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Move libflake/flake/* to libflake

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Eelco Dolstra 2025-04-23 17:11:55 +02:00
parent 876f676d90
commit bc67e47298
9 changed files with 12 additions and 12 deletions
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src/libflake/lockfile.cc Normal file
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#include <unordered_set>
#include "nix/fetchers/fetch-settings.hh"
#include "nix/flake/settings.hh"
#include "nix/flake/lockfile.hh"
#include "nix/store/store-api.hh"
#include "nix/util/strings.hh"
#include <algorithm>
#include <iomanip>
#include <iterator>
#include <nlohmann/json.hpp>
namespace nix::flake {
static FlakeRef getFlakeRef(
const fetchers::Settings & fetchSettings,
const nlohmann::json & json,
const char * attr,
const char * info)
{
auto i = json.find(attr);
if (i != json.end()) {
auto attrs = fetchers::jsonToAttrs(*i);
// FIXME: remove when we drop support for version 5.
if (info) {
auto j = json.find(info);
if (j != json.end()) {
for (auto k : fetchers::jsonToAttrs(*j))
attrs.insert_or_assign(k.first, k.second);
}
}
return FlakeRef::fromAttrs(fetchSettings, attrs);
}
throw Error("attribute '%s' missing in lock file", attr);
}
LockedNode::LockedNode(
const fetchers::Settings & fetchSettings,
const nlohmann::json & json)
: lockedRef(getFlakeRef(fetchSettings, json, "locked", "info")) // FIXME: remove "info"
, originalRef(getFlakeRef(fetchSettings, json, "original", nullptr))
, isFlake(json.find("flake") != json.end() ? (bool) json["flake"] : true)
, parentInputAttrPath(json.find("parent") != json.end() ? (std::optional<InputAttrPath>) json["parent"] : std::nullopt)
{
if (!lockedRef.input.isLocked() && !lockedRef.input.isRelative()) {
if (lockedRef.input.getNarHash())
warn(
"Lock file entry '%s' is unlocked (e.g. lacks a Git revision) but does have a NAR hash. "
"This is deprecated since such inputs are verifiable but may not be reproducible.",
lockedRef.to_string());
else
throw Error("Lock file contains unlocked input '%s'. Use '--allow-dirty-locks' to accept this lock file.",
fetchers::attrsToJSON(lockedRef.input.toAttrs()));
}
// For backward compatibility, lock file entries are implicitly final.
assert(!lockedRef.input.attrs.contains("__final"));
lockedRef.input.attrs.insert_or_assign("__final", Explicit<bool>(true));
}
StorePath LockedNode::computeStorePath(Store & store) const
{
return lockedRef.input.computeStorePath(store);
}
static std::shared_ptr<Node> doFind(const ref<Node> & root, const InputAttrPath & path, std::vector<InputAttrPath> & visited)
{
auto pos = root;
auto found = std::find(visited.cbegin(), visited.cend(), path);
if (found != visited.end()) {
std::vector<std::string> cycle;
std::transform(found, visited.cend(), std::back_inserter(cycle), printInputAttrPath);
cycle.push_back(printInputAttrPath(path));
throw Error("follow cycle detected: [%s]", concatStringsSep(" -> ", cycle));
}
visited.push_back(path);
for (auto & elem : path) {
if (auto i = get(pos->inputs, elem)) {
if (auto node = std::get_if<0>(&*i))
pos = *node;
else if (auto follows = std::get_if<1>(&*i)) {
if (auto p = doFind(root, *follows, visited))
pos = ref(p);
else
return {};
}
} else
return {};
}
return pos;
}
std::shared_ptr<Node> LockFile::findInput(const InputAttrPath & path)
{
std::vector<InputAttrPath> visited;
return doFind(root, path, visited);
}
LockFile::LockFile(
const fetchers::Settings & fetchSettings,
std::string_view contents, std::string_view path)
{
auto json = [=] {
try {
return nlohmann::json::parse(contents);
} catch (const nlohmann::json::parse_error & e) {
throw Error("Could not parse '%s': %s", path, e.what());
}
}();
auto version = json.value("version", 0);
if (version < 5 || version > 7)
throw Error("lock file '%s' has unsupported version %d", path, version);
std::map<std::string, ref<Node>> nodeMap;
std::function<void(Node & node, const nlohmann::json & jsonNode)> getInputs;
getInputs = [&](Node & node, const nlohmann::json & jsonNode)
{
if (jsonNode.find("inputs") == jsonNode.end()) return;
for (auto & i : jsonNode["inputs"].items()) {
if (i.value().is_array()) { // FIXME: remove, obsolete
InputAttrPath path;
for (auto & j : i.value())
path.push_back(j);
node.inputs.insert_or_assign(i.key(), path);
} else {
std::string inputKey = i.value();
auto k = nodeMap.find(inputKey);
if (k == nodeMap.end()) {
auto & nodes = json["nodes"];
auto jsonNode2 = nodes.find(inputKey);
if (jsonNode2 == nodes.end())
throw Error("lock file references missing node '%s'", inputKey);
auto input = make_ref<LockedNode>(fetchSettings, *jsonNode2);
k = nodeMap.insert_or_assign(inputKey, input).first;
getInputs(*input, *jsonNode2);
}
if (auto child = k->second.dynamic_pointer_cast<LockedNode>())
node.inputs.insert_or_assign(i.key(), ref(child));
else
// FIXME: replace by follows node
throw Error("lock file contains cycle to root node");
}
}
};
std::string rootKey = json["root"];
nodeMap.insert_or_assign(rootKey, root);
getInputs(*root, json["nodes"][rootKey]);
// FIXME: check that there are no cycles in version >= 7. Cycles
// between inputs are only possible using 'follows' indirections.
// Once we drop support for version <= 6, we can simplify the code
// a bit since we don't need to worry about cycles.
}
std::pair<nlohmann::json, LockFile::KeyMap> LockFile::toJSON() const
{
nlohmann::json nodes;
KeyMap nodeKeys;
std::unordered_set<std::string> keys;
std::function<std::string(const std::string & key, ref<const Node> node)> dumpNode;
dumpNode = [&](std::string key, ref<const Node> node) -> std::string
{
auto k = nodeKeys.find(node);
if (k != nodeKeys.end())
return k->second;
if (!keys.insert(key).second) {
for (int n = 2; ; ++n) {
auto k = fmt("%s_%d", key, n);
if (keys.insert(k).second) {
key = k;
break;
}
}
}
nodeKeys.insert_or_assign(node, key);
auto n = nlohmann::json::object();
if (!node->inputs.empty()) {
auto inputs = nlohmann::json::object();
for (auto & i : node->inputs) {
if (auto child = std::get_if<0>(&i.second)) {
inputs[i.first] = dumpNode(i.first, *child);
} else if (auto follows = std::get_if<1>(&i.second)) {
auto arr = nlohmann::json::array();
for (auto & x : *follows)
arr.push_back(x);
inputs[i.first] = std::move(arr);
}
}
n["inputs"] = std::move(inputs);
}
if (auto lockedNode = node.dynamic_pointer_cast<const LockedNode>()) {
n["original"] = fetchers::attrsToJSON(lockedNode->originalRef.toAttrs());
n["locked"] = fetchers::attrsToJSON(lockedNode->lockedRef.toAttrs());
/* For backward compatibility, omit the "__final"
attribute. We never allow non-final inputs in lock files
anyway. */
assert(lockedNode->lockedRef.input.isFinal() || lockedNode->lockedRef.input.isRelative());
n["locked"].erase("__final");
if (!lockedNode->isFlake)
n["flake"] = false;
if (lockedNode->parentInputAttrPath)
n["parent"] = *lockedNode->parentInputAttrPath;
}
nodes[key] = std::move(n);
return key;
};
nlohmann::json json;
json["version"] = 7;
json["root"] = dumpNode("root", root);
json["nodes"] = std::move(nodes);
return {json, std::move(nodeKeys)};
}
std::pair<std::string, LockFile::KeyMap> LockFile::to_string() const
{
auto [json, nodeKeys] = toJSON();
return {json.dump(2), std::move(nodeKeys)};
}
std::ostream & operator <<(std::ostream & stream, const LockFile & lockFile)
{
stream << lockFile.toJSON().first.dump(2);
return stream;
}
std::optional<FlakeRef> LockFile::isUnlocked(const fetchers::Settings & fetchSettings) const
{
std::set<ref<const Node>> nodes;
std::function<void(ref<const Node> node)> visit;
visit = [&](ref<const Node> node)
{
if (!nodes.insert(node).second) return;
for (auto & i : node->inputs)
if (auto child = std::get_if<0>(&i.second))
visit(*child);
};
visit(root);
/* Return whether the input is either locked, or, if
`allow-dirty-locks` is enabled, it has a NAR hash. In the
latter case, we can verify the input but we may not be able to
fetch it from anywhere. */
auto isConsideredLocked = [&](const fetchers::Input & input)
{
return input.isLocked() || (fetchSettings.allowDirtyLocks && input.getNarHash());
};
for (auto & i : nodes) {
if (i == ref<const Node>(root)) continue;
auto node = i.dynamic_pointer_cast<const LockedNode>();
if (node
&& (!isConsideredLocked(node->lockedRef.input)
|| !node->lockedRef.input.isFinal())
&& !node->lockedRef.input.isRelative())
return node->lockedRef;
}
return {};
}
bool LockFile::operator ==(const LockFile & other) const
{
// FIXME: slow
return toJSON().first == other.toJSON().first;
}
InputAttrPath parseInputAttrPath(std::string_view s)
{
InputAttrPath path;
for (auto & elem : tokenizeString<std::vector<std::string>>(s, "/")) {
if (!std::regex_match(elem, flakeIdRegex))
throw UsageError("invalid flake input attribute path element '%s'", elem);
path.push_back(elem);
}
return path;
}
std::map<InputAttrPath, Node::Edge> LockFile::getAllInputs() const
{
std::set<ref<Node>> done;
std::map<InputAttrPath, Node::Edge> res;
std::function<void(const InputAttrPath & prefix, ref<Node> node)> recurse;
recurse = [&](const InputAttrPath & prefix, ref<Node> node)
{
if (!done.insert(node).second) return;
for (auto &[id, input] : node->inputs) {
auto inputAttrPath(prefix);
inputAttrPath.push_back(id);
res.emplace(inputAttrPath, input);
if (auto child = std::get_if<0>(&input))
recurse(inputAttrPath, *child);
}
};
recurse({}, root);
return res;
}
static std::string describe(const FlakeRef & flakeRef)
{
auto s = fmt("'%s'", flakeRef.to_string());
if (auto lastModified = flakeRef.input.getLastModified())
s += fmt(" (%s)", std::put_time(std::gmtime(&*lastModified), "%Y-%m-%d"));
return s;
}
std::ostream & operator <<(std::ostream & stream, const Node::Edge & edge)
{
if (auto node = std::get_if<0>(&edge))
stream << describe((*node)->lockedRef);
else if (auto follows = std::get_if<1>(&edge))
stream << fmt("follows '%s'", printInputAttrPath(*follows));
return stream;
}
static bool equals(const Node::Edge & e1, const Node::Edge & e2)
{
if (auto n1 = std::get_if<0>(&e1))
if (auto n2 = std::get_if<0>(&e2))
return (*n1)->lockedRef == (*n2)->lockedRef;
if (auto f1 = std::get_if<1>(&e1))
if (auto f2 = std::get_if<1>(&e2))
return *f1 == *f2;
return false;
}
std::string LockFile::diff(const LockFile & oldLocks, const LockFile & newLocks)
{
auto oldFlat = oldLocks.getAllInputs();
auto newFlat = newLocks.getAllInputs();
auto i = oldFlat.begin();
auto j = newFlat.begin();
std::string res;
while (i != oldFlat.end() || j != newFlat.end()) {
if (j != newFlat.end() && (i == oldFlat.end() || i->first > j->first)) {
res += fmt("• " ANSI_GREEN "Added input '%s':" ANSI_NORMAL "\n %s\n",
printInputAttrPath(j->first), j->second);
++j;
} else if (i != oldFlat.end() && (j == newFlat.end() || i->first < j->first)) {
res += fmt("• " ANSI_RED "Removed input '%s'" ANSI_NORMAL "\n", printInputAttrPath(i->first));
++i;
} else {
if (!equals(i->second, j->second)) {
res += fmt("• " ANSI_BOLD "Updated input '%s':" ANSI_NORMAL "\n %s\n → %s\n",
printInputAttrPath(i->first),
i->second,
j->second);
}
++i;
++j;
}
}
return res;
}
void LockFile::check()
{
auto inputs = getAllInputs();
for (auto & [inputAttrPath, input] : inputs) {
if (auto follows = std::get_if<1>(&input)) {
if (!follows->empty() && !findInput(*follows))
throw Error("input '%s' follows a non-existent input '%s'",
printInputAttrPath(inputAttrPath),
printInputAttrPath(*follows));
}
}
}
void check();
std::string printInputAttrPath(const InputAttrPath & path)
{
return concatStringsSep("/", path);
}
}