/// <summary>
/// Creates a LabelFile object.
/// </summary>
/// <param name="CollectionName">Name of collection.</param>
/// <param name="TimeoutMilliseconds">Timeout, in milliseconds, to wait for access to the database layer.</param>
/// <param name="Encrypted">If the files should be encrypted or not.</param>
/// <param name="Provider">Reference to the files provider.</param>
/// <returns>LabelFile object.</returns>
public static async Task <LabelFile> Create(string CollectionName, int TimeoutMilliseconds, bool Encrypted, FilesProvider Provider)
{
string FileName = Provider.GetFileName(CollectionName);
string LabelsFileName = FileName + ".labels";
bool LabelsExists = File.Exists(LabelsFileName);
LabelFile Result = new LabelFile(LabelsFileName, CollectionName, TimeoutMilliseconds, Encrypted);
uint LastCode = 0;
uint Code = 1;
await GetKeys(Result, Provider);
if (LabelsExists)
{
long Len = await Result.GetLength();
long Pos = 0;
while (Pos < Len)
{
try
{
KeyValuePair <string, long> P = await Result.ReadLabel(Pos);
Result.codesByLabel[P.Key] = Code;
Result.labelsByCode[Code] = P.Key;
LastCode = Code;
Code++;
Pos = P.Value;
}
catch (Exception)
{
await Result.Truncate(Pos);
Len = Pos;
}
}
}
else
{
string NamesFileName = FileName + ".names";
if (File.Exists(NamesFileName))
{
SortedDictionary <uint, string> NewCodes = null;
using (StringDictionary Names = await StringDictionary.Create(NamesFileName, string.Empty, CollectionName, Provider, false))
{
foreach (KeyValuePair <string, object> Rec in await Names.ToArrayAsync())
{
if (Rec.Value is ulong Code2 && Code2 <= uint.MaxValue && !Result.labelsByCode.ContainsKey(Code = (uint)Code2))
{
if (NewCodes is null)
{
NewCodes = new SortedDictionary <uint, string>();
}
Result.codesByLabel[Rec.Key] = Code;
Result.labelsByCode[Code] = Rec.Key;
NewCodes[Code] = Rec.Key;
}
}
}
while (!(NewCodes is null))
{
LastCode++;
if (NewCodes.TryGetValue(LastCode, out string Label))
{
await Result.WriteLabel(Label);
NewCodes.Remove(LastCode);
if (NewCodes.Count == 0)
{
NewCodes = null;
}
}
else
{
await Result.WriteLabel(LastCode.ToString());
}
}
File.Delete(NamesFileName);
}
}
return(Result);
}
