json-to-value: use unique_ptr instead of raw pointers

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Yorick 2020-01-09 22:46:41 +01:00
parent f1fac0b5c3
commit a350d0beb0
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@ -5,6 +5,7 @@
#include <nlohmann/detail/exceptions.hpp> #include <nlohmann/detail/exceptions.hpp>
using json = nlohmann::json; using json = nlohmann::json;
using std::unique_ptr;
namespace nix { namespace nix {
@ -13,14 +14,14 @@ namespace nix {
class JSONSax : nlohmann::json_sax<json> { class JSONSax : nlohmann::json_sax<json> {
class JSONState { class JSONState {
protected: protected:
JSONState* parent; unique_ptr<JSONState> parent;
Value * v; Value * v;
public: public:
virtual JSONState* resolve(EvalState &) virtual unique_ptr<JSONState> resolve(EvalState &)
{ {
throw std::logic_error("tried to close toplevel json parser state"); throw std::logic_error("tried to close toplevel json parser state");
}; };
explicit JSONState(JSONState* p) : parent(p), v(nullptr) {}; explicit JSONState(unique_ptr<JSONState>&& p) : parent(std::move(p)), v(nullptr) {};
explicit JSONState(Value* v) : v(v) {}; explicit JSONState(Value* v) : v(v) {};
JSONState(JSONState& p) = delete; JSONState(JSONState& p) = delete;
Value& value(EvalState & state) Value& value(EvalState & state)
@ -36,13 +37,13 @@ class JSONSax : nlohmann::json_sax<json> {
class JSONObjectState : public JSONState { class JSONObjectState : public JSONState {
using JSONState::JSONState; using JSONState::JSONState;
ValueMap attrs = ValueMap(); ValueMap attrs = ValueMap();
virtual JSONState* resolve(EvalState & state) override virtual unique_ptr<JSONState> resolve(EvalState & state) override
{ {
Value& v = parent->value(state); Value& v = parent->value(state);
state.mkAttrs(v, attrs.size()); state.mkAttrs(v, attrs.size());
for (auto & i : attrs) for (auto & i : attrs)
v.attrs->push_back(Attr(i.first, i.second)); v.attrs->push_back(Attr(i.first, i.second));
return parent; return std::move(parent);
} }
virtual void add() override { v = nullptr; }; virtual void add() override { v = nullptr; };
public: public:
@ -54,28 +55,28 @@ class JSONSax : nlohmann::json_sax<json> {
class JSONListState : public JSONState { class JSONListState : public JSONState {
ValueVector values = ValueVector(); ValueVector values = ValueVector();
virtual JSONState* resolve(EvalState & state) override virtual unique_ptr<JSONState> resolve(EvalState & state) override
{ {
Value& v = parent->value(state); Value& v = parent->value(state);
state.mkList(v, values.size()); state.mkList(v, values.size());
for (size_t n = 0; n < values.size(); ++n) { for (size_t n = 0; n < values.size(); ++n) {
v.listElems()[n] = values[n]; v.listElems()[n] = values[n];
} }
return parent; return std::move(parent);
} }
virtual void add() override { virtual void add() override {
values.push_back(v); values.push_back(v);
v = nullptr; v = nullptr;
}; };
public: public:
JSONListState(JSONState* p, std::size_t reserve) : JSONState(p) JSONListState(unique_ptr<JSONState>&& p, std::size_t reserve) : JSONState(std::move(p))
{ {
values.reserve(reserve); values.reserve(reserve);
} }
}; };
EvalState & state; EvalState & state;
JSONState* rs; unique_ptr<JSONState> rs;
template<typename T, typename... Args> inline bool handle_value(T f, Args... args) template<typename T, typename... Args> inline bool handle_value(T f, Args... args)
{ {
@ -86,7 +87,6 @@ class JSONSax : nlohmann::json_sax<json> {
public: public:
JSONSax(EvalState & state, Value & v) : state(state), rs(new JSONState(&v)) {}; JSONSax(EvalState & state, Value & v) : state(state), rs(new JSONState(&v)) {};
~JSONSax() { delete rs; };
bool null() bool null()
{ {
@ -120,21 +120,18 @@ public:
bool start_object(std::size_t len) bool start_object(std::size_t len)
{ {
JSONState* old = rs; rs = std::make_unique<JSONObjectState>(std::move(rs));
rs = new JSONObjectState(old);
return true; return true;
} }
bool key(string_t& name) bool key(string_t& name)
{ {
dynamic_cast<JSONObjectState*>(rs)->key(name, state); dynamic_cast<JSONObjectState*>(rs.get())->key(name, state);
return true; return true;
} }
bool end_object() { bool end_object() {
JSONState* old = rs; rs = rs->resolve(state);
rs = old->resolve(state);
delete old;
rs->add(); rs->add();
return true; return true;
} }
@ -144,8 +141,8 @@ public:
} }
bool start_array(size_t len) { bool start_array(size_t len) {
JSONState* old = rs; rs = std::make_unique<JSONListState>(std::move(rs),
rs = new JSONListState(old, len != std::numeric_limits<size_t>::max() ? len : 128); len != std::numeric_limits<size_t>::max() ? len : 128);
return true; return true;
} }