public IHttpContext EventsQuery(IHttpContext context)
{
Double epsilon = Double.Parse(context.Request.QueryString["epsilon"] ?? "0.1", new CultureInfo("en"));
string query = context.Request.QueryString["query"];
try
{
StringBuilder response = new StringBuilder();
response.AppendLine("Source,Target,Count");
PINQ.PINQueryable <Event> eventQuery = PDDPServer.EventQuery;
if (query != null)
{
var type = Expression.Parameter(typeof(Event), "E");
LambdaExpression linqQuery = System.Linq.Dynamic.DynamicExpression.ParseLambda(new[] { type }, null, query);
Delegate @delegate = linqQuery.Compile();
eventQuery = eventQuery.Where(e => (Boolean)@delegate.DynamicInvoke(e));
}
var parts = eventQuery.Partition(PDDPServer.Relations, e => e.Relation);
foreach (var part in parts)
{
var keys = part.Key.Split(',').ToArray();
response.AppendLine(keys[0] + "," + keys[1] + "," + Math.Round(Math.Abs(part.Value.NoisyCount(epsilon))));
}
context.Response.SendResponse(response.ToString());
}
catch (Exception e)
{
if (e.Source == "PINQ")
{
context.Response.StatusCode = HttpStatusCode.Forbidden;
context.Response.SendResponse("Privacy budget depleted");
}
else
{
context.Response.StatusCode = HttpStatusCode.InternalServerError;
context.Response.SendResponse(e.Message);
}
}
return(context);
}
public IHttpContext TracesQuery(IHttpContext context)
{
Double epsilon = Double.Parse(context.Request.QueryString["epsilon"] ?? "0.1", new CultureInfo("en"));
Int16 sequence_threshold = Int16.Parse(context.Request.QueryString["sequence_threshold"] ?? "25", new CultureInfo("en"));
Int16 sequence_length = Int16.Parse(context.Request.QueryString["sequence_length"] ?? "10", new CultureInfo("en"));
string query = context.Request.QueryString["query"];
try
{
StringBuilder response = new StringBuilder();
response.AppendLine("Sequence,Count");
PINQ.PINQueryable <Trace> traceQuery = PDDPServer.TraceQuery;
if (query != null)
{
var type = Expression.Parameter(typeof(Trace), "E");
LambdaExpression linqQuery = System.Linq.Dynamic.DynamicExpression.ParseLambda(new[] { type }, null, query);
Delegate @delegate = linqQuery.Compile();
traceQuery = traceQuery.Where(e => (Boolean)@delegate.DynamicInvoke(e));
}
var actIds = PDDPServer.ActToId.Values.Except(new[] { PDDPServer.ActToId["Start"] }).ToArray();
string startId = PDDPServer.ActToId["Start"];
string endId = PDDPServer.ActToId["End"];
List <string> candidates = new List <string>();
string[] wrappedStart = { startId };
candidates.AddRange(wrappedStart.SelectMany(x => actIds.Where(a => a != endId)
.Select(y => x + "<" + y)));
var current_length = 2;
while (current_length < sequence_length)
{
var parts = traceQuery.Partition(candidates.ToArray(), t => string.Join("<", t.Sequence.Split('<').Take(current_length)));
candidates.Clear();
foreach (var part in parts)
{
var key = part.Key;
var innerQuery = part.Value;
var count = Math.Round(Math.Abs(innerQuery.NoisyCount(epsilon)));
var lastAct = key.Split('<').Last();
if (lastAct == endId)
{
// We have a complete trace
response.AppendLine(key + "," + count);
}
else
{
if (count > sequence_threshold)
{
// Add all possible suffixes
string[] wrappedKey = { key };
var newCandidates = wrappedKey.SelectMany(x => actIds.Select(y => x + "<" + y));
candidates.AddRange(newCandidates);
}
}
}
current_length++;
}
context.Response.SendResponse(response.ToString());
}
catch (Exception e)
{
if (e.Source == "PINQ")
{
context.Response.StatusCode = HttpStatusCode.Forbidden;
context.Response.SendResponse("Privacy budget depleted");
}
else
{
context.Response.StatusCode = HttpStatusCode.InternalServerError;
context.Response.SendResponse(e.Message);
throw e;
}
}
return(context);
}
