/// <inheritdoc />
public Task Delete(TKey key, string concurrencyToken)
{
Logger.LogDebug("Deleting model with primary key '{Pk}'", key);
using (var file = VisionFileSystem.GetVisionFile(FileName))
{
// Read the record with lock
file.Open(FileOpenMode.InputOutput);
var record = file.GetNewRecord();
// Check for concurrency
MapPrimaryKeyToVisionRecord(key, record);
var oldRecord = file.ReadLock(record);
if (oldRecord == null)
{
return(Task.CompletedTask);
}
var oldModel = GetModel(oldRecord);
if (concurrencyToken != oldModel.ConcurrencyToken)
{
throw new ConcurrencyException($"Data for model with primary key '{key}' are changed since the last read. Cannot delete the record");
}
// Delete the record
file.Delete(oldRecord);
file.Close();
Logger.LogDebug("Deleted record {Record}", oldRecord);
}
return(Task.CompletedTask);
}
/// <inheritdoc />
public Task Insert(TModel model)
{
if (model == null)
{
throw new ArgumentNullException(nameof(model));
}
Logger.LogDebug("Inserting model {Model}", model);
using (var file = VisionFileSystem.GetVisionFile(FileName))
{
file.Open(FileOpenMode.InputOutput);
var record = file.GetNewRecord();
MapModelToVisionRecord(model, record);
file.Write(record);
file.Close();
Logger.LogDebug("Inserted record {Record}", record);
}
return(Task.CompletedTask);
}
/// <inheritdoc />
public Task Update(TModel model)
{
if (model == null)
{
throw new ArgumentNullException(nameof(model));
}
Logger.LogDebug("Updating model {Model}", model);
using (var file = VisionFileSystem.GetVisionFile(FileName))
{
// Read the record with lock
file.Open(FileOpenMode.InputOutput);
var record = file.GetNewRecord();
// Check for concurrency
MapPrimaryKeyToVisionRecord(model.Pk, record);
var oldRecord = file.ReadLock(record);
if (oldRecord == null)
{
throw new ConcurrencyException($"Data for model with primary key '{model.Pk}' are deleted. Cannot update the record");
}
var oldModel = GetModel(oldRecord);
if (model.ConcurrencyToken != oldModel.ConcurrencyToken)
{
throw new ConcurrencyException($"Data for model with primary key '{model.Pk}' are changed since the last read. Cannot update the record");
}
// Update the record
MapModelToVisionRecord(model, oldRecord);
file.Rewrite(oldRecord);
file.Close();
Logger.LogDebug("Updated record {Record}", oldRecord);
}
return(Task.CompletedTask);
}
/// <summary>
/// Creates a new instance of VisionRestHandler
/// </summary>
/// <param name="root">Root of the request to handle</param>
/// <param name="memoryCache">Memory cache implementation</param>
/// <param name="options">Data option</param>
internal VisionRestHandler(string root, IMemoryCache memoryCache, DataRequestOptions options)
: base(root, new VisionDataContext(VisionFileSystem.GetInstance()), memoryCache, options)
{
}
