database: Implement updates to match my current design

- Force the primary key to be a string
- Throw error codes rather than 0

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

design.txt

@@ -240,9 +240,10 @@ Database: (lib/database.cpp)
 - DatabaseEntry:
 	class DatabaseEntry { /* let database modify valid flag */
 	public:
+		const std::string primary_key;
 		bool valid;
 
-		virtual const std::string &primary_key() = 0;
+		DatabaseEntry(const std::string &);
 		virtual void write(File &) = 0;
 		virtual void read(File &) = 0;
 		virtual void print() = 0;
@@ -253,13 +254,13 @@ Database: (lib/database.cpp)
 - IndexEntry:
 	class IndexEntry : public DatabaseEntry {
 	public:
-		string key;
 		set<unsigned int> values;
 
-		const std::string &primary_key();
 		void write(File &);
 		void read(File &);
 		void print();
+		void insert(unsigned int);
+		void remove(unsigned int);
 	};
 
 	File << key << endl;
@@ -283,7 +284,7 @@ Database: (lib/database.cpp)
 		void print_keys();
 
 		unsigned int insert(T);
-		void delete(unsigned int);
+		void remove(unsigned int);
 		unsigned int size();
 		unsigned int num_rows();
 
@@ -332,7 +333,7 @@ Database: (lib/database.cpp)
 		mapping is also created into the keys map to map the primary
 		key back to the id of the newly added item.
 
-	void Database :: delete(unsigned int index);
+	void Database :: remove(unsigned int index);
 		Mark db[index] as invalid (quick deletion).
 
 	unsigned int Database :: size();
@@ -342,14 +343,16 @@ Database: (lib/database.cpp)
 		Return db.size().
 
 	unsigned int Database :: first();
-		Return the id to the first valid row.
+		Return the id to the first valid row.  Return db.size() if
+		there are no valid rows.
 
 	unsigned int Database :: last();
-		Return the id of the last valid row.
+		Return the id of the last valid row.  Return db.size() if
+		there are no valid rows.
 
 	unsigned int Database :: next(unsigned int &id);
-		Return the id of the next valid row or throw -EINVAL if there
+		Return the id of the next valid row or return db.size() if
-		are no remaining valid rows.
+		there are no valid rows.
 
 	bool Database :: has_key(const std::string &key);
 		Return true if an item with primary key "key" exists in the
@@ -363,13 +366,15 @@ Database: (lib/database.cpp)
 	template <class T>
 	T &Database :: find(const std::string &key);
 		Search for primary key "key" in the database.  The reverse
-		mapping should be used to make this operation faster.  Throw
+		mapping should be used to make this operation faster.
-		-EEXIST if the key is not found in the mapping.
+		Throw -EEXIST if the key is not found in the mapping.
+		Throw -EINVAL if the key points to an invalid entry.
 
 	template <class T>
 	T &Database :: operator[](unsigned int index);
-		Return a reference to db[index].  Throw -EEXIST if index is out
+		Return a reference to db[index].
-		of range.
+		Throw -EEXIST if index is out of range.
+		Throw -EINVAL if index is invalid.
 
 
 

design/database.txt

@@ -32,9 +32,10 @@ Database: (lib/database.cpp)
 - DatabaseEntry:
 	class DatabaseEntry { /* let database modify valid flag */
 	public:
+		const std::string primary_key;
 		bool valid;
 
-		virtual const std::string &primary_key() = 0;
+		DatabaseEntry(const std::string &);
 		virtual void write(File &) = 0;
 		virtual void read(File &) = 0;
 		virtual void print() = 0;
@@ -45,13 +46,13 @@ Database: (lib/database.cpp)
 - IndexEntry:
 	class IndexEntry : public DatabaseEntry {
 	public:
-		string key;
 		set<unsigned int> values;
 
-		const std::string &primary_key();
 		void write(File &);
 		void read(File &);
 		void print();
+		void insert(unsigned int);
+		void remove(unsigned int);
 	};
 
 	File << key << endl;
@@ -75,7 +76,7 @@ Database: (lib/database.cpp)
 		void print_keys();
 
 		unsigned int insert(T);
-		void delete(unsigned int);
+		void remove(unsigned int);
 		unsigned int size();
 		unsigned int num_rows();
 
@@ -124,7 +125,7 @@ Database: (lib/database.cpp)
 		mapping is also created into the keys map to map the primary
 		key back to the id of the newly added item.
 
-	void Database :: delete(unsigned int index);
+	void Database :: remove(unsigned int index);
 		Mark db[index] as invalid (quick deletion).
 
 	unsigned int Database :: size();
@@ -134,14 +135,16 @@ Database: (lib/database.cpp)
 		Return db.size().
 
 	unsigned int Database :: first();
-		Return the id to the first valid row.
+		Return the id to the first valid row.  Return db.size() if
+		there are no valid rows.
 
 	unsigned int Database :: last();
-		Return the id of the last valid row.
+		Return the id of the last valid row.  Return db.size() if
+		there are no valid rows.
 
 	unsigned int Database :: next(unsigned int &id);
-		Return the id of the next valid row or throw -EINVAL if there
+		Return the id of the next valid row or return db.size() if
-		are no remaining valid rows.
+		there are no valid rows.
 
 	bool Database :: has_key(const std::string &key);
 		Return true if an item with primary key "key" exists in the
@@ -155,10 +158,12 @@ Database: (lib/database.cpp)
 	template <class T>
 	T &Database :: find(const std::string &key);
 		Search for primary key "key" in the database.  The reverse
-		mapping should be used to make this operation faster.  Throw
+		mapping should be used to make this operation faster.
-		-EEXIST if the key is not found in the mapping.
+		Throw -EEXIST if the key is not found in the mapping.
+		Throw -EINVAL if the key points to an invalid entry.
 
 	template <class T>
 	T &Database :: operator[](unsigned int index);
-		Return a reference to db[index].  Throw -EEXIST if index is out
+		Return a reference to db[index].
-		of range.
+		Throw -EEXIST if index is out of range.
+		Throw -EINVAL if index is invalid.

include/database.h

@@ -12,43 +12,42 @@
 #include <vector>
 
 
-template <class T>
 class DatabaseEntry {
 public:
+	std::string primary_key;
 	bool valid;
 
 	DatabaseEntry();
-	virtual T &primary_key() = 0;
 	virtual void write(File &) = 0;
 	virtual void read(File &) = 0;
-#ifdef CONFIG_DEBUG
+#ifdef CONFIG_TEST
 	virtual void print() = 0;
-#endif /* CONFIG_DEBUG */
+#endif /* CONFIG_TEST */
 };
 
 
-class IndexEntry : public DatabaseEntry<const std::string> {
+class IndexEntry : public DatabaseEntry {
 public:
-	std::string key;
 	std::set<unsigned int> values;
 
 	IndexEntry();
 	IndexEntry(const std::string &, unsigned int);
 	~IndexEntry();
-	const std::string &primary_key();
 	void write(File &);
 	void read(File &);
+#ifdef CONFIG_TEST
 	void print();
+#endif /* CONFIG_TEST */
 	void insert(unsigned int);
 	void remove(unsigned int);
 };
 
 
-template <class T, class U>
+template <class T>
 class Database {
 private:
 	std::vector<T> db;
-	std::map<U, unsigned int> keys;
+	std::map<const std::string, unsigned int> keys;
 	unsigned int _size;
 	File file;
 
@@ -57,11 +56,11 @@ public:
 	~Database();
 	void save();
 	void load();
-#ifdef CONFIG_DEBUG
+#ifdef CONFIG_TEST
 	void clear();
 	void print();
 	void print_keys();
-#endif /* CONFIG_DEBUG */
+#endif /* CONFIG_TEST */
 
 	unsigned int insert(T);
 	void remove(unsigned int);
@@ -71,13 +70,13 @@ public:
 	unsigned int first();
 	unsigned int last();
 	unsigned int next(unsigned int);
+	bool has_key(const std::string &);
 	unsigned int find_index(const std::string &);
 	T &find(const std::string &);
 	T &operator[](unsigned int);
 };
 
-template <class T>
+static inline void index_insert(Database<IndexEntry> &db,
-static inline void index_insert(Database<IndexEntry, T> &db,
 				const std::string &key,
 				unsigned int val)
 {
@@ -88,8 +87,7 @@ static inline void index_insert(Database<IndexEntry, T> &db,
 	}
 }
 
-template <class T>
+static inline void index_remove(Database<IndexEntry> &db,
-static inline void index_remove(Database<IndexEntry, T> &db,
 				const std::string &key,
 				unsigned int val)
 {

include/database.hpp

@@ -7,30 +7,27 @@
 #ifndef OCARINA_DATABASE_HPP
 #define OCARINA_DATABASE_HPP
 
+#include <error.h>
+
 template <class T>
-DatabaseEntry<T> :: DatabaseEntry()
+Database<T> :: Database(std::string filepath)
-	       : valid(false)
-{
-}
-
-
-
-template <class T, class U>
-Database<T, U> :: Database(std::string filepath)
 	     : _size(0), file(filepath, FILE_TYPE_DATA)
 {
 }
 
-template <class T, class U>
+template <class T>
-Database<T, U> :: ~Database()
+Database<T> :: ~Database()
 {
 }
 
-template <class T, class U>
+template <class T>
-void Database<T, U> :: save()
+void Database<T> :: save()
 {
-	if (file.open(OPEN_WRITE) == false)
+	try {
+		file.open(OPEN_WRITE);
+	} catch (int error) {
 		return;
+	}
 
 	file << db.size() << std::endl;
 	for (unsigned int i = 0; i < db.size(); i++) {
@@ -43,12 +40,16 @@ void Database<T, U> :: save()
 	file.close();
 }
 
-template <class T, class U>
+template <class T>
-void Database<T, U> :: load()
+void Database<T> :: load()
 {
 	unsigned int db_size;
-	if (file.open(OPEN_READ) == false)
+
+	try {
+		file.open(OPEN_READ);
+	} catch (int error) {
 		return;
+	}
 
 	file >> db_size;
 	db.resize(db_size);
@@ -56,7 +57,7 @@ void Database<T, U> :: load()
 		file >> db[i].valid;
 		if (db[i].valid == true) {
 			db[i].read(file);
-			keys.insert(std::pair<std::string, unsigned int>(db[i].primary_key(), i));
+			keys.insert(std::pair<std::string, unsigned int>(db[i].primary_key, i));
 			_size++;
 		}
 	}
@@ -64,17 +65,17 @@ void Database<T, U> :: load()
 	file.close();
 }
 
-#ifdef CONFIG_DEBUG
+#ifdef CONFIG_TEST
-template <class T, class U>
+template <class T>
-void Database<T, U> :: clear()
+void Database<T> :: clear()
 {
 	db.clear();
 	keys.clear();
 	_size = 0;
 }
 
-template <class T, class U>
+template <class T>
-void Database<T, U> :: print()
+void Database<T> :: print()
 {
 	:: print("Allocated rows: %u\n", db.size());
 	:: print("Valid rows: %u\n", _size);
@@ -87,8 +88,8 @@ void Database<T, U> :: print()
 	}
 }
 
-template <class T, class U>
+template <class T>
-void Database<T, U> :: print_keys()
+void Database<T> :: print_keys()
 {
 	std::map<const std::string, unsigned int>::iterator it;
 	:: print("Found keys:");
@@ -96,15 +97,15 @@ void Database<T, U> :: print_keys()
 		:: print(" %s", it->first.c_str());
 	:: print("\n");
 }
-#endif /* CONFIG_DEBUG */
+#endif /* CONFIG_TEST */
 
-template <class T, class U>
+template <class T>
-unsigned int Database<T, U> :: insert(T val)
+unsigned int Database<T> :: insert(T val)
 {
 	unsigned int id;
-	typename std::map<U, unsigned int>::iterator it;
+	typename std::map<const std::string, unsigned int>::iterator it;
 
-	it = keys.find(val.primary_key());
+	it = keys.find(val.primary_key);
 	if (it != keys.end())
 		return it->second;
 
@@ -113,34 +114,34 @@ unsigned int Database<T, U> :: insert(T val)
 	 */
 	id = db.size();
 	db.push_back(val);
-	keys.insert(std::pair<U, unsigned int>(val.primary_key(), id));
+	keys.insert(std::pair<const std::string, unsigned int>(val.primary_key, id));
 	db[id].valid = true;
 	_size++;
 	return id;
 }
 
-template <class T, class U>
+template <class T>
-void Database<T, U> :: remove(unsigned int id)
+void Database<T> :: remove(unsigned int id)
 {
-	keys.erase(db[id].primary_key());
+	keys.erase(db[id].primary_key);
 	db[id].valid = false;
 	_size--;
 }
 
-template <class T, class U>
+template <class T>
-unsigned int Database<T, U> :: size()
+unsigned int Database<T> :: size()
 {
 	return _size;
 }
 
-template <class T, class U>
+template <class T>
-unsigned int Database<T, U> :: num_rows()
+unsigned int Database<T> :: num_rows()
 {
 	return db.size();
 }
 
-template <class T, class U>
+template <class T>
-unsigned int Database<T, U> :: first()
+unsigned int Database<T> :: first()
 {
 	for (unsigned int i = 0; i < db.size(); i++) {
 		if (db[i].valid == true)
@@ -150,8 +151,8 @@ unsigned int Database<T, U> :: first()
 	return db.size();
 }
 
-template <class T, class U>
+template <class T>
-unsigned int Database<T, U> :: last()
+unsigned int Database<T> :: last()
 {
 	if (_size == 0)
 		return db.size();
@@ -164,8 +165,8 @@ unsigned int Database<T, U> :: last()
 	return db.size();
 }
 
-template <class T, class U>
+template <class T>
-unsigned int Database<T, U> :: next(unsigned int id)
+unsigned int Database<T> :: next(unsigned int id)
 {
 	for (unsigned int i = id + 1; i < db.size(); i++) {
 		if (db[i].valid == true)
@@ -175,25 +176,40 @@ unsigned int Database<T, U> :: next(unsigned int id)
 	return db.size();
 }
 
-template <class T, class U>
+template <class T>
-unsigned int Database<T, U> :: find_index(const std::string &key)
+bool Database<T> :: has_key(const std::string &key)
 {
-	typename std::map<U, unsigned int>::iterator it;
+	std::map<const std::string, unsigned int>::iterator it;
+	it = keys.find(key);
+	return it != keys.end();
+}
+
+template <class T>
+unsigned int Database<T> :: find_index(const std::string &key)
+{
+	std::map<const std::string, unsigned int>::iterator it;
 	it = keys.find(key);
 	if (it == keys.end())
-		throw 0;
+		throw -EEXIST;
 	return it->second;
 }
 
-template <class T, class U>
+template <class T>
-T &Database<T, U> :: find(const std::string &key)
+T &Database<T> :: find(const std::string &key)
 {
-	return db[find_index(key)];
+	unsigned int index = find_index(key);
+	if (db[index].valid == false)
+		throw -EINVAL;
+	return db[index];
 }
 
-template <class T, class U>
+template <class T>
-T &Database<T, U> :: operator[](unsigned int id)
+T &Database<T> :: operator[](unsigned int id)
 {
+	if (id >= db.size())
+		throw -EEXIST;
+	else if (db[id].valid == false)
+		throw -EINVAL;
 	return db[id];
 }
 

lib/database.cpp

@@ -3,13 +3,21 @@
  */
 #include <database.h>
 
+
+DatabaseEntry :: DatabaseEntry()
+	       : primary_key(""), valid(false)
+{
+}
+
+
+
 IndexEntry :: IndexEntry()
 {
 }
 
-IndexEntry :: IndexEntry(const std::string &k, unsigned int v)
+IndexEntry :: IndexEntry(const std::string &key, unsigned int v)
-	    : key(k)
 {
+	primary_key = key;
 	insert(v);
 }
 
@@ -17,15 +25,10 @@ IndexEntry :: ~IndexEntry()
 {
 }
 
-const std::string &IndexEntry :: primary_key()
-{
-	return key;
-}
-
 void IndexEntry :: write(File &f)
 {
 	std::set<unsigned int>::iterator it;
-	f << key << std::endl << values.size() << " ";
+	f << primary_key << std::endl << values.size() << " ";
 	for (it = values.begin(); it != values.end(); it++)
 		f << *it << " ";
 }
@@ -34,13 +37,14 @@ void IndexEntry :: read(File &f)
 {
 	unsigned int num, val;
 
-	f >> key >> num;
+	f >> primary_key >> num;
 	for (unsigned int i = 0; i < num; i++) {
 		f >> val;
 		values.insert(val);
 	}
 }
 
+#ifdef CONFIG_TEST
 void IndexEntry :: print()
 {
 	std::set<unsigned int>::iterator it;
@@ -52,6 +56,7 @@ void IndexEntry :: print()
 	}
 	:: print("}");
 }
+#endif /* CONFIG_TEST */
 
 void IndexEntry :: insert(unsigned int val)
 {

tests/database/database.cpp

@@ -6,14 +6,12 @@
 
 #include <sstream>
 
-class DBTest : public DatabaseEntry<const std::string> {
+class DBTest : public DatabaseEntry {
 public:
 	unsigned int value;
-	std::string key;
 
 	DBTest();
 	DBTest(unsigned int);
-	const std::string &primary_key();
 	void write(File &);
 	void read(File &);
 	void print();
@@ -29,7 +27,7 @@ DBTest :: DBTest(unsigned int val)
 
 	value = val;
 	ss << value;
-	key = ss.str();
+	primary_key = ss.str();
 }
 
 void DBTest :: write(File &file)
@@ -47,14 +45,9 @@ void DBTest :: print()
 	:: print("%u", value);
 }
 
-const std::string &DBTest :: primary_key()
-{
-	return key;
-}
 
 
-
+void print_db(Database<DBTest> &db)
-void print_db(Database<DBTest, const std::string> &db)
 {
 	print("Database size: %u\n", db.size());
 	print("Num rows: %u\n", db.num_rows());
@@ -65,14 +58,14 @@ void print_db(Database<DBTest, const std::string> &db)
 		print("db[%u] = %u\n", i, db[i].value);
 }
 
-void test_insertion(Database<DBTest, const std::string> &db)
+void test_insertion(Database<DBTest> &db)
 {
 	for (unsigned int i = 1; i <= 100000; i++)
 		db.insert(DBTest(i));
 	print_db(db);
 }
 
-void test_deletion(Database<DBTest, const std::string> &db)
+void test_deletion(Database<DBTest> &db)
 {
 	for (unsigned int i = db.first(); i < db.num_rows(); i = db.next(i)) {
 		db.remove(i);
@@ -87,7 +80,7 @@ void test_deletion(Database<DBTest, const std::string> &db)
 void test_0()
 {
 	print("Test 0\n");
-	Database<DBTest, const std::string> db("test.db");
+	Database<DBTest> db("test.db");
 
 	test_insertion(db);
 	test_deletion(db);
@@ -102,7 +95,7 @@ void test_0()
 void test_1()
 {
 	print("\nTest 1\n");
-	Database<DBTest, const std::string> db("test.db");
+	Database<DBTest> db("test.db");
 	db.load();
 	print_db(db);
 }
@@ -113,7 +106,7 @@ void test_1()
 void test_2()
 {
 	print("\nTest 2\n");
-	Database<DBTest, const std::string> db("");
+	Database<DBTest> db("");
 
 	test_insertion(db);
 	db.save();
@@ -125,7 +118,7 @@ void test_2()
 void test_3()
 {
 	print("\nTest 3\n");
-	Database<DBTest, const std::string> db("");
+	Database<DBTest> db("");
 	db.load();
 }
 
@@ -135,7 +128,7 @@ void test_3()
 void test_4()
 {
 	print("\nTest 4\n");
-	Database<DBTest, const std::string> db("");
+	Database<DBTest> db("");
 
 	for (unsigned int i = 0; i < 100; i++)
 		db.insert(DBTest(i % 5));
@@ -149,7 +142,7 @@ void test_4()
 void test_5()
 {
 	print("\nTest 5\n");
-	Database<DBTest, const std::string> db("");
+	Database<DBTest> db("");
 	for (unsigned int i = 0; i < 10; i++)
 		db.insert(DBTest(i));
 	db.print();
@@ -161,7 +154,7 @@ void test_5()
 void test_6()
 {
 	print("\nTest 6\n");
-	Database<DBTest, const std::string> db("");
+	Database<DBTest> db("");
 	for (unsigned int i = 0; i < 10; i++)
 		db.insert(DBTest(i));
 	print_db(db);
@@ -175,7 +168,7 @@ void test_6()
 void test_7()
 {
 	print("\nTest 7\n");
-	Database<DBTest, const std::string> db("");
+	Database<DBTest> db("");
 	print_db(db);
 
 	for (unsigned int i = 0; i < 10; i++)

tests/index/index.cpp

@@ -4,7 +4,7 @@
 #include <database.h>
 #include <print.h>
 
-void print_index(Database<IndexEntry, const std::string> &index)
+void print_index(Database<IndexEntry> &index)
 {
 	std::set<std::string>::iterator s_it;
 	std::set<unsigned int>::iterator u_it;
@@ -13,7 +13,7 @@ void print_index(Database<IndexEntry, const std::string> &index)
 	index.print_keys();
 
 	for (unsigned int i = index.first(); i != index.num_rows(); i = index.next(i)) {
-		print("index[%s] = ", index[i].key.c_str());
+		print("index[%s] = ", index[i].primary_key.c_str());
 		index[i].print();
 		print("\n");
 	}
@@ -21,7 +21,7 @@ void print_index(Database<IndexEntry, const std::string> &index)
 	print("\n");
 }
 
-void populate_index(Database<IndexEntry, const std::string> &index)
+void populate_index(Database<IndexEntry> &index)
 {
 	std::string key_str;
 
@@ -32,17 +32,19 @@ void populate_index(Database<IndexEntry, const std::string> &index)
 	}
 }
 
-void remove_keys(Database<IndexEntry, const std::string> &index)
+void remove_keys(Database<IndexEntry> &index)
 {
 	std::string key_str;
 
 	for (char key = 'a'; key <= 'z'; key+=2) {
 		key_str = key;
 		index.remove(index.find_index(key_str));
+		if (index.has_key(key_str))
+			print("Failed to remove key!\n");
 	}
 }
 
-void remove_values(Database<IndexEntry, const std::string> &index)
+void remove_values(Database<IndexEntry> &index)
 {
 	std::string key_str;
 	unsigned int limit = 0;
@@ -52,8 +54,11 @@ void remove_values(Database<IndexEntry, const std::string> &index)
 		for (unsigned int i = 0; i < limit; i++)
 			index_remove(index, key_str, i);
 		limit++;
-		if (limit == 11)
+		if (limit == 11) {
 			limit = 0;
+			if (index.has_key(key_str))
+				print("Failed to remove key!\n");
+		}
 	}
 }
 
@@ -63,7 +68,7 @@ void remove_values(Database<IndexEntry, const std::string> &index)
 void test_0()
 {
 	print("Test 0\n");
-	Database<IndexEntry, const std::string> index("");
+	Database<IndexEntry> index("");
 
 	populate_index(index);
 	print_index(index);
@@ -75,7 +80,7 @@ void test_0()
 void test_1()
 {
 	print("Test 1\n");
-	Database<IndexEntry, const std::string> index("");
+	Database<IndexEntry> index("");
 
 	populate_index(index);
 	remove_keys(index);
@@ -88,7 +93,7 @@ void test_1()
 void test_2()
 {
 	print("Test 2\n");
-	Database<IndexEntry, const std::string> index("");
+	Database<IndexEntry> index("");
 
 	populate_index(index);
 	remove_values(index);
@@ -101,7 +106,7 @@ void test_2()
 void test_3()
 {
 	print("Test 3\n");
-	Database<IndexEntry, const std::string> index("test.idx");
+	Database<IndexEntry> index("test.idx");
 
 	populate_index(index);
 	remove_values(index);
@@ -114,7 +119,7 @@ void test_3()
 void test_4()
 {
 	print("Test 4\n");
-	Database<IndexEntry, const std::string> index("test.idx");
+	Database<IndexEntry> index("test.idx");
 
 	index.load();
 	print_index(index);
@@ -126,7 +131,7 @@ void test_4()
 void test_5()
 {
 	print("Test 5\n");
-	Database<IndexEntry, const std::string> index("");
+	Database<IndexEntry> index("");
 	print("index[nokey].size() = ");
 	try {
 		print("%u\n", index.find("nokey").values.size());