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/*
* This source code is released into the public domain.
*/
module;
#include <coroutine>
#include <expected>
#include <filesystem>
#include <format>
#include <string>
#include <system_error>
#include <fcntl.h>
module liblfvm;
import nihil;
import nihil.ucl;
namespace lfvm {
auto make_disk_config(std::string_view name, std::string_view filename)
-> std::expected<disk_config, nihil::error>
{
if (name.empty())
return std::unexpected(nihil::error("disk name missing"));
if (filename.empty())
return std::unexpected(nihil::error("disk path missing"));
return disk_config(name, filename);
}
disk_config::disk_config(std::string_view name, std::filesystem::path path)
: m_name(name)
, m_path(std::move(path))
{
}
auto disk_config::name(this disk_config const &self) -> std::string_view
{
return self.m_name;
}
auto disk_config::path(this disk_config const &self) -> std::filesystem::path const &
{
return self.m_path;
}
auto disk_config::exists(this disk_config const &self) -> bool
{
auto ec = std::error_code();
return std::filesystem::exists(self.path(), ec);
}
auto disk_config::serialize(this disk_config const &self)
-> std::expected<std::string, nihil::error>
{
using namespace nihil::ucl;
using namespace std::literals;
auto uobj = map<object>();
uobj.insert({"name"sv, string(self.name())});
uobj.insert({"path"sv, string(self.path().string())});
return std::format("{:c}", uobj);
}
auto disk_config::deserialize(std::string_view text)
-> std::expected<disk_config, nihil::error>
{
using namespace nihil::ucl;
auto uobj = co_await parse(text);
// Name
auto name = std::string();
if (auto o = uobj.find("name"); o)
name = (co_await object_cast<string>(*o)).value();
else
co_return std::unexpected(nihil::error("missing name"));
// Path
auto path = std::string();
if (auto o = uobj.find("path"); o)
path = (co_await object_cast<string>(*o)).value();
else
co_return std::unexpected(nihil::error("missing path"));
auto disk = co_await make_disk_config(name, path);
co_return disk;
}
auto disk_load(context const &ctx, std::string_view name)
-> std::expected<disk_config, nihil::error>
{
auto filename = ctx.disk_config_file(name);
auto text = std::string();
co_await nihil::read_file(filename, std::back_inserter(text));
auto config = co_await disk_config::deserialize(text);
co_return config;
}
auto disk_create(context const &ctx, disk_config const &d)
-> std::expected<void, nihil::error>
{
auto ucltext = co_await d.serialize();
auto filename = ctx.disk_config_file(d.name());
/*
* We can't do the usual atomic write method of writing to a temporary
* file and renaming because we need to open the file with O_EXCL, so
* instead just attempt to delete the target file if something fails.
*/
auto file = co_await nihil::open_file(
filename, O_WRONLY|O_CREAT|O_EXCL, 0600);
auto file_guard = nihil::guard([&] {
std::filesystem::remove(filename);
});
co_await write(file, ucltext);
file_guard.release();
// TODO: Perhaps sync the file?
co_return {};
}
auto disk_save(context const &ctx, disk_config const &d)
-> std::expected<void, nihil::error>
{
auto ucltext = co_await d.serialize();
auto filename = ctx.disk_config_file(d.name());
co_await nihil::safe_write_file(filename, ucltext);
// TODO: Perhaps sync the file?
co_return {};
}
auto disk_list(context const &ctx)
-> std::expected<std::vector<std::string>, nihil::error>
{
auto ret = std::vector<std::string>();
auto files = std::filesystem::directory_iterator{ctx.diskconfdir()};
for (auto &&file : files) {
if (!file.is_regular_file())
continue;
auto path = file.path();
if (path.extension() != ".ucl")
continue;
path.replace_extension();
auto name = path.filename().string();
if (name[0] == '.')
continue;
ret.push_back(name);
}
return ret;
}
} // namespace lfvm
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