/// <summary>
/// Loads the most recent Device telemetry.
/// </summary>
/// <param name="deviceId">
/// The ID of the Device for which telemetry should be returned.
/// </param>
/// <param name="minTime">
/// The minimum time of record of the telemetry that should be returned.
/// </param>
/// <returns>
/// Telemetry for the Device specified by deviceId, inclusively since
/// minTime.
/// </returns>
public async Task<IEnumerable<DeviceTelemetryModel>> LoadLatestDeviceTelemetryAsync(
string deviceId,
IList<DeviceTelemetryFieldModel> telemetryFields,
DateTime minTime)
{
IEnumerable<DeviceTelemetryModel> result = new DeviceTelemetryModel[0];
IEnumerable<DeviceTelemetryModel> blobModels;
var telemetryBlobReader = await _blobStorageManager.GetReader(_telemetryDataPrefix, minTime);
foreach (var telemetryStream in telemetryBlobReader)
{
try
{
blobModels = LoadBlobTelemetryModels(telemetryStream.Data, telemetryFields);
}
catch
{
continue;
}
if (blobModels == null)
{
break;
}
int preFilterCount = blobModels.Count();
blobModels =
blobModels.Where(
t =>
(t != null) &&
t.Timestamp.HasValue &&
t.Timestamp.Value >= minTime);
if (preFilterCount == 0)
{
break;
}
result = result.Concat(blobModels);
}
if (!string.IsNullOrEmpty(deviceId))
{
result = result.Where(t => t.DeviceId == deviceId);
}
return result;
}
/// <summary>
/// Loads the most recent Device telemetry.
/// </summary>
/// <param name="deviceId">
/// The ID of the Device for which telemetry should be returned.
/// </param>
/// <param name="minTime">
/// The minimum time of record of the telemetry that should be returned.
/// </param>
/// <returns>
/// Telemetry for the Device specified by deviceId, inclusively since
/// minTime.
/// </returns>
public async Task<IEnumerable<DeviceTelemetryModel>> LoadLatestDeviceTelemetryAsync(
string deviceId,
DateTime minTime)
{
IEnumerable<DeviceTelemetryModel> blobModels;
IEnumerable<IListBlobItem> blobs;
CloudBlockBlob blockBlob;
CloudBlobContainer container;
int preFilterCount;
IEnumerable<DeviceTelemetryModel> result;
minTime = minTime.ToUniversalTime();
result = new DeviceTelemetryModel[0];
container =
await BlobStorageHelper.BuildBlobContainerAsync(
this._telemetryStoreConnectionString,
_telemetryContainerName);
blobs =
await BlobStorageHelper.LoadBlobItemsAsync(
async (token) =>
{
return await container.ListBlobsSegmentedAsync(
_telemetryDataPrefix,
true,
BlobListingDetails.None,
null,
token,
null,
null);
});
blobs =
blobs.OrderByDescending(
t => BlobStorageHelper.ExtractBlobItemDate(t));
foreach (IListBlobItem blob in blobs)
{
if ((blockBlob = blob as CloudBlockBlob) == null)
{
continue;
}
try
{
blobModels = await LoadBlobTelemetryModelsAsync(blockBlob);
}
catch
{
continue;
}
if (blobModels == null)
{
break;
}
preFilterCount = blobModels.Count();
blobModels =
blobModels.Where(
t =>
(t != null) &&
t.Timestamp.HasValue &&
t.Timestamp.Value.ToUniversalTime() >= minTime);
if (preFilterCount == 0)
{
break;
}
result = result.Concat(blobModels);
if (preFilterCount != blobModels.Count())
{
break;
}
}
if (!string.IsNullOrEmpty(deviceId))
{
result = result.Where(t => t.DeviceId == deviceId);
}
return result;
}