diff --git a/clone_format/format_tags.hpp b/clone_format/format_tags.hpp
index 05624b1..bf37452 100644
--- a/clone_format/format_tags.hpp
+++ b/clone_format/format_tags.hpp
@@ -20,6 +20,7 @@ class format_tags
 	static inline const QString FILE_TABLE="file_table";
 	static inline const QString RESULTS="results";
 	static inline const QString CLONE_PAIRS="clone_pairs";
+	static inline const QString CLONE_PAIR_SIZE="clone_pair_size";
 	static inline const QString RESULT_ID="result_id";
 	static inline const QString FILE_ID="file_id";
 	static inline const QString PATH="path";
diff --git a/clone_format/jcln.cpp b/clone_format/jcln.cpp
index 4e0115f..e83cf67 100644
--- a/clone_format/jcln.cpp
+++ b/clone_format/jcln.cpp
@@ -44,46 +44,45 @@ bool jcln::write(const detection_results &results, const QString &path) noexcept
 }
 
 
-QJsonValue jcln::to_qjson(const file &file) noexcept
+QJsonValue jcln::to_qjson(const std::shared_ptr<file> &file_ptr, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept
 {
 	return QJsonObject
 	{
-		{FILE_ID, int(file.id())},
-		{PATH, file.canonical_file_path()}
+		{FILE_ID, file_index_map[file_ptr]},
+		{PATH, file_ptr->canonical_file_path()}
 	};
 }
 
-QJsonValue jcln::to_qjson(const fragment &fragment) noexcept
+QJsonValue jcln::to_qjson(const fragment &fragment, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept
 {
 	return QJsonObject
 	{
-		{FILE_ID, int(fragment.file_id())},
+		{FILE_ID, int(file_index_map[fragment.file_ptr()])},
 		{BEGIN, int(fragment.begin())},
 		{END, int(fragment.end())}
 	};
 }
 
-QJsonValue jcln::to_qjson(const clone_pair &clone_pair) noexcept
+QJsonValue jcln::to_qjson(const std::shared_ptr<clone_pair> &clone_pair, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept
 {
 	return QJsonObject
 	{
-		{CLONE_PAIR_ID, int(clone_pair.id())},
-		{SIMILARITY, int(clone_pair.similarity())},
-		{FRAGMENT1, to_qjson(clone_pair.fragment1())},
-		{FRAGMENT2, to_qjson(clone_pair.fragment2())}
+		{SIMILARITY, int(clone_pair->similarity())},
+		{FRAGMENT1, to_qjson(clone_pair->fragment1(), file_index_map)},
+		{FRAGMENT2, to_qjson(clone_pair->fragment2(), file_index_map)}
 	};
 }
 
-QJsonValue jcln::to_qjson(const detection_result &detection_result) noexcept
+QJsonValue jcln::to_qjson(const std::shared_ptr<detection_result> &detection_result, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept
 {
 	QJsonArray json_clone_pairs_array;
-	for(const auto &p:detection_result.clone_pair_table())
+	for(const auto &p:detection_result->clone_pairs())
 	{
-		json_clone_pairs_array.append(to_qjson(p));
+		json_clone_pairs_array.append(to_qjson(p, file_index_map));
 	}
 
 	QJsonObject json_parameters;
-	const auto parameters=detection_result.context().parameters();
+	const auto parameters=detection_result->environment().parameters();
 	for(const auto &k:parameters.keys())
 	{
 		json_parameters[k]=parameters[k];
@@ -91,37 +90,32 @@ QJsonValue jcln::to_qjson(const detection_result &detection_result) noexcept
 
 	return QJsonObject
 	{
-		{CLONE_PAIRS, json_clone_pairs_array},
 		{ENVIRONMENT, QJsonObject{
-			{SOURCE, detection_result.context().source()},
+			{SOURCE, detection_result->environment().source()},
 			{PARAMETERS, json_parameters}
 		}},
-		{RESULT_ID, int(detection_result.id())}
+		{CLONE_PAIR_SIZE, detection_result->clone_pairs().size()},
+		{CLONE_PAIRS, json_clone_pairs_array}
 	};
 }
 
 QJsonValue jcln::to_qjson(const detection_results &detection_results) noexcept
 {
-	QJsonArray files, results, clone_pairs;
-	for(const auto &f:detection_results.file_table())
+	QJsonArray files, results;
+	auto file_index_map=detection_results.file_index_map();
+	for(const auto &f:detection_results.files())
 	{
-		files.append(to_qjson(f));
+		files.append(to_qjson(f, file_index_map));
 	}
 
-	for(const auto &r:detection_results.result_table())
+	for(const auto &r:detection_results.results())
 	{
-		results.append(to_qjson(r));
-		clone_pairs.append(QJsonObject{{RESULT_ID, int(r.id())}, {SIZE, r.clone_pairs().size()}});
+		results.append(to_qjson(r, file_index_map));
 	}
 
 	return QJsonObject
 	{
 		{GLOBAL, QJsonObject{
-			{SIZE, QJsonObject{
-				{RESULTS, detection_results.result_table().size()},
-				{FILE_TABLE, detection_results.file_table().size()},
-				{CLONE_PAIRS, clone_pairs}
-			}},
 			{TARGET, detection_results.target_path()}}
 		},
 		{FILE_TABLE, files},
@@ -210,8 +204,6 @@ std::optional<detection_result> jcln::read_detection_result(const QJsonObject &j
 		return std::nullopt;
 	}
 
-	auto context=result_environment(clone_detector[NAME].toString(), environment[SOURCE].toString());
-
 	shared_set<clone_pair> clone_pairs;
 	for(auto pj:json[CLONE_PAIRS].toArray())
 	{
@@ -225,7 +217,7 @@ std::optional<detection_result> jcln::read_detection_result(const QJsonObject &j
 		clone_pairs.insert(std::make_shared<clone_pair>(std::move(p.value())));
 	}
 
-	return detection_result(std::move(context), std::move(clone_pairs));
+	return detection_result(result_environment(clone_detector[NAME].toString(), environment[SOURCE].toString()), std::move(clone_pairs));
 }
 
 std::optional<detection_results> jcln::read_detection_results(const QJsonObject &json) noexcept
@@ -270,7 +262,7 @@ std::optional<detection_results> jcln::read_detection_results(const QJsonObject
 			return std::nullopt;
 		}
 
-		id_file_ptr_map[f[FILE_ID].toInt()]=rs.add(to_canonical_file_path(f[PATH].toString()));
+		id_file_ptr_map[f[FILE_ID].toInt()]=rs.emplace(to_canonical_file_path(f[PATH].toString()));
 	}
 
 	// results
@@ -288,11 +280,8 @@ std::optional<detection_results> jcln::read_detection_results(const QJsonObject
 			qCritical()<<code_clone_loading_error::invalid_file_format;
 			return std::nullopt;
 		}
-		results.insert(std::make_shared<detection_result>(std::move(r)));
 	}
 
-	rs.emplace_detection_result();
-
 	return std::make_optional(rs);
 }
 
diff --git a/clone_format/jcln.hpp b/clone_format/jcln.hpp
index 11924cf..f1c0089 100644
--- a/clone_format/jcln.hpp
+++ b/clone_format/jcln.hpp
@@ -20,10 +20,10 @@ class jcln final
 	static bool write(const detection_results &results, const QString &path) noexcept;
 
 private:
-	static QJsonValue to_qjson(const file &file) noexcept;
-	static QJsonValue to_qjson(const fragment &fragment) noexcept;
-	static QJsonValue to_qjson(const clone_pair &clone_pair) noexcept;
-	static QJsonValue to_qjson(const detection_result &detection_result) noexcept;
+	static QJsonValue to_qjson(const std::shared_ptr<file> &file_ptr, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept;
+	static QJsonValue to_qjson(const fragment &fragment, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept;
+	static QJsonValue to_qjson(const std::shared_ptr<clone_pair> &clone_pair, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept;
+	static QJsonValue to_qjson(const std::shared_ptr<detection_result> &detection_result, const QHash<std::shared_ptr<file>, int> file_index_map) noexcept;
 	static QJsonValue to_qjson(const detection_results &detection_results) noexcept;
 
 	static std::optional<fragment> read_fragment(const QJsonObject &json, const shared_map<int, file> &id_file_ptr_map) noexcept;
diff --git a/core/detection_results.cpp b/core/detection_results.cpp
index dce8d0a..c14c072 100644
--- a/core/detection_results.cpp
+++ b/core/detection_results.cpp
@@ -12,7 +12,7 @@ detection_results::detection_results(const QString &target_path) noexcept
 
 std::shared_ptr<file> detection_results::emplace(QString &&canonical_file_path) noexcept
 {
-	auto itr=std::find_if(this->files_.begin(), this->files_.end(), [&](const auto &f){ return f==canonical_file_path; });
+	auto itr=std::find_if(this->files_.begin(), this->files_.end(), [&](const auto &f){ return f->canonical_file_path()==canonical_file_path; });
 	if(itr==this->files_.end())
 	{
 		itr=this->files_.insert(std::make_shared<file>(std::move(canonical_file_path)));
@@ -20,12 +20,22 @@ std::shared_ptr<file> detection_results::emplace(QString &&canonical_file_path)
 	return *itr;
 }
 
-std::shared_ptr<detection_result> detection_results::empalce(result_environment &&context, shared_set<clone_pair> &&clone_pairs) noexcept
+std::shared_ptr<detection_result> detection_results::emplace(detection_result &&result) noexcept
 {
-	auto itr=std::find_if(this->results_.begin(), this->results_.end(), [&](const detection_result &r){ return r.context().source()==context.source(); });
+	auto itr=std::find_if(this->results_.begin(), this->results_.end(), [&](const auto &r){ return r->environment()==result.environment(); });
 	if(itr==this->results_.end())
 	{
-		itr=this->results_.insert(std::make_shared<detection_result>(std::move(context), std::move(clone_pairs)));
+		itr=this->results_.insert(std::make_shared<detection_result>(std::move(result)));
+	}
+	return *itr;
+}
+
+std::shared_ptr<detection_result> detection_results::empalce(result_environment &&environment, shared_set<clone_pair> &&clone_pairs) noexcept
+{
+	auto itr=std::find_if(this->results_.begin(), this->results_.end(), [&](const auto &r){ return r->environment()==environment; });
+	if(itr==this->results_.end())
+	{
+		itr=this->results_.insert(std::make_shared<detection_result>(std::move(environment), std::move(clone_pairs)));
 	}
 	return *itr;
 }
@@ -42,6 +52,31 @@ bool detection_results::remove(std::shared_ptr<detection_result> &&ptr) noexcept
 	return false;
 }
 
+const shared_set<detection_result>& detection_results::results() const noexcept
+{
+	return this->results_;
+}
+
+const shared_set<file>& detection_results::files() const noexcept
+{
+	return this->files_;
+}
+
+QHash<std::shared_ptr<file>, int> detection_results::file_index_map() const noexcept
+{
+	auto list=this->files_.toList();
+	std::sort(list.begin(), list.end(), [](const auto &f1, const auto &f2){ return *f1<*f2; });
+
+	QHash<std::shared_ptr<file>, int> r;
+	int index=0;
+	for(const auto &key:list)
+	{
+		r.insert(key, index);
+		++index;
+	}
+	return r;
+}
+
 QString detection_results::target_path() const noexcept
 {
 	return this->target_path_;
diff --git a/core/detection_results.hpp b/core/detection_results.hpp
index ca4a97f..3d7edb5 100644
--- a/core/detection_results.hpp
+++ b/core/detection_results.hpp
@@ -17,11 +17,14 @@ class detection_results final
 	detection_results(const QString &target_path) noexcept;
 
 	std::shared_ptr<file> emplace(QString &&canonical_file_path) noexcept;
-	std::shared_ptr<detection_result> empalce(result_environment &&context, shared_set<clone_pair> &&clone_pairs) noexcept;
+	std::shared_ptr<detection_result> emplace(detection_result &&detection_result) noexcept;
+	std::shared_ptr<detection_result> empalce(result_environment &&environment, shared_set<clone_pair> &&clone_pairs) noexcept;
 
 	bool remove(std::shared_ptr<detection_result> &&ptr) noexcept;
 
-	shared_list<detection_result> results() const noexcept;
+	const shared_set<detection_result>& results() const noexcept;
+	const shared_set<file>& files() const noexcept;
+	QHash<std::shared_ptr<file>, int> file_index_map() const noexcept;
 
 	void set_target_path(const QString &target_path) noexcept;
 	QString target_path() const noexcept;
diff --git a/core/matching_table.cpp b/core/matching_table.cpp
index aac870b..5191f67 100644
--- a/core/matching_table.cpp
+++ b/core/matching_table.cpp
@@ -2,7 +2,7 @@
 
 namespace asterism
 {
-
+/*
 matching_table_unit::matching_table_unit() noexcept
 {}
 
@@ -184,5 +184,5 @@ uint qHash(const matching_table::key &key, uint seed) noexcept
 {
 	return uint(key.key1_)^seed+uint(key.key2_);
 }
-
+*/
 }
diff --git a/core/matching_table.hpp b/core/matching_table.hpp
index 787d34f..9b93f84 100644
--- a/core/matching_table.hpp
+++ b/core/matching_table.hpp
@@ -13,32 +13,28 @@
 namespace asterism
 {
 
-
+/*
 class matching_table_unit final
 {
 public:
 	matching_table_unit() noexcept;
 	matching_table_unit(const detection_result &left, const detection_result &right, const float t) noexcept;
 
-	std::optional<clone_pair::id_t> has_left_clone_pair_of(const clone_pair::id_t &right_clone_pair_id) const noexcept;
-	std::optional<clone_pair::id_t> has_right_clone_pair_of(const clone_pair::id_t &left_clone_pair_id) const noexcept;
-
-	int count_left_clone_pair_of(const clone_pair::id_t &right_clone_pair_id) const noexcept;
-	int count_right_clone_pair_of(const clone_pair::id_t &left_clone_pair_id) const noexcept;
+	std::optional<std::shared_ptr<clone_pair>> has_left_clone_pair_of(const std::shared_ptr<clone_pair> &ptr) const noexcept;
+	std::optional<std::shared_ptr<clone_pair>> has_right_clone_pair_of(const std::shared_ptr<clone_pair> &ptr) const noexcept;
 
-	detection_result::id_t left_result_id() const noexcept;
-	detection_result::id_t right_result_id() const noexcept;
+	int count_left_clone_pair_of(const std::shared_ptr<clone_pair> &ptr) const noexcept;
+	int count_right_clone_pair_of(const std::shared_ptr<clone_pair> &ptr) const noexcept;
 
-	QVector<clone_pair::id_t> left_clone_pair_of(const clone_pair::id_t &right_clone_pair_id) const noexcept;
-	QVector<clone_pair::id_t> right_clone_pair_of(const clone_pair::id_t &left_clone_pair_id) const noexcept;
+	shared_vector<clone_pair> left_clone_pair_of(const std::shared_ptr<clone_pair> &ptr) const noexcept;
+	shared_vector<clone_pair> right_clone_pair_of(const std::shared_ptr<clone_pair> &ptr) const noexcept;
 
 private:
-	detection_result::id_t left_result_id_, right_result_id_;
-	QVector<QPair<clone_pair::id_t, clone_pair::id_t>> matching_list_;
+	QVector<QPair<std::shared_ptr<clone_pair>, std::shared_ptr<clone_pair>>> matching_list_;
 
 	bool better(const float ok_v, const float good_v, QPair<float, float> &&ok_good_max, const float t) const noexcept;
-	QVector<QPair<clone_pair::id_t, clone_pair::id_t>> unidirectional_matching(const detection_result &first, const detection_result &second, const float t) const noexcept;
-	QVector<QPair<clone_pair::id_t, clone_pair::id_t>> bidirectional_matching(const detection_result &left, const detection_result &right, const float t) const noexcept;
+	QVector<QPair<std::shared_ptr<clone_pair>, std::shared_ptr<clone_pair>>> unidirectional_matching(const detection_result &first, const detection_result &second, const float t) const noexcept;
+	QVector<QPair<std::shared_ptr<clone_pair>, std::shared_ptr<clone_pair>>> bidirectional_matching(const detection_result &left, const detection_result &right, const float t) const noexcept;
 };
 
 
@@ -73,7 +69,7 @@ class matching_table final
 };
 
 uint qHash(const matching_table::key &key, uint seed) noexcept;
-
+*/
 }
 
 #endif // MATCHING_TABLE_HPP
diff --git a/gui/mainwindow.cpp b/gui/mainwindow.cpp
index 8fbe358..9ad3fd9 100644
--- a/gui/mainwindow.cpp
+++ b/gui/mainwindow.cpp
@@ -39,6 +39,7 @@ MainWindow::~MainWindow()
 
 void MainWindow::open()
 {
+	/*
 	auto results=clone_io::read(QFileDialog::getOpenFileName(this, tr("open file"), QDir::currentPath(), tr("Asterism Project (*.jcln)")));
 	if(results)
 	{
@@ -49,6 +50,7 @@ void MainWindow::open()
 			this->scatter_plot_model_->set_heatmap_layer(std::move(h.value()));
 		}
 	}
+	*/
 }
 
 
diff --git a/layer/clone_pair_grid_layer.cpp b/layer/clone_pair_grid_layer.cpp
index dcb64ad..daef892 100644
--- a/layer/clone_pair_grid_layer.cpp
+++ b/layer/clone_pair_grid_layer.cpp
@@ -6,22 +6,26 @@ namespace asterism
 clone_pair_grid_layer::clone_pair_grid_layer() noexcept
 {}
 
-clone_pair_grid_layer::clone_pair_grid_layer(const QList<clone_pair> &clone_pairs, const uint32_t width) noexcept
-	: file_separated_grid_layer(width)
+clone_pair_grid_layer::clone_pair_grid_layer(const shared_set<clone_pair> &clone_pairs, const QMap<std::shared_ptr<file>, int> file_index_map) noexcept
+	: file_separated_grid_layer(file_index_map.size())
 {
 	for(const auto &p:clone_pairs)
 	{
-		this->values_[grid_2d_coordinate(p.fragment1().file_id(), p.fragment2().file_id()).to_linear()].append(p);
+		auto x=file_index_map[p->fragment1().file_ptr()];
+		auto y=file_index_map[p->fragment2().file_ptr()];
+		this->values_[grid_2d_coordinate(x, y).to_linear()].append(p);
 	}
 }
 
 
-void clone_pair_grid_layer::make_layer(const QList<clone_pair> &clone_pairs, const uint32_t width) noexcept
+void clone_pair_grid_layer::make_layer(const shared_set<clone_pair> &clone_pairs, const QMap<std::shared_ptr<file>, int> file_index_map) noexcept
 {
-	this->width_=width;
+	this->width_=file_index_map.size();
 	for(const auto &p:clone_pairs)
 	{
-		this->values_[grid_2d_coordinate(p.fragment1().file_id(), p.fragment2().file_id()).to_linear()].append(p);
+		auto x=file_index_map[p->fragment1().file_ptr()];
+		auto y=file_index_map[p->fragment2().file_ptr()];
+		this->values_[grid_2d_coordinate(x, y).to_linear()].append(p);
 	}
 }
 
diff --git a/layer/clone_pair_grid_layer.hpp b/layer/clone_pair_grid_layer.hpp
index 53a9ba0..de761c0 100644
--- a/layer/clone_pair_grid_layer.hpp
+++ b/layer/clone_pair_grid_layer.hpp
@@ -3,6 +3,7 @@
 
 #include <memory>
 
+#include <QMap>
 #include <QHash>
 #include <QList>
 
@@ -12,26 +13,14 @@
 namespace asterism
 {
 
-template <class T>
-using shared_set=QSet<std::shared_ptr<T>>;
-
-template <class T>
-using shared_list=QList<std::shared_ptr<T>>;
-
-template <class T>
-using shared_vector=QVector<std::shared_ptr<T>>;
-
-template <class K, class V>
-using shared_map=QMap<K, std::shared_ptr<V>>;
-
 class clone_pair_grid_layer final
 	: public file_separated_grid_layer<shared_vector<clone_pair>>
 {
 public:
 	clone_pair_grid_layer() noexcept;
-	clone_pair_grid_layer(const shared_set<clone_pair> &clone_pairs, const uint32_t width) noexcept;
+	clone_pair_grid_layer(const shared_set<clone_pair> &clone_pairs, const QMap<std::shared_ptr<file>, int> file_index_map) noexcept;
 
-	void make_layer(const QList<clone_pair> &clone_pairs, const uint32_t width) noexcept;
+	void make_layer(const shared_set<clone_pair> &clone_pairs, const QMap<std::shared_ptr<file>, int> file_index_map) noexcept;
 };
 
 }
diff --git a/model/clone_pair.cpp b/model/clone_pair.cpp
index ad51d81..cce55df 100644
--- a/model/clone_pair.cpp
+++ b/model/clone_pair.cpp
@@ -49,9 +49,9 @@ QPair<fragment, fragment> clone_pair::canonical(fragment &&fragment1, fragment &
 				qMakePair(fragment2, fragment1);
 }
 
-uint qHash(const clone_pair &key, [[maybe_unused]]uint seed) noexcept
+uint qHash(const clone_pair &key, uint seed) noexcept
 {
-	return key.fragments_.first.begin()+key.fragments_.second.begin();
+	return key.fragments_.first.begin()^seed+key.fragments_.second.begin();
 }
 
 float good(const clone_pair &p1, const clone_pair &p2) noexcept
diff --git a/model/detection_result.cpp b/model/detection_result.cpp
index dabd240..d468152 100644
--- a/model/detection_result.cpp
+++ b/model/detection_result.cpp
@@ -6,19 +6,19 @@ namespace asterism
 detection_result::detection_result() noexcept
 {}
 
-detection_result::detection_result(result_environment &&context, shared_set<clone_pair> &&clone_pairs) noexcept
-	: context_(std::move(context)), clone_pairs_(std::move(clone_pairs))
+detection_result::detection_result(result_environment &&environment, shared_set<clone_pair> &&clone_pairs) noexcept
+	: environment_(std::move(environment)), clone_pairs_(std::move(clone_pairs))
 {}
 
 
-clone_pair_grid_layer detection_result::to_layer() const noexcept
+clone_pair_grid_layer detection_result::to_layer(const QMap<std::shared_ptr<file>, int> file_index_map) const noexcept
 {
-	return this->clone_pair_grid_layer_;
+	return clone_pair_grid_layer(this->clone_pairs_, file_index_map);
 }
 
-const result_environment& detection_result::context() const noexcept
+const result_environment& detection_result::environment() const noexcept
 {
-	return this->context_;
+	return this->environment_;
 }
 
 shared_set<clone_pair>& detection_result::clone_pairs() noexcept
@@ -31,4 +31,18 @@ const shared_set<clone_pair>& detection_result::clone_pairs() const noexcept
 	return this->clone_pairs_;
 }
 
+bool detection_result::operator ==(const detection_result &detection_result) const noexcept
+{
+	return this->environment_.source()==detection_result.environment_.source();
+}
+
+uint qHash(const detection_result &key, uint seed) noexcept
+{
+	return qHash(key.environment().source(), seed);
+}
+
+uint qHash(const std::shared_ptr<detection_result> &key, uint seed) noexcept
+{
+	return qHash(key->environment().source(), seed);
+}
 }
diff --git a/model/detection_result.hpp b/model/detection_result.hpp
index e0a8281..d591ba0 100644
--- a/model/detection_result.hpp
+++ b/model/detection_result.hpp
@@ -15,18 +15,22 @@ class detection_result final
 {
 public:
 	detection_result() noexcept;
-	detection_result(result_environment &&context, shared_set<clone_pair> &&clone_pairs) noexcept;
+	detection_result(result_environment &&environment, shared_set<clone_pair> &&clone_pairs) noexcept;
 
-	clone_pair_grid_layer to_layer(const shared_list<file> &header) const noexcept;
+	clone_pair_grid_layer to_layer(const QMap<std::shared_ptr<file>, int> file_index_map) const noexcept;
 
-	const result_environment& context() const noexcept;
+	const result_environment& environment() const noexcept;
 	shared_set<clone_pair>& clone_pairs() noexcept;
 	const shared_set<clone_pair>& clone_pairs() const noexcept;
 
+	bool operator ==(const detection_result &detection_result) const noexcept;
+
 private:
-	result_environment context_;
+	result_environment environment_;
 	shared_set<clone_pair> clone_pairs_;
 };
 
+uint qHash(const detection_result &key, uint seed) noexcept;
+uint qHash(const std::shared_ptr<detection_result> &key, uint seed) noexcept;
 }
 #endif // DETECTION_RESULT_HPP
diff --git a/model/file.cpp b/model/file.cpp
index b39961e..b3583e0 100644
--- a/model/file.cpp
+++ b/model/file.cpp
@@ -16,14 +16,6 @@ file::file(QString &&canonical_file_path) noexcept
 	: canonical_file_path_(std::move(canonical_file_path))
 {}
 
-file::file(const id_t id, const QString &canonical_file_path) noexcept
-	: canonical_file_path_(canonical_file_path)
-{}
-
-file::file(const id_t id, QString &&canonical_file_path) noexcept
-	: canonical_file_path_(std::move(canonical_file_path))
-{}
-
 QString file::canonical_file_path() const noexcept
 {
 	return this->canonical_file_path_;
@@ -34,6 +26,11 @@ file::id_t file::id() const noexcept
 	return this->id_;
 }
 
+bool file::operator <(const file &other) const noexcept
+{
+	return this->canonical_file_path_<other.canonical_file_path_;
+}
+
 bool file::operator ==(const QString &path) const noexcept
 {
 	return this->canonical_file_path_==to_canonical_file_path(path);
@@ -56,5 +53,10 @@ uint qHash(const file &key, uint seed) noexcept
 	return qHash(key.canonical_file_path_, seed);
 }
 
+uint qHash(const std::shared_ptr<file> &key, uint seed) noexcept
+{
+	return qHash(key->canonical_file_path(), seed);
+}
+
 }
 
diff --git a/model/file.hpp b/model/file.hpp
index a696310..f91b837 100644
--- a/model/file.hpp
+++ b/model/file.hpp
@@ -12,6 +12,24 @@
 namespace asterism
 {
 
+template <class T>
+uint qHash(const std::shared_ptr<T> &t, uint seed) noexcept
+{
+	return qHash(*t, seed);
+}
+
+template <class T>
+using shared_set=QSet<std::shared_ptr<T>>;
+
+template <class T>
+using shared_list=QList<std::shared_ptr<T>>;
+
+template <class T>
+using shared_vector=QVector<std::shared_ptr<T>>;
+
+template <class K, class V>
+using shared_map=QMap<K, std::shared_ptr<V>>;
+
 class file final
 {
 public:
@@ -21,12 +39,10 @@ class file final
 	file(const QString &canonical_file_path) noexcept;
 	file(QString &&canonical_file_path) noexcept;
 
-	file(const id_t id, const QString &canonical_file_path) noexcept;
-	file(const id_t id, QString &&canonical_file_path) noexcept;
-
 	id_t id() const noexcept;
 	QString canonical_file_path() const noexcept;
 
+	bool operator <(const file &other) const noexcept;
 	bool operator ==(const QString &path) const noexcept;
 	bool operator ==(const file &other) const noexcept;
 
@@ -41,6 +57,7 @@ class file final
 };
 
 uint qHash(const file &key, uint seed) noexcept;
+uint qHash(const std::shared_ptr<file> &key, uint seed) noexcept;
 }
 
 #endif // FILE_HPP
diff --git a/model/fragment.cpp b/model/fragment.cpp
index 53eee8e..7b96885 100644
--- a/model/fragment.cpp
+++ b/model/fragment.cpp
@@ -15,7 +15,7 @@ fragment::fragment(const std::shared_ptr<file> &file, const uint32_t begin, cons
 // operator
 bool fragment::operator <(const fragment &other) const noexcept
 {
-	if(this->file_.owner_before(other.file_))
+	if(this->file_<other.file_)
 	{
 		return true;
 	}
diff --git a/model/result_environment.cpp b/model/result_environment.cpp
index a9679a2..ce16a21 100644
--- a/model/result_environment.cpp
+++ b/model/result_environment.cpp
@@ -71,4 +71,9 @@ QHash<QString, QString> result_environment::parameters() const noexcept
 	return this->parameters_;
 }
 
+bool result_environment::operator ==(const result_environment &other) const noexcept
+{
+	return this->source_==other.source_;
+}
+
 }
diff --git a/model/result_environment.hpp b/model/result_environment.hpp
index b90abf4..1d3e145 100644
--- a/model/result_environment.hpp
+++ b/model/result_environment.hpp
@@ -47,6 +47,8 @@ class result_environment final
 	QString clone_detector_string() const noexcept;
 	QHash<QString, QString> parameters() const noexcept;
 
+	bool operator ==(const result_environment &other) const noexcept;
+
 private:
 	clone_detector clone_detector_;
 	QString source_;
diff --git a/ref.jcln b/ref.jcln
index 8de5335..05d4802 100644
--- a/ref.jcln
+++ b/ref.jcln
@@ -1,16 +1,6 @@
 {
 	"global":{
-		"target":"target_path",
-		"size":{
-			"file_table":2,
-			"results":1,
-			"clone_pairs":[
-				{
-					"result_id":0,
-					"size":1
-				}
-			]
-		}
+		"target":"target_path"
 	},
 	"file_table":[
 		{
@@ -24,7 +14,6 @@
 	],
 	"results":[
 		{
-			"result_id":0,
 			"environment":{
 				"source":"r1_src",
 				"clone_detector":{
@@ -35,6 +24,7 @@
 					}
 				}
 			},
+			"clone_pair_size":0,
 			"clone_pairs":[
 				{
 					"clone_pair_id":0,