Search Results

Search found 4125 results on 165 pages for 'hash cluster'.

Page 128/165 | < Previous Page | 124 125 126 127 128 129 130 131 132 133 134 135  | Next Page >

  • Why does Color.IsNamedColor not work when I create a color using Color.FromArgb()?

    - by Jon B
    In my app I allow the user to build a color, and then show him the name or value of the color later on. If the user picks red (full red, not red-ish), I want to show him "red". If he picks some strange color, then the hex value would be just fine. Here's sample code that demonstrates the problem: static string GetName(int r, int g, int b) { Color c = Color.FromArgb(r, g, b); // Note that specifying a = 255 doesn't make a difference if (c.IsNamedColor) { return c.Name; } else { // return hex value } } Even with very obvious colors like red IsNamedColor never returns true. Looking at the ARGB values for my color and Color.Red, I see no difference. However, calling Color.Red.GetHashCode() returns a different hash code than Color.FromArgb(255, 0, 0).GetHashCode(). How can I create a color using user specified RGB values and have the Name property come out right?

    Read the article

  • EJB3.1 Remote invocation - is it distributed automatically? is it expensive?

    - by Hank
    I'm building a JEE6 application with performance and scalability in the forefront of my mind. Business logic and JPA2-facade is held in stateless session beans (EJB3.1). As of right now, the SLSBs implement only @Remote-interfaces. When a bean needs to access another bean, it does so via RMI. My reasoning behind this is the assumption that, once the application runs on a bunch of clustered application servers, the RMI-part allows the execution to be distributed across the whole cluster automagically. Is that a correct assumption? I'm fine with dealing with the downsides of that (objects lose entityManager session, pass-by-value), at least I think so. But I am wondering if constant remote invocation isn't adding more load then necessary.

    Read the article

  • How to preserve data integrity while minimizing the transmission size

    - by user1500578
    we have sensors in the wild that send their data to a server every day via TCP/IP, either through 3G or through satellite for the physical layer. The sensors can automatically switch from one to the other depending on their location and the quality of the signal with the local 3G operator. Given that the 3G and satellite communications are very expensive, we want to minimize the amount of data to send. But also, we want to protect ourselves from lost data. What would be the best strategy to ensure with reasonable certainty that the integrity of our data is preserved, while minimizing the amount of redundancy, i.e the amount of data transmitted ? I've read about the zfec codec, but I'm not sure if we need to transmit all the chunks, or if we need to send a hash code along each chunk.

    Read the article

  • Separation of static and dynamic content in Java EE applications

    - by Dan
    We work with IBM products and we typically use IBM Http Servers (read Apache) as a reverse proxy for our application servers. For performance reasons we serve static content (.gif, .jpg, .css, .html etc.) from our http servers, to ease the burden a bit from the application server. So far, we have to distribute files to http server and configure it manually (writing custom scripts at best.) The problem is the effort needed to keep everything in synch, especially when you need to update the app. Does any Java EE product support this “out of the box”? Is there a way to have application server do this automatically, like in cluster configuration for example, where master node is in charge of distributing the application to other nodes and for keeping everything in synch.

    Read the article

  • How to verify a digital signature with openssl

    - by Aaron Carlino
    I'm using a thirdparty credit card processing service (Paybox) that, after a successful transaction, redirects back to the website with a signature in the URL as a security measure to prevent people from manipulating data. It's supposed to prove that the request originated from this service. So my success URL looks something like this: /success.php?signature=[HUGE HASH] I have no idea where to start with verifying this signature. This service does provide a public key, and I assume I need to create a private key, but I don't know much beyond that. I'm pretty good with linux, and I know I'll have to run some openssl commands. I'm writing the verification script in PHP, which also has native openssl() functions. If anyone could please push me in the right direction with some pseudo code, or even functional code, I'd be very grateful. Thanks.

    Read the article

  • Convert byte array to understandable String

    - by Ender
    I have a program that handles byte arrays in Java, and now I would like to write this into a XML file. However, I am unsure as to how I can convert the following byte array into a sensible String to write to a file. Assuming that it was Unicode characters I attempted the following code: String temp = new String(encodedBytes, "UTF-8"); Only to have the debugger show that the encodedBytes contain "\ufffd\ufffd ^\ufffd\ufffd-m\ufffd\ufffd\/ufffd \ufffd\ufffdIA\ufffd\ufffd". The String should contain a hash in alphanumerical format. How would I turn the above String into a sensible String for output?

    Read the article

  • Genetic programming in c++, library suggestions?

    - by shuttle87
    I'm looking to add some genetic algorithms to an Operations research project I have been involved in. Currently we have a program that aids in optimizing some scheduling and we want to add in some heuristics in the form of genetic algorithms. Are there any good libraries for generic genetic programming/algorithms in c++? Or would you recommend I just code my own? I should add that while I am not new to c++ I am fairly new to doing this sort of mathematical optimization work in c++ as the group I worked with previously had tended to use a proprietary optimization package. We have a fitness function that is fairly computationally intensive to evaluate and we have a cluster to run this on so parallelized code is highly desirable. So is c++ a good language for this? If not please recommend some other ones as I am willing to learn another language if it makes life easier. thanks!

    Read the article

  • List of fundamental data structures - what am I missing?

    - by jboxer
    I've been studying my fundamental data structures a bunch recently, trying to make sure I've got them down cold. By "fundamental", I mean the real basic ones. Fancy ones like Red-Black Trees and Bloom Filters are clearly worth knowing, but they're usually either enhancements of fundamental ones (Red-Black Trees are binary search trees with special properties to keep them balanced) or they're only useful in very specific situations (Bloom Filters). So far, I'm "fluent" in the following data structures: Arrays Linked Lists Stacks/Queues Binary Search Trees Heaps/Priority Queues Hash Tables However, I feel like I'm missing something. Are there any fundamental ones that I'm forgetting about? EDIT: Added these after posting the question Strings (suggested by catchmeifyoutry) Sets (suggested by Peter) Graphs (suggested by Nick D and aJ) B-Trees (Suggested by tloach) I'm a little on-the-fence about whether these are too fancy or not, but I think they're different enough from the fundamental structures (and important enough) to be worth studying as fundamental.

    Read the article

  • When does ref($variable) return 'IO'?

    - by Zaid
    Here's the relevant excerpt from the documentation of the ref function: The value returned depends on the type of thing the reference is a reference to. Builtin types include: SCALAR ARRAY HASH CODE REF GLOB LVALUE FORMAT IO VSTRING Regexp Based on this, I imagined that calling ref on a filehandle would return 'IO'. Surprisingly, it doesn't: use strict; use warnings; open my $fileHandle, '<', 'aValidFile'; close $fileHandle; print ref $fileHandle; # prints 'GLOB', not 'IO' perlref tries to explain why: It isn't possible to create a true reference to an IO handle (filehandle or dirhandle) using the backslash operator. The most you can get is a reference to a typeglob, which is actually a complete symbol table entry [...] However, you can still use type globs and globrefs as though they were IO handles. In what circumstances would ref return 'IO' then?

    Read the article

  • Illegal instruction gcc assembler.

    - by Bernt
    In assembler: .globl _test _test: pushl %ebp movl %esp, %ebp movl $0, %eax pushl %eax popl %ebp ret Calling from c main() { _test(); } Compile: gcc -m32 -o test test.c test.s This code gives me illegal instruction sometimes and segment fault other times. In gdc i always get illegal instruction, this is just a simple test, i had a larger program that was working and suddenly after no apperant reason stopped working, now i always get this error even if i start from scratch like above. I have narrowed it down to pushl %eax (or any other register....), if i comment out that line the code runs fine. Any ideas? (I'm running the program at my universities linux cluster, so I have not changed any settings..)

    Read the article

  • Comparison of collection datatypes in C#

    - by Joel in Gö
    Does anyone know of a good overview of the different C# collection types? I am looking for something showing which basic operations such as Add, Remove, RemoveLast etc. are supported, and giving the relative performance. It would be particularly interesting for the various generic classes - and even better if it showed eg. if there is a difference in performance between a List<T> where T is a class and one where T is a struct. A start would be a nice cheat-sheet for the abstract data structures, comparing Linked Lists, Hash Tables etc. etc. Thanks!

    Read the article

  • SHA-256 encryption wrong result in Android

    - by user642966
    I am trying to encrypt 12345 using 1111 as salt using SHA-256 encoding and the answer I get is: 010def5ed854d162aa19309479f3ca44dc7563232ff072d1c87bd85943d0e930 which is not same as the value returned by this site: http://hash.online-convert.com/sha256-generator Here's the code snippet: public String getHashValue(String entity, String salt){ byte[] hashValue = null; try { MessageDigest digest = MessageDigest.getInstance("SHA-256"); digest.update(entity.getBytes("UTF-8")); digest.update(salt.getBytes("UTF-8")); hashValue = digest.digest(); } catch (NoSuchAlgorithmException e) { Log.i(TAG, "Exception "+e.getMessage()); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } return BasicUtil.byteArrayToHexString(hashValue); } I have verified my printing method with a sample from SO and result is fine. Can someone tell me what's wrong here? And just to clarify - when I encrypt same value & salt in iOS code, the returned value is same as the value given by the converting site.

    Read the article

  • c# multi threaded file processing

    - by user177883
    There is a folder that contains 1000 of small text files. I aim to parse and process all of them while more files are being populated in to the folder. My intention is to multithread this operation as the single threaded prototype took 6 minutes to process 1000 files. I like to have reader and writer thread(s) as following : while the reader thread(s) are reading the files, I d like to have writer thread(s) to process them. Once the reader is started reading a file, I d like to mark it as being processed, such as by renaming it, once it s read, rename it to completed. How to approach such multithreaded application ? Is it better to use a distributed hash table or a queue? Which data structure to use that would avoid locks? Would you have a better approach to this scheme that you like to share?

    Read the article

  • Why use hashing to create pathnames for large collections of files?

    - by Stephen
    Hi, I noticed a number of cases where an application or database stored collections of files/blobs using a has to determine the path and filename. I believe the intended outcome is a situation where the path never gets too deep, or the folders ever get too full - too many files (or folders) in a folder making for slower access. EDIT: Examples are often Digital libraries or repositories, though the simplest example I can think of (that can be installed in about 30s) is the Zotero document/citation database. Why do this? EDIT: thanks Mat for the answer - does this technique of using a hash to create a file path have a name? Is it a pattern? I'd like to read more, but have failed to find anything in the ACM Digital Library

    Read the article

  • Data Structure for a particular problem??

    - by AGeek
    Hi, Which data structure can perform insertion, deletion and searching operation in O(1) time in the worst case. We may assume the set of elements are integers drawn from a finite set 1,2,...,n, and initialization can take O(n) time. I can only think of implementing a hash table. Implementing it with Trees will not give O(1) time complexity for any of the operation. Or is it possible?? Kindly share your views on this, or any other data structure apart from these.. Thanks..

    Read the article

  • Cassandra performance slow down with counter column

    - by tubcvt
    I have a cluster (4 node ) and a node have 16 core and 24 gb ram: 192.168.23.114 datacenter1 rack1 Up Normal 44.48 GB 25.00% 192.168.23.115 datacenter1 rack1 Up Normal 44.51 GB 25.00% 192.168.23.116 datacenter1 rack1 Up Normal 44.51 GB 25.00% 192.168.23.117 datacenter1 rack1 Up Normal 44.51 GB 25.00% We use about 10 column family (counter column) to make some system statistic report. Problem on here is that When i set replication_factor of this keyspace from 1 to 2 (contain 10 counter column family ), all cpu of node increase from 10% ( when use replication factor=1) to --- 90%. :( :( who can help me work around that :( . why counter column consume too much cpu time :(. thanks all

    Read the article

  • call value inside a JS variable as a JS function name

    - by user1640668
    Hello I have a function to perform actions but name of the function is inside a variable... below code will get the URL's hashed part example: #JHON and remove # and store it inside URLHASH variable..example: JHON var urlhash = document.location.hash; urlhash = urlhash.replace(/^.*#/, ''); always there is a function name from that value inside variable and i want to call value inside that variable as a function name window.onload=function() { Value inside URLHASH variable should run as a name of a variable. example: jhon(); }; Is it possible ? I tried some codes but it calls variable name as a function not value inside the variable..help me..

    Read the article

  • pipelined function

    - by user289429
    Can someone provide an example of how to use parallel table function in oracle pl/sql. We need to run massive queries for 15 years and combine the result. SELECT * FROM Table(TableFunction(cursor(SELECT * FROM year_table))) ...is what we want effectively. The innermost select will give all the years, and the table function will take each year and run massive query and returns a collection. The problem we have is that all years are being fed to one table function itself, we would rather prefer the table function being called in parallel for each of the year. We tried all sort of partitioning by hash and range and it didn't help. Also, can we drop the keyword PIPELINED from the function declaration? because we are not performing any transformation and just need the aggregate of the resultset.

    Read the article

  • Accessing GMail "View as HTML" content programatically?

    - by Amethi
    I love the "View as HTML" option in GMail when viewing attachments. I would love to be able to use this feature programatically, i.e. check a GMail inbox, read emails, if there are attachments, get the html view and use that content. I'm looking to do this in C Sharp (on a Mac, can't find the hash symbol). Does anyone know if this is possible or if there's another solution to easily get content from a GMail account, regardless of what format it's in? I.E html, pdf, Word doc, etc. The GMail Inbox Feed api isn't good enough and before I start trying to build an IMAP solution that pulls in PDF/Word doc converters, I thought it'd be good to ask here.

    Read the article

  • How to make GhostScript PS2PDF stop subsetting fonts

    - by gavin-softyolk
    I am using the ps2pdf14 utility that ships with GhostScript, and I am having a problem with fonts. It does not seem to matter what instructions I pass to the command, it insists on subsetting any fonts it finds in the source document. e.g -dPDFSETTINGS#/prepress -dEmbedAllFonts#true -dSubsetFonts#false -dMaxSubsetPct#0 Note that the # is because the command is running on windows, it is the same as =. If anyone has any idea how to tell ps2pdf not to subset fonts, I would be very greatful. Thanks --------------------------Notes ------------------------------------------ The source file is a pdf containing embedded fonts, so it is the fonts already embedded in the source file, that I need to prevent being subset in the destination file. Currently all source file embedded fonts are subset, in some cases this is not apparent from the font name, i.e it contains no hash, and appears at first glance to be the full font, however the widths array has been subset in all cases.

    Read the article

  • Does to_json require parameters? what about within rails?

    - by Harry Wood
    Does to_json require parameters? what about within rails? I started getting the error "wrong number of arguments (0 for 1)" when doing myhash.to_json Unfortunately I'm not sure when this error started happening, but I guess it relates to some versions of either rails or the json gem. I suppose my code (in a rails controller) is using the ActiveSupport::JSON version of to_json, rather than the to_josn method supported by the json gem. ActiveSupport::JSON vs JSON In environment.rb I have RAILS_GEM_VERSION = '2.3.2' and also config.gem "json", :version=> '1.1.7' It's just a simple hash structure containing primitives which I want to convert in my controller, and it was working, but now I can't seem to run to_json without passing parameters.

    Read the article

  • resizing arrays when close to memory capacity

    - by user548928
    So I am implementing my own hashtable in java, since the built in hashtable has ridiculous memory overhead per entry. I'm making an open-addressed table with a variant of quadratic hashing, which is backed internally by two arrays, one for keys and one for values. I don't have the ability to resize though. The obvious way to do it is to create larger arrays and then hash all of the (key, value) pairs into the new arrays from the old ones. This falls apart though when my old arrays take up over 50% of my current memory, since I can't fit both the old and new arrays in memory at the same time. Is there any way to resize my hashtable in this situation Edit: the info I got for current hashtable memory overheads is from here How much memory does a Hashtable use? Also, for my current application, my values are ints, so rather than store references to Integers, I have an array of ints as my values.

    Read the article

  • Best solution for language documentation.

    - by Simone Margaritelli
    I'm developing a new object oriented scripting language and the project itself is quite ready for audience now, so i'm starting to think about a serious (not as "drafty" as it is right now) way of document its grammar, functions from standard library and standard library classes. I've looked a bit around and almost every language hash its own web application for the documentation, Python uses Sphinx for instance. Which is the best PHP (don't have the time/will to install mod_who_knows_what on my server) application to accomplish this? I've used mediawiki a bit but i found its tag system a little bit hard to use in this context. Thanks for your answers.

    Read the article

  • Should I go with Varnish instead of nginx?

    - by gotts
    I really like nginx. But recently I've found that varnish gives you an opportunity to implement smart caching revers proxy layer(with URL purging). I have a cluster of mongrels which are pretty resource-intensive so if this caching layer can remove some load from mongrels this can be a great thing. I didn't find a way to implement the caching layer(with for application pages; static content is cacheable of course) same with nginx.. Should I use Varnish instead? What would you recommend?

    Read the article

  • does a switch idiom make sense in this case?

    - by the ungoverned
    I'm writing a parser/handler for a network protocol; the protocol is predefined and I am writing an adapter, in python. In the process of decoding the incoming messages, I've been considering using the idiom I've seen suggested elsewhere for "switch" in python: use a hash table whose keys are the field you want to match on (a string in this case) and whose values are callable expressions: self.switchTab = { 'N': self.handleN, 'M': self.handleM, ... } Where self.handleN, etc., are methods on the current class. The actual switch looks like this: self.switchTab[selector]() According to some profiling I've done with cProfile (and Python 2.5.2) this is actually a little bit faster than a chain of if..elif... statements. My question is, do folks think this is a reasonable choice? I can't imagine that re-framing this in terms of objects and polymorphism would be as fast, and I think the code looks reasonably clear to a reader.

    Read the article

< Previous Page | 124 125 126 127 128 129 130 131 132 133 134 135  | Next Page >