I'm using Fog to access a cloud environment at Terremark. When I pull down our organizational data it returns a data structure that, while I know it should be straight forward, confuses me.
Using irb I initialize the connection and then request the data using conn.organizations and display it with awesome_print. It returns:
[
[0] <Fog::Compute::Ecloud::Organization
href="/cloudapi/ecloud/organizations/#######",
name="****************************** (***-###-###)",
type="application/vnd.tmrk.cloud.organization",
other_links=[{:href=>"/cloudapi/ecloud/admin/organizations/#######", :name=>"****************************** (***-###-###)", :type=>"application/vnd.tmrk.cloud.admin.organization", :rel=>"alternate"}, {:href=>"/cloudapi/ecloud/environments/organizations/#######", :type=>"application/vnd.tmrk.cloud.environment; type=collection", :rel=>"down"}, {:href=>"/cloudapi/ecloud/devicetags/organizations/#######", :type=>"application/vnd.tmrk.cloud.deviceTag; type=collection", :rel=>"down"}, {:href=>"/cloudapi/ecloud/alerts/organizations/#######", :type=>"application/vnd.tmrk.cloud.alertLog", :rel=>"down"}]
>
]
So it is returning an array with a singular element. That element is comprised of another data structure surrounded by < and >. But I'm not certain if that's accurate because there also appears to be another array containing a hash embedded within that structure.
My issue is that I need to extract the value represented by the ####### but I don't know how to access any of the sections of the output which contain that value.
What am I looking at as far as the data structure is concerned and how do I go about access the data contained within?
It's a Fog::Compute::Ecloud::Organization object and the documentation of that class should tell you what methods are available. Or you can just ask the object itself, by calling Object#methods.
Related
Hi so I have been going over Big O but had a question about the access and search operation I'm aware of the search is basically iteration and access in the context of arrays would be something like array[3] to access specific part of the array, I just wanted to verify how it looks for other data structure's so am I correct when it comes to access for these data structures in my example:
// linked list access
head.next.next.next.value
// tree access
root.left.right.left.value
// graph access
node.id
node.edge[2]
node.edge[2].id
node.edge
I a developing a macOS commandline application in Xcode, which uses User Defaults. I have the following code for my User Defaults
if let configDefaults = UserDefaults.init(suiteName: "com.tests.configuration") {
configDefaults.set("myStringValue", forKey: "stringKey")
configDefaults.synchronize()
print(configDefaults.dictionaryRepresentation())
}
This will create my own .plist file in the ~/Library/Preferences folder. If I look into the file, I can see only my single value which I added, which is perfectly fine. But when I call dictionaryRepresentation() on my UserDefaults object, the there are a lot of other attributes (I guess from the shared UserDefaults object), like
com.apple.trackpad.twoFingerFromRightEdgeSwipeGesture or AKLastEmailListRequestDateKey
Looking into the documentation of UserDefaults, it seems that this has to do with the search list of UserDefaults and that the standard object is in the search list:
func dictionaryRepresentation() -> [String : Any]
Returns a dictionary that contains a union of all key-value pairs in the domains in the search list.
There are also the methods addSuite and removeSuite for a UserDefaults object, so I am guessing I need to remove the .standard suite from my configDefaults object, but I don't know the name, which should be used for that in the method.
Is it possible to remove the .standard defaults from the dictionary representation? I basically just want all of my own data in a dictionary, nothing more.
The reason I am trying to get only my values from the UserDefaults, is that a have a number of object of a custom type Connection (which store the configuration to connect to a server), which are saved in the UserDefaults. On program start I want to be able to load all objects into my app. Therefore I thought I could use dictionaryRepresentation(), as it would return all elements in the UserDefaults. But then there should be only my Connection objects in the dictionary, so that I can cast it to [String: Connection].
Given your purpose (in your latest edit of your question), what you should do is store a collection of Connection objects under a single key. Then, look up that key to get the collection.
It's not clear if the collection should be an array of Connection objects or a dictionary mapping strings to Connections. That's a choice you can make.
But, in any case, you shouldn't rely on the defaults being empty of everything else.
In other words, you would do:
UserDefaults.standard.set(yourStringToConnectionDictionary, forKey:"yourSingleKey")
and later:
let connectionMap = UserDefaults.dictionary(forKey:"yourSingleKey")
then look up Connections in the connectionMap by their name/ID/whatever.
Though the other solution proposed by Ken Thomases may be better from a design standpoint, I've found a solution that does exactly what I initially wanted. Calling
UserDefaults.standard.persistentDomain(forName: "com.company.TestApp.configuration")
Returns a dictionary containing only the values I've added to the domain com.company.TestApp.configuration, using
let configs = UserDefaults.init(suiteName: "com.company.TestApp.configuration")!
configs.set(someData, forKey: someKey)
Strangely in the Apple documentation says this about persistentDomain(forName:):
Calling this method is equivalent to initializing a user defaults object with init(suiteName:) passing domainName and calling the dictionaryRepresentation() method on it.
But this is not the case (see my question). Clarification on that subject is more than welcome.
When I create a function like this:
v8::Function::New(<Isolate>, <C_Function>, <Data_Value>);
The Data_Value that I supply is useful for many things and I can access that when the function is called, with something like FunctionCallbackInfo->GetData().
But I have found no way to get back this data in a different scenario. Let's say I store that Function in a Persistent object, and then I would like to read which data is currently bound to it. Any ideas?
I don't think it's exposed via the API.
But there's an alternative:
manually construct a v8::FunctionTemplate
set its ->InstanceTemplate()->SetInternalFieldCount(num_fields)
get the v8::Function from the template with template->GetFunction(context),
now you should have function->InternalFieldCount() == num_fields
you can use function->SetInternalField(index, value) and function->GetInternalField(index) to store any data you want.
For complete examples, search for "SetInternalFieldCount" in V8's test-api.cc.
I have a choice between two ways of scanning through a key level in a large global array and am trying to figure out if one method is more efficient than the other.
This is a vendor supplied application and database on the Intersystems Caché database platform. It is written in the old MUMPS style and does not use any of Caché's object persistence functions: all data is stored in globals directly and any indexes are application maintained.
There is a common convention for repeating data elements attached to entities where the first record will contain a count of child records and then each child record is numbered sequentially at the next key level. For example:
^GBDATA(12345,100)="3"
^GBDATA(12345,100,1)="A^Record"
^GBDATA(12345,100,2)="B^Record"
^GBDATA(12345,100,3)="C^Record"
Where "12345" is the entity key, and "100" is one of the attached detail types. Note that the first "100" record with no other keys has the count of subrecords. There could be anywhere between 0 and hundreds of subrecords attached. The entities are often very wide and there is a lot of other data besides this subrecord type (not shown in example).
Given an entity key, I want to scan through all the subrecords of one type. Would it be faster to use $ORDER to go through the subkeys or to use a FOR loop to anticipate the key values? Does it matter?
$ORDER method:
SET EKEY=12345
SET SEQ=""
FOR
{
SET SEQ=$ORDER(^GBDATA(EKEY,100,SEQ), 1, ROWDATA)
QUIT:SEQ=""
WRITE ROWDATA,!
}
FOR count method:
SET EKEY=12345
SET LIM=^GBDATA(EKEY,100)
FOR SEQ=1:1:LIM
{
WRITE ^GBDATA(EKEY,100,SEQ),!
}
Does anyone know how $ORDER vs $GET is implemented internally in Caché?
I'm having trouble testing this empirically since we only have one production instance with appropriate data and I can't take it offline to clear the cache. I'm most interested in from-disk performance as opposed to from-cache performance.
You could use %SYS.MONLBL to figure out definitively. My guess is that $ORDER is slightly better.
http://docs.intersystems.com/cache20122/csp/docbook/DocBook.UI.Page.cls?KEY=GCM_monlbl
In regards to your question, "Does anyone know how $ORDER vs $GET is implemented internally in Caché?" The two are completely different functions.
$Order is used for the direction that you're going in when reviewing your ^Global.
$Get is used to pull the data within the ^Global. Below is an example of it's use. I use Cache ObjectScript; however, this should give you a general idea
Global Structure
^People(LastName,FirstName)="Phone"
Global Data
^People(Doe,John)="1035001234"
^People(Smith,Jane)="7405241305"
^People(Wood,Edgar)="7555127598"
Code Sample
SET LASTNAME=0
FOR QUIT:LASTNAME?." " DO
.SET LASTNAME=$ORDER(^People(LASTNAME)) QUIT:LASTNAME?." "
.SET FIRSTNAME=0
.FOR QUIT:FIRSTNAME?." " DO
..SET FIRSTNAME=$ORDER(^People(LASTNAME,FIRSTNAME)) QUIT:FIRSTNAME?." "
..SET PHONE=$GET(^People(LASTNAME,FIRSTNAME))
In the sample provided above, it will start with the first record within the ^People global and then start with the first record within the last name by utilizing $Order. It will then $Get the data for the ^People(LASTNAME,FIRSTNAME) node, which is the phone number.
For some samples and reference areas, check out the following links:
$Get Information
$Order Information
I have been using MongoDB and RoR to store logging data. I am pulling out the data and looking to page the results. Has anyone done paging with MongoDB or know of any resources online that might help get me started?
Cheers
Eef
Pagination in MongoDB can be accomplished by using a combination of limit() and skip().
For example, assume we have a collection called users in our active database.
>> db.users.find().limit(3)
This retrieves a list of the first three user documents for us. Note, this is essentially the same as writing:
>> db.users.find().skip(0).limit(3)
For the next three, we can do this:
>> db.users.find().skip(3).limit(3)
This skips over the first three user records, and gives us the next three. If there is only one more user in your database, don't worry; MongoDB is smart enough to only return data that is present, and won't crash.
This can be generalised like so, and would be roughly equivalent to what you would do in a web application. Assuming we have variables called PAGE_SIZE which is set to 3, and an arbitrary PAGE_NUMBER:
>> db.users.find().skip(PAGE_SIZE * (PAGE_NUMBER - 1)).limit(PAGE_SIZE)
I cannot speak directly as to how to employ this method in Ruby on Rails, but I suspect the Ruby MongoDB library exposes these methods.