//-------< Add child relation to a particular DB-element >---------------------------
public static bool addRelation <Key, Value, Data>(this DBEngine <Key, Value> db_edit, Key key1, Key key2)
{
Value val1, val2;
bool key2_present = db_edit.getValue(key2, out val2);
if (key2_present)
{
bool key1_present = db_edit.getValue(key1, out val1);
if (key1_present)
{
DBElement <Key, Data> elem = val1 as DBElement <Key, Data>;
elem.children.Add(key2);
elem.timeStamp = DateTime.Now;
return(true);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
// delegate for time stamp query.
public Func <Key, bool> defineTimeStampQuery(DateTime startTime, DateTime?endTime = null)
{
Func <Key, bool> queryPredicate = (Key key) =>
{
if (!db.Keys().Contains(key))
{
return(false);
}
else
{
if (endTime == null)
{
endTime = DateTime.Now;
}
DBElement <Key, Value> value;
db.getValue(key, out value);
DBElement <Key, Value> elem = value as DBElement <Key, Value>;
int cond1 = DateTime.Compare(elem.timeStamp, startTime);
int cond2 = DateTime.Compare(elem.timeStamp, (DateTime)endTime);
if (cond1 >= 0 && cond2 <= 0)
{
return(true);
}
}
return(false);
};
return(queryPredicate);
}
//-------< Get keys of DBElements containing a pattern in the metadata section >-------------
public List <Key> get_keys_with_metadata <Key, Value, Data>(DBEngine <Key, Value> db, string pat)
{
List <Key> key_collection = new List <Key>();
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
if (elem.name.Contains(pat) || elem.descr.Contains(pat) || elem.timeStamp.ToString().Contains(pat))
{
key_collection.Add(key);
}
else if (elem.children.Count() > 0)
{
foreach (Key x in elem.children)
{
if (x.ToString().Contains(pat))
{
key_collection.Add(key);
}
}
}
}
if (key_collection.Count > 0)
{
return(key_collection);
}
else
{
return(default(List <Key>));
}
}
public List <string> dateTimeSearch(DateTime fromDate, DateTime toDate, DBEngine <string, DBElement <string, List <string> > > db)
{
if (toDate == default(DateTime))
{
toDate = DateTime.Now;
}
List <string> foundKeys = new List <string>();
IEnumerable <string> keys = db.Keys();
foreach (string key in keys)
{
DBElement <string, List <string> > elem = new DBElement <string, List <string> >();
db.getValue(key, out elem);
if (elem.timeStamp <= toDate && elem.timeStamp > fromDate)
{
foundKeys.Add(key);
}
}
if (foundKeys.Count == 0)
{
return(null);
}
else
{
return(foundKeys);
}
}
public Action<Message>edit(DBEngine<int, DBElement<int, string>> db)
{
Action<Message> Edit = (msg) =>
{
XDocument xml = XDocument.Parse(msg.content.ToString());
XElement element = xml.Descendants("Msg").ElementAt(0).Descendants("Data").ElementAt(0);
int key = int.Parse(element.Descendants("key").ElementAt(0).Value);
DBElement<int, string> elem = new DBElement<int, string>();
Console.Write("\n\n --- edit a element which key ={0}--- ",key);
Write("\n\n ---Database before edit---");
db.showDB();
if (!db.getValue(key, out elem))
{
msg.content = "edit fail";
return;
}
elem.name = element.Descendants("value").Descendants("name").ElementAt(0).Value;
elem.descr = element.Descendants("value").Descendants("descr").ElementAt(0).Value;
elem.timeStamp = (DateTime)element.Descendants("value").Descendants("timestamp").ElementAt(0);
IEnumerable<XElement> children = element.Descendants("value").Descendants("children").Descendants("key");
elem.children = new List<int>();
foreach (var child in children)
elem.children.Add(int.Parse(child.Value));
IEnumerable<XElement> items = element.Descendants("value").Descendants("payload");
if (items.Count() == 1)
elem.payload = items.ElementAt(0).Value;
msg.content = "edit success";
Utilities.swapUrls(ref msg);
Console.Write("\n\n --- Database after edit ---");
db.showDB();
};
return Edit;
}
public List <string> metaDataPattern(string pattern, DBEngine <string, DBElement <string, List <string> > > db)
{
List <string> foundKeys = new List <string>();
IEnumerable <string> keys = db.Keys();
foreach (string key in keys)
{
DBElement <string, List <string> > elem = new DBElement <string, List <string> >();
db.getValue(key, out elem);
if (elem.name.Contains(pattern))
{
foundKeys.Add(key);
}
else if (elem.descr.Contains(pattern))
{
foundKeys.Add(key);
}
else if (elem.timeStamp.ToString().Contains(pattern))
{
foundKeys.Add(key);
}
}
if (foundKeys.Count == 0)
{
return(null);
}
else
{
return(foundKeys);
}
}
public static DBElement <Key, Value> searchValue <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, Key key)
{
//ToDo: Check whether key exist
DBElement <Key, Value> val;
dbEngine.getValue(key, out val);
return(val);
}
//----< write simple db elements out to Console >------------------
public static void show <Key, Value, Data>(this DBEngine <Key, Value> db)
{
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
Write("\n\n -- key = {0} --", key);
Write(elem.showElement());
}
}
public List <Key> childrenByKey(Key key, DBEngine <Key, DBElement <Key, List <string> > > db)
{
if (db.getValue(key, out elemPay))
{
if (elemPay.children.Count() > 0)
{
return(elemPay.children);
}
return(null);
}
return(null);
}
//-------< Get the children list in DBelement of a particular key. >--------------
public List <Key> getChildren <Key, Value, Data>(DBEngine <Key, Value> db, Key key)
{
Value val;
List <Key> ret = new List <Key>();
if (db.getValue(key, out val))
{
DBElement <Key, Data> elem = val as DBElement <Key, Data>;
return(elem.children);
}
return(default(List <Key>));
}
public static bool addRelationship <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, Key key, List <Key> children)
{
DBElement <Key, Value> elem;
if (dbEngine.containsKey(key))
{
dbEngine.getValue(key, out elem);
elem.children.AddRange(children);
return(true);
}
return(false);
}
public List <string> valueByKey(Key key, DBEngine <Key, DBElement <Key, List <string> > > db)
{
if (db.getValue(key, out elemPay))
{
if (elemPay.payload.Count() > 0)
{
return(elemPay.payload);
}
return(null);
}
return(null);
}
//-------< Find the DBElement of a particular key. >---------------------------
public DBElement <Key, Data> findValue <Key, Value, Data>(DBEngine <Key, Value> db, Key key)
{
Value val;
if (db.getValue(key, out val))
{
return(val as DBElement <Key, Data>);
}
else
{
return(default(DBElement <Key, Data>));
}
}
public static bool modifyMetadata <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, Key key, string name, string description)
{
DBElement <Key, Value> elem;
if (dbEngine.containsKey(key))
{
dbEngine.getValue(key, out elem);
elem.name = name;
elem.descr = description;
return(true);
}
return(false);
}
//----< write simple db elements out to Console >------------------
public static void show <Key, Value, Data>(this DBEngine <Key, Value> db)
{
"Displaying DB contents :".title('_');
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
Write("\n\n -- key = {0} --", key);
Write(elem.showElement());
Write("\n -- key = {0} --", key);
}
"".demarcation();
}
//----< write enumerable db elements out to Console >--------------
public static string show <Key, Value, Data, T>(this DBEngine <Key, Value> db)
where Data : IEnumerable <T>
{
StringBuilder displayString = new StringBuilder();
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
displayString.Append("\n\n -- key = " + key + " --");
displayString.Append(elem.showElement <Key, Data, T>());
}
return(displayString.ToString());
}
//-------< Replace payload of a particular DB-element with a new payload.>--------------------
public static bool editInstance <Key, Value, Data>(this DBEngine <Key, Value> db_edit, Key key1, Data new_instance)
{
Value value;
if (db_edit.getValue(key1, out value))
{
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
elem.payload = new_instance;
elem.timeStamp = DateTime.Now;
return(true);
}
else
{
return(false);
}
}
//-------< Edit description of a particular DB-element >--------------------
public static bool editDescr <Key, Value, Data>(this DBEngine <Key, Value> db_edit, Key key1, string new_descr)
{
Value value;
if (db_edit.getValue(key1, out value))
{
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
elem.descr = new_descr;
elem.timeStamp = DateTime.Now;
return(true);
}
else
{
return(false);
}
}
public static List <Key> searchChildren <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, Key key)
{
List <Key> children = new List <Key>();
DBElement <Key, Value> val;
if (dbEngine.containsKey(key))
{
dbEngine.getValue(key, out val);
foreach (var child in val.children)
{
children.Add(child);
}
return(children);
}
return(children);
}
public static List <Key> searchMetadata <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, string searchString)
{
List <Key> matchedKeys = new List <Key>();
dynamic keys = dbEngine.Keys();
DBElement <Key, Value> val;
foreach (var key in keys)
{
dbEngine.getValue(key, out val);
if (Regex.IsMatch(val.name, searchString) || Regex.IsMatch(val.descr, searchString))
{
matchedKeys.Add(key);
}
}
return(matchedKeys);
}
public static List <Key> searchForKeyPattern <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, string keyPattern)
{
List <Key> matchedKeys = new List <Key>();
dynamic keys = dbEngine.Keys();
DBElement <Key, Value> val;
foreach (var key in keys)
{
dbEngine.getValue(key, out val);
if ((Regex.IsMatch(key, keyPattern)))
{
matchedKeys.Add(key);
}
}
return(matchedKeys);
}
public static bool removeRelationship <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, Key key, List <Key> children)
{
DBElement <Key, Value> elem;
if (dbEngine.containsKey(key))
{
dbEngine.getValue(key, out elem);
foreach (var child in children)
{
if (elem.children.Contains(child))
{
elem.children.Remove(child);
}
}
return(true);
}
return(false);
}
public static void toXml(this DBEngine <string, DBElement <string, List <string> > > dbEngine)
{
dynamic dict = dbEngine.Keys();
DBElement <string, List <string> > result;
XDocument xmlDoc = new XDocument();
XElement root = new XElement("noSqlDb");
xmlDoc.Add(root);
foreach (var key in dict)
{
dbEngine.getValue(key, out result);
XElement element = new XElement("element");
root.Add(element);
XElement keyValue = new XElement("key", key);
element.Add(keyValue);
XElement value = new XElement("value");
element.Add(value);
XElement children = new XElement("children");
value.Add(children);
foreach (var item in result.children)
{
XElement child = new XElement("child", item);
children.Add(child);
}
XElement description = new XElement("description", result.descr);
XElement name = new XElement("name");
name.SetValue(result.name);
XElement timestamp = new XElement("timestamp", result.timeStamp);
XElement payLoad = new XElement("payload");
value.Add(description);
value.Add(name);
value.Add(timestamp);
value.Add(payLoad);
foreach (var item in result.payload)
{
XElement load = new XElement("load", item);
payLoad.Add(load);
}
}
saveXml(xmlDoc);
}
//-------< Get keys of DBElements written within a specified time interval >-------------
public List <Key> get_keys_within_timeInterval <Key, Value, Data>(DBEngine <Key, Value> db, DateTime t1, DateTime t2 = default(DateTime))
{
List <Key> key_collection = new List <Key>();
if (t2 == default(DateTime))
{
t2 = DateTime.Now;
}
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
if (DateTime.Compare(elem.timeStamp, t1) >= 0 && DateTime.Compare(elem.timeStamp, t2) <= 0)
{
key_collection.Add(key);
}
}
return(key_collection);
}
public static List <Key> searchForTimeStamp <Key, Value>(this DBEngine <Key, DBElement <Key, Value> > dbEngine, DateTime from, DateTime?to)
{
List <Key> matchedKeys = new List <Key>();
dynamic keys = dbEngine.Keys();
DBElement <Key, Value> val;
if (!to.HasValue)
{
to = DateTime.Now;
}
foreach (var key in keys)
{
dbEngine.getValue(key, out val);
if (val.timeStamp >= from && val.timeStamp <= to)
{
matchedKeys.Add(key);
}
}
return(matchedKeys);
}
//-------< Remove child relation of a particular DB-element >--------------------
public static bool removeRelation <Key, Value, Data>(this DBEngine <Key, Value> db_edit, Key key1, Key key2)
{
Value value;
if (db_edit.getValue(key1, out value))
{
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
if (elem.children.Contains(key2))
{
elem.children.Remove(key2);
elem.timeStamp = DateTime.Now;
return(true);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
//-------< Save all the contents in the database to a single XML file. >---------------------------
public string persistDB <Key, Value, Data>(DBEngine <Key, Value> db)
{
XDocument xml = new XDocument();
xml.Declaration = new XDeclaration("1.0", "utf-8", "yes");
XComment comment = new XComment("This is a No-SQL Database.");
xml.Add(comment);
XElement noSqlDb = new XElement("NoSqlDb");
XElement keyType = new XElement("KeyType", typeof(Key));
XElement payloadType = new XElement("PayloadType", typeof(Data));
xml.Add(noSqlDb);
noSqlDb.Add(keyType);
noSqlDb.Add(payloadType);
//-------< Save the Key and DBElement in a single XML Element called Key-Value-Pair >---------
foreach (Key k in db.Keys())
{
XElement pair = new XElement("Key-Value-Pair");
XElement key = new XElement("Key", k);
pair.Add(key);
Value val1;
db.getValue(k, out val1);
DBElement <Key, Data> elem = val1 as DBElement <Key, Data>;
XElement dbelem = persistDBelement <Key, Data>(elem);
pair.Add(dbelem);
noSqlDb.Add(pair);
}
string file_name = generate_file_name();
xml.Save(file_name);
return(file_name);
}
static void Main(string[] args)
{
"Testing DBEngine Package".title('=');
WriteLine();
Write("\n --- Test DBElement<int,string> ---");
DBElement <int, string> elem1 = new DBElement <int, string>();
elem1.payload = "a payload";
Write(elem1.showElement <int, string>());
WriteLine();
DBElement <int, string> elem2 = new DBElement <int, string>("Darth Vader", "Evil Overlord");
elem2.payload = "The Empire strikes back!";
Write(elem2.showElement <int, string>());
WriteLine();
var elem3 = new DBElement <int, string>("Luke Skywalker", "Young HotShot");
elem3.children.AddRange(new List <int> {
1, 5, 23
});
elem3.payload = "X-Wing fighter in swamp - Oh oh!";
Write(elem3.showElement <int, string>());
WriteLine();
Write("\n --- Test DBEngine<int,DBElement<int,string>> ---");
int key = 0;
Func <int> keyGen = () => { ++key; return(key); }; // anonymous function to generate keys
DBEngine <int, DBElement <int, string> > db = new DBEngine <int, DBElement <int, string> >();
bool p1 = db.insert(keyGen(), elem1);
bool p2 = db.insert(keyGen(), elem2);
bool p3 = db.insert(keyGen(), elem3);
if (p1 && p2 && p3)
{
Write("\n all inserts succeeded");
}
else
{
Write("\n at least one insert failed");
}
db.show <int, DBElement <int, string>, string>();
WriteLine();
Write("\n --- Test DBElement<string,List<string>> ---");
DBElement <string, List <string> > newelem1 = new DBElement <string, List <string> >();
newelem1.name = "newelem1";
newelem1.descr = "test new type";
newelem1.payload = new List <string> {
"one", "two", "three"
};
Write(newelem1.showElement <string, List <string> >());
WriteLine();
Write("\n --- Test DBElement<string,List<string>> ---");
DBElement <string, List <string> > newerelem1 = new DBElement <string, List <string> >();
newerelem1.name = "newerelem1";
newerelem1.descr = "better formatting";
newerelem1.payload = new List <string> {
"alpha", "beta", "gamma"
};
newerelem1.payload.Add("delta");
newerelem1.payload.Add("epsilon");
Write(newerelem1.showElement <string, List <string>, string>());
WriteLine();
DBElement <string, List <string> > newerelem2 = new DBElement <string, List <string> >();
newerelem2.name = "newerelem2";
newerelem2.descr = "better formatting";
newerelem1.children.AddRange(new[] { "first", "second" });
newerelem2.payload = new List <string> {
"a", "b", "c"
};
newerelem2.payload.Add("d");
newerelem2.payload.Add("e");
Write(newerelem2.showElement <string, List <string>, string>());
WriteLine();
Write("\n --- Test DBEngine<string,DBElement<string,List<string>>> ---");
int seed = 0;
string skey = seed.ToString();
Func <string> skeyGen = () => {
++seed;
skey = "string" + seed.ToString();
skey = skey.GetHashCode().ToString();
return(skey);
};
DBEngine <string, DBElement <string, List <string> > > newdb =
new DBEngine <string, DBElement <string, List <string> > >();
newdb.insert(skeyGen(), newerelem1);
newdb.insert(skeyGen(), newerelem2);
newdb.show <string, DBElement <string, List <string> >, List <string>, string>();
WriteLine();
"testing edits".title();
db.show <int, DBElement <int, string>, string>();
DBElement <int, string> editElement = new DBElement <int, string>();
db.getValue(1, out editElement);
editElement.showElement <int, string>();
editElement.name = "editedName";
editElement.descr = "editedDescription";
db.show <int, DBElement <int, string>, string>();
Write("\n\n");
}