/// <summary>
/// Decrements the mappings of a masked object in the Map table, specifically during an update operation,
/// where a record used for the update must be passed in as well to determine whether columns are being updated.
/// </summary>
/// <param name="updateRecord">The record being used for the update.</param>
/// <param name="maskedObject">The object to decrement the mappings for.</param>
/// <returns>(bool) whether the function executed without exception</returns>
public async Task <bool> DecrementMappingForUpdateAsync(IMaskableRecord updateRecord, IUnMaskableObject maskedObject)
{
if (maskedObject.IsUnMasked())
{
throw new ArgumentException(Constants.DecrementUpdateUnmasked);
}
List <Tuple <object, bool> > recordInfo = updateRecord.GetMaskInformation();
List <Tuple <object, bool> > objectInfo = maskedObject.GetMaskInformation();
for (int i = 0; i < recordInfo.Count; i++)
{
Tuple <object, bool> recordData = recordInfo[i];
Tuple <object, bool> objectData = objectInfo[i];
// If the column is masked...
if (recordData.Item2)
{
// The data is being updated if the corresponding record data is not null or -1.
bool beingUpdated = true;
if (recordData.Item1 is int)
{
if ((int)recordData.Item1 == -1)
{
beingUpdated = false;
}
}
if (recordData.Item1 == null)
{
beingUpdated = false;
}
if (recordData.Item1 is long)
{
if ((long)recordData.Item1 == -1)
{
beingUpdated = false;
}
}
// If the data is being updated and it is not the primary key (first entry in the mask information),
// decrement the occurrences of the hash.
if (beingUpdated && i != 0)
{
await DecrementOccurrencesAsync(objectData.Item1.ToString()).ConfigureAwait(false);
}
}
}
return(true);
}
/// <summary>
/// Takes in a IMaskableRecord and masks all the data necessary based on which columns are masked in
/// the DAO.
/// </summary>
/// <param name="record">The record to mask.</param>
/// <param name="isCreate">Whether this is being used for a create (lets the function know whether to increment
/// the mapping).</param>
/// <returns>(IMaskableRecord) the masked version of the record</returns>
public async Task <IMaskableRecord> MaskAsync(IMaskableRecord record, bool isCreate)
{
// If the record is already masked we will simply return what was passed.
if (!record.IsMasked())
{
// Get the mask information: a list of tuples<object, bool>, the data and whether it's column is masked.
List <Tuple <object, bool> > info = record.GetMaskInformation();
// The list of objects to pass to the constructor.
object[] parameters = new object[info.Count];
for (int i = 0; i < info.Count; i++)
{
// Loop through the list and get all individual tuples.
Tuple <object, bool> data = info[i];
// If the data's column is masked...
if (data.Item2)
{
// Only compute the hash if data is being inserted into the table (i.e. not null or -1).
bool computeHash = true;
if (data.Item1 is int)
{
if ((int)data.Item1 == -1)
{
computeHash = false;
}
}
if (data.Item1 == null)
{
computeHash = false;
}
if (data.Item1 is long)
{
if ((long)data.Item1 == -1)
{
computeHash = false;
}
}
if (computeHash)
{
// Convert everything to a string including numerical values (to store in the "actual" column of the MapDAO).
string input = data.Item1.ToString();
string hashString;
// If the data is a string, simply double hash the input.
if (data.Item1 is string)
{
string hash = SecurityService.HashWithSHA256(SecurityService.HashWithSHA256(input));
parameters[i] = hash;
hashString = hash;
}
else
{
// Otherwise get the hash is the count of the amount of times this code block has been reached.
// Our current approach to hashing integer values:
int count = Int32.Parse(Environment.GetEnvironmentVariable("COUNT", EnvironmentVariableTarget.User));
int hash = count;
parameters[i] = hash;
hashString = hash.ToString();
Environment.SetEnvironmentVariable("COUNT", (count + 1).ToString(), EnvironmentVariableTarget.User);
}
// If this is the first time this hash string has been seen, create the record in the MapDAO with an occurrence of 1.
if (!await _mapDAO.CheckHashExistenceAsync(hashString).ConfigureAwait(false))
{
MapRecord mapRecord = new MapRecord(hashString, input, 1);
await _mapDAO.CreateAsync(mapRecord).ConfigureAwait(false);
}
else if (isCreate)
{
// Otherwise, if this function is being used in a creation, increment the occurrences. Do nothing otherwise.
MapObject mapObj = await _mapDAO.ReadByIdAsync(hashString).ConfigureAwait(false) as MapObject;
await UpdateOccurrencesAsync(hashString, mapObj.Occurrences + 1).ConfigureAwait(false);
}
// HACK: should log here but this ruins the tests... (ASK VONG)
//await LoggingService.LogAsync(DateTime.UtcNow.ToString(Constants.LoggingFormatString), Constants.MapTableModifiedOperation,
// Constants.SystemIdentifier, Constants.LocalHost).ConfigureAwait(false);
}
else
{
// If the computation was not needed, keep the same data.
parameters[i] = data.Item1;
}
}
else
{
// If the column was not masked, keep the same data.
parameters[i] = data.Item1;
}
}
// Create a record of the type that was passed to this function by getting the constructor and invoking it with
// the collected parameters.
IMaskableRecord resultRecord = (IMaskableRecord)record.GetType().GetConstructor(record.GetParameterTypes()).Invoke(parameters);
resultRecord.SetToMasked();
return(resultRecord);
}
else
{
return(record);
}
}