public InitializeResult Initialize()
{
using (FileStream stream = new FileStream(this.Path, FileMode.OpenOrCreate, FileAccess.Read))
{
byte[] magicBytes = new byte[NanoDBConstants.MagicBytes.Length];
if (stream.Read(magicBytes, 0, NanoDBConstants.MagicBytes.Length) != NanoDBConstants.MagicBytes.Length)
{
return(InitializeResult.FileEmpty);
}
int version = stream.ReadByte();
if (version != NanoDBConstants.DatabaseStructureVersion)
{
return(version > 0 ? InitializeResult.VersionMismatch : InitializeResult.FileEmpty);
}
int layoutSize = stream.ReadByte();
if (layoutSize <= 0)
{
return(InitializeResult.FileCorrupt);
}
int recommendedIndex = stream.ReadByte();
if (recommendedIndex < 0 || recommendedIndex >= layoutSize)
{
return(InitializeResult.FileCorrupt);
}
this.RecommendedIndex = recommendedIndex;
byte[] layoutIds = new byte[layoutSize];
if (stream.Read(layoutIds, 0, layoutSize) < layoutSize)
{
return(InitializeResult.FileCorrupt);
}
NanoDBElement[] elements = new NanoDBElement[layoutSize];
for (int i = 0; i < layoutSize; i++)
{
NanoDBElement element = NanoDBElement.Elements[layoutIds[i]];
if (element == null)
{
return(InitializeResult.UnknownDataType);
}
elements[i] = element;
}
this.Layout = new NanoDBLayout(elements);
if ((stream.Length - this.Layout.HeaderSize) % this.Layout.RowSize != 0)
{
return(InitializeResult.UnexpectedFileEnd);
}
this.initialized = true;
return(InitializeResult.Success);
}
}
public bool UpdateLine(NanoDBLine line, params object[] objects)
{
lock (this.readLock)
{
if (!this.Accessible || !this.contentIndex.ContainsKey(line.Key) || objects.Length != this.Layout.LayoutSize || this.shutdown)
{
return(false);
}
Interlocked.Increment(ref this.RunningTasks);
int position = 1;
byte[] data = new byte[this.Layout.RowSize];
data[0] = NanoDBConstants.LineFlagCorrupt;
for (int i = 0; i < objects.Length; i++)
{
NanoDBElement element = this.Layout.Elements[i];
if (element.IsValidElement(objects[i]))
{
if (i == this.indexedBy)
{
string newKey = (string)objects[i];
if (newKey != line.Key && this.contentIndex.ContainsKey(newKey))
{
Interlocked.Decrement(ref this.RunningTasks);
return(false);
}
this.contentIndex.Remove(line.Key);
this.contentIndex[newKey] = line;
line.Key = newKey;
}
else if (this.Sorted && i == this.sortedBy)
{
string newSortKey = (string)objects[i];
if (this.sortIndex.ContainsKey(newSortKey))
{
this.sortIndex[newSortKey].Add(line);
}
else
{
this.sortIndex[newSortKey] = new List <NanoDBLine> {
line
};
}
this.sortIndex[line.SortKey].Remove(line);
line.SortKey = newSortKey;
}
element.Write(objects[i], data, position);
position += element.Size;
line.Content[i] = objects[i];
}
}
this.writer.AddTask(new NanoDBTask {
Type = TaskType.UpdateLine, LineNumber = line.LineNumber, Data = data
});
}
return(true);
}
public bool UpdateObject(NanoDBLine line, int layoutIndex, object obj)
{
lock (this.readLock)
{
if (!this.Accessible || !this.contentIndex.ContainsKey(line.Key) || layoutIndex < 0 || layoutIndex >= this.Layout.LayoutSize || this.shutdown)
{
return(false);
}
Interlocked.Increment(ref this.RunningTasks);
NanoDBElement element = this.Layout.Elements[layoutIndex];
if (!element.IsValidElement(obj))
{
Interlocked.Decrement(ref this.RunningTasks);
return(false);
}
if (layoutIndex == this.indexedBy)
{
string newKey = (string)obj;
if (this.contentIndex.ContainsKey(newKey))
{
Interlocked.Decrement(ref this.RunningTasks);
return(false);
}
this.contentIndex[newKey] = line;
this.contentIndex.Remove(line.Key);
line.Key = newKey;
}
else if (this.Sorted && layoutIndex == this.sortedBy)
{
string newSortKey = (string)obj;
if (this.sortIndex.ContainsKey(newSortKey))
{
this.sortIndex[newSortKey].Add(line);
}
else
{
this.sortIndex[newSortKey] = new List <NanoDBLine> {
line
};
}
this.sortIndex[line.SortKey].Remove(line);
line.SortKey = newSortKey;
}
line.Content[layoutIndex] = obj;
byte[] data = new byte[element.Size];
element.Write(obj, data, 0);
this.writer.AddTask(new NanoDBTask {
Type = TaskType.UpdateObject, LineNumber = line.LineNumber, Data = data, LayoutIndex = layoutIndex
});
}
return(true);
}
public NanoDBLine AddLine(params object[] objects)
{
string key;
lock (this.readLock)
{
if (!this.Accessible || objects.Length != this.Layout.LayoutSize || this.shutdown)
{
return(null);
}
Interlocked.Increment(ref this.RunningTasks);
key = (string)objects[this.indexedBy];
if (key == null || this.contentIndex.ContainsKey(key))
{
Interlocked.Decrement(ref this.RunningTasks);
return(null);
}
}
int position = 1;
byte[] data = new byte[this.Layout.RowSize];
data[0] = NanoDBConstants.LineFlagIncomplete;
for (int i = 0; i < objects.Length; i++)
{
NanoDBElement element = this.Layout.Elements[i];
if (element.IsValidElement(objects[i]))
{
element.Write(objects[i], data, position);
position += element.Size;
}
else
{
Interlocked.Decrement(ref this.RunningTasks);
return(null);
}
}
NanoDBLine line = new NanoDBLine(this, NanoDBConstants.LineFlagActive, this.TotalLines, key, objects);
lock (this.readLock)
{
if (!this.Accessible || this.contentIndex.ContainsKey(key))
{
Interlocked.Decrement(ref this.RunningTasks);
return(null);
}
this.TotalLines++;
this.contentIndex[key] = line;
if (this.Sorted)
{
string sortKey = (string)objects[this.sortedBy];
if (this.sortIndex.ContainsKey(sortKey))
{
this.sortIndex[sortKey].Add(line);
}
else
{
this.sortIndex[sortKey] = new List <NanoDBLine> {
line
};
}
}
this.writer.AddTask(new NanoDBTask {
Type = TaskType.AddLine, Data = data
});
}
return(line);
}