大约有 3,500 项符合查询结果（耗时：0.0112秒） [XML]
How to get execution time in rails console?
...u already see during requests.
Sample:
[METRICS] Completed in 908.3ms | Allocations: 2894 | ActiveRecord: 0.9ms (queries: 13)
share
|
improve this answer
|
follow
...
Most common C# bitwise operations on enums
... all by the way.
HasFlag is rather slow as it requires boxing which causes allocations and thus more garbage collections.
Due in part to .NET's limited support for flag enums I wrote the OSS library Enums.NET which addresses each of these issues and makes dealing with flag enums much easier.
Belo...
What exactly are “spin-locks”?
...als), making statically dispatched calls into any code one doesn't own, or allocating memory.
It's also important to note that SpinLock is a value type, for performance reasons. As such, one must be very careful not to accidentally copy a SpinLock instance, as the two instances (the original and the...
When is each sorting algorithm used? [closed]
...usly.
/**
* Some VMs reserve some header words in an array.
* Attempts to allocate larger arrays may result in
* OutOfMemoryError: Requested array size exceeds VM limit
*/
private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
(even though it actually will allow to MAX_VALUE-2)
see:
Do ...
Correct way to detach from a container without stopping it
...t comes down to the following when the container was launched:
was a TTY allocated (-t)
was stdin left open (-i)
^P^Q does work, BUT only when -t and -i is used to launch the container:
[berto@g6]$ docker run -ti -d --name test python:3.6 /bin/bash -c 'while [ 1 ]; do sleep 30; done;'
b26e39632...
Why does .NET foreach loop throw NullRefException when collection is null?
... either return an empty collection — it is a call to constructor, memory allocation, and perhaps a bunch of a code to be executed. Either you could just return «null» → obviously there's only a code to return and a very short code to check is the argument is «null». It's just a performance.
...
What breaking changes are introduced in C++11?
...ing two templates.
In C++03, >> would always be the shift-operator token.
Allow dependent calls of functions with internal linkage.
Example by me:
static void f(int) { }
void f(long) { }
template<typename T>
void g(T t) { f(t); }
int main() { g(0); }
In C++03, this calls ...
How do I print to the debug output window in a Win32 app?
...GL project), you don't need to edit the properties, as this works better:
AllocConsole();
freopen("CONIN$", "r",stdin);
freopen("CONOUT$", "w",stdout);
freopen("CONOUT$", "w",stderr);
printf and cout will work as usual.
If you call AllocConsole before the creation of a window, the console will a...
Base64 length calculation?
...ss the point of the original question, which is how much space needs to be allocated to fit the base64 encoding for a given binary string of length n bytes.
The answer is (floor(n / 3) + 1) * 4 + 1
This includes padding and a terminating null character. You may not need the floor call if you are ...
How to identify CAAnimation within the animationDidStop delegate?
... wasted hours): don't expect to see the original animation object that you allocated passed back to you by
- (void)animationDidStop:(CAAnimation*)animation finished:(BOOL)flag
when the animation finishes, because [CALayer addAnimation:forKey:] makes a copy of your animation.
What you can rely ...