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  • Memory problems while code is running (Python, Networkx)

    - by MIN SU PARK
    I made a code for generate a graph with 379613734 edges. But the code couldn't be finished because of memory. It takes about 97% of server memory when it go through 62 million lines. So I killed it. Do you have any idea to solve this problem? My code is like this: import os, sys import time import networkx as nx G = nx.Graph() ptime = time.time() j = 1 for line in open("./US_Health_Links.txt", 'r'): #for line in open("./test_network.txt", 'r'): follower = line.strip().split()[0] followee = line.strip().split()[1] G.add_edge(follower, followee) if j%1000000 == 0: print j*1.0/1000000, "million lines done", time.time() - ptime ptime = time.time() j += 1 DG = G.to_directed() # P = nx.path_graph(DG) Nn_G = G.number_of_nodes() N_CC = nx.number_connected_components(G) LCC = nx.connected_component_subgraphs(G)[0] n_LCC = LCC.nodes() Nn_LCC = LCC.number_of_nodes() inDegree = DG.in_degree() outDegree = DG.out_degree() Density = nx.density(G) # Diameter = nx.diameter(G) # Centrality = nx.betweenness_centrality(PDG, normalized=True, weighted_edges=False) # Clustering = nx.average_clustering(G) print "number of nodes in G\t" + str(Nn_G) + '\n' + "number of CC in G\t" + str(N_CC) + '\n' + "number of nodes in LCC\t" + str(Nn_LCC) + '\n' + "Density of G\t" + str(Density) + '\n' # sys.exit() # j += 1 The edge data is like this: 1000 1001 1000245 1020191 1000 10267352 1000653 10957902 1000 11039092 1000 1118691 10346 11882 1000 1228281 1000 1247041 1000 12965332 121340 13027572 1000 13075072 1000 13183162 1000 13250162 1214 13326292 1000 13452672 1000 13844892 1000 14061830 12340 1406481 1000 14134703 1000 14216951 1000 14254402 12134 14258044 1000 14270791 1000 14278978 12134 14313332 1000 14392970 1000 14441172 1000 14497568 1000 14502775 1000 14595635 1000 14620544 1000 14632615 10234 14680596 1000 14956164 10230 14998341 112000 15132211 1000 15145450 100 15285998 1000 15288974 1000 15300187 1000 1532061 1000 15326300 Lastly, is there anybody who has an experience to analyze Twitter link data? It's quite hard to me to take a directed graph and calculate average/median indegree and outdegree of nodes. Any help or idea?

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  • Let multiple highcharts charts appear automatically from mysql data

    - by martini1993
    I have the following problem. I want to make multiple Highcharts webcharts appear automatically based on the data from the database. Let's say we have the following database: ___________________________________________________________________ | | | | | | | | Year | Month | ID | Name User | Wins | Losses | |_______|___________|______|_______________|____________|__________| | 2013 1 21 Tony Stark 3 12 | | 2013 1 52 Bruce Wayne 5 4 | | 2013 1 76 Clark Kent 9 5 | |__________________________________________________________________| (This database is an example, there are a lot more rows in the real database.) And i have the following query: SELECT a.year AS year1, a.month AS month1, a.id AS id, a.name AS nameuser, a.wins AS wins, a.losses AS losses FROM Sales a WHERE a.month = 1 AND a.year = YEAR(NOW()) With this, it is very easy to hardcode a chart with Highcharts. But what I want is that there has to be a webchart per user. So instead of a single webchart with all the users in it, I want multiple charts next to each other based on the data from the database. So instead of this: http://jsfiddle.net/CWSb6/ I want this (But then next to each other): http://jsfiddle.net/DReMD/ It has to be generated automatically with php and mysql. So if there is a new user starting this month, and the new user is saved in the database, the page automatically displays the new user with the related web chart. I find this very hard to accomplish and I need some help to get to the right direction for the solution. Many thanks in advance! (Sorry for my bad english.)

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  • Select * from 'many to many' SQL relationship

    - by Rampant Creative Group
    I'm still learning SQL and my brain is having a hard time with this one. Say I have 3 tables: teams players and teams_players as my link table All I want to do is run a query to get each team and the players on them. I tried this: SELECT * FROM teams INNER JOIN teams_players ON teams.id = teams_players.team_id INNER JOIN players ON teams_players.player_id = players.id But it returned a separate row for each player on each team. Is JOIN the right way to do it or should I be doing something else? ----------------------------------------- Edit Ok, so from what I'm hearing, this isn't necessarily a bad way to do it. I'll just have to group the data by team while I'm doing my loop. I have not yet tried the modified SQL statements provided, but I will today and get back to you. To answer the question about structure - I guess I wasn't thinking about the returned row structure which is part of what lead to my confusion. In this particular case, each team is limited to 4 players (or less) so I guess the structure that would be helpful to me is something like the following: teams.id, teams.name, players.id, players.name, players.id, players.name, players.id, players.name, players.id, players.name, 1 Team ABC 1 Jim 2 Bob 3 Ned 4 Roy 2 Team XYZ 2 Bob 3 Ned 5 Ralph 6 Tom

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  • Suggestions of the easiest algorithms for some Graph operations

    - by Nazgulled
    Hi, The deadline for this project is closing in very quickly and I don't have much time to deal with what it's left. So, instead of looking for the best (and probably more complicated/time consuming) algorithms, I'm looking for the easiest algorithms to implement a few operations on a Graph structure. The operations I'll need to do is as follows: List all users in the graph network given a distance X List all users in the graph network given a distance X and the type of relation Calculate the shortest path between 2 users on the graph network given a type of relation Calculate the maximum distance between 2 users on the graph network Calculate the most distant connected users on the graph network A few notes about my Graph implementation: The edge node has 2 properties, one is of type char and another int. They represent the type of relation and weight, respectively. The Graph is implemented with linked lists, for both the vertices and edges. I mean, each vertex points to the next one and each vertex also points to the head of a different linked list, the edges for that specific vertex. What I know about what I need to do: I don't know if this is the easiest as I said above, but for the shortest path between 2 users, I believe the Dijkstra algorithm is what people seem to recommend pretty often so I think I'm going with that. I've been searching and searching and I'm finding it hard to implement this algorithm, does anyone know of any tutorial or something easy to understand so I can implement this algorithm myself? If possible, with C source code examples, it would help a lot. I see many examples with math notations but that just confuses me even more. Do you think it would help if I "converted" the graph to an adjacency matrix to represent the links weight and relation type? Would it be easier to perform the algorithm on that instead of the linked lists? I could easily implement a function to do that conversion when needed. I'm saying this because I got the feeling it would be easier after reading a couple of pages about the subject, but I could be wrong. I don't have any ideas about the other 4 operations, suggestions?

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  • howto distinguish composition and self-typing use-cases

    - by ayvango
    Scala has two instruments for expressing object composition: original self-type concept and well known trivial composition. I'm curios what situations I should use which in. There are obvious differences in their applicability. Self-type requires you to use traits. Object composition allows you to change extensions on run-time with var declaration. Leaving technical details behind I can figure two indicators to help with classification of use cases. If some object used as combinator for a complex structure such as tree or just have several similar typed parts (1 car to 4 wheels relation) than it should use composition. There is extreme opposite use case. Lets assume one trait become too big to clearly observe it and it got split. It is quite natural that you should use self-types for this case. That rules are not absolute. You may do extra work to convert code between this techniques. e.g. you may replace 4 wheels composition with self-typing over Product4. You may use Cake[T <: MyType] {part : MyType} instead of Cake { this : MyType => } for cake pattern dependencies. But both cases seem counterintuitive and give you extra work. There are plenty of boundary use cases although. One-to-one relations is very hard to decide with. Is there any simple rule to decide what kind of technique is preferable? self-type makes you classes abstract, composition makes your code verbose. self-type gives your problems with blending namespaces and also gives you extra typing for free (you got not just a cocktail of two elements but gasoline-motor oil cocktail known as a petrol bomb). How can I choose between them? What hints are there? Update: Let us discuss the following example: Adapter pattern. What benefits it has with both selt-typing and composition approaches?

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  • Can I automatically throw descriptive exceptions with parameter values and class feild information?

    - by Robert H.
    I honestly don't throw exceptions often. I catch them even less, ironically. I currently work in shop where we let them bubble up to avicode. For whatever reason, however, avicode isn't configured to capture some of the critical bits I need when these exceptions come bouncing back to my attention. Specifically, I'd like to see the parameter values and the class’s field data at the time of the exception. I’d guess with the large suite of .Net services that I could create a static method to crawl up the stack, gather these bits and store them in a string that I could stick in my exception message. I really don't are how long such a method would take to execute as performance is no longer a concern when I hit one of these scenarios. If it's possible, I'm sure someone has done it. If that's the case, I'm having a hard time finding it. I think any search containing "exception" brings back too many resutls. Anyway, can this be done? If so, some examples or links would be great. Thanks in advance for your time, Robert

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  • Need a SQL statement focus on combination of tables but entries always with uinque ID

    - by Registered User KC
    Hi All, I need SQL code to solve the tables combination problem, described on below: Table old data: name version status lastupdate ID A 0.1 on 6/8/2010 1 B 0.1 on 6/8/2010 2 C 0.1 on 6/8/2010 3 D 0.1 on 6/8/2010 4 E 0.1 on 6/8/2010 5 F 0.1 on 6/8/2010 6 G 0.1 on 6/8/2010 7 Table new data: name version status lastupdate ID A 0.1 on 6/18/2010 #B entry deleted C 0.3 on 6/18/2010 #version_updated C1 0.1 on 6/18/2010 D 0.1 on 6/18/2010 E 0.1 off 6/18/2010 #status_updated F 0.1 on 6/18/2010 G 0.1 on 6/18/2010 H 0.1 on 6/18/2010 #new_added H1 0.1 on 6/18/2010 #new_added the difference of new data and old date: B entry deleted C entry version updated E entry status updated C1/H/H1 entry new added What I want is always keeping the ID - name mapping relationship in old data table no matter how data changed later, a.k.a the name always has a unique ID number bind with it. If entry has update, then update the data, if entry is new added, insert to the table then give a new assigned unique ID. However, I can only use SQL with simple select or update statement then it may too hard for me to write such code, then I hope someone with expertise can give direction, no details needed on the different of SQL variant, a standard sql code as sample is enough. Thanks in advance! Rgs KC

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  • Ocaml Pattern Matching

    - by Atticus
    Hey guys, I'm pretty new to OCaml and pattern matching, so I was having a hard time trying to figure this out. Say that I have a list of tuples. What I want to do is match a parameter with one of the tuples based on the first element in the tuple, and upon doing so, I want to return the second element of the tuple. So for example, I want to do something like this: let list = [ "a", 1; "b", 2"; "c", 3; "d", 4 ] ;; let map_left_to_right e rules = match e with | first -> second | first -> second | first -> second If I use map_left_to_right "b" list, I want to get 2 in return. I therefore want to list out all first elements in the list of rules and match the parameter with one of these elements, but I am not sure how to do so. I was thinking that I need to use either List.iter or List.for_all to do something like this. Any help would be appreciated. Thanks!

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  • Ruby array, javascript and json issue

    - by JohnMerlino
    Hey all, I am unable to get a highcharts plugin to render a chart in a rails application: http://github.com/loudpixel/highcharts-rails I believe it has something to do with the sql queries to the database placed in a ruby array, which the javascript is unable to intepret. This is what I have: def panels pass = Student.find_by_sql('SELECT COUNT(*) FROM students WHERE student_state = 1') fail = Student.find_by_sql('SELECT COUNT(*) FROM students WHERE student_state = 2') student_data = [ {:name => 'Pass', :y => pass}, {:name => 'Fail', :y => fail} ] pie_label_formatter = ' function() { if (this.y > 15) return this.point.name; }' pie_tooltip_formatter = ' function() { return "<strong>" + this.point.name + "</strong>: " + this.y + " %"; }' @pie_chart = Highchart.pie({ :chart => { :renderTo => "pie-chart-container", :margin => [50, 30, 0, 30] }, :plotOptions => { :pie => { :dataLabels => { :formatter => pie_label_formatter, :style => { :textShadow => '#000000 1px 1px 2px' } } } }, :series => [ { :type => 'pie', :data => student_data } ], :subtitle => { :text => 'April 2010' }, :title => { :text => 'Student Status Chart' }, :tooltip => { :formatter => pie_tooltip_formatter }, }) Note if I put this: :data = student_data.to_json It actually returns a json string of my query as text in the browser. Also, if I hard code values (e.g. :y = 1), it will render the chart properly. However, any database query will not render the chart properly. So I'm not sure exactly what the issue is. Any suggestions? Thanks.

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  • Appropriate SQL Server Permissions for Developers

    - by BJ Safdie
    After a couple of Google searches and a quick look at questions here, I cannot seem to find what I thought would be a cookbook answer for SQL Server permissions. As I often see in small shops, most developers here were using an admin account for SQL Server while developing. I want to set up roles and permissions that I can assign to developers so that we can get our jobs done, but also do so with the minimum permissions required. Can anyone offer advice on what SQL Server permissions to assign? Components: SQL Server 2008 SQL Server Reporting Services (SSRS) 2008 SQL Server Integration Services (SSIS) 2008 Platforms: Production Staging/QA Development/Integration We are running "Mixed Mode" security because of some legacy apps and networks, but are moving to Windows Auth. I am not sure if that really affects the role set up. I plan to set up access for Developers to Prod and Staging/QA DBs as Read-Only. However, I still want developers to retain the ability to run Profiling. We need Deployment accounts with higher privilege levels. We are currently trying to figure out exactly what privileges we need for SSIS package deployments. Within the Development Server, Developers need broad privileges. However, I am not sure that just making them all admins is really the best choice. It's hard to believe that no one has published a decent example script that sets up these kinds of roles with a good set of appropriate permissions for developers and deployers. We can probably figure this all out by locking things down and then adding permissions as we discover the need, but that will be way too big a PITA for everyone. Can anyone point me to, or provide, a good exemplar for permissions for these kinds of roles on these kinds of platforms?

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  • red black tree balancing?

    - by Anirudh Kaki
    i am working to generate tango tree, where i need to check whether every sub tree in tango is balanced or not. if its not balanced i need to make it balance? I trying so hard to make entire RB-tree balance but i not getting any proper logic so can any one help me out?? here i am adding code to check how to find my tree is balanced are not but when its not balanced how can i make it balance. static boolean verifyProperty5(rbnode n) { int left = 0, right = 0; if (n != null) { bh++; left = blackHeight(n.left, 0); right = blackHeight(n.right, 0); } if (left == right) { System.out.println("black height is :: " + bh); return true; } else { System.out.println("in balance"); return false; } } public static int blackHeight(rbnode root, int len) { bh = 0; blackHeight(root, path1, len); return bh; } private static void blackHeight(rbnode root, int path1[], int len) { if (root == null) return; if (root.color == "black"){ root.black_count = root.parent.black_count+1; } else{ root.black_count = root.parent.black_count; } if ((root.left == null) && (root.right == null)) { bh = root.black_count; } blackHeight(root.left, path1, len); blackHeight(root.right, path1, len); }

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  • Cocoa/AppleScript move file

    - by bogdan
    I have a list of file paths and a destination path. I need something (AppleScript, Cocoa) that will move the files from one location to an other. I first tried using the following AppleScript, just to see what happens: set the_folder to (choose folder) tell application "Finder" move selection to the_folder end tell The problem is that it just blindly tries to move a file, nothing like the way Finder actually moves files (i.e. if a file with that name already exists, the AppleScript just throws an error, while Finder would ask you if you want to replace the file). The solution I came up with involved NSFileManager. I won't post the code because it's quite long, but basically I just check if the file already exists before trying to move, and if it exists a NSAlert with Replace/Cancel buttons appear. I have 2 remaining problems: Authorization - if you try to do something to files where you don't have access, the Finder would ask you to authorize. My code just fails... Moving to external drives - when you try to move a file to a different drive, NSFileManager copies the file and then deletes the original. The problem is that NSFileManager doesn't provide anything which I could use to display a progress indicator of what's happening during the copy. Is there anything I could use that is able to move files without these problems? The way I see it, I'm pretty much stuck with checking if the files are writable by the current user and authorize NSFileManager if not (from my understanding of the Authorization Services, this will be quite hard to implement). Oh and, I would also need to check if the destination is on the same drive and if not, implement something with FSCopyObjectAsync so that it shows a progress indicator... Thanks!

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  • Intellisense on custom types in Iron Python

    - by Anish Patel
    Hi everybody, I'm just starting to play around with IronPython and am having a hard time using it with custom types created in C#. I can get IronPython to load in assemblies from C# classes, but I'm struggling without the help of intellisense. If I have a class in C# as defined below, how can I make it so that IronPython will be able to see the methods/properties that are available in it? public class Person { public string Name { get; set; } public int Age{ get; set; } public double Weight{ get; set; } public double Height { get; set; } public double CalculateBMI() { return Weight/Math.Pow(Height, 2); } } In Iron python I'd instance a Person object as follows: newPerson = Person() newPerson.Name = 'John' newPerson.Age = 25 newPerson.Weight = 75 newPerson.Height = 1.70 newPerson.CalculateBMI() The thing that is annoying me is that I want to be able to say newPerson = Person() And then be able to see all the methods and properties associated with the person object whenever I type: newPerson. Anyone have any ideas if this can be done?

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  • Java Client .class File Protection

    - by Zac
    I am in the requirements phase of building a JEE application that will most likely run on a GlassFish/JBoss backend (doesn't matter for now). I know I shouldn't be thinking about architecture at requirements time, but one can't help but start to imagine how the components would all snap together :-) Here are some hard, non-flexible requirements on the client-side: (1) The client application will be a Swing box (2) The client is free to download, but will use a subscription model (thus requiring a login mechanism with server-side authentication/authorization, etc.) (3) Yes, Java is the best platform solution for the problem at hand for reasons outside the scope of this post (4) The client-side .class files need safeguarding against decompiling That last (4th) requirement is the basis of this post. I'm not really worried about someone actually decompiling and getting at my source code: in the end, it's just Swing controls driven by some lightweight business logic. I'm worried about a scenario where someone decompiles my code, modifies it to exploit/attack the server, re-compiles, and fires it up. I've envisioned all sorts of nasty solutions, but didn't know if this was a common problem with a common solution for JEE developers. Any thoughts? Not interested in "code obfuscation" techniques! Thanks for any input!

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  • Looking for fast, minimal, preferrably free disc cloning software [closed]

    - by Dave
    We have to test our application installation and functionality on many Windows operating system versions and languages (XP, Vista, Win7; English, Spanish, Portuguese, etc; 32-bit & b4-bit.) While we can do much of this in virtual machines, we have noticed that VM's sometimes hide problems, or raise false bugs. So, we need to do "bare metal" OS installation for much of our testing. I have been using Acronis True Image for the past year, and am not impressed. It often gives random errors which require a reboot, and is really slow. For example, when trying to restore an image, it goes through a "Locking partition" cycle about three times (once after you click OK on each step of the wizard), each of which can take 5 minutes to complete. This all happens BEFORE it actually starts the image copy, which is sometimes quick (3-5 minutes), sometimes long (hours). The size of all of our images are roughly the same, so that is not related. So, anyway, I'm looking to switch to something else: I only need very basic functionality--just creating images of entire discs, and then restoring those images onto the exact same hard drive at a later date. That's it. I'm not opposed to paying for a good piece of software, but if there is something free out there that does the job well, that would be a preference. My OS on which the imaging software would run is Windows Vista, but a bootable media (into a Linux flavor) would be fine also, as long as its quick to use and reliable. Recommendations? (Also, moderators, if this should be a CW, I'll be happy to mark it as such; unclear about the rules there.)

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  • Client Web Browser Behavior When Handling 301 Redirect

    - by Jon Swanson
    The RFC seems to suggest that the client should permanently cache the response: http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html 10.3.2 301 Moved Permanently The requested resource has been assigned a new permanent URI and any future references to this resource SHOULD use one of the returned URIs. Clients with link editing capabilities ought to automatically re-link references to the Request-URI to one or more of the new references returned by the server, where possible. This response is cacheable unless indicated otherwise. The new permanent URI SHOULD be given by the Location field in the response. Unless the request method was HEAD, the entity of the response SHOULD contain a short hypertext note with a hyperlink to the new URI(s). If the 301 status code is received in response to a request other than GET or HEAD, the user agent MUST NOT automatically redirect the request unless it can be confirmed by the user, since this might change the conditions under which the request was issued. Note: When automatically redirecting a POST request after receiving a 301 status code, some existing HTTP/1.0 user agents will erroneously change it into a GET request. I'm having a hard time finding concrete browser documentation for any major browser that states how they handle these. I've started digging through the source code of firefox, but quickly got lost. Is the following scenario true for which (if any) browsers, and is there definitive documentation for either Firefox or IE that states as much?: First Time Around: 1.1: User enters link to site A, or clicks on a link directed at Site A 1.2: Browser interprets link at Site A, first time, no cache. Sends GET to Site A. 1.2: Site A responds with 301 Redirect to Site B 1.3: Browser sends GET to Site B. Any Subsequent Times Around: 2.2: User clicks on a link directed at Site A 2.2: Browser sees that, due to a past 301 redirect, Site A should now be Site B. 2.3: Without initiating any request whatsoever at Site A, browser initiates GET at Site B.

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  • JavaScript Exception/Error Handling Not Working

    - by Seán Hayes
    This might be a little hard to follow. I've got a function inside an object: f_openFRHandler: function(input) { console.debug('f_openFRHandler'); try{ //throw 'foo'; DragDrop.FileChanged(input); //foxyface.window.close(); } catch(e){ console.error(e); jQuery('#foxyface_open_errors').append('<div>Max local storage limit reached, unable to store new images in your browser. Please remove some images and try again.</div>'); } }, inside the try block it calls: this.FileChanged = function(input) { // FileUploadManager.addFileInput(input); console.debug(input); var files = input.files; for (var i = 0; i < files.length; i++) { var file = files[i]; if (!file.type.match(/image.*/)) continue; var reader = new FileReader(); reader.onload = (function(f, isLast) { return function(e) { if (files.length == 1) { LocalStorageManager.addImage(f.name, e.target.result, false, true); LocalStorageManager.loadCurrentImage(); //foxyface.window.close(); } else { FileUploadManager.addFileData(f, e.target.result); // add multiple files to list if (isLast) setTimeout(function() { LocalStorageManager.loadCurrentImage() },100); } }; })(file, i == files.length - 1); reader.readAsDataURL(file); } return true; LocalStorageManager.addImage calls: this.setItem = function(data){ localStorage.setItem('ImageStore', $.json_encode(data)); } localStorage.setItem throws an error if too much local storage has been used. I want to catch that error in f_openFRHandler (first code sample), but it's being sent to the error console instead of the catch block. I tried the following code in my Firebug console to make sure I'm not crazy and it works as expected despite many levels of function nesting: try{ (function(){ (function(){ throw 'foo' })() })() } catch(e){ console.debug(e) } Any ideas?

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  • JTextField vs JComboBox behaviour in JTable

    - by Ash
    Okay, this is a hard one to explain but I'll try my best. I have a JTextField and a JComboBox in a JTable, whose getCellEditor method has been overriden as follows: public TableCellEditor getCellEditor( int row, int column ) { if ( column == 3 ) { // m_table is the JTable if ( m_table.getSelectedRowCount() == 1 ) { JComboBox choices = new JComboBox(); choices.setEditable( true ); choices.addItem( new String( "item 1" ) ); return new DefaultCellEditor( choices ); } return super.getCellEditor( row, column ); } Here are the behavioral differences (NOTE that from this point on, when I say JTextField or JComboBox, I mean the CELL in the JTable containing either component): When I click once on a JTextField, the cell is highlighted. Double clicking brings up the caret and I can input text. Whereas, with a JComboBox, single clicking brings up the caret to input text, as well as the combo drop down button. When I tab or use the arrow keys to navigate to a JTextField and then start typing, the characters I type automatically get entered into the cell. Whereas, when I navigate to a JComboBox the same way and then start typing, nothing happens apart from the combo drop down button appearing. None of the characters I type get entered unless I hit F2 first. So here's my question: What do I need to do have JComboBoxes behave exactly like JTextFields in the two instances described above? Please do not ask why I'm doing what I'm doing or suggest alternatives (it's the way it is and I need to do it this way) and yes, I've read the API for all components in question....the problem is, it's a swing API. Thanks in advance, Ash

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  • File Storage for Web Applications: Filesystem vs DB vs NoSQL engines

    - by El Yobo
    I have a web application that stores a lot of user generated files. Currently these are all stored on the server filesystem, which has several downsides for me. When we move "folders" (as defined by our application) we also have to move the files on disk (although this is more due to strange design decisions on the part of the original developers than a requirement of storing things on the filesystem). It's hard to write tests for file system actions; I have a mock filesystem class that logs actions like move, delete etc, without performing them, which more or less does the job, but I don't have 100% confidence in the tests. I will be adding some other jobs which need to access the files from other service to perform additional tasks (e.g. indexing in Solr, generating thumbnails, movie format conversion), so I need to get at the files remotely. Doing this over network shares seems dodgy... Dealing with permissions on the filesystem as sometimes given us problems in the past, although now that we've moved to a pure Linux environment this should be less of an issue. What are the downsides of storing files as BLOBs in MySQL? I guess that it would massively increase the database size and reduce the effectiveness of caches, but are there other problems? Do the same problems exist with NoSQL systems like Cassandra? Does anyone have any other suggestions that might be appropriate?

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  • Sell me Distributed revision control

    - by ring bearer
    I know 1000s of similar topics floating around. I read at lest 5 threads here in SO But why am I still not convinced about DVCS? I have only following questions (note that I am selfishly worried only about Java projects) What is the advantage or value of committing locally? What? really? All modern IDEs allows you to keep track of your changes? and if required you can restore a particular change. Also, they have a feature to label your changes/versions at IDE level!? what if I crash my hard drive? where did my local repository go? (so how is it cool compared to checking in to a central repo?) Working offline or in an air plane. What is the big deal?In order for me to build a release with my changes, I must eventually connect to the central repository. Till then it does not matter how I track my changes locally. Ok Linus Torvalds gives his life to Git and hates everything else. Is that enough to blindly sing praises? Linus lives in a different world compared to offshore developers in my mid-sized project? Pitch me!

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  • .net real time stream processing - needed huge and fast RAM buffer

    - by mack369
    The application I'm developing communicates with an digital audio device, which is capable of sending 24 different voice streams at the same time. The device is connected via USB, using FTDI device (serial port emulator) and D2XX Drivers (basic COM driver is to slow to handle transfer of 4.5Mbit). Basically the application consist of 3 threads: Main thread - GUI, control, ect. Bus reader - in this thread data is continuously read from the device and saved to a file buffer (there is no logic in this thread) Data interpreter - this thread reads the data from file buffer, converts to samples, does simple sample processing and saves the samples to separate wav files. The reason why I used file buffer is that I wanted to be sure that I won't loose any samples. The application doesn't use recording all the time, so I've chosen this solution because it was safe. The application works fine, except that buffered wave file generator is pretty slow. For 24 parallel records of 1 minute, it takes about 4 minutes to complete the recording. I'm pretty sure that eliminating the use of hard drive in this process will increase the speed much. The second problem is that the file buffer is really heavy for long records and I can't clean this up until the end of data processing (it would slow down the process even more). For RAM buffer I need at lest 1GB to make it work properly. What is the best way to allocate such a big amount of memory in .NET? I'm going to use this memory in 2 threads so a fast synchronization mechanism needed. I'm thinking about a cycle buffer: one big array, the Bus Reader saves the data, the Data Interpreter reads it. What do you think about it? [edit] Now for buffering I'm using classes BinaryReader and BinaryWriter based on a file.

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  • How do I update a progress bar in Cocoa during a long running loop?

    - by Nic
    Hi, I've got a while loop, that runs for many seconds and that's why I want to update a progress bar (NSProgressIndicator) during that process, but it updates only once after the loop has finished. The same happens if I want to update a label text, by the way. I believe, my loop prevents other things of that application to happen. There must be another technique. Does this have to do with threads or something? Am I on the right track? Can someone please give me a simple example, how to “optimize” my application? My application is a Cocoa Application (Xcode 3.2.1) with these two methods in my Example_AppDelegate.m: // This method runs when a start button is clicked. - (IBAction)startIt:(id)sender { [progressbar setDoubleValue:0.0]; [progressbar startAnimation:sender]; running = YES; // this is a instance variable int i = 0; while (running) { if (i++ = processAmount) { // processAmount is something like 1000000 running = NO; continue; } // Update progress bar double progr = (double)i / (double)processAmount; NSLog(@"progr: %f", progr); // Logs values between 0.0 and 1.0 [progressbar setDoubleValue:progr]; [progressbar needsDisplay]; // Do I need this? // Do some more hard work here... } } // This method runs when a stop button is clicked, but as long // as -startIt is busy, a click on the stop button does nothing. - (IBAction)stopIt:(id)sender { NSLog(@"Stop it!"); running = NO; [progressbar stopAnimation:sender]; } I'm really new to Objective-C, Cocoa and applications with a UI. Thank you very much for any helpful answer.

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  • Play framework does not return page and static content

    - by Anton
    I'm using play framework in production for one of my web projects. From time to time Play does not render main page or does not return some of the static content files. I have attached few screenshots below. First screenshot displays firebug console, loading of the site is stucked at the beginning, when serving home page. Second screenshot display fiddler console, when 2 static resources are not loading. This issue is hard to reproduce, it happens 1 of 15 time, I have to delete cache data and reload page. (pressing CRTL-F5 in FF). Issue can be reproduced in most of the browsers. Initially, I was thinging that there is something wrong with hosting provider. But I have changed hosting provided and issue has not gone. Version of the play is 1.2.2. Play is running as standalone server. Not sure, but probably deploying Play to Jetty/Tomcat/Resin would help. Also I'm thinging about rewriting application to another stack (well-known for me - j2ee, spring, whatever) I have no idea how to debug and resolve this issue. Any clue ? Has anyone faced same issue with Play before ?

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  • Is it possible to group records belonging to an entity in dbunit?

    - by Joshua
    Our JPA entity model auto-generates primary key identifiers for user, user_address tables. Would it be possible to group these entities given below via dbunit, so that I don't need to provide neither the primary key as well as the foreign key reference from user_address.user_id. It is getting very hard to maintain these keys (i.e. I would prefer to group the primary record 'user' and the child records 'user_address' so that dbunit can group them automatically by looking up the entity metadata). Is it achievable? <user id="1" first_name="Josh" creation_date="2009-07-11 15:45:28"/> <user_address id="1" user_id="1" address="Main St" city="Los Angeles"/> I would prefer something like this <!-- First user --> <user first_name="Josh" creation_date="2009-07-11 15:45:28"/> <user_address address="Main St" city="Los Angeles"/> <!-- Second user --> <user first_name="Mary" creation_date="2009-07-11 15:45:28"/> <user_address address="Taylors St" city="San Jose"/>

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  • How should I generate the partitions / pairs for the Chinese Postman problem?

    - by Simucal
    I'm working on a program for class that involves solving the Chinese Postman problem. Our assignment only requires us to write a program to solve it for a hard-coded graph but I'm attempting to solve it for the general case on my own. The part that is giving me trouble is generating the partitions of pairings for the odd vertices. For example, if I had the following labeled odd verticies in a graph: 1 2 3 4 5 6 I need to find all the possible pairings / partitions I can make with these vertices. I've figured out I'll have i paritions given: n = num of odd verticies k = n / 2 i = ((2k)(2k-1)(2k-2)...(k+1))/2 So, given the 6 odd verticies above, we will know that we need to generate i = 15 partitions. The 15 partions would look like: 1 2 3 4 5 6 1 2 3 5 4 6 1 2 3 6 4 5 ... 1 6 ... Then, for each partition, I take each pair and find the shortest distance between them and sum them for that partition. The partition with the total smallest distance between its pairs is selected, and I then double all the edges between the shortest path between the odd vertices (found in the selected partition). These represent the edges the postman will have to walk twice. At first I thought I had worked out an appropriate algorithm for generating these partitions / pairs but it is flawed. I found it wasn't a simple permutation/combination problem. Does anyone who has studied this problem before have any tips that can help point me in the right direction for generating these partitions?

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