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When is SQLiteOpenHelper onCreate() / onUpgrade() run?
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SQLiteOpenHelper onCreate() and onUpgrade() callbacks are invoked when the database is actually opened, for example by a call to getWritableDatabase(). The database is not opened when the database helper object itself is created.
SQLiteOpenHelper versi...
Get escaped URL parameter
I'm looking for a jQuery plugin that can get URL parameters, and support this search string without outputting the JavaScript error: "malformed URI sequence". If there isn't a jQuery plugin that supports this, I need to know how to modify it to support this.
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(this == null) in C#!
...spec (section 7.5.7), you shouldn't be able to access this in that context and the ability to do so in C# 3.0 compiler is a bug. C# 4.0 compiler is behaving correctly according to the spec (even in Beta 1, this is a compile time error):
§ 7.5.7 This access
A this-access consists of the res...
What is the meaning of “non temporal” memory accesses in x86
...to be seen by other processors in a timely fashion.
When data is produced and not (immediately) consumed again, the fact that memory store operations read a full cache line first and then modify the cached data is detrimental to performance. This operation pushes data out of the caches which might ...
Is 'switch' faster than 'if'?
...ntly increase performance in some scenarios, is as general as a switch is, and does not result in greater generated code size. But to see that, your test code would need a LOT more branches to see any difference.
To answer your specific questions:
Clang generates one that looks like this:
test_s...
What is the performance of Objects/Arrays in JavaScript? (specifically for Google V8)
Performance associated with Arrays and Objects in JavaScript (especially Google V8) would be very interesting to document. I find no comprehensive article on this topic anywhere on the Internet.
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Force browser to clear cache
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If this is about .css and .js changes, one way is to to "cache busting" is by appending something like "_versionNo" to the file name for each release. For example:
script_1.0.css // This is the URL for release 1.0
script_1.1.css // This is the...
Event system in Python
...raries to choose from, using very different terminology (events, signals, handlers, method dispatch, hooks, ...).
I'm trying to keep an overview of the above packages, plus the techniques mentioned in the answers here.
First, some terminology...
Observer pattern
The most basic style of event system ...
twig: IF with multiple conditions
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If I recall correctly Twig doesn't support || and && operators, but requires or and and to be used respectively. I'd also use parentheses to denote the two statements more clearly although this isn't technically a requirement.
{%if ( fields | length > 0 ) or ...
When should I choose Vector in Scala?
It seems that Vector was late to the Scala collections party, and all the influential blog posts had already left.
6 Answ...