public static List <NodeBlock> SelectAllNodeBlocks()
{
var result = new List <NodeBlock>();
var lastNodeId = DbControl.FetchLastId(DbControl.NodePath);
for (var nodeId = 1; nodeId < lastNodeId; ++nodeId)
{
var candidateNodeBlock = DbReader.ReadNodeBlock(nodeId);
if (candidateNodeBlock.Used)
{
result.Add(candidateNodeBlock);
}
}
return(result);
}
public static HashSet <NodeBlock> SelectNodeBlocksByLabelAndProperties(string label,
Dictionary <string, object> props)
{
if (label == null && props.Count == 0)
{
return(new HashSet <NodeBlock>(SelectAllNodeBlocks()));
}
var labelId = 0;
if (label != null)
{
bool ok = DbControl.LabelInvertedIndex.TryGetValue(label, out labelId);
if (!ok)
{
return(new HashSet <NodeBlock>());
}
}
if (label != null && props.Count == 0)
{
var result = new HashSet <NodeBlock>();
foreach (var nodeBlock in SelectAllNodeBlocks())
{
if (nodeBlock.LabelId == labelId)
{
result.Add(nodeBlock);
}
}
return(result);
}
var rawProps = new Dictionary <int, object>();
var fromPropNameIdToGoodNodeBlocks = new Dictionary <int, HashSet <NodeBlock> >();
foreach (var keyValuePair in props)
{
bool ok = DbControl.PropertyNameInvertedIndex.TryGetValue(keyValuePair.Key, out var propertyNameId);
if (!ok)
{
return(new HashSet <NodeBlock>());
}
fromPropNameIdToGoodNodeBlocks[propertyNameId] = new HashSet <NodeBlock>();
rawProps[propertyNameId] = keyValuePair.Value;
}
var propertyNameIds = new HashSet <int>(fromPropNameIdToGoodNodeBlocks.Keys);
var lastPropertyId = DbControl.FetchLastId(DbControl.NodePropertyPath);
for (var propertyId = 1; propertyId < lastPropertyId; ++propertyId)
{
var currentPropertyBlock =
new NodePropertyBlock(DbReader.ReadPropertyBlock(DbControl.NodePropertyPath, propertyId));
if (!currentPropertyBlock.Used)
{
continue;
}
if (!propertyNameIds.Contains(currentPropertyBlock.PropertyNameId))
{
continue;
}
switch (currentPropertyBlock.PropertyType)
{
case PropertyType.Int:
if (BitConverter.ToInt32(currentPropertyBlock.Value, 0) !=
(int)rawProps[currentPropertyBlock.PropertyNameId])
{
continue;
}
break;
case PropertyType.String:
if (!(DbReader.ReadGenericStringBlock(DbControl.StringPath,
BitConverter.ToInt32(currentPropertyBlock.Value, 0)).Data)
.Equals((string)rawProps[currentPropertyBlock.PropertyNameId]))
{
continue;
}
break;
case PropertyType.Bool:
if (BitConverter.ToBoolean(currentPropertyBlock.Value, 3) !=
(bool)rawProps[currentPropertyBlock.PropertyNameId])
{
continue;
}
break;
case PropertyType.Float:
if (BitConverter.ToSingle(currentPropertyBlock.Value, 0) !=
(float)rawProps[currentPropertyBlock.PropertyNameId])
{
continue;
}
break;
default:
throw new NotSupportedException();
}
var currentNodeBlock = DbReader.ReadNodeBlock(currentPropertyBlock.NodeId);
if (labelId != 0 && currentNodeBlock.LabelId != labelId)
{
continue;
}
fromPropNameIdToGoodNodeBlocks[currentPropertyBlock.PropertyNameId].Add(currentNodeBlock);
}
var listOfSets = new List <HashSet <NodeBlock> >(fromPropNameIdToGoodNodeBlocks.Values);
var outputNodes = listOfSets.Aggregate(
(h, e) =>
{
h.IntersectWith(e);
return(h);
}
);
return(outputNodes);
}
/// <summary>
/// Create storage files if missing
/// </summary>
public static void InitializeIO()
{
if (initializedIOFlag)
{
return;
}
try
{
if (!Directory.Exists(DbPath))
{
Directory.CreateDirectory(DbPath);
}
foreach (var filePath in DbControl.DbFilePaths)
{
FileStreamDictionary[filePath] = new FileStream(Path.Combine(DbControl.DbPath, filePath),
FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite, 5 * 1024 * 1024);
}
// Create new empty IdStorage if not present with next free id.
// Else initialize .storage.db -> ID mapping
if (!File.Exists(Path.Combine(DbPath, IdStoragePath)))
{
idFileStream = new FileStream(Path.Combine(DbPath, IdStoragePath),
FileMode.Create,
FileAccess.ReadWrite, FileShare.Read);
foreach (var filePath in DbFilePaths)
{
idFileStream.Write(BitConverter.GetBytes(1), 0, 4);
IdStorageDictionary[filePath] = 1;
}
idFileStream.Flush();
}
else
{
idFileStream = new FileStream(Path.Combine(DbPath, IdStoragePath),
FileMode.Open,
FileAccess.ReadWrite, FileShare.Read);
foreach (var filePath in DbFilePaths)
{
var blockNumber = IdStoreOrderNumber[filePath];
var storedIdBytes = new byte[4];
idFileStream.Seek(blockNumber * 4, SeekOrigin.Begin);
idFileStream.Read(storedIdBytes, 0, 4);
IdStorageDictionary[filePath] = BitConverter.ToInt32(storedIdBytes, 0);
}
}
// Initialize Inverted Indexes
for (var i = 1; i < FetchLastId(LabelPath); ++i)
{
var labelBlock = new LabelBlock(DbReader.ReadGenericStringBlock(LabelPath, i));
LabelInvertedIndex[labelBlock.Data] = labelBlock.Id;
}
for (var i = 1; i < FetchLastId(PropertyNamePath); ++i)
{
var propertyNameBlock =
new PropertyNameBlock(DbReader.ReadGenericStringBlock(PropertyNamePath, i));
PropertyNameInvertedIndex[propertyNameBlock.Data] = propertyNameBlock.Id;
}
}
catch (Exception ex)
{
TraceSource.TraceEvent(TraceEventType.Error, 1,
$"Database Initialization Falied: {ex}");
}
finally
{
initializedIOFlag = true;
}
}