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What makes JNI calls slow?
...thods, in 2010 I measured calls at an average 40 ns on my Windows desktop, and 11 ns on my Mac desktop. Unless you're making many calls, you're not going to notice.
That said, calling a native method can be slower than making a normal Java method call. Causes include:
Native methods will not be i...
Using R to list all files with a specified extension
I'm very new to R and am working on updating an R script to iterate through a series of .dbf tables created using ArcGIS and produce a series of graphs.
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How to force IntelliJ IDEA to reload dependencies from build.sbt after they changed?
...orce SBT to reload changes:
Open SBT toolwindow (on the right side of IDE) and press refresh button.
If you use auto-import feature you need to save your file to force auto-refresh.
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C# short/long/int literal format?
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Just to add that upper case and lower case of these literal suffixes are equivalent e.g. 1l and 1L both will be treated as long integer but certainly 1L is more readable than 1l.
– RBT
Mar 21 '17 at 3:14
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How to add “on delete cascade” constraints?
... You have to drop the constraint first, then add the correct version. In standard SQL, I believe the easiest way to do this is to
start a transaction,
drop the foreign key,
add a foreign key with on delete cascade, and finally
commit the transaction
Repeat for each foreign key you want to change...
How to create a protocol with methods that are optional?
...ly denote the semantics of
the default behavior. You can use
@optional and @required to partition
your protocol into sections as you see
fit. If you do not specify any
keyword, the default is @required.
@protocol MyProtocol
- (void)requiredMethod;
@optional
- (void)anOptionalMethod;
- ...
MySQL DISTINCT on a GROUP_CONCAT()
...n a string like:
test1 test2 test3 test1 test3 test4
(notice that test1 and test3 are duplicated) while the OP wants to return this string:
test1 test2 test3 test4
the problem here is that the string "test1 test3" is duplicated and is inserted only once, but all of the others are distinct to e...
Method to Add new or update existing item in Dictionary
... indexer setters of both classes call this.Insert(key, value, add: false); and the add parameter is responsible for throwing an exception, when inserting a duplicate key. So the behavior is the same for both classes.
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Is there a more elegant way of adding an item to a Dictionary safely?
... Add if the existence of the key indicates a bug (so you want it to throw) and the indexer otherwise. (It's a bit like the difference between casting and using as for reference conversions.)
If you're using C# 3 and you have a distinct set of keys, you can make this even neater:
var currentViews =...
Web deployment task build failed
...n you install web deploy it sets up two local accounts WDeployConfigWriter and WDeployAdmin. The passwords on these accounts are set to expire. So reset the passwords on the web server and set to "never expire". Then go to Management Service Delegation in IIS. Each of the presented rules has a UserN...