//----< process children query using queryPredicate >-----------------------------------
public bool processChildrenQuery <Key, Value, Data>(Func <Key, bool> queryPredicate,
out List <Key> keyCollection, Key searchKey, DBEngine <Key, Value> db)
{
keyCollection = new List <Key>();
Value value;
if (db.Keys().Contains(searchKey))
{
db.getValue(searchKey, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
foreach (Key child in elem.children)
{
if (queryPredicate(child))
{
keyCollection.Add(child);
}
}
}
if (keyCollection.Count() > 0)
{
return(true);
}
return(false);
}
//----< Public Constructor >-----------------------------------------------------
public DBFactory(DBEngine <Key, Value> db)
{
dbStore = new Dictionary <Key, Value>();
foreach (Key key in db.Keys())
{
Value value;
db.getValue(key, out value);
dbStore[key] = value;
}
}
//----< 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());
}
}
//----< build queryPredicate for querying children >------------------------------------
/*
* Query returns true if query(key) condition is satisfied.
* In this example the query is checking to see if the query
* parameter, the captured string, test, is a substring of
* the database element referenced by key.
*/
public Func <Key, bool> queryChildren <Key, Value, Data>(DBEngine <Key, Value> db)
{
Func <Key, bool> queryPredicate = (Key key) =>
{
if (db.Keys().Contains(key))
{
return(true);
}
return(false);
};
return(queryPredicate);
}
//----< Convert Enumerable DB to XML file format >---------------------------------
public static XDocument PersistToXML <Key, Value, Data, T>(this DBEngine <Key, Value> dbStore) where Data : IEnumerable <T>
{
XDocument xDocument = new XDocument();
xDocument.Declaration = new XDeclaration("1.0", "utf-8", "yes");
xDocument.Add(new XComment("Persisting DB to XML at " + DateTime.Now.ToString()));
XElement root = new XElement("NoSqlDb");
root.Add(new XElement("KeyType", typeof(Key).ToString()));
root.Add(new XElement("PayloadType", typeof(Data).ToString()));
foreach (Key key in dbStore.Keys())
{
XElement dbEntry = new XElement("DBEntry");
root.Add(dbEntry);
dbEntry.Add(new XElement("Key", key.ToString()));
Value element;
dbStore.getValue(key, out element);
DBElement <Key, Data> dbElement = element as DBElement <Key, Data>;
XElement xmlElement = new XElement("element");
xmlElement.Add(new XElement("name", dbElement.name));
xmlElement.Add(new XElement("descr", dbElement.descr));
xmlElement.Add(new XElement("timestamp", dbElement.timeStamp));
XElement children = new XElement("children");
if (dbElement.children.Count > 0)
{
foreach (Key child in dbElement.children)
{
children.Add(new XElement("key", child.ToString()));
}
}
xmlElement.Add(children);
XElement payload = new XElement("payload");
Data data = dbElement.payload;
foreach (T item in data)
{
payload.Add(new XElement("item", item.ToString()));
}
xmlElement.Add(payload);
dbEntry.Add(xmlElement);
}
xDocument.Add(root);
return(xDocument);
}
//----< Query for value of a given key >------------------------------------------------
public static Value queryValue <Key, Value, Data>(Key key, DBEngine <Key, Value> db)
{
Value value = default(Value);
if (db.Keys().Contains(key))
{
db.getValue(key, out value);
DBElement <Key, Data> elem = value as DBElement <Key, Data>;
return(value);
}
else
{
"Key doesn't exist!".error();
return(value);
}
}
//----< process query using queryPredicate >---------------------------------------------
public bool processQuery <Key, Value>(Func <Key, bool> queryPredicate,
out List <Key> keyCollection, DBEngine <Key, Value> db)
{
/*
* step through all the keys in the db to see if
* the queryPredicate is true for one or more keys.
*/
keyCollection = new List <Key>();
foreach (Key key in db.Keys())
{
if (queryPredicate(key))
{
keyCollection.Add(key);
}
}
if (keyCollection.Count() > 0)
{
return(true);
}
return(false);
}
//----< Convert primitive DB to XML format >---------------------------------------
public static XDocument ToXML <Key, Value, Data>(this DBEngine <Key, Value> dbStore)
{
XDocument xDocument = new XDocument();
XElement root = new XElement("NoSqlDb");
foreach (Key key in dbStore.Keys())
{
XElement dbEntry = new XElement("DBEntry");
root.Add(dbEntry);
dbEntry.Add(new XElement("Key", key.ToString()));
Value element;
dbStore.getValue(key, out element);
DBElement <Key, Data> dbElement = element as DBElement <Key, Data>;
XElement xmlElement = new XElement("element");
xmlElement.Add(new XElement("name", dbElement.name));
xmlElement.Add(new XElement("descr", dbElement.descr));
xmlElement.Add(new XElement("timestamp", dbElement.timeStamp));
XElement children = new XElement("children");
if (dbElement.children.Count > 0)
{
foreach (Key child in dbElement.children)
{
children.Add(new XElement("key", child.ToString()));
}
}
xmlElement.Add(children);
XElement payload = new XElement("payload");
payload.Add(new XElement("item", dbElement.payload.ToString()));
xmlElement.Add(payload);
dbEntry.Add(xmlElement);
}
xDocument.Add(root);
return(xDocument);
}
