I have an iPhone app that grabs information from different sources in XML format. For example i have a UITableView displaying information, in xml format after being parsed, from an url like this one http://mysite.com/posts.php?top=100 -> returns posts information like this
<postsList><post><title>test1</title><pubDate>..</pubdate></item><post><title>test1</title><pubDate>..</pubdate></item></postsList>
so i have one request only for showing the table with posts. when i click on a cell i have to make three calls to three different sources to gather the data i want to show in the details of the cell.
I was thinking to write some ASP.NET C# webservices that, when called, gather all the info i need and return a single response(so i make one request) when i show the initial UITableView.
The xml response will have 10-15kb max with all the data included. From my experience network access(wireless or 3g) is expensive on the iphone from the performance point of view and if possible i would like to avoid it if it's not necessary.
So the question is: is it a good idea to get as much data as possible from a single request or is it better to make requests only when data is needed(in this case when a cell is displayed)?
If you're on a slow cellular connection, the latency will hurt you more than the limited bandwidth. This means that setting up a connection will take a lot of time because of the latency.
If you're talking about 10-15 kb, I would get all the data at once (of course, you should do that asynchronously)
Let's say you're on a GPRS connection, which is 384kbps (in our country at least). The latency is in the order of 500ms, so setting up a HTTP connection could take about 1 second (best case). Transfer speed is about 40KB/s.
Using a single download:
1 second setup + 0.5 second download = 1.5 seconds
Using 10 small downloads:
10 x 1 second setup + 10 x 0.05 second download = 10.5 seconds
This is not a scientific test, but it simply shows how you should tackle these kind of decisions.
I have been dealing with these issues alot on my current project. It has more to do with the 3G performance and latency then the actual iphone itself. Even with larger amounts of data it would be more efficient to download it all in one hit.
So i would agree with Philippe.
Related
is there any possibility to get exact time spent on a certain level in a game via firebase analytics? Thank you so much 🙏
I tried to use logEvents.
The best way to do so would be measuring the time on the level within your codebase, then have a very dedicated event for level completion, in which you would pass the time spent on the level.
Let's get to details. I will use Kotlin as an example, but it should be obvious what I'm doing here and you can see more language examples here.
firebaseAnalytics.setUserProperty("user_id", userId)
firebaseAnalytics.logEvent("level_completed") {
param("name", levelName)
param("difficulty", difficulty)
param("subscription_status", subscriptionStatus)
param("minutes", minutesSpentOnLevel)
param("score", score)
}
Now see how I have a bunch of parameters with the event? These parameters are important since they will allow you to conduct a more thorough and robust analysis later on, answer more questions. Like, Hey, what is the most difficult level? Do people still have troubles on it when the game difficulty is lower? How many times has this level been rage-quit or lost (for that you'd likely need a level_started event). What about our paid players, are they having similar troubles on this level as well? How many people have ragequit the game on this level and never played again? That would likely be easier answer with sql at this point, taking the latest value of the level name for the level_started, grouped by the user_id. Or, you could also have levelName as a UserProperty as well as the EventProperty, then it would be somewhat trivial to answer in the default analytics interface.
Note that you're limited in the number of event parameters you can send per event. The total number of unique parameter names is limited too. As well as the number of unique event names you're allowed to have. In our case, the event name would be level_completed. See the limits here.
Because of those limitations, it's important to name your event properties in somewhat generic way so that you would be able to efficiently reuse them elsewhere. For this reason, I named minutes and not something like minutes_spent_on_the_level. You could then reuse this property to send the minutes the player spent actively playing, minutes the player spent idling, minutes the player spent on any info page, minutes they spent choosing their upgrades, etc. Same idea about having name property rather than level_name. Could as well be id.
You need to carefully and thoughtfully stuff your event with event properties. I normally have a wrapper around the firebase sdk, in which I would enrich events with dimensions that I always want to be there, like the user_id or subscription_status to not have to add them manually every time I send an event. I also usually have some more adequate logging there Firebase Analytics default logging is completely awful. I also have some sanitizing there, lowercasing all values unless I'm passing something case-sensitive like base64 values, making sure I don't have double spaces (so replacing \s+ with " " (space)), maybe also adding the user's local timestamp as another parameter. The latter is very helpful to indicate time-cheating users, especially if your game is an idler.
Good. We're halfway there :) Bear with me.
Now You need to go to firebase and register your eps (event parameters) into cds (custom dimensions and metrics). If you don't register your eps, they won't be counted towards the global cd limit count (it's about 50 custom dimensions and 50 custom metrics). You register the cds in the Custom Definitions section of FB.
Now you need to know whether this is a dimension or a metric, as well as the scope of your dimension. It's much easier than it sounds. The rule of thumb is: if you want to be able to run mathematical aggregation functions on your dimension, then it's a metric. Otherwise - it's a dimension. So:
firebaseAnalytics.setUserProperty("user_id", userId) <-- dimension
param("name", levelName) <-- dimension
param("difficulty", difficulty) <-- dimension (or can be a metric, depends)
param("subscription_status", subscriptionStatus) <-- dimension (can be a metric too, but even less likely)
param("minutes", minutesSpentOnLevel) <-- metric
param("score", score) <-- metric
Now another important thing to understand is the scope. Because Firebase and GA4 are still, essentially just in Beta being actively worked on, you only have user or hit scope for the dimensions and only hit for the metrics. The scope basically just indicates how the value persists. In my example, we only need the user_id as a user-scoped cd. Because user_id is the user-level dimension, it is set separately form the logEvent function. Although I suspect you can do it there too. Haven't tried tho.
Now, we're almost there.
Finally, you don't want to use Firebase to look at your data. It's horrible at data presentation. It's good at debugging though. Cuz that's what it was intended for initially. Because of how horrible it is, it's always advised to link it to GA4. Now GA4 will allow you to look at the Firebase values much more efficiently. Note that you will likely need to re-register your custom dimensions from Firebase in GA4. Because GA4 is capable of getting multiple data streams, of which firebase would be just one data source. But GA4's CDs limits are very close to Firebase's. Ok, let's be frank. GA4's data model is almost exactly copied from that of Firebase's. But GA4 has a much better analytics capabilities.
Good, you've moved to GA4. Now, GA4 is a very raw not-officially-beta product as well as Firebase Analytics. Because of that, it's advised to first change your data retention to 12 months and only use the explorer for analysis, pretty much ignoring the pre-generated reports. They are just not very reliable at this point.
Finally, you may find it easier to just use SQL to get your analysis done. For that, you can easily copy your data from GA4 to a sandbox instance of BQ. It's very easy to do.This is the best, most reliable known method of using GA4 at this moment. I mean, advanced analysts do the export into BQ, then ETL the data from BQ into a proper storage like Snowflake or even s3, or Aurora, or whatever you prefer and then on top of that, use a proper BI tool like Looker, PowerBI, Tableau, etc. A lot of people just stay in BQ though, it's fine. Lots of BI tools have BQ connectors, it's just BQ gets expensive quickly if you do a lot of analysis.
Whew, I hope you'll enjoy analyzing your game's data. Data-driven decisions rock in games. Well... They rock everywhere, to be honest.
I'm looking for some ideas/hints for streaming protocol (similar to video/audio streaming) to send any data in so called real-time.
In simple words:
I'm producing some data each second (let's say one array with 1MB of data per second) and I'm sorting that data from most important to not so important (like putting them to priority queues or similar)
I would like to keep streaming those data via some protocol and in perfect case I would like to send all of it
If not possible (bandwidth, dropping packets etc.) I would like to send from each produced array as much as possible (first n-bytes) just to keep data going (it is important to start sending new produced array each second).
And now - I'm looking for such protocol/library that will handle adaptive bit rate stuff for any data. I would expect from it to tell me how much data I can send (put into send buffers or similar approach). The most similar thing is video/audio streaming when in poor network conditions (en)coder is changing quality depending on network conditions.
It is also OK if I miss some send data (so UDP deep down of this stuff is OK) but preferably I would like to send as much data as possible per second without loosing anything (from those first n-bytes send).
Do you have any ideas of what protocol/libraries I could use for client/server? (hopefully some libs in python, C or C++).
I think IPFIX (the generic NetFlow standard) has everything you need.
You can avoid a timestamp per sample by sending a samplingInterval update every time you change your rate. You can also add other updating the change in sampling asynchronously.
As for where to put your data. You can create a new field or just use an existing one with that has a datatype you want. IE: if you are just sending uint64 sample values then it might be easier to use packetDeltaCount then create your own field definition.
There are plenty of IPFIX libraries.
I must do a RPC call when my Presenter is revealled. That call result in a String[] with large amount of data. But this call is very very slow. It takes about 1min to finish.
After some tests, i discovered that ListBox.addItem() takes over 30% of this call. It's a huge time for just add String on that Widget.
What can I do to minimize this time?
Assuming that i need to load everything when my Presenter reveal.
Things that I've already done:
Put my Query inside a View(Doesn't affect too much)
Server read a Txt file instead of call DB(worst then View).
Use Collections classes ArrayList,Vector...(Vector reduced time by 5%)
I've noticed that GWT designed a LightweightCollections to improve use of Collections on Client side(It's my next step).
But what can I do about ListBox?
Too much choice is no choice.
You will not be able to tune up GWT Listbox/ValueListBox for purpose of displaying such huge amount data ( i am guessing entries in 1000's considering 20 seconds i.e 30% of 1 min). GWT Listbox is meant for selection. You cannot expect user to see 1000's of values , scroll and then select. Its a User Interaction nightmare.
The right approach is use to Async loaded SuggestBox for such huge data. With SuggestBox you can filters and display lesser data as choice based on users input keys.
If using SuggestBox is not feasible you must give a try for CellList in Cell Widgets ( they might show better performance ) - https://developers.google.com/web-toolkit/doc/latest/DevGuideUiCellWidgets
I am not sure but give GWTChosen a try - http://jdramaix.github.com/gwtchosen/
It's common to see messages like "Installation will take 10 min aprox." , etc in desktop applications. So, I wonder how can I calculate an approximate of how much time a certain process will take. Off course I won't install anything but I want to update some internal data and depending on the user usage this might take some time.
Is this possible in a iPhone app? How Cocoa guys do this, would it be the same way in iPhone apps?
Thanks in advance.
UPDATE: I want to rewrite/edit some files on disk, most of the time these files are not the same size so I cannot use timers for the first iteration and calculate the rest from that.
Is there any API that helps on calculating this?
If you have some list of things to process, each "thing" - usually better to measure a group of 10 or so "things" - is a unit of work. Your goal is to see how long it takes to process a single group and report the estimated time to completion.
One way is to create an NSDate at the start of each group and a new one at the end (the top and bottom of your for loop) for each group. Multiply the difference in seconds by however many groups you have left (minus the one you just processed) and that should be a reasonable estimate of the time remaining.
Of course this gets more complicated if one "thing" takes a lot longer to process than another "thing" - the above approach assumes all things take the same amount of time. In this case, however, you may need to keep track of an average window (across the last n "things" or groups thereof).
A more detailed response would require more details about your model and what work you're performing.
SqlDataReader is a faster way to process the stored procedure. What are some of the advantage/disadvantages of using SQLDataReader?
I assume you mean "instead of loading the results into a DataTable"?
Advantages: you're in control of how the data is loaded. You can ask for specific data types, and you don't end up loading the whole set of data into memory all at the same time unless you want to. Basically, if you want the data but don't need a data table (e.g. you're going to populate your own kind of collection) you don't get the overhead of the intermediate step.
Disadvantages: you're in control of how the data is loaded, which means it's easier to make a mistake and there's more work to do.
What's your use case here? Do you have a good reason to believe that the overhead of using a normal (or strongly typed) data table is significantly hurting performance? I'd only use SqlDataReader directly if I had a good reason to do so.
The key advantage is obviously speed - that's the main reason you'd choose a SQLDataReader.
One potential disadvantage not already mentioned is that the SQLDataReader is forward only, so you can only go through the records once in sequence - that's one of the things that allows it to be so fast. In many cases that's fine but if you need to iterate over the records more than once or add/edit/delete data you'll need to use one of the alternatives.
It also remains connected until you've worked through all the records and close the reader (of course, you can opt to close it earlier, but then you can't access any of the remaining records). If you're going to perform any lengthy processing on the records as you iterate over them, you may find that you impact other connections to the database.
It depends on what you need to do. If you get back a page of results from the database (say 20 records), it would be better to use a data adapter to fill a DataSet, and bind that to something in the UI.
But if you need to process many records, 1 at a time, use SqlDataReader.
Advantages: Faster, less memory.
Disadvantages: Must remain connected, must remember to close the reader.
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