference '%s' is not an absolute path", url);
path = canonPath(path + "/" + getOr(query, "dir", ""));
}
fetchers::Attrs attrs;
attrs.insert_or_assign("type", "path");
attrs.insert_or_assign("path", path);
return std::make_pair(FlakeRef(fetchers::Input::fromAttrs(std::move(attrs)), ""), fragment);
};
/* Check if 'url' is a flake ID. This is an abbreviated syntax for
'flake:<flake-id>?ref=<ref>&rev=<rev>'. */
std::optional<std::pair<FlakeRef, std::string>> parseFlakeIdRef(
const std::string & url,
bool isFlake
)
{
std::smatch match;
static std::regex flakeRegex(
"((" + flakeIdRegexS + ")(?:/(?:" + refAndOrRevRegex + "))?)"
+ "(?:#(" + queryRegex + "))?",
std::regex::ECMAScript);
if (std::regex_match(url, match, flakeRegex)) {
auto parsedURL = ParsedURL{
.url = url,
.base = "flake:" + match.str(1),
.scheme = "flake",
.authority = "",
.path = match[1],
};
return std::make_pair(
FlakeRef(fetchers::Input::fromURL(parsedURL, isFlake), ""),
percentDecode(match.str(6)));
}
return {};
}
std::optional<std::pair<FlakeRef, std::string>> parseURLFlakeRef(
const std::string & url,
const std::optional<Path> & baseDir,
bool isFlake
)
{
ParsedURL parsedURL;
try {
parsedURL = parseURL(url);
} catch (BadURL &) {
return std::nullopt;
}
std::string fragment;
std::swap(fragment, parsedURL.fragment);
auto input = fetchers::Input::fromURL(parsedURL, isFlake);
input.parent = baseDir;
return std::make_pair(
FlakeRef(std::move(input), getOr(parsedURL.query, "dir", "")),
fragment);
}
std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
const std::string & url,
const std::optional<Path> & baseDir,
bool allowMissing,
bool isFlake)
{
using namespace fetchers;
std::smatch match;
if (auto res = parseFlakeIdRef(url, isFlake)) {
return *res;
} else if (auto res = parseURLFlakeRef(url, baseDir, isFlake)) {
return *res;
} else {
return parsePathFlakeRefWithFragment(url, baseDir, allowMissing, isFlake);
}
}
std::optional<std::pair<FlakeRef, std::string>> maybeParseFlakeRefWithFragment(
const std::string & url, const std::optional<Path> & baseDir)
{
try {
return parseFlakeRefWithFragment(url, baseDir);
} catch (Error & e) {
return {};
}
}
FlakeRef FlakeRef::fromAttrs(const fetchers::Attrs & attrs)
{
auto attrs2(attrs);
attrs2.erase("dir");
return FlakeRef(
fetchers::Input::fromAttrs(std::move(attrs2)),
fetchers::maybeGetStrAttr(attrs, "dir").value_or(""));
}
std::pair<StorePath, FlakeRef> FlakeRef::fetchTree(ref<Store> store) const
{
auto [storePath, lockedInput] = input.fetch(store);
return {std::move(storePath), FlakeRef(std::move(lockedInput), subdir)};
}
std::tuple<FlakeRef, std::string, ExtendedOutputsSpec> parseFlakeRefWithFragmentAndExtendedOutputsSpec(
const std::string & url,
const std::optional<Path> & baseDir,
bool allowMissing,
bool isFlake)
{
auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse(url);
auto [flakeRef, fragment] = parseFlakeRefWithFragment(std::string { prefix }, baseDir, allowMissing, isFlake);
return {std::move(flakeRef), fragment, std::move(extendedOutputsSpec)};
}
std::regex flakeIdRegex(flakeIdRegexS, std::regex::ECMAScript);
}