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  • Power surge PC damage: How can I test all components of my PC without access to a second computer?

    - by Doug T.
    Ever since we had some crazy power surges last week my 64 bit Windows 7 PC has been acting strange. My USB network adapter disconnects from the wireless and can't detect the signal. I have to disable/reenable the adapter to detect it again. Also my wife has reported that the PC has rebooted a few times while I'm not sitting at it. Today I finally caught the reboot while I was using the PC. I got this blue screen of death. Stop Code 0x00000109: "Modification of system code or a critical data structure was detected." I followed the advice at the linked article and ran a memory test. I used memtest86 and its already found around 300,000 errors out of 8 gigs of ram. Now I'm worried -- what are the odds this is isolated to just my memory and not just a system wide problem? Isn't there a good chance that many other components are fried? More importantly, how can I test those other components? Are there tools similar to memtest I can use to test my motherboard/video card/power supply? If these are vender specific, is it typical for vendors to provide testing tools?

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  • MySQL : table organisation for very large sets with high update frequency

    - by Remiz
    I'm facing a dilemma in the choice of my MySQL schema application. So before I start here is a picture extremely simplified of my database : Schema here : http://i43.tinypic.com/2wp5lxz.png In one sentence : for each customer, the application harvest text data and attached tags to each data collected. As approximation of the usage of each table, here is what I expect : customer : ~5000, shouldn't grow fast data : 5 millions per customer, could double or triple for big customers. tag : ~1000, quite fixed size data_tag : hundred of millions per customer easily. Each data can be tagged a lot. The harvesting process is permanent, that means that around every 15 minutes new data come and are tagged, that require a very constant index refreshing. A lot of my queries are a SELECT COUNT of DATA between specific DATES and tagged with a specific TAG on a specific CUSTOMER (very rarely it will involve several customers). Here is the situation, you can imagine with this kind of volume of data I'm facing a challenge in term of data organization and indexing. Again, it's a very minimalistic and simplified version of my structure. My question is, is it better: to stick with this model and to manage crazy index optimization ? (which involves potentially having billions of rows in the data_tag table) change the schema and use one data table and one data_tag table per customer ? (which involves having 5000 tables on my database) I'm running all of this on a MySQL 5.0 dedicated server (quad-core, 8Go of ram) replicated. I only use InnoDB, I also have another server that run Sphinx. So knowing all of this, I can't wait to hear your opinion about this. Thanks.

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  • How can records be deleted without activating the delete trigger?

    - by Servaas Phlips
    Hello there, Since about a month we are experiencing records that are disappearing from our database without any reason. (part of) Our database structure is at http://i.imgur.com/i15nG.png Now users and credentials can never be deleted. We noticed however that thanks to our backups that unfortanetely users disappeared from the database. The users and credentials that disappear appear to be completely random. In order to find out which application deletes this records we created triggers with the following checks: CREATE TRIGGER Credential_SoftDelete ON [Credential] INSTEAD OF DELETE AS DECLARE @message nvarchar(255) DECLARE @hostName nvarchar(30) DECLARE @loginName nvarchar(30) DECLARE @deletedId nvarchar(30) SELECT @deletedId=credentialid FROM deleted; SELECT @hostName=host_name,@loginName=login_name FROM sys.dm_exec_sessions WHERE session_id=@@SPID; SELECT @message = '[FAULT] Credential : ' + USER_NAME() + ' deleted ' +@deletedId + ' on ' + @@SERVERNAME + ' from [' + @hostname + ' by ' + @loginName; EXEC xp_logevent 50001,@message,ERROR GO Now after we added this trigger we hoped to find out which application deletes these credentials by searching in the log files. Unfortanetely the credentials are still deleted and the trigger Credential_SoftDelete is never logged. I did try run a delete on the database where the trigger is installed and where the users have disappeared. I ran the following query on the database: DELETE FROM [User] WHERE userid=296 and the trigger prevented deletion of this user and also logged this in the log events. This was actually on exact the same database where the users disappeared. (so no test copy or something like that) Please note that we also use replication, the type of replication we use is merge replication. How is this possible? Can the fact that we use replication on this database be the cause of this problem?

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  • Anyone have a script to delete a specific local windows profile?

    - by Jordan Weinstein
    I'm looking for Powershell (preferred) script, or .CMD or .VBS, to delete a specific user profile on a workstation (WinXP) or terminal server (2000, '03 or '08). I know all about the delprof utility... That only allows you delete based on a period of inactivity. I want a script to: prompt admin for a username delete that username's profile and to delete the entire profile - registry hive too (not just the folder structure within Documents and Settings). The same way it would if you went to My Computer Properties Advanced tab User Profiles Settings and deleted profiles from there. Any ideas? All I can think of is doing an AD lookup to get the SID of the user specified, then using that to delete the correct registry hive too... something simpler would be nice though... Basically, my HelpDesk used to be local administrators on our Citrix servers and a common fix for various issues was for them to delete a user's profile on the citrix server(s) and have that user log back in - voila, whatever issue they had was resolved. Going forward, in new Citrix environment, they will no longer be local admins on those boxes, but still need to be able to delete profiles (deleting the entire profile: folder and reg hive is key). thanks.

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  • Mysql: create index on 1.4 billion records

    - by SiLent SoNG
    I have a table with 1.4 billion records. The table structure is as follows: CREATE TABLE text_page ( text VARCHAR(255), page_id INT UNSIGNED ) ENGINE=MYISAM DEFAULT CHARSET=ascii The requirement is to create an index over the column text. The table size is about 34G. I have tried to create the index by the following statement: ALTER TABLE text_page ADD KEY ix_text (text) After 10 hours' waiting I finally give up this approach. Is there any workable solution on this problem? UPDATE: the table is unlikely to be updated or inserted or deleted. The reason why to create index on the column text is because this kind of sql query would be frequently executed: SELECT page_id FROM text_page WHERE text = ? UPDATE: I have solved the problem by partitioning the table. The table is partitioned into 40 pieces on column text. Then creating index on the table takes about 1 hours to complete. It seems that MySQL index creation becomes very slow when the table size becomes very big. And partitioning reduces the table into smaller trunks.

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  • Looking for a powershell script that can pull a file from a set of PC's and FTP

    - by DangeRuss
    I'm looking to write a script (preferably powershell) that will essentially copy a file from a bunch of PC's and FTP it to a server. So the structure of the environment is that we have a file on multiple PC's (around 50 or so) that need to placed on a server. Sometimes one of the PC's may be turned off so the script would first need to ensure the PC is up and running (maybe a ping result), then it would need to go into a directory on that PC, pull a file off of it, rename the file, place into a source directory, then remove the file. Naming convention doesn't matter, but date/time stamp would be easiest. Ideally, it would be best to first move all the files to a source directory to save on FTP bandwidth, but since the files will be named the same, the files must be renamed during the move process. Move not copy because the directory needs to be empty so the file can be re-created the next day. So once moved to the source directory, now all the files need to be FTP'd to a server for processing. After all of this, we need to know which PC's on the list did not respond so we can manually retrieve the file so the script should output a file (txt is fine) that will show which PC's were offline. Everything is one domain and script will be run from an server with admin creds. Thank you!

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  • "merging" multiple internet connections

    - by Spencer R
    I've seen this question asked several times here on SF, but I'm looking for some updated information; specifically concerning Server 2012. I'm in the process of buying a home so I'm trying to get some plans together on how I want to structure my network. Internet speeds aren't the greatest and connections can be unreliable where the house is so I was thinking of having two DSL lines installed. My question is, how could I leverage those two connections to create the best network I can, in terms of speed and reliability. My parents will be moving in with me - they consume a lot of bandwidth as it is, but then add my internet traffic to it, and I'm headed for a lot of frustration. I thought I remember reading somewhere that Server 2012 has some new functionality to utilize multiple connections on multiple NICs in a way that wasn't possible in earlier versions of Server. Not sure if Windows will work but, I'm an application developer and spend the majority of my time in Windows environments. However, I've only recently returned to the Windows world, so I'd like my main server at home to run Win Server 2012 so that I can become more familiar with it.

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  • How can I recover my data from a damaged hard drive?

    - by krk
    a few days ago when I was working on windows my laptop was beaten on the side where the hard drive is located. As a result, it was damaged and I couldn't access the windows partition. I had to boot the linux one, which is working without any trouble. I have 2 partition formatted with ntfs, the one with windows on it, and the other one intended to store data. I mounted the windows partition from ubuntu and I could see all my files. But when I tried to mount the data partition it was impossible. It threw me an error, it couldn't recognize ntfs partition. I try to copy the damaged disk into an external hard drive using the command: dd if=/dev/sda of=/dev/sdb conv=noerror,sync The progress stopped at 60%. I was still unable to mount the data partition. Now I'm trying to backup my files using an utility called Photorec. The problem is that it is recovering my files in a disorderly way, it is all mixed up and I need my original directory structure, it will become an endless task to organize the files as they were before. Is there any way I can get my partition back?

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  • htaccess rewriting all subdomains to subdirectories

    - by indorock
    I'm trying to build a catch-all for any subdomains (not captured by previous rewrite rules) for a certain domain, and serve a website from a subdirectory that resides in the same folder as the .htaccess file. I already have my vhosts.conf to send all unmapped requests to a "playground" folder, where I want to easily create new subdomains by simply adding a subfolder. So, my structure looks like this: /var/www/playground |-> /foo |-> /bar The .htacces living inside the /playground folder and /foo and /bar being seperate websites. I want http://foo.domain.com to point to /foo and http://bar.domain.com to /bar. Here is my .htaccess file: RewriteEngine On RewriteCond %{HTTP_HOST} ^([^.]+).domain.com$ [NC] RewriteCond %{REQUEST_URI} !^/%1/(.*) RewriteRule ^(.*) /%1/$1 [L] This is supposed to capture the subdomain, add it as a subfolder in RewriteRule, then append after the slash and path information. The second RewriteCond is there to prevent an infinite loop. My idea was that %1 in the second RewriteCond would be able to capture the capture group in the first RewriteCond. But so far I haven't had any success, it's always ending up in a redirect loop. If I would replace %1 in the second RewriteCond with hardcoded 'foo' or 'bar', it works, which leads me to believe that you cannot refer to a capture group inside a RewriteCond. Is is true? Or am I missing something?

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  • Folder Sharing NTFS permissions with Share Permission

    - by Muhammad Adly
    i have a problem on my domain, the history starting from when i had a server with WIN 2008 r2 installed with the following roles installed on it (AD, DNS, DHCP, File). From 1 month i decided to install a new server 2008 r2 server to get (AD, DNS, DHCP) and leave the file server on the old one. i did the following exactly: 1) robocopy all my data on external HDD 2) Install a new server with 2008 r2 3) transfer all 5 roles to transfer the domain to the new server (MainDC) 4) issue (NETLOGON, SYSVOL) not transferred but i decided to reinitialize them again an now they are operating (MainDC) 5) re-create and re-configure a new GPOs and link it to my OUs 6) reinstall Old server operating system with a fresh installation of WIN 2008 R2 (FileServer) 7) join my domain with my domain credentials. the issue when i tried to share folder on \fileserver the permissions that i had set in sharing permissions are applied on the main shared folder and subfolders. the security settings are not applied. i.e. Say i'm sharing \fileserver\MainFolder with sharing permission for Authenticated Users that can read, so every one can read this main shared folder, if i set security permission for \fileserver\MainFolder\User1 that User1 can Read\Write\Modify. User1 can not perform this processes when accessing it from Network Share, i tried alot of steps from topics online get ownership for folder, remove inheritance from parent folder, applying changes for child objects, i tried also to construct a new folder structure but also the same issue, i tried another host PC, also i get the same issue.

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  • Winodws server 2003 Setup

    - by Barracksbuilder
    I work at a university maintaining the computer science department server. I am looking for a more economical way to stream line the set up of student accounts. CS students are granted a Username and password an IIS virtual directory, FTP virtual directory, and a mysql database. Server is running windows server 2003R2 (Possibly migrating to 2008R2) The server is running a domain though no students physically log a terminal into it (No computers are part of my domain.) Creating the account is a manual process. I did right a PHP script to query the Universities AD and copy the information and write it to my AD. I then have to create basically the users home directory. I tried having AD do it but since the user never physically logs in it never creates the directory. Permissions on this folder are set to User - full, Instructors (group) - full, Users (group) - read, IUSER - read. Inside of the users folder their is a "Private" folder with permissions User - full, instructors (group) - full. Next step is IIS I create a virtual directory in the default web site pointed to the users home directory so they have a website. Same goes for FTP virtual directory in the default ftp configuration to allow the users to upload files to their website. Mysql I have to create a user and password then create a mysql scheme (database) full access for the user and full access to the instructors account to be able to access the students database. All of this is done manually and takes me a week to do. The closest description is maybe a shared hosting environment. Is there a better way to do this? Scripting wise, or better structure setup?

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  • How to get apache to look for files in different subfolders folders?

    - by prb
    I am definitely new to mod-rewrite stuff. Note:- here the URL is common, and all the folders and subfolders on same host. The url a user uses to access their page is http://myurl.com/1234/filename.jpg Here the name of the subfolder is an integer is unique and generated dynamically by another application. The subfolder stores images specific to an individual user. So the folder structure is as follows main1 = document root main2 is another folder within main1 or document root. /main1/1234/filename.jpg /main1/5678/filename.jpg /main1/2345/filename.jpg /main1/1212/filename.jpg /main1/main2/2367/filename.jpg /main1/main2/8790/filename.jpg /main1/main2/9966/filename.jpg So, I want to write a rewrite a rule so that if a user tries to type in http://myurl.com/1234/filename.jpg, the rewrite rule will need to look where the file is and serve the request; so for request http:/myurl.com/1234/filename.jpg the actual page is located at /main1/1234/filename.jpg and then need to serve that page from that folder. So, if another users makes a request as http://myurl.com/9966/filename.jpg, it should serve the page from the following destination /main1/main2/9966/filename.jpg Please let me know if the question is still not clear. This is what i have done so far and does not work at all. RewriteCond {DOCUMENT_ROOT}/%{REQUEST_FILENAME} -f RewriteRule ^(.*)$ {DOCUMENT_ROOT}/$1 [L] RewriteCond {DOCUMENT_ROOT}/main2/%{REQUEST_FILENAME} -f RewriteRule ^(.*)$ {DOCUMENT_ROOT}/main2/$1 [L] any help is really grateful

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  • Convert Public Folder to Shared Mailbox

    - by Lilienthal
    Due to a change in company policy, all existing Public Folders (PF) have to be phased out in favour of shared mailboxes. Unfortunately, they don't seem to have any procedures or guidelines for this migration and I can't find much online either. I've already migrated one of our public folders so far as a sort of test case. Because we still use Exchange 2003, we can't create real shared mailboxes as we would in 2007 or 2010 (With New-Mailbox -Shared ... in the Exchange Shell). Instead, I simply created a new account on the AD and assigned it a mailbox. I then set the PF's permissions to read-only to keep it in a consistent state and copied the entire folder to a local PST in Outlook 2010, from which the folder was in turn copied to the new mailbox. Permissions and Folder Visible were set for all users and the migration was successful. While this works, the whole procedure feels very hackish to me and not at all efficient. I'd welcome some input on automating or at least streamlining the process. Additionally, we are unsure of what to do with our mail-enabled Public Folders. Several of these are nested under other PFs, some of which are also mail-enabled. Preserving folder structure is a key requirement and this seems impossible at first glance. I've considered creating dummy accounts for all the email addresses from our mail-enabled PFs and then setting up automated rules to forward messages to a subfolder of the new shared mailboxes, but I am not familiar enough with Exchange to know if this is even possible. Further points of concern are the Calendars and Contact lists in our public folders. I suppose I'll be forced to create new mailboxes for every one of these we have as well, then set up share permissions for their Calendar and Contact items, but would be happy to be proven wrong.

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  • How do I get Apache 2 to read this directory?

    - by Mike
    I'm on Mac OSX and i I have apache2 installed via MacPorts, running as the _www user. I have some files I want to serve in the /Users/Me/Documents/abc folder. Right now, though, the permissions of /Users/Me/Documents are 700. So, _www can't get in, even if abc is chmod 777. I recognize the following options: Allow _www access to my Documents folder. Put the files I want to share outside of my Documents folder. Hard-link the files outside of my Documents folder, and point apache to the hard links. None of these solutions are acceptable to me, however. I don't feel safe allowing _www access to my entire Documents folder. I really want to keep the files in my Documents folder for other reasons. The files are changing all the time, so hard-linking would not always reflect the right file structure, and, as I understand it, you can't hard-link a directory (though, if you could, that would solve it). Any ideas for a solution? Is there a way to run a few httpd processes as my user account so it can get in there? Or, is there some way to hard-link a directory, or some way to get httpd to follow a symlink past a directory that is 700 not owned by _www? Thanks!

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  • Finding Font Issues in Acrobat

    - by Jayme
    Ok let me try this again, so sorry for not be clear. We create our PDFs through Quark, then send to print. I usually create outlines on my EPS files before I load in Quark but forgot this time. We bypassed the font error that Quark gave us by accident and found out our PDF was bad too late and it cost a lot of money to fix. We are trying to find a way to check our PDF for font problems before we send it to print, in case this problem happens again. We just want to be extra sure that we have tried everything. What I see in Quark is what the font is supposed to look like. When I view my PDF, the text is mixed up. Its readable but doesn't look like its supposed to and the spacing is all off within the text. My boss told me about the preflight in Quark and the Internal Structure for the fonts. She was asking me if this would help and what the lingo all meant. (which is where my first question started) The image on the left is my EPS that is correct, the image on the right is from the PDF. The white text in the top right and the website at the bottom left is what is messed up. I am running Mac 10.5.8, Quark 7.5 and Acrobat 8.3.1. Thanks, Jayme

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  • Adding user groups from a remote domain server to permissions of a remote desktop terminal server fails. why?

    - by doveyg
    I have 3 computers, two of which are servers running Windows Server 2008 and another running Windows 7. One of the servers has the following roles installed; Active Directory, DHCP and DNS. The other server has a Terminal Server role installed. I am trying to log-on to the Terminal Server via Remote Desktop using the Windows 7 machine with credentials from the Active Directory server. Sounds simple enough, right? Well, no. Whenever I try to add users or groups from the Active Directory Domain server to the Terminal Server's permissions for RDP it seems to ignore, or forget, them. Though the various methods I was able to find it either adds a strange sting of numbers after the user group or the logo to the left has a question mark on it, reopening the dialogue box replaces the user group with the name of the Domain. I am confident I have the Domain setup correctly as I am able to log-on to users in the Active Directory from other computers I have put in the Domain, and when I attempt to browse the user objects from the Domain I am prompted with a username/password field and am able to view the structure of Active Directory objects. Please advise.

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  • Did Windows 7 Startup Repair trash My Documents?

    - by Metaphile
    Earlier today, I rebooted my computer. Partway through the boot process, it shut down suddenly. When I tried again, I was prompted to run Startup Repair, and I did. Afterwards, my computer booted normally and everything seemed to be in order. Then I noticed that my My Documents folder contains a mix of old and new files. On closer inspection, it appears that Windows has reverted my system to a previous state. Two things puzzle me: 1) According to Microsoft, "System Restore does not affect personal files, such as e-mail, documents, or photos [...]", yet many of my personal files have been affected. 2) Why were some things reverted, but not others? I had recently reorganized a bunch of files in My Documents. The reverted directory structure seems to be a hybrid of old a new, with a lot of new stuff missing. It's hard to say for sure, but it looks like the stuff that's missing would have been in conflict (two folders with the same name, for example), and Windows favored the old stuff. Is this normal behavior for Startup Repair/System Restore? To modify personal files, I mean? Is there a pattern to the mess it's made of My Documents?

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  • oracle access on vmware fusion

    - by gaudi_br
    Hello, I'm running snow leopard and I'm doing some development that requires some network knowledge. I've installed vmware fusion 3.0 and I've set up a virtual machine with windows 2003 server. I need to mimic the exact configuration of another server in the network, so I really need to run the versions I'll be mentioning here. Besides, I set up two network configurations on the VM: one NAT config (so that I can have internet access) and one host-only config (because I need to use another server's mac adress and my local area network might have a problem with it) From the installation of windows 2003, I then installed oracle 10.2.0.1. During the installation I received a warning about the primary ip-address of the system being dhcp assigned, but I ignored it (maybe it was a mistake)... Now, from experience, unless the DHCP assigned address changes, I should be able to access the guest system's database from the host system, so I went to safari and tried to access the oracle em. As it turns out, because my computer is on a company network, the company's DNS doesn't know about the virtual machine, unless of course I switch to a bridged network config. However, I don't want to do that because I don't to mix up the domains. So I guess the question is, how can I define my own dns or router, or whatever it is that I need to define so that whenever I try the guest system's ip address form the host, it will use the vmnet1 or vmnet8 interface define by vmware and bypass the dns configuration of my local area network. I'd also like to know what to do incase I want to change ip addresses on the guest machine without having oracle go haywire (I've noticed a few folders on the structure which are specific for the very first IP Address)... Any help would be appreciated. Thanks in advance.

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  • Integrating external computer into a domain - some recommendations please

    - by TomTom
    Given: * A multi loation company. Every office has local routers that connect to a central VPN capable rouer in a data center. All fine so far. We now need to move a computer off site into a hosting center across the globe, to get it closer to some supplier computers we work for. it will run limited logic but latency is important, and our latency so far is too large. This computer will be in a data center and does no require incoming connections except for adminsitrative purposes, although it needs outgoing connetions. I have no real chance to put one of my VPN routers there, sadly - otherwise I would have no problem. Usage of RRAs is not recommended (we had various probblems there over time). I could deal with it. The computer MUSt integrate into the corporate structure via VPN and join the domain and be fully "tracked" (controlled for performance). What is the best suggestion? So far it looks like my best bets woudl be to log in via RRAS and deal with whatever issues arise there plus uise the local firewall the limit incoming connections to this computer to what is needed (which runs down to an emergency RDP connection allowance). Anyone a better idea?

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  • Is there any equivalence of `--depth immediates` in `git`?

    - by ???
    Currently, I'm try to setup git front-end to the Subversion repository. My Subversion repository is a single large repository which consists of several co-related projects: svn-root |-- project1 | |-- branches | |-- tags | `-- trunk |-- project2 | |-- branches | |-- tags | `-- trunk `-- project3 |-- branches |-- tags `-- trunk Because it's sometimes needs to move files between different projects, so I don't want to break the repository to separate ones. I'm going to use git-svn to setup a git front-end, but I don't see how to exactly mapping the svn to git structure. The two systems treat branches and tags very different and I doubt it is possible. To simplify the problem, I would just git svn clone the whole root directory and let branches/tags/trunk directories just sit there. But this will definitely result in too many files in branches and tags directories. In Subversion, it's easy to just set the depth of checkout to immediates, which will only checkout the branch/tag titles, without the directory contents. but I don't know if this can be done in git. The git-svn messed me up. I hope there's more elegant solution.

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  • How to print PCL Directly to the printer? Vb.net VS 2010

    - by Justin
    Good day, I've been trying to upgrade an old Print Program that prints raw pcl directly to the printer. The print program takes a PCL Mask and a PCL Batch Spool File (just pcl with page turn commands, I think) merges them and sends them off to the printer. I'm able to send to the Printer a file stream of PCL but I get mixed results and i do not understand why printing is so difficult under .net. I mean yes there is the PrintDocument class, but to print PCL... Let's just say I'm ready to detach my printer from the network and burn it a live. Here is my class PrintDirect (rather a hybrid class) Imports System Imports System.Text Imports System.Runtime.InteropServices <StructLayout(LayoutKind.Sequential)> _ Public Structure DOCINFO <MarshalAs(UnmanagedType.LPWStr)> _ Public pDocName As String <MarshalAs(UnmanagedType.LPWStr)> _ Public pOutputFile As String <MarshalAs(UnmanagedType.LPWStr)> _ Public pDataType As String End Structure 'DOCINFO Public Class PrintDirect <DllImport("winspool.drv", CharSet:=CharSet.Unicode, ExactSpelling:=False, CallingConvention:=CallingConvention.StdCall)> _ Public Shared Function OpenPrinter(ByVal pPrinterName As String, ByRef phPrinter As IntPtr, ByVal pDefault As Integer) As Long End Function <DllImport("winspool.drv", CharSet:=CharSet.Unicode, ExactSpelling:=False, CallingConvention:=CallingConvention.StdCall)> _ Public Shared Function StartDocPrinter(ByVal hPrinter As IntPtr, ByVal Level As Integer, ByRef pDocInfo As DOCINFO) As Long End Function <DllImport("winspool.drv", CharSet:=CharSet.Unicode, ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _ Public Shared Function StartPagePrinter(ByVal hPrinter As IntPtr) As Long End Function <DllImport("winspool.drv", CharSet:=CharSet.Ansi, ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _ Public Shared Function WritePrinter(ByVal hPrinter As IntPtr, ByVal data As String, ByVal buf As Integer, ByRef pcWritten As Integer) As Long End Function <DllImport("winspool.drv", CharSet:=CharSet.Unicode, ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _ Public Shared Function EndPagePrinter(ByVal hPrinter As IntPtr) As Long End Function <DllImport("winspool.drv", CharSet:=CharSet.Unicode, ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _ Public Shared Function EndDocPrinter(ByVal hPrinter As IntPtr) As Long End Function <DllImport("winspool.drv", CharSet:=CharSet.Unicode, ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _ Public Shared Function ClosePrinter(ByVal hPrinter As IntPtr) As Long End Function 'Helps uses to work with the printer Public Class PrintJob ''' <summary> ''' The address of the printer to print to. ''' </summary> ''' <remarks></remarks> Public PrinterName As String = "" Dim lhPrinter As New System.IntPtr() ''' <summary> ''' The object deriving from the Win32 API, Winspool.drv. ''' Use this object to overide the settings defined in the PrintJob Class. ''' </summary> ''' <remarks>Only use this when absolutly nessacary.</remarks> Public OverideDocInfo As New DOCINFO() ''' <summary> ''' The PCL Control Character or the ascii escape character. \x1b ''' </summary> ''' <remarks>ChrW(27)</remarks> Public Const PCL_Control_Character As Char = ChrW(27) ''' <summary> ''' Opens a connection to a printer, if false the connection could not be established. ''' </summary> ''' <returns></returns> ''' <remarks></remarks> Public Function OpenPrint() As Boolean Dim rtn_val As Boolean = False PrintDirect.OpenPrinter(PrinterName, lhPrinter, 0) If Not lhPrinter = 0 Then rtn_val = True End If Return rtn_val End Function ''' <summary> ''' The name of the Print Document. ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Public Property DocumentName As String Get Return OverideDocInfo.pDocName End Get Set(ByVal value As String) OverideDocInfo.pDocName = value End Set End Property ''' <summary> ''' The type of Data that will be sent to the printer. ''' </summary> ''' <value>Send the print data type, usually "RAW" or "LPR". To overide use the OverideDocInfo Object</value> ''' <returns>The DataType as it was provided, if it is not part of the enumeration it is set to "UNKNOWN".</returns> ''' <remarks></remarks> Public Property DocumentDataType As PrintDataType Get Select Case OverideDocInfo.pDataType.ToUpper Case "RAW" Return PrintDataType.RAW Case "LPR" Return PrintDataType.LPR Case Else Return PrintDataType.UNKOWN End Select End Get Set(ByVal value As PrintDataType) OverideDocInfo.pDataType = [Enum].GetName(GetType(PrintDataType), value) End Set End Property Public Property DocumentOutputFile As String Get Return OverideDocInfo.pOutputFile End Get Set(ByVal value As String) OverideDocInfo.pOutputFile = value End Set End Property Enum PrintDataType UNKOWN = 0 RAW = 1 LPR = 2 End Enum ''' <summary> ''' Initializes the printing matrix ''' </summary> ''' <param name="PrintLevel">I have no idea what the hack this is...</param> ''' <remarks></remarks> Public Sub OpenDocument(Optional ByVal PrintLevel As Integer = 1) PrintDirect.StartDocPrinter(lhPrinter, PrintLevel, OverideDocInfo) End Sub ''' <summary> ''' Starts the next page. ''' </summary> ''' <remarks></remarks> Public Sub StartPage() PrintDirect.StartPagePrinter(lhPrinter) End Sub ''' <summary> ''' Writes a string to the printer, can be used to write out a section of the document at a time. ''' </summary> ''' <param name="data">The String to Send out to the Printer.</param> ''' <returns>The pcWritten as an integer, 0 may mean the writter did not write out anything.</returns> ''' <remarks>Warning the buffer is automatically created by the lenegth of the string.</remarks> Public Function WriteToPrinter(ByVal data As String) As Integer Dim pcWritten As Integer = 0 PrintDirect.WritePrinter(lhPrinter, data, data.Length - 1, pcWritten) Return pcWritten End Function Public Sub EndPage() PrintDirect.EndPagePrinter(lhPrinter) End Sub Public Sub CloseDocument() PrintDirect.EndDocPrinter(lhPrinter) End Sub Public Sub ClosePrint() PrintDirect.ClosePrinter(lhPrinter) End Sub ''' <summary> ''' Opens a connection to a printer and starts a new document. ''' </summary> ''' <returns>If false the connection could not be established. </returns> ''' <remarks></remarks> Public Function Open() As Boolean Dim rtn_val As Boolean = False rtn_val = OpenPrint() If rtn_val Then OpenDocument() End If Return rtn_val End Function ''' <summary> ''' Closes the document and closes the connection to the printer. ''' </summary> ''' <remarks></remarks> Public Sub Close() CloseDocument() ClosePrint() End Sub End Class End Class 'PrintDirect Here is how I print my file. I'm simple printing the PCL Masks, to show proof of concept. But I can't even do that. I can effectively create PCL and send it the printer without reading the file and it works fine... Plus I get mixed results with different stream reader text encoding as well. Dim pJob As New PrintDirect.PrintJob pJob.DocumentName = " test doc" pJob.DocumentDataType = PrintDirect.PrintJob.PrintDataType.RAW pJob.PrinterName = sPrinter.GetDevicePath '//This is where you'd stick your device name, sPrinter stands for Selected Printer from a dropdown (combobox). 'pJob.DocumentOutputFile = "C:\temp\test-spool.txt" If Not pJob.OpenPrint() Then MsgBox("Unable to connect to " & pJob.PrinterName, MsgBoxStyle.OkOnly, "Print Error") Exit Sub End If pJob.OpenDocument() pJob.StartPage() Dim sr As New IO.StreamReader(Me.txtFile.Text, Text.Encoding.ASCII) '//I've got best results with ASCII before, but only mized. Dim line As String = sr.ReadLine 'Fix for fly code on first run 'If line = 27 Then line = PrintDirect.PrintJob.PCL_Control_Character Do While (Not line Is Nothing) pJob.WriteToPrinter(line) line = sr.ReadLine Loop 'pJob.WriteToPrinter(ControlChars.FormFeed) pJob.EndPage() pJob.CloseDocument() sr.Close() sr.Dispose() sr = Nothing pJob.Close() I was able to get to print the mask, in the morning... now I'm getting strange printer characters scattered through 5 pages... I'm totally clueless. I must have changed something or the printer is at fault. You can access my test Check Mask, here http://kscserver.com/so/chk_mask.zip .

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  • c++ stl priority queue insert bad_alloc exception

    - by bsg
    Hi, I am working on a query processor that reads in long lists of document id's from memory and looks for matching id's. When it finds one, it creates a DOC struct containing the docid (an int) and the document's rank (a double) and pushes it on to a priority queue. My problem is that when the word(s) searched for has a long list, when I try to push the DOC on to the queue, I get the following exception: Unhandled exception at 0x7c812afb in QueryProcessor.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x0012ee88.. When the word has a short list, it works fine. I tried pushing DOC's onto the queue in several places in my code, and they all work until a certain line; after that, I get the above error. I am completely at a loss as to what is wrong because the longest list read in is less than 1 MB and I free all memory that I allocate. Why should there suddenly be a bad_alloc exception when I try to push a DOC onto a queue that has a capacity to hold it (I used a vector with enough space reserved as the underlying data structure for the priority queue)? I know that questions like this are almost impossible to answer without seeing all the code, but it's too long to post here. I'm putting as much as I can and am anxiously hoping that someone can give me an answer, because I am at my wits' end. The NextGEQ function is too long to put here, but it reads a list of compressed blocks of docids block by block. That is, if it sees that the lastdocid in the block (in a separate list) is larger than the docid passed in, it decompresses the block and searches until it finds the right one. If it sees that it was already decompressed, it just searches. Below, when I call the function the first time, it decompresses a block and finds the docid; the push onto the queue after that works. The second time, it doesn't even need to decompress; that is, no new memory is allocated, but after that time, pushing on to the queue gives a bad_alloc error. struct DOC{ long int docid; long double rank; public: DOC() { docid = 0; rank = 0.0; } DOC(int num, double ranking) { docid = num; rank = ranking; } bool operator>( const DOC & d ) const { return rank > d.rank; } bool operator<( const DOC & d ) const { return rank < d.rank; } }; struct listnode{ int* metapointer; int* blockpointer; int docposition; int frequency; int numberdocs; int* iquery; listnode* nextnode; }; void QUERYMANAGER::SubmitQuery(char *query){ vector<DOC> docvec; docvec.reserve(20); DOC doct; //create a priority queue to use as a min-heap to store the documents and rankings; //although the priority queue uses the heap as its underlying data structure, //I found it easier to use the STL priority queue implementation priority_queue<DOC, vector<DOC>,std::greater<DOC>> q(docvec.begin(), docvec.end()); q.push(doct); //do some processing here; startlist is a pointer to a listnode struct that starts the //linked list cout << "Opening lists:" << endl; //point the linked list start pointer to the node returned by the OpenList method startlist = &OpenList(value); listnode* minpointer; q.push(doct); //more processing here; else{ //start by finding the first docid in the shortest list int i = 0; q.push(doct); num = NextGEQ(0, *startlist); q.push(doct); while(num != -1) cout << "finding nextGEQ from shortest list" << endl; q.push(doct); //the is where the problem starts - every previous q.push(doct) works; the one after //NextGEQ(num +1, *startlist) gives the bad_alloc error num = NextGEQ(num + 1, *startlist); q.push(doct); //if you didn't break out of the loop; i.e., all lists contain a matching docid, //calculate the document's rank; if it's one of the top 20, create a struct //containing the docid and the rank and add it to the priority queue if(!loop) { cout << "found match" << endl; if(num < 0) { cout << "reached end of list" << endl; //reached the end of the shortest list; close the list CloseList(startlist); break; } rank = calculateRanking(table, num); try{ //if the heap is not full, create a DOC struct with the docid and //rank and add it to the heap if(q.size() < 20) { doc.docid = num; doc.rank = rank; q.push(doct); q.push(doc); } } catch (exception& e) { cout << e.what() << endl; } } } Thank you very much, bsg.

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  • Binary Search Tree Implementation

    - by Gabe
    I've searched the forum, and tried to implement the code in the threads I found. But I've been working on this real simple program since about 10am, and can't solve the seg. faults for the life of me. Any ideas on what I'm doing wrong would be greatly appreciated. BST.h (All the implementation problems should be in here.) #ifndef BST_H_ #define BST_H_ #include <stdexcept> #include <iostream> #include "btnode.h" using namespace std; /* A class to represent a templated binary search tree. */ template <typename T> class BST { private: //pointer to the root node in the tree BTNode<T>* root; public: //default constructor to make an empty tree BST(); /* You have to document these 4 functions */ void insert(T value); bool search(const T& value) const; bool search(BTNode<T>* node, const T& value) const; void printInOrder() const; void remove(const T& value); //function to print out a visual representation //of the tree (not just print the tree's values //on a single line) void print() const; private: //recursive helper function for "print()" void print(BTNode<T>* node,int depth) const; }; /* Default constructor to make an empty tree */ template <typename T> BST<T>::BST() { root = NULL; } template <typename T> void BST<T>::insert(T value) { BTNode<T>* newNode = new BTNode<T>(value); cout << newNode->data; if(root == NULL) { root = newNode; return; } BTNode<T>* current = new BTNode<T>(NULL); current = root; current->data = root->data; while(true) { if(current->left == NULL && current->right == NULL) break; if(current->right != NULL && current->left != NULL) { if(newNode->data > current->data) current = current->right; else if(newNode->data < current->data) current = current->left; } else if(current->right != NULL && current->left == NULL) { if(newNode->data < current->data) break; else if(newNode->data > current->data) current = current->right; } else if(current->right == NULL && current->left != NULL) { if(newNode->data > current->data) break; else if(newNode->data < current->data) current = current->left; } } if(current->data > newNode->data) current->left = newNode; else current->right = newNode; return; } //public helper function template <typename T> bool BST<T>::search(const T& value) const { return(search(root,value)); //start at the root } //recursive function template <typename T> bool BST<T>::search(BTNode<T>* node, const T& value) const { if(node == NULL || node->data == value) return(node != NULL); //found or couldn't find value else if(value < node->data) return search(node->left,value); //search left subtree else return search(node->right,value); //search right subtree } template <typename T> void BST<T>::printInOrder() const { //print out the value's in the tree in order // //You may need to use this function as a helper //and create a second recursive function //(see "print()" for an example) } template <typename T> void BST<T>::remove(const T& value) { if(root == NULL) { cout << "Tree is empty. No removal. "<<endl; return; } if(!search(value)) { cout << "Value is not in the tree. No removal." << endl; return; } BTNode<T>* current; BTNode<T>* parent; current = root; parent->left = NULL; parent->right = NULL; cout << root->left << "LEFT " << root->right << "RIGHT " << endl; cout << root->data << " ROOT" << endl; cout << current->data << "CURRENT BEFORE" << endl; while(current != NULL) { cout << "INTkhkjhbljkhblkjhlk " << endl; if(current->data == value) break; else if(value > current->data) { parent = current; current = current->right; } else { parent = current; current = current->left; } } cout << current->data << "CURRENT AFTER" << endl; // 3 cases : //We're looking at a leaf node if(current->left == NULL && current->right == NULL) // It's a leaf { if(parent->left == current) parent->left = NULL; else parent->right = NULL; delete current; cout << "The value " << value << " was removed." << endl; return; } // Node with single child if((current->left == NULL && current->right != NULL) || (current->left != NULL && current->right == NULL)) { if(current->left == NULL && current->right != NULL) { if(parent->left == current) { parent->left = current->right; cout << "The value " << value << " was removed." << endl; delete current; } else { parent->right = current->right; cout << "The value " << value << " was removed." << endl; delete current; } } else // left child present, no right child { if(parent->left == current) { parent->left = current->left; cout << "The value " << value << " was removed." << endl; delete current; } else { parent->right = current->left; cout << "The value " << value << " was removed." << endl; delete current; } } return; } //Node with 2 children - Replace node with smallest value in right subtree. if (current->left != NULL && current->right != NULL) { BTNode<T>* check; check = current->right; if((check->left == NULL) && (check->right == NULL)) { current = check; delete check; current->right = NULL; cout << "The value " << value << " was removed." << endl; } else // right child has children { //if the node's right child has a left child; Move all the way down left to locate smallest element if((current->right)->left != NULL) { BTNode<T>* leftCurrent; BTNode<T>* leftParent; leftParent = current->right; leftCurrent = (current->right)->left; while(leftCurrent->left != NULL) { leftParent = leftCurrent; leftCurrent = leftCurrent->left; } current->data = leftCurrent->data; delete leftCurrent; leftParent->left = NULL; cout << "The value " << value << " was removed." << endl; } else { BTNode<T>* temp; temp = current->right; current->data = temp->data; current->right = temp->right; delete temp; cout << "The value " << value << " was removed." << endl; } } return; } } /* Print out the values in the tree and their relationships visually. Sample output: 22 18 15 10 9 5 3 1 */ template <typename T> void BST<T>::print() const { print(root,0); } template <typename T> void BST<T>::print(BTNode<T>* node,int depth) const { if(node == NULL) { std::cout << std::endl; return; } print(node->right,depth+1); for(int i=0; i < depth; i++) { std::cout << "\t"; } std::cout << node->data << std::endl; print(node->left,depth+1); } #endif main.cpp #include "bst.h" #include <iostream> using namespace std; int main() { BST<int> tree; cout << endl << "LAB #13 - BINARY SEARCH TREE PROGRAM" << endl; cout << "----------------------------------------------------------" << endl; // Insert. cout << endl << "INSERT TESTS" << endl; // No duplicates allowed. tree.insert(0); tree.insert(5); tree.insert(15); tree.insert(25); tree.insert(20); // Search. cout << endl << "SEARCH TESTS" << endl; int x = 0; int y = 1; if(tree.search(x)) cout << "The value " << x << " is on the tree." << endl; else cout << "The value " << x << " is NOT on the tree." << endl; if(tree.search(y)) cout << "The value " << y << " is on the tree." << endl; else cout << "The value " << y << " is NOT on the tree." << endl; // Removal. cout << endl << "REMOVAL TESTS" << endl; tree.remove(0); tree.remove(1); tree.remove(20); // Print. cout << endl << "PRINTED DIAGRAM OF BINARY SEARCH TREE" << endl; cout << "----------------------------------------------------------" << endl; tree.print(); cout << endl << "Program terminated. Goodbye." << endl << endl; } BTNode.h #ifndef BTNODE_H_ #define BTNODE_H_ #include <iostream> /* A class to represent a node in a binary search tree. */ template <typename T> class BTNode { public: //constructor BTNode(T d); //the node's data value T data; //pointer to the node's left child BTNode<T>* left; //pointer to the node's right child BTNode<T>* right; }; /* Simple constructor. Sets the data value of the BTNode to "d" and defaults its left and right child pointers to NULL. */ template <typename T> BTNode<T>::BTNode(T d) : left(NULL), right(NULL) { data = d; } #endif Thanks.

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  • Marshalling to a native library in C#

    - by Daniel Baulig
    I'm having trouble calling functions of a native library from within managed C# code. I am developing for the 3.5 compact framework (Windows Mobile 6.x) just in case this would make any difference. I am working with the waveIn* functions from coredll.dll (these are in winmm.dll in regular Windows I believe). This is what I came up with: // namespace winmm; class winmm [StructLayout(LayoutKind.Sequential)] public struct WAVEFORMAT { public ushort wFormatTag; public ushort nChannels; public uint nSamplesPerSec; public uint nAvgBytesPerSec; public ushort nBlockAlign; public ushort wBitsPerSample; public ushort cbSize; } [StructLayout(LayoutKind.Sequential)] public struct WAVEHDR { public IntPtr lpData; public uint dwBufferLength; public uint dwBytesRecorded; public IntPtr dwUser; public uint dwFlags; public uint dwLoops; public IntPtr lpNext; public IntPtr reserved; } public delegate void AudioRecordingDelegate(IntPtr deviceHandle, uint message, IntPtr instance, ref WAVEHDR wavehdr, IntPtr reserved2); [DllImport("coredll.dll")] public static extern int waveInAddBuffer(IntPtr hWaveIn, ref WAVEHDR lpWaveHdr, uint cWaveHdrSize); [DllImport("coredll.dll")] public static extern int waveInPrepareHeader(IntPtr hWaveIn, ref WAVEHDR lpWaveHdr, uint Size); [DllImport("coredll.dll")] public static extern int waveInStart(IntPtr hWaveIn); // some other class private WinMM.WinMM.AudioRecordingDelegate waveIn; private IntPtr handle; private uint bufferLength; private void setupBuffer() { byte[] buffer = new byte[bufferLength]; GCHandle bufferPin = GCHandle.Alloc(buffer, GCHandleType.Pinned); WinMM.WinMM.WAVEHDR hdr = new WinMM.WinMM.WAVEHDR(); hdr.lpData = bufferPin.AddrOfPinnedObject(); hdr.dwBufferLength = this.bufferLength; hdr.dwFlags = 0; int i = WinMM.WinMM.waveInPrepareHeader(this.handle, ref hdr, Convert.ToUInt32(Marshal.SizeOf(hdr))); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInPrepare"; return; } i = WinMM.WinMM.waveInAddBuffer(this.handle, ref hdr, Convert.ToUInt32(Marshal.SizeOf(hdr))); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInAddrBuffer"; return; } } private void setupWaveIn() { WinMM.WinMM.WAVEFORMAT format = new WinMM.WinMM.WAVEFORMAT(); format.wFormatTag = WinMM.WinMM.WAVE_FORMAT_PCM; format.nChannels = 1; format.nSamplesPerSec = 8000; format.wBitsPerSample = 8; format.nBlockAlign = Convert.ToUInt16(format.nChannels * format.wBitsPerSample); format.nAvgBytesPerSec = format.nSamplesPerSec * format.nBlockAlign; this.bufferLength = format.nAvgBytesPerSec; format.cbSize = 0; int i = WinMM.WinMM.waveInOpen(out this.handle, WinMM.WinMM.WAVE_MAPPER, ref format, Marshal.GetFunctionPointerForDelegate(waveIn), 0, WinMM.WinMM.CALLBACK_FUNCTION); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInOpen"; return; } setupBuffer(); WinMM.WinMM.waveInStart(this.handle); } I read alot about marshalling the last few days, nevertheless I do not get this code working. When my callback function is called (waveIn) when the buffer is full, the hdr structure passed back in wavehdr is obviously corrupted. Here is an examlpe of how the structure looks like at that point: - wavehdr {WinMM.WinMM.WAVEHDR} WinMM.WinMM.WAVEHDR dwBufferLength 0x19904c00 uint dwBytesRecorded 0x0000fa00 uint dwFlags 0x00000003 uint dwLoops 0x1990f6a4 uint + dwUser 0x00000000 System.IntPtr + lpData 0x00000000 System.IntPtr + lpNext 0x00000000 System.IntPtr + reserved 0x7c07c9a0 System.IntPtr This obiously is not what I expected to get passed. I am clearly concerned about the order of the fields in the view. I do not know if Visual Studio .NET cares about actual memory order when displaying the record in the "local"-view, but they are obviously not displayed in the order I speciefied in the struct. Then theres no data pointer and the bufferLength field is far to high. Interestingly the bytesRecorded field is exactly 64000 - bufferLength and bytesRecorded I'd expect both to be 64000 though. I do not know what exactly is going wrong, maybe someone can help me out on this. I'm an absolute noob to managed code programming and marshalling so please don't be too harsh to me for all the stupid things I've propably done. Oh here's the C code definition for WAVEHDR which I found here, I believe I might have done something wrong in the C# struct definition: /* wave data block header */ typedef struct wavehdr_tag { LPSTR lpData; /* pointer to locked data buffer */ DWORD dwBufferLength; /* length of data buffer */ DWORD dwBytesRecorded; /* used for input only */ DWORD_PTR dwUser; /* for client's use */ DWORD dwFlags; /* assorted flags (see defines) */ DWORD dwLoops; /* loop control counter */ struct wavehdr_tag FAR *lpNext; /* reserved for driver */ DWORD_PTR reserved; /* reserved for driver */ } WAVEHDR, *PWAVEHDR, NEAR *NPWAVEHDR, FAR *LPWAVEHDR; If you are used to work with all those low level tools like pointer-arithmetic, casts, etc starting writing managed code is a pain in the ass. It's like trying to learn how to swim with your hands tied on your back. Some things I tried (to no effect): .NET compact framework does not seem to support the Pack = 2^x directive in [StructLayout]. I tried [StructLayout(LayoutKind.Explicit)] and used 4 bytes and 8 bytes alignment. 4 bytes alignmentgave me the same result as the above code and 8 bytes alignment only made things worse - but that's what I expected. Interestingly if I move the code from setupBuffer into the setupWaveIn and do not declare the GCHandle in the context of the class but in a local context of setupWaveIn the struct returned by the callback function does not seem to be corrupted. I am not sure however why this is the case and how I can use this knowledge to fix my code. I'd really appreciate any good links on marshalling, calling unmanaged code from C#, etc. Then I'd be very happy if someone could point out my mistakes. What am I doing wrong? Why do I not get what I'd expect.

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  • Implementing a robust async stream reader for a console

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. Edit: There are comments below correctly stating that since the data is coming from a stream, there is absolutely nothing that the receiver can infer about the structure of the data unless it is fully prepared to parse it. What I am trying to do here is leverage the "flush the output" "structure" that the owner of the console imparts while writing on it. I am prepared to assume (better: allow my caller to have the option to assume) that the OS will pass me the data written between two flushes of the stream in exactly one piece. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

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