database: Make read() and write() functions for database entries

I had planned on using the stream operator for my database class but
this created some crazy compiler error that I was having difficulty
figuring out.  I decided to take the easy route for now and instead
create read() and write() functions that do exactly the same thing.

Signed-off-by: Anna Schumaker <schumaker.anna@gmail.com>

design/database.txt

@@ -34,9 +34,8 @@ Database: (lib/database.cpp)
 	private:
 		bool valid;
 	public:
-		virtual File &operator>>(File &) = 0;
+		virtual void write(File &) = 0;
-		virtual File &operator<<(File &) = 0;
+		virtual void read(File &) = 0;
-		friend class Database;
 	};
 
 	File << <CHILD_CLASS_DATA>

include/database.h

@@ -5,6 +5,7 @@
 #define OCARINA_DATABASE_H
 
 #include <file.h>
+#include <print.h>
 
 #include <vector>
 
@@ -14,6 +15,8 @@ public:
 	bool valid;
 
 	DatabaseEntry();
+	virtual void write(File &) = 0;
+	virtual void read(File &) = 0;
 };
 
 
@@ -27,6 +30,8 @@ private:
 public:
 	Database(std::string);
 	~Database();
+	void save();
+	void load();
 
 	unsigned int insert(T);
 	void remove(unsigned int);

include/database.hpp

@@ -19,6 +19,41 @@ Database<T> :: ~Database()
 
 }
 
+template <class T>
+void Database<T> :: save()
+{
+	file.open(OPEN_WRITE);
+
+	file << db.size() << std::endl;
+	for (unsigned int i = 0; i < db.size(); i++) {
+		file << db[i].valid << " ";
+		if (db[i].valid == true)
+			db[i].write(file);
+		file << std::endl;
+	}
+
+	file.close();
+}
+
+template <class T>
+void Database<T> :: load()
+{
+	unsigned int db_size;
+	file.open(OPEN_READ);
+
+	file >> db_size;
+	db.resize(db_size);
+	for (unsigned int i = 0; i < db_size; i++) {
+		file >> db[i].valid;
+		if (db[i].valid == true) {
+			db[i].read(file);
+			_size++;
+		}
+	}
+
+	file.close();
+}
+
 template <class T>
 unsigned int Database<T> :: insert(T val)
 {

tests/database/database.cpp

@@ -7,15 +7,34 @@
 class DBTest : public DatabaseEntry {
 public:
 	unsigned int value;
+
+	DBTest();
 	DBTest(unsigned int);
+	void write(File &);
+	void read(File &);
 };
 
+DBTest :: DBTest()
+{
+}
+
 DBTest :: DBTest(unsigned int val)
 {
 	value = val;
 	valid = true;
 }
 
+void DBTest :: write(File &file)
+{
+	file << value;
+}
+
+void DBTest :: read(File &file)
+{
+	file >> value;
+}
+
+
 
 void print_db(Database<DBTest> &db)
 {
@@ -30,7 +49,7 @@ void print_db(Database<DBTest> &db)
 
 void test_insertion(Database<DBTest> &db)
 {
-	for (unsigned int i = 1; i <= 1000; i++)
+	for (unsigned int i = 1; i <= 100000; i++)
 		db.insert(DBTest(i));
 	print_db(db);
 }
@@ -44,7 +63,10 @@ void test_deletion(Database<DBTest> &db)
 	print_db(db);
 }
 
-int main(int argc, char **argv)
+/*
+ * Test everything except reloading.
+ */
+void test_0()
 {
 	Database<DBTest> db("test.db");
 
@@ -52,5 +74,23 @@ int main(int argc, char **argv)
 	test_deletion(db);
 	test_deletion(db);
 
+	db.save();
+}
+
+/*
+ * Reload the database from disk.
+ */
+void test_1()
+{
+	Database<DBTest> db("test.db");
+	db.load();
+	print_db(db);
+}
+
+int main(int argc, char **argv)
+{
+	test_0();
+	test_1();
+
 	return 0;
 }