java - Can I constrain a HashMap by the amount of memory it takes up? -

-

I am implementing a simple cache using LinkedHashMap based on the instructions I've seen . I use the following code: 

  Public class cache LinkedHashMap {Private FINAL INC. Capabilities; Public cache {super (capacity + 1, 1.1f, true); This.capacity = ability; } Largest entries removed from the protected boolean (entry senior) {return size ()> Capacity; }}

It is very easy though, it only puts a fixed size on the map. I am running on a very small pile and depending on the size of the cached objects and the capacity of my chosen it can still run out of memory, it is arbitrary of the objects and therefore I can not predict how big they can be. . To cut the cache I do not want to depend on SoftReferences because the way it is cleaned is incredible; It changes from VM to VM, and they can either be retrieved soon, or they can never be recovered until they reach my heap.

Do I have a way to monitor the size of the map and constrain it based on that?

If the soft / weak reference is out of the question, then I have 2 non-trivial options:

1) Use Java Instrumentation to check the actual size of objects added in the map. Instrumentation interface provides an object, and you will need more code to explore references (and to avoid duplicates counting!). A solution that calculates the deeper shape of an object.

2) Use the JMX to track the size of the pile after GCX, and when changing to some dangerous threshold, change the map behavior. See the "Notifications" section.


Comments

Post a Comment

Popular posts from this blog

paypal - How to know the URL referrer in PHP? -

-
I'm new to integrating PayPal with sites, so easily from the service I can use Can the available method be? What am I trying to do, when the user clicks on "Return to my website", I want my return URL to know that the referrer is PayPal so I can send it automatically to the homepage . how to do this? I tried $ _ SERVER ['HTTP_REFERER'] but it does not seem like anything. During the IPN conversation I set the cookie and session (though I am not sure whether I am correcting it or doing this right), but on returning to my website, it does not seem to recognize any session . If I use it by using $ _ SERVER ['HTTP_REFERER'] , then I'm afraid it's a security risk, is not it? If so, is there any other way I remember? help please. Should you really know the referrer? Set the PayPal Return URL to a "secret" URL which is always redirected to the homepage. If someone reaches there and gets redirected without coming from PayPal, then ...
Read more

oauth - Facebook OAuth2 Logout does not remove fb_ cookie -

-
This is used to work so I'm not sure what's wrong the user just logs in to Facebook properly Is capable of Logging problem. I log out the user logout by redirecting them to the php script. $ facebook-> GetLogoutUrl (); When users click on that link, they are logged out from the Facebook page. However, when they return to my site, I find that the FB_ cookie is still there. PHP SDK still gives user FB session details. The strange thing is that www.facebook.com shows that I am already logged out of Facebook. What can be wrong here? Thanks, I've been stumped: (. OK, finally, what did I do? > GetLogoutUrl () with a next = address url on my logout script which will remove the Facebook cookie by setSession (null) .
Read more

wpf - Line breaks and indenting for the XAML of a saved FlowDocument? -

-
Is there a way to format XAM generated when a flow document is saved? Currently, all of this is run simultaneously in one line, and I want to break it into my elements, with line break and indenting it makes it a little easier to read. Here is the code I'm using to save a FlowDocument in a WPF RichTextBox as a XAML file: // entire document around TextRange textRange Create a TextRange side = new TextRange (myRichTextBox.Document.ContentStart, myRichTextBox.Document .contentEnd); // save the file using the file (file stream fs = file. Create (filename)) {textRange.Save (fs, DataFormats.Xaml); } Savings work fine, but as I mentioned, JPAM has been generated, all this goes together, no indentation or line breaks for its various elements Is: & lt; Section xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation" xml: space = "preserve" Tekstelinement = "left" Lainhait = "auto" Hashipineshn = enabled = "false...
Read more