public byte[] Read(OnDiscAdress Adress)
{
byte[] Readin;
lock (DatabaseFile)
{
// seek to the position
DatabaseFile.Seek(Adress.Start, SeekOrigin.Begin);
Readin = new byte[Adress.End - Adress.Start];
// read it in
DatabaseFile.Read(Readin, 0, Readin.Length);
}
return Readin;
}
public byte[] Read(OnDiscAdress Adress)
{
byte[] Readin;
lock (DatabaseFile)
{
// seek to the position
DatabaseFile.Seek(Adress.Start, SeekOrigin.Begin);
Readin = new byte[Adress.End - Adress.Start];
// read it in
DatabaseFile.Read(Readin, 0, Readin.Length);
}
return(Readin);
}
public object ReadFromCache(OnDiscAdress adress)
{
lock (Cache)
{
if (!Cache.ContainsKey(adress.End))
{
// it's not in the cache
return(null);
}
else
{
return(Cache[adress.End]);
}
}
return(null);
}
public object ReadFromCache(OnDiscAdress adress)
{
lock(Cache)
{
if (!Cache.ContainsKey(adress.End))
{
// it's not in the cache
return null;
}
else
{
return Cache[adress.End];
}
}
return null;
}
private OnDiscAdress WriteToDatabase(byte[] ToWrite)
{
OnDiscAdress OutputAdress = new OnDiscAdress();
lock (DatabaseFile)
{
// seek to the end...
DatabaseFile.Seek(DatabaseFile.Length, SeekOrigin.Begin);
OutputAdress.Start = DatabaseFile.Position;
DatabaseFile.Write(ToWrite, 0, ToWrite.Length);
OutputAdress.End = DatabaseFile.Position;
DatabaseFile.Flush();
}
return(OutputAdress);
}
private static XS1_DataObject ReadFromCache(TinyOnDiskStorage sensor_data, OnDiscAdress adress)
{
XS1_DataObject dataobject = null;
object cacheditem = sensor_data.Cache.ReadFromCache(adress);
if (cacheditem == null)
{
// not found in cache, read from disk and add to cache
dataobject.Deserialize(sensor_data.Read(adress));
sensor_data.Cache.AddToCache(adress,dataobject);
}
else
{
// found in cache, take it...
dataobject = (XS1_DataObject)cacheditem;
}
return dataobject;
}
private void WriteToIndex(OnDiscAdress Adresspattern)
{
lock (DatabaseIndexFile)
{
// seek to the end...
DatabaseIndexFile.Seek(DatabaseIndexFile.Length, SeekOrigin.Begin);
byte[] ToWrite = Adresspattern.Serialize();
DatabaseIndexFile.Write(ToWrite, 0, ToWrite.Length);
DatabaseIndexFile.Flush();
lock (InMemoryIndex)
{
// append to the inmemory index
InMemoryIndex.Add(Adresspattern);
}
}
}
private XS1_DataObject ReadFromCache(OnDiscAdress adress)
{
XS1_DataObject dataobject = new XS1_DataObject();
object cacheditem = sensor_data.Cache.ReadFromCache(adress);
if (cacheditem == null)
{
// not found in cache, read from disk and add to cache
dataobject.Deserialize(sensor_data.Read(adress));
sensor_data.Cache.AddToCache(adress, dataobject);
}
else
{
// found in cache, take it...
dataobject = (XS1_DataObject)cacheditem;
}
return(dataobject);
}
public void ReadCompleteIndexFromDiskIntoMemory()
{
lock (DatabaseIndexFile)
{
DatabaseIndexFile.Seek(0, SeekOrigin.Begin);
long currentPosition = 0;
byte[] _SerializedData;
OnDiscAdress _deserializedAdress;
InMemoryIndex = new List <OnDiscAdress>();
try
{
while (currentPosition != DatabaseIndexFile.Length)
{
// read through the index...
// one OnDiskAdress is 33 bytes
_SerializedData = new byte[33];
DatabaseIndexFile.Read(_SerializedData, 0, 33);
_deserializedAdress = new OnDiscAdress();
_deserializedAdress.Deserialize(_SerializedData);
InMemoryIndex.Add(_deserializedAdress);
currentPosition = currentPosition + 33;
/// HACK
//if (InMemoryIndex.Count > 50000)
// break;
}
}
catch (Exception)
{
}
}
}
public void AddToCache(OnDiscAdress adress, object data)
{
lock (Cache)
{
if (Cache.ContainsKey(adress.End))
{
// update it...
Cache.Remove(adress.End);
Cache.Add(adress.End, data);
}
else
{
// add it
Cache.Add(adress.End, data);
HouseKeepingList.Add(adress.End);
if (HouseKeepingList.Count > MaximumNoOfCacheItems)
{
Cache.Remove(HouseKeepingList[0]);
HouseKeepingList.RemoveAt(0);
}
}
}
}
public void AddToCache(OnDiscAdress adress,object data)
{
lock(Cache)
{
if (Cache.ContainsKey(adress.End))
{
// update it...
Cache.Remove(adress.End);
Cache.Add(adress.End,data);
}
else
{
// add it
Cache.Add(adress.End,data);
HouseKeepingList.Add(adress.End);
if (HouseKeepingList.Count > MaximumNoOfCacheItems)
{
Cache.Remove(HouseKeepingList[0]);
HouseKeepingList.RemoveAt(0);
}
}
}
}
private void WriteToIndex(OnDiscAdress Adresspattern)
{
lock (DatabaseIndexFile)
{
// seek to the end...
DatabaseIndexFile.Seek(DatabaseIndexFile.Length, SeekOrigin.Begin);
byte[] ToWrite = Adresspattern.Serialize();
DatabaseIndexFile.Write(ToWrite, 0, ToWrite.Length);
DatabaseIndexFile.Flush();
lock(InMemoryIndex)
{
// append to the inmemory index
InMemoryIndex.Add(Adresspattern);
}
}
}
private OnDiscAdress WriteToDatabase(byte[] ToWrite)
{
OnDiscAdress OutputAdress = new OnDiscAdress();
lock (DatabaseFile)
{
// seek to the end...
DatabaseFile.Seek(DatabaseFile.Length, SeekOrigin.Begin);
OutputAdress.Start = DatabaseFile.Position;
DatabaseFile.Write(ToWrite, 0, ToWrite.Length);
OutputAdress.End = DatabaseFile.Position;
DatabaseFile.Flush();
}
return OutputAdress;
}
public void ReadCompleteIndexFromDiskIntoMemory()
{
lock (DatabaseIndexFile)
{
DatabaseIndexFile.Seek(0, SeekOrigin.Begin);
long currentPosition = 0;
byte[] _SerializedData;
OnDiscAdress _deserializedAdress;
InMemoryIndex = new List<OnDiscAdress>();
try
{
while (currentPosition != DatabaseIndexFile.Length)
{
// read through the index...
// one OnDiskAdress is 33 bytes
_SerializedData = new byte[33];
DatabaseIndexFile.Read(_SerializedData, 0, 33);
_deserializedAdress = new OnDiscAdress();
_deserializedAdress.Deserialize(_SerializedData);
InMemoryIndex.Add(_deserializedAdress);
currentPosition = currentPosition + 33;
/// HACK
//if (InMemoryIndex.Count > 50000)
// break;
}
}
catch (Exception)
{
}
}
}
public void Write(byte[] Data)
{
OnDiscAdress adress = WriteToDatabase(Data);
WriteToIndex(adress);
}
