internal static string SerializeFile(ServiceTagFile file)
{
var options = new JsonSerializerOptions()
{
PropertyNameCaseInsensitive = true,
IgnoreNullValues = true
};
return(JsonSerializer.Serialize(file, typeof(ServiceTagFile), options));
}
public static async Task FnCompareFiles(
[QueueTrigger("nextazureipfile", Connection = "FileStorAcc")] string fileName,
ILogger log)
{
var containerName = Environment.GetEnvironmentVariable("region");
var storage = new StorageProvider();
// in case of multiple runs check so see if there's already a delta - set to run as singleton , so this is belt and brace
var existingDelta = await storage.FileExistsBlobStorageAsync(containerName, $"{fileName}.delta");
if (existingDelta)
{
log.LogInformation($"Existing Delta found for {fileName}, duplicate run for the same file?");
return;
}
// check for a previous change number
var currentFileStream = await storage.ReadFileFromBlobToStorageAsync(containerName, fileName);
var currentFile = DeserializeFile(StreamToString(currentFileStream));
if (currentFile == null)
{
throw new Exception($"No valid file named {fileName} for container {containerName}");
}
if (currentFile.Values == null || currentFile.Values.Count == 0)
{
// empty file , remove (this can happen?)
log.LogInformation("empty current file found, removing.");
await storage.DeleteFileFromBlobStorageAsync(containerName, fileName);
return;
}
var previousFile = await GetPreviousFileAsync(storage, containerName, fileName);
var delta = CompareFiles(currentFile, previousFile);
if (null != delta)
{
var newFileName = $"{fileName}.delta";
var newFile = new ServiceTagFile()
{
Values = delta
};
var stream = StringToStream(SerializeFile(newFile));
// AEG event will be raised for next func
await storage.WriteStreamAsBlobToStorageAsync(stream, containerName, newFileName);
// enqueue reference to delta for function to write access restrictions
log.LogInformation($"C# function processed: {fileName} and wrote delta {newFileName}");
}
log.LogInformation($"C# function processed: {fileName}. No delta.");
}
public static async Task FnActionDelta(
[EventGridTrigger] EventGridEvent eventGridEvent,
ILogger log)
{
// pull the filename from the event
log.LogInformation($"Event received {eventGridEvent.Id}");
StorageBlobCreatedEventData data = (eventGridEvent.Data as JObject).ToObject <StorageBlobCreatedEventData>();
var fileName = string.Empty;
var uri = new Uri(data.Url);
fileName = System.IO.Path.GetFileName(uri.LocalPath);
log.LogInformation($"filename is {fileName}");
// check its the file we're interested in
if (!fileName.EndsWith(".delta"))
{
log.LogInformation($"Not interested in this event { fileName}");
return;
}
var storage = new StorageProvider();
var newFileName = $"{fileName}.completed";
var containerName = Environment.GetEnvironmentVariable("region");
// set to run as singleton so this is belt and brace
if (await storage.FileExistsBlobStorageAsync(containerName, newFileName))
{
log.LogInformation($"This delta received already and completed. No further action.");
return;
}
log.LogInformation($"delta {fileName} received");
//
// action delta
//
var newFile = new ServiceTagFile()
{
ChangeNumber = fileName
};
var stream = StringToStream(SerializeFile(newFile));
await storage.WriteStreamAsBlobToStorageAsync(stream, containerName, newFileName);
// enqueue reference to delta for function to write access restrictions
log.LogInformation($"C# function actioned {fileName} and wrote completed {newFileName}");
}
internal static List <ServiceTagResult> CompareFiles(ServiceTagFile currentFile, ServiceTagFile previousFile)
{
if (currentFile == null || currentFile.Values == null || currentFile.Values.Count == 0)
{
throw new Exception("Invalid current file, no values");
}
if (previousFile == null)
{
// no prior file , no delta
return(currentFile.Values);
}
if (previousFile.Values == null || previousFile.Values.Count == 0)
{
throw new Exception("prior file found, but no values");
}
var delta = new List <ServiceTagResult>();
foreach (var value in currentFile.Values)
{
var priorValueById = previousFile.Values.Find(v => v.Id == value.Id);
if (null == priorValueById)
{
// did not exist before, or must be new this time as current value property is #1
delta.Add(value);
}
else
{
// compare versions
var isNewer = CompareChangeNumbers(value, priorValueById);
if (isNewer)
{
delta.Add(value);
}
}
}
if (delta.Count == 0)
{
delta = null;
}
return(delta);
}