Database: Improve on the insert() return value

Rather than returning an index into the database, instead return an
iterator pointing at the item we just inserted.

Signed-off-by: Anna Schumaker <anna@ocarinaproject.net>

DESIGN

@@ -280,7 +280,7 @@ Database:
 		void save();
 		void load();
 
-		unsigned int insert(T);
+		iterator insert(T);
 		void remove(unsigned int);
 		unsigned int size();
 		unsigned int actual_size();
@@ -311,10 +311,10 @@ Database:
 	void Database :: load();
 		Load the database from disk.
 
-	unsigned int Database :: insert(T &item);
+	iterator Database :: insert(T &item);
 		Look up the item in the _keys map.
 		If we find an item with the same key:
-			- Return the index of the item to the caller.
+			- Return an iterator to the found item.
 		Otherwise:
 			- Add the new item to the end of the _db.
 			- Add the new item to _keys.
@@ -322,7 +322,7 @@ Database:
 			- Set item.id to the index of the new item.
 			_ Increment _size.
 			- If autosave == true: save().
-			- Return item.id.
+			- Return an iterator to the new item.
 
 	unsigned int Database :: remove();
 		- Remove the item from the _keys map.

TODO

@@ -96,3 +96,4 @@ Future work:
 	- Investigate "Bulk insert" callbacks for performance
 	- Initialize PQs with multiple flags
 	- Prefill Song structures in each library :: Track
+	- Use "friend" class for valid and id flags of a DatabaseEntry

include/database.h

@@ -43,7 +43,7 @@ public:
 	void autosave();
 	void load();
 
-	unsigned int insert(T);
+	iterator insert(T);
 	void remove(unsigned int);
 	unsigned int size();
 	unsigned int actual_size();

include/database.hpp

@@ -72,25 +72,21 @@ void Database<T> :: load()
 }
 
 template <class T>
-unsigned int Database<T> :: insert(T val)
+typename Database<T>::iterator Database<T> :: insert(T val)
 {
-	unsigned int id;
 	iterator it = find(val.primary_key());
 
 	if (it != end())
-		return it - _db.begin();
+		return it;
 
-	/*
-	 * Check primary key stuff here
-	 */
-	id = _db.size();
-	_db.push_back(val);
-	_keys[val.primary_key()] = id;
-	_db[id].valid = true;
-	_db[id].id = id;
+	it = _db.insert(_db.end(), val);
+	it->valid = true;
+	it->id = it - _db.begin();
+
+	_keys[it->primary_key()] = it->id;
 	_size++;
 	autosave();
-	return id;
+	return it;
 }
 
 template <class T>

lib/index.cpp

@@ -53,7 +53,7 @@ void Index :: insert(const std::string &key, unsigned int val)
 {
 	iterator it = find(key);
 	if (it == end())
-		it = at(Database :: insert(IndexEntry(key)));
+		it = Database :: insert(IndexEntry(key));
 
 	it->insert(val);
 	autosave();

lib/library.cpp

@@ -276,11 +276,11 @@ static void read_tags(unsigned int lib_id, const std :: string &path)
 
 	audio = ref.audioProperties();
 
-	artist_id = artist_db.insert(library :: AGInfo(library :: DB_ARTIST, tag));
-	album_id  = album_db.insert(library :: Album(tag, artist_id));
-	genre_id  = genre_db.insert(library :: AGInfo(library :: DB_GENRE, tag));
+	artist_id = artist_db.insert(library :: AGInfo(library :: DB_ARTIST, tag))->id;
+	album_id  = album_db.insert(library :: Album(tag, artist_id))->id;
+	genre_id  = genre_db.insert(library :: AGInfo(library :: DB_GENRE, tag))->id;
 	track_id  = track_db.insert(library :: Track(tag, audio, lib_id,
-					artist_id, album_id, genre_id, path));
+					artist_id, album_id, genre_id, path))->id;
 
 	if (track_db.at(track_id)->valid == false)
 		return;
@@ -400,11 +400,11 @@ static void do_import_track(File &f, unsigned int lib_id)
 	f >> tmp >> tmp >>tmp >> banned; /* bitrate, sample, channels, banned */
 	f.getline(); /* get rest of line */
 
-	artist_id = artist_db.insert(library :: AGInfo(library :: DB_ARTIST, artist));
-	album_id  = album_db.insert(library :: Album(album, year, artist_id));
-	genre_id  = genre_db.insert(library :: AGInfo(library :: DB_GENRE, genre));
+	artist_id = artist_db.insert(library :: AGInfo(library :: DB_ARTIST, artist))->id;
+	album_id  = album_db.insert(library :: Album(album, year, artist_id))->id;
+	genre_id  = genre_db.insert(library :: AGInfo(library :: DB_GENRE, genre))->id;
 	track_id  = track_db.insert(library :: Track(&data, lib_id, artist_id,
-					album_id, genre_id));
+					album_id, genre_id))->id;
 	library_db.at(lib_id)->size++;
 
 	filter::add(artist_db.at(artist_id)->name, track_id);
@@ -440,7 +440,7 @@ static void do_import_library(std::string &s)
 		return;
 	}
 	print("Adding path: %s\n", path.c_str());
-	id = library_db.insert(library :: Library(path, enabled));
+	id = library_db.insert(library :: Library(path, enabled))->id;
 	get_callbacks()->on_library_add(id, &(*library_db.at(id)));
 	library_db.save();
 
@@ -490,7 +490,7 @@ void library :: add_path(const std::string &dir)
 	if (library_db.find(dir) != library_db.end())
 		return;
 
-	id = library_db.insert(library :: Library(dir, true));
+	id = library_db.insert(library :: Library(dir, true))->id;
 	library_db.save();
 
 	get_callbacks()->on_library_add(id, &(*library_db.at(id)));

tests/src/database.cpp

@@ -85,7 +85,7 @@ int main(int argc, char **argv)
 	 * 1: Test insertion
 	 */
 	for (unsigned int i = 0; i < n; i++) {
-		if (db.insert(IntEntry(i)) != i)
+		if (db.insert(IntEntry(i))->id != i)
 			test_results(false, __LINE__);
 	}
 	test_results(true, __LINE__);
@@ -103,7 +103,7 @@ int main(int argc, char **argv)
 	 * 3: Test inserting ... again.
 	 */
 	for (unsigned int i = 0; i < n; i++) {
-		if (db.insert(IntEntry(i)) != i)
+		if (db.insert(IntEntry(i))->id != i)
 			test_results(false, __LINE__);
 	}
 	test_results(true, __LINE__);
@@ -169,7 +169,7 @@ int main(int argc, char **argv)
 	 * 9. Test inserting once again
 	 */
 	for (unsigned int i = 0; i < n; i++) {
-		index = db.insert(i);
+		index = db.insert(i)->id;
 		if ((i % 2) == 0) {
 			size++;
 			actual++;