How to attach metadata to LLVM IR using the C++ API? - llvm

Can anyone point me to a concrete example of attaching metadata to llvm-ir using the c++ api?
I've read this page http://llvm.org/docs/SourceLevelDebugging.html.
Thanks

The above answer is not quite correct (or complete). You can also create metadata at the module level with just MDNode::get(...) which takes a context and an array of values to create metadata from. Named metadata is very heavyweight and you should only use it as an anchor for top level metadata values.
For attaching to instructions you do want to use the setMetadata call on the Instruction to set any particular metadata, however, you'll want to make sure you're using the correct context - otherwise you could overwrite other metadata.

There are two things you can do.
Attach metadata nodes to instructions (like the !dbg nodes from the link you referenced). For that, there's the Instruction::setMetadata method
Create named metadata nodes in a Module, not attached to any particular instruction. For that, use Module::getOrInsertNamedMetadata.

Related

How to check for an internal edge via TraCI?

I am trying to figure out whether an edge/lane is internal. When SuMO creates internal edges/lanes, it prefixes them with a colon [1]. Currently, I am exploiting this information, however, it seems that you also can annotate arbitrary other edges as internal using the tag function. This is also set for internal edges created by SuMO [1]. Therefore, I want to retrieve the information via TraCI.
To my knowledge, there is no TraCI command to retrieve this information (i.e. either the value of function or whether the edge/lane is internal).
The classes MSEdge and MSLane in the microsim directory have methods to retrieve both of those values, however, the classes Edge and Lane from libsumo do not.
I also checked whether the value of the function tag might get added to the parameter map during initialization, which I could access via TraCI's getParameter. This also does not seem to be the case. I checked some files from the netimport directory but could not find anything satisfactory.
Is there any other way to retrieve the function/isInternal information via TraCI without adding a new TraCI command (and the aforementioned missing methods in libsumo)?
This is a static property of the network so the easiest way of retrieving the information is to parse the network. In Python you can use sumolib for that:
import sumolib
net = sumolib.net.readNet("my.net.xml")
function = {}
for e in net.getEdges():
function[e.getID()] = e.getFunction()
There is currently no TraCI call for that but the colon thing is a very good indicator. The main developers are also a bit reluctant to add all static information retrieval to the TraCI API in order not to overload it.

Tensorboard logging non-tensor (numpy) information (AUC)

I would like to record in tensorboard some per-run information calculated by some python-blackbox function.
Specifically, I'm envisioning using sklearn.metrics.auc after having run sess.run().
If "auc" was actually a tensor node, life would be simple. However, the setup is more like:
stuff=sess.run()
auc=auc(stuff)
If there is a more tensorflow-onic way of doing this I am interested in that. My current setup involves creating separate train&test graphs.
If there is a way to complete the task as stated above, I am interested in that as well.
You can make a custom summary with your own data using this code:
tf.Summary(value=[tf.Summary.Value(tag="auc", simple_value=auc)]))
Then you can add that summary to the summary writer yourself. (Don't forget to add a step).

what's the difference between a collection and a store in REST?

I'm trying to wrap my head around the difference between a "collection" and a "store" in REST. From what I've read so far,
a collection is:
"a server-managed directory of resources"
and a store is a:
"client-managed resource repository"
I found this post: How "store" REST archetype isn't creating a new resource and a new URI?
but it didn't really help me clarify the difference. I mean, I understand one is controlled by the server and the other by the client... but can someone give me a concrete example of what a store might be in a real world application?
I *think it's something like this:
GET http://myrestapplication.com/widgets/{widget_id} -- retrieves a widget from db
POST http://myrestapplication.com/widgets/{widget_id} -- creates a new widget from db
PUT http://myrestapplication.com/widgets/{widget_id},[list of updated parms & their vals] -- update widget
PUT http://myrestapplication.com/users/johndoe/mywishlist/{widget_id} -- updates john doe's profile to add a widget that already exists in the database... but links to it as his favorite one or one that he wants to buy
Is this correct?
if so, could the last PUT also be expressed as a POST somehow?
EDIT 1
I found an online link to the book i'm reading... where it makes the distinction between the two:
https://books.google.ca/books?id=4lZcsRwXo6MC&pg=PA16&lpg=PA16&dq=A+store+is+a+client-managed+resource+repository.+A+store+resource+lets+an+API+client:+put+resources+in,+get+them+back+out,+and+decide+when+to+delete+them&source=bl&ots=F4CkbFkweL&sig=H6eKZMPR_jQdeBZkBL1h6hVkK_E&hl=en&sa=X&ei=BB-vVJX6HYWvyQTByYHIAg&ved=0CB0Q6AEwAA#v=onepage&q=A%20store%20is%20a%20client-managed%20resource%20repository.%20A%20store%20resource%20lets%20an%20API%20client%3A%20put%20resources%20in%2C%20get%20them%20back%20out%2C%20and%20decide%20when%20to%20delete%20them&f=false
REST uses http verbs to manipulate resources. Full-Stop. That's it. To build some classes of browser-based application developers sometimes use local storage (a store), but that has absolutely nothing to do with REST (in fact, it's the opposite). Collections are a special consideration in REST-based API design because the REST principles place considerable constraints on how they are represented in the results of your queries -- special consideration also because there are no standards on how these things should be represented and access if you're using anything other than html as a resource type.
Edit:
REST suggests that when we ask for a resource we receive that resource and only that resource and that things referenced by that resource are returned as links, not as data. This mimics the http standard by which we return the requested page and links to other pages rather than embedding linked pages. So, our resources should return links to related resources, not the resources themselves.
So, what about collections?
Let's use as an example a college management system that has Course objects each of which contains a huge lists of Students.
When I GET the course I don't want to have the collection of students returned as an embedded list, because that could be huge and because my user might not be interested. Instead, I want to know that the course has a students collection and I want to be able to query that collection separately (when I need to) and I want to be able to page it on demand. For this to work, the course needs to link to the students collection URL (maybe with an appropriate type so that my code knows how to handle the link). Then, I want to use the given collection's url to request a paged list of resources. In this example, the collection's url could be something like: course/1/students, with the convention that I can add paging info to the search string to constrain the results with something like course/1/students?page=1&count=10. Embedding the students collection into the course resource would be a violation of REST. I would not be returning a course, I'd be returning course-and-students.

Can a Custom DataProvider class expose Custom Templates?

I am currently in the process of writing a custom DataProvider. Using the Intergrate External Data documentation.
I've managed to show the external data in the Sitecore back end. However whenever I try to view the data in the items I created, I am getting an error
Null ids are not allowed. <br> Parameter name: displayName
There seems to be precious little on the subject on how to create a custom DataProvider on the Sitecore Developer Network.
The example on their website seems to only show how to import a SINGLE item into a static database. However I am simply trying to merge some items into the hierarchy and I can't find any useful documentation.
It seems that one of your methods that should return an ID doesn't. It might be GetChildIds and/or GetParentId.
Nick Wesselman wrote a good article about it gathering all the information including an example on the Marketplace. I think that is your best start. You can read it here.
Turns out I needed to include at the very least, the Fields->Section->Template in the GetParent method. To be on the safe side I included the Fields/Sections/Templates into my implementations of
GetChildIDs
GetItemDefinition
GetParentID
It wasn't obvious that this was the case, since I had in fact implemented the GetTemplates method correctly, and I had expected that should be enough.

How to Tell if Neo4j Embedded Database Is Newly Created

I have a Clojure application using Neo4j in embedded mode. I call (new GraphDatabaseFactory).newEmbeddedDatabase with a new path. How can I tell if the resulting GraphDatabaseService was newly created / empty?
Bonus question: if it wasn't newly created, how can I read metadata in the database to tell what version of my system it was built with? If someone accidentally passes in a path to a valid Neo4j database that wasn't created with my application, I want to throw an Exception.
Full disclosure: I don't know clojure.
Programmatically, I do not see a way to determine this, but you can implement this by checking if the directory exists prior to making the call to the GraphDatabaseFactory.
As for the meta data, you can do this if you cast the GraphDatabaseService to an InternalAbstractGraphDatabase and perform a getConfig() on it. This will allow you access to the Config class, which has a property map that contains arguments that can show you the version, as well as other things.