1 files changed, 231 insertions, 0 deletions
diff --git a/src/libutil/config.cc b/src/libutil/config.cc
new file mode 100644
index 000000000000..f7a46bfee63f
--- /dev/null
+++ b/src/libutil/config.cc
@@ -0,0 +1,231 @@
+#include "config.hh"
+#include "args.hh"
+#include "json.hh"
+
+namespace nix {
+
+void Config::set(const std::string & name, const std::string & value)
+{
+    auto i = _settings.find(name);
+    if (i == _settings.end())
+        throw UsageError("unknown setting '%s'", name);
+    i->second.setting->set(value);
+    i->second.setting->overriden = true;
+}
+
+void Config::addSetting(AbstractSetting * setting)
+{
+    _settings.emplace(setting->name, Config::SettingData(false, setting));
+    for (auto & alias : setting->aliases)
+        _settings.emplace(alias, Config::SettingData(true, setting));
+
+    bool set = false;
+
+    auto i = initials.find(setting->name);
+    if (i != initials.end()) {
+        setting->set(i->second);
+        setting->overriden = true;
+        initials.erase(i);
+        set = true;
+    }
+
+    for (auto & alias : setting->aliases) {
+        auto i = initials.find(alias);
+        if (i != initials.end()) {
+            if (set)
+                warn("setting '%s' is set, but it's an alias of '%s' which is also set",
+                    alias, setting->name);
+            else {
+                setting->set(i->second);
+                setting->overriden = true;
+                initials.erase(i);
+                set = true;
+            }
+        }
+    }
+}
+
+void Config::warnUnknownSettings()
+{
+    for (auto & i : initials)
+        warn("unknown setting '%s'", i.first);
+}
+
+StringMap Config::getSettings(bool overridenOnly)
+{
+    StringMap res;
+    for (auto & opt : _settings)
+        if (!opt.second.isAlias && (!overridenOnly || opt.second.setting->overriden))
+            res.emplace(opt.first, opt.second.setting->to_string());
+    return res;
+}
+
+void Config::applyConfigFile(const Path & path, bool fatal)
+{
+    try {
+        string contents = readFile(path);
+
+        unsigned int pos = 0;
+
+        while (pos < contents.size()) {
+            string line;
+            while (pos < contents.size() && contents[pos] != '\n')
+                line += contents[pos++];
+            pos++;
+
+            string::size_type hash = line.find('#');
+            if (hash != string::npos)
+                line = string(line, 0, hash);
+
+            vector<string> tokens = tokenizeString<vector<string> >(line);
+            if (tokens.empty()) continue;
+
+            if (tokens.size() < 2 || tokens[1] != "=")
+                throw UsageError("illegal configuration line ‘%1%’ in ‘%2%’", line, path);
+
+            string name = tokens[0];
+
+            vector<string>::iterator i = tokens.begin();
+            advance(i, 2);
+
+            try {
+                set(name, concatStringsSep(" ", Strings(i, tokens.end()))); // FIXME: slow
+            } catch (UsageError & e) {
+                if (fatal) throw;
+                warn("in configuration file '%s': %s", path, e.what());
+            }
+        };
+    } catch (SysError &) { }
+}
+
+void Config::resetOverriden()
+{
+    for (auto & s : _settings)
+        s.second.setting->overriden = false;
+}
+
+void Config::toJSON(JSONObject & out)
+{
+    for (auto & s : _settings)
+        if (!s.second.isAlias) {
+            JSONObject out2(out.object(s.first));
+            out2.attr("description", s.second.setting->description);
+            JSONPlaceholder out3(out2.placeholder("value"));
+            s.second.setting->toJSON(out3);
+        }
+}
+
+AbstractSetting::AbstractSetting(
+    const std::string & name,
+    const std::string & description,
+    const std::set<std::string> & aliases)
+    : name(name), description(description), aliases(aliases)
+{
+}
+
+void AbstractSetting::toJSON(JSONPlaceholder & out)
+{
+    out.write(to_string());
+}
+
+template<typename T>
+void BaseSetting<T>::toJSON(JSONPlaceholder & out)
+{
+    out.write(value);
+}
+
+template<> void BaseSetting<std::string>::set(const std::string & str)
+{
+    value = str;
+}
+
+template<> std::string BaseSetting<std::string>::to_string()
+{
+    return value;
+}
+
+template<typename T>
+void BaseSetting<T>::set(const std::string & str)
+{
+    static_assert(std::is_integral<T>::value, "Integer required.");
+    if (!string2Int(str, value))
+        throw UsageError("setting '%s' has invalid value '%s'", name, str);
+}
+
+template<typename T>
+std::string BaseSetting<T>::to_string()
+{
+    static_assert(std::is_integral<T>::value, "Integer required.");
+    return std::to_string(value);
+}
+
+template<> void BaseSetting<bool>::set(const std::string & str)
+{
+    if (str == "true" || str == "yes" || str == "1")
+        value = true;
+    else if (str == "false" || str == "no" || str == "0")
+        value = false;
+    else
+        throw UsageError("Boolean setting '%s' has invalid value '%s'", name, str);
+}
+
+template<> std::string BaseSetting<bool>::to_string()
+{
+    return value ? "true" : "false";
+}
+
+template<> void BaseSetting<Strings>::set(const std::string & str)
+{
+    value = tokenizeString<Strings>(str);
+}
+
+template<> std::string BaseSetting<Strings>::to_string()
+{
+    return concatStringsSep(" ", value);
+}
+
+template<> void BaseSetting<Strings>::toJSON(JSONPlaceholder & out)
+{
+    JSONList list(out.list());
+    for (auto & s : value)
+        list.elem(s);
+}
+
+template<> void BaseSetting<StringSet>::set(const std::string & str)
+{
+    value = tokenizeString<StringSet>(str);
+}
+
+template<> std::string BaseSetting<StringSet>::to_string()
+{
+    return concatStringsSep(" ", value);
+}
+
+template<> void BaseSetting<StringSet>::toJSON(JSONPlaceholder & out)
+{
+    JSONList list(out.list());
+    for (auto & s : value)
+        list.elem(s);
+}
+
+template class BaseSetting<int>;
+template class BaseSetting<unsigned int>;
+template class BaseSetting<long>;
+template class BaseSetting<unsigned long>;
+template class BaseSetting<long long>;
+template class BaseSetting<unsigned long long>;
+template class BaseSetting<bool>;
+template class BaseSetting<std::string>;
+
+void PathSetting::set(const std::string & str)
+{
+    if (str == "") {
+        if (allowEmpty)
+            value = "";
+        else
+            throw UsageError("setting '%s' cannot be empty", name);
+    } else
+        value = canonPath(str);
+}
+
+}