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  • Sending large serialized objects over sockets is failing only when trying to grow the byte Array, bu

    - by FinancialRadDeveloper
    I have code where I am trying to grow the byte array while receiving the data over my socket. This is erroring out. public bool ReceiveObject2(ref Object objRec, ref string sErrMsg) { try { byte[] buffer = new byte[1024]; byte[] byArrAll = new byte[0]; bool bAllBytesRead = false; int iRecLoop = 0; // grow the byte array to match the size of the object, so we can put whatever we // like through the socket as long as the object serialises and is binary formatted while (!bAllBytesRead) { if (m_socClient.Receive(buffer) > 0) { byArrAll = Combine(byArrAll, buffer); iRecLoop++; } else { m_socClient.Close(); bAllBytesRead = true; } } MemoryStream ms = new MemoryStream(buffer); BinaryFormatter bf1 = new BinaryFormatter(); ms.Position = 0; Object obj = bf1.Deserialize(ms); objRec = obj; return true; } catch (System.Runtime.Serialization.SerializationException se) { objRec = null; sErrMsg += "SocketClient.ReceiveObject " + "Source " + se.Source + "Error : " + se.Message; return false; } catch (Exception e) { objRec = null; sErrMsg += "SocketClient.ReceiveObject " + "Source " + e.Source + "Error : " + e.Message; return false; } } private byte[] Combine(byte[] first, byte[] second) { byte[] ret = new byte[first.Length + second.Length]; Buffer.BlockCopy(first, 0, ret, 0, first.Length); Buffer.BlockCopy(second, 0, ret, first.Length, second.Length); return ret; } Error: mscorlibError : The input stream is not a valid binary format. The starting contents (in bytes) are: 68-61-73-43-68-61-6E-67-65-73-3D-22-69-6E-73-65-72 ... Yet when I just cheat and use a MASSIVE buffer size its fine. public bool ReceiveObject(ref Object objRec, ref string sErrMsg) { try { byte[] buffer = new byte[5000000]; m_socClient.Receive(buffer); MemoryStream ms = new MemoryStream(buffer); BinaryFormatter bf1 = new BinaryFormatter(); ms.Position = 0; Object obj = bf1.Deserialize(ms); objRec = obj; return true; } catch (Exception e) { objRec = null; sErrMsg += "SocketClient.ReceiveObject " + "Source " + e.Source + "Error : " + e.Message; return false; } } This is really killing me. I don't know why its not working. I have lifted the Combine from a suggestion on here too, so I am pretty sure this is not doing the wrong thing? I hope someone can point out where I am going wrong

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  • Why use buffers to read/write Streams

    - by James Hay
    Following reading various questions on reading and writing Streams, all the various answers define something like this as the correct way to do it: private void CopyStream(Stream input, Stream output) { byte[] buffer = new byte[16 * 1024]; int read; while ((read = input.Read(buffer, 0, buffer.Length)) > 0) { output.Write(buffer, 0, read); } } Two questions: Why read and write in these smaller chunks? What is the significance of the buffer size used?

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  • ConsumeStructuredBuffer, what am I doing wrong?

    - by John
    I'm trying to implement the 3rd exercise in chapter 12 of Introduction to 3D Game Programming with DirectX 11, that is: Implement a Compute Shader to calculate the length of 64 vectors. Previous exercises ask you to do the same with typed buffers and regular structured buffers and I had no problems with them. For what I've read, [Consume|Append]StructuredBuffers are bound to the pipeline using UnorderedAccessViews (as long as they use the D3D11_BUFFER_UAV_FLAG_APPEND, and the buffers have both D3D11_BIND_SHADER_RESOURCE and D3D11_BIND_UNORDERED_ACCESS bind flags). Problem is: my AppendStructuredBuffer works, since I can append data to it and retrieve it from the application to write to a results file, but the ConsumeStructuredBuffer always returns zeroed data. Data is in the buffer, since if I change the UAV to a ShaderResourceView and to a StructuredBuffer in the HLSL side it works. I don't know what I am missing: Should I initialize the ConsumeStructuredBuffer on the GPU, or can I do it when I create the buffer (as I amb currently doing). Is it OK to bind the buffer with a UAV as described above? Do I need to bind it as a ShaderResourceView somehow? Maybe I am missing some step? This is the declaration of buffers in the Compute Shader: struct Data { float3 v; }; struct Result { float l; }; ConsumeStructuredBuffer<Data> gInput; AppendStructuredBuffer<Result> gOutput; And here the creation of the buffer and UAV for input data: D3D11_BUFFER_DESC inputDesc; inputDesc.Usage = D3D11_USAGE_DEFAULT; inputDesc.ByteWidth = sizeof(Data) * mNumElements; inputDesc.BindFlags = D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_UNORDERED_ACCESS; inputDesc.CPUAccessFlags = 0; inputDesc.StructureByteStride = sizeof(Data); inputDesc.MiscFlags = D3D11_RESOURCE_MISC_BUFFER_STRUCTURED; D3D11_SUBRESOURCE_DATA vinitData; vinitData.pSysMem = &data[0]; HR(md3dDevice->CreateBuffer(&inputDesc, &vinitData, &mInputBuffer)); D3D11_UNORDERED_ACCESS_VIEW_DESC uavDesc; uavDesc.Format = DXGI_FORMAT_UNKNOWN; uavDesc.ViewDimension = D3D11_UAV_DIMENSION_BUFFER; uavDesc.Buffer.FirstElement = 0; uavDesc.Buffer.Flags = D3D11_BUFFER_UAV_FLAG_APPEND; uavDesc.Buffer.NumElements = mNumElements; md3dDevice->CreateUnorderedAccessView(mInputBuffer, &uavDesc, &mInputUAV); Initial data is an array of Data structs, which contain a XMFLOAT3 with random data. I bind the UAV to the shader using the Effects framework: ID3DX11EffectUnorderedAccessViewVariable* Input = mFX->GetVariableByName("gInput")->AsUnorderedAccessView(); Input->SetUnorderedAccessView(uav); // uav is mInputUAV Any ideas? Thank you.

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  • SQLAuthority News – Guest Post – Performance Counters Gathering using Powershell

    - by pinaldave
    Laerte Junior Laerte Junior has previously helped me personally to resolve the issue with Powershell installation on my computer. He did awesome job to help. He has send this another wonderful article regarding performance counter for readers of this blog. I really liked it and I expect all of you who are Powershell geeks, you will like the same as well. As a good DBA, you know that our social life is restricted to a few movies over the year and, when possible, a pizza in a restaurant next to your company’s place, of course. So what we have to do is to create methods through which we can facilitate our daily processes to go home early, and eventually have a nice time with our family (and not sleeping on the couch). As a consultant or fixed employee, one of our daily tasks is to monitor performance counters using Perfmom. To be honest, IDE is getting more complicated. To deal with this, I thought a solution using Powershell. Yes, with some lines of Powershell, you can configure which counters to use. And with one more line, you can already start collecting data. Let’s see one scenario: You are a consultant who has several clients and has just closed another project in troubleshooting an SQL Server environment. You are to use Perfmom to collect data from the server and you already have its XML configuration files made with the counters that you will be using- a file for memory bottleneck f, one for CPU, etc. With one Powershell command line for each XML file, you start collecting. The output of such a TXT file collection is set to up in an SQL Server. With two lines of command for each XML, you make the whole process of data collection. Creating an XML configuration File to Memory Counters: Get-PerfCounterCategory -CategoryName "Memory" | Get-PerfCounterInstance  | Get-PerfCounterCounters |Save-ConfigPerfCounter -PathConfigFile "c:\temp\ConfigfileMemory.xml" -newfile Creating an XML Configuration File to Buffer Manager, counters Page lookups/sec, Page reads/sec, Page writes/sec, Page life expectancy: Get-PerfCounterCategory -CategoryName "SQLServer:Buffer Manager" | Get-PerfCounterInstance | Get-PerfCounterCounters -CounterName "Page*" | Save-ConfigPerfCounter -PathConfigFile "c:\temp\BufferManager.xml" –NewFile Then you start the collection: Set-CollectPerfCounter -DateTimeStart "05/24/2010 08:00:00" -DateTimeEnd "05/24/2010 22:00:00" -Interval 10 -PathConfigFile c:\temp\ConfigfileMemory.xml -PathOutputFile c:\temp\ConfigfileMemory.txt To let the Buffer Manager collect, you need one more counters, including the Buffer cache hit ratio. Just add a new counter to BufferManager.xml, omitting the new file parameter Get-PerfCounterCategory -CategoryName "SQLServer:Buffer Manager" | Get-PerfCounterInstance | Get-PerfCounterCounters -CounterName "Buffer cache hit ratio" | Save-ConfigPerfCounter -PathConfigFile "c:\temp\BufferManager.xml" And start the collection: Set-CollectPerfCounter -DateTimeStart "05/24/2010 08:00:00" -DateTimeEnd "05/24/2010 22:00:00" -Interval 10 -PathConfigFile c:\temp\BufferManager.xml -PathOutputFile c:\temp\BufferManager.txt You do not know which counters are in the Category Buffer Manager? Simple! Get-PerfCounterCategory -CategoryName "SQLServer:Buffer Manager" | Get-PerfCounterInstance | Get-PerfCounterCounters Let’s see one output file as shown below. It is ready to bulk insert into the SQL Server. As you can see, Powershell makes this process incredibly easy and fast. Do you want to see more examples? Visit my blog at Shell Your Experience You can find more about Laerte Junior over here: www.laertejuniordba.spaces.live.com www.simple-talk.com/author/laerte-junior www.twitter.com/laertejuniordba SQL Server Powershell Extension Team: http://sqlpsx.codeplex.com/ Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: SQL, SQL Add-On, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology Tagged: Powershell

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  • In Flex 3 is there a way to pre-buffer an image so that it appears without flickering?

    - by Brad Urani
    In my application I have an VBox control on top of another VBox that contains an Image control that loads a jpg from a URL (you can't see the bottom panel initially since it's underneath, but the image does fully download). When one clicks on the top VBox, the bottom one gets set to visible=false, then an effect causes the top VBox to vanish, then the bottom VBox is set to visible=true and an effect causes it to appear. Continuously clicking the VBoxes causes them to alternate appearing and disappearing. The problem is that the first time the bottom VBox appears, it flickers once when it draws. After that, there's no problem and it smoothly appears and disappears with the effect with no problem. It's as if the first time the bottom VBox appears, it flickers because even though the image has been downloaded, it has never been displayed before. Can I pre-buffer the image in the bottom VBox somehow to avoid this flicker?

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  • insufficient buffer when call DocumentProperties, also, global unlock wouldn't unlock...

    - by Quincy
    please see comments inline bool res = false; DWORD dwNeeded = DocumentPropertiesW(NULL, m_currPrinterHandle, (LPWSTR) m_currPrinterName.c_str(), NULL, NULL, 0); if (m_devmode_buf) { GlobalFree(m_devmode_buf); } m_devmode_buf = GlobalAlloc(GPTR, dwNeeded); GetLastError(); // = 0; if (m_devmode_buf) { LPDEVMODEW devmode_buf = (LPDEVMODEW) GlobalLock(m_devmode_buf); GetLastError(); // = 0 if (devmode_buf) { if (devmode_buf) { lala = DocumentPropertiesW(NULL, m_currPrinterHandle, (LPWSTR) m_currPrinterName.c_str(), devmode_buf, NULL, DM_OUT_BUFFER); if (lala == IDOK) { res = true; } GetLastError(); // = 122. insufficient buffer here. why???? } UInt32 res1 = GlobalUnlock(m_devmode_buf); // res1 is 1. should be 0 res2 = GetLastError(); // = 0 if (!(res1 == 0 && (res2 == ERROR_NOT_LOCKED || res2 == NO_ERROR))) { //res = false; } } }

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  • How do I run a vim script that alters the current buffer?

    - by Dan
    I'm trying to write a beautify.vim script that makes C-like code adhere to a standard that I can easily read. My file contains only substitution commands that all begin with %s/... However, when I try to run the script with my file open, in the manner :source beautify.vim, or :runtime beautify.vim, it runs but all the substitute commands state that their pattern wasn't found (patterns were tested by entering them manually and should work). Is there some way to make vim run the commands in the context of the current buffer? beautify.vim: " add spaces before open braces sil! :%s/\%>1c>\s\@<!{/ {/g " beautify for sil! :%s/for *( *\([^;]*\) *; *\([^;]*\) *; *\([^;]*\) *)/for (\1; \2; \3)/ " add spaces after commas sil! :%s/,\s\@!/, /g In my tests the first :s command should match (it matches when applied manually).

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  • How can I access the copy buffer on the web?

    - by Ólafur Waage
    Wild question here. Is it possible to access the copy buffer on the web. What I mean is. Can I go into Photoshop. Select a piece of a photo. Copy that piece and paste it into some element. That something would be like a Java applet or Flash or Silverlight or anything. I am just wondering if it is possible and if someone could point me in a direction. Since a few google searches have only found where you can copy files and paste via a Java applet.

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  • Restoring a saved opengl ES buffer (i.e. writing it back to screen)

    - by Adam
    I'm writing an iPhone app where I need to save and load the screen contents. I was able to save the screen using glReadPixels(), but since there's no glDrawPixels() in openGL ES, I'm having a lot of trouble restoring that buffer to the screen. I gather that I need to save the screen as a texture: http://stackoverflow.com/questions/708760/what-is-the-equivalent-of-gldrawpixels-in-opengl-es-1-1 But I'm not sure how to implement this. Does anyone have or know of any code samples that do this? I'm an openGL noob, so any help would be greatly appreciated :)

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  • How do I prevent buffer overflow converting a double to char?

    - by Tommy
    I'm converting a double to a char string: char txt[10]; double num; num = 45.344322345 sprintf(txt, "%.1f", num); and using ".1f" to truncate the decimal places, to the tenths digit. i.e. - txt contains 45.3 I usually use precision in sprintf to ensure the char buffer is not overflowed. How can I do that here also truncating the decimal, without using snprintf? (i.e. if num = 345694876345.3 for some reason) Thanks

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  • SQL SERVER – PAGEIOLATCH_DT, PAGEIOLATCH_EX, PAGEIOLATCH_KP, PAGEIOLATCH_SH, PAGEIOLATCH_UP – Wait Type – Day 9 of 28

    - by pinaldave
    It is very easy to say that you replace your hardware as that is not up to the mark. In reality, it is very difficult to implement. It is really hard to convince an infrastructure team to change any hardware because they are not performing at their best. I had a nightmare related to this issue in a deal with an infrastructure team as I suggested that they replace their faulty hardware. This is because they were initially not accepting the fact that it is the fault of their hardware. But it is really easy to say “Trust me, I am correct”, while it is equally important that you put some logical reasoning along with this statement. PAGEIOLATCH_XX is such a kind of those wait stats that we would directly like to blame on the underlying subsystem. Of course, most of the time, it is correct – the underlying subsystem is usually the problem. From Book On-Line: PAGEIOLATCH_DT Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Destroy mode. Long waits may indicate problems with the disk subsystem. PAGEIOLATCH_EX Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Exclusive mode. Long waits may indicate problems with the disk subsystem. PAGEIOLATCH_KP Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Keep mode. Long waits may indicate problems with the disk subsystem. PAGEIOLATCH_SH Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Shared mode. Long waits may indicate problems with the disk subsystem. PAGEIOLATCH_UP Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Update mode. Long waits may indicate problems with the disk subsystem. PAGEIOLATCH_XX Explanation: Simply put, this particular wait type occurs when any of the tasks is waiting for data from the disk to move to the buffer cache. ReducingPAGEIOLATCH_XX wait: Just like any other wait type, this is again a very challenging and interesting subject to resolve. Here are a few things you can experiment on: Improve your IO subsystem speed (read the first paragraph of this article, if you have not read it, I repeat that it is easy to say a step like this than to actually implement or do it). This type of wait stats can also happen due to memory pressure or any other memory issues. Putting aside the issue of a faulty IO subsystem, this wait type warrants proper analysis of the memory counters. If due to any reasons, the memory is not optimal and unable to receive the IO data. This situation can create this kind of wait type. Proper placing of files is very important. We should check file system for the proper placement of files – LDF and MDF on separate drive, TempDB on separate drive, hot spot tables on separate filegroup (and on separate disk), etc. Check the File Statistics and see if there is higher IO Read and IO Write Stall SQL SERVER – Get File Statistics Using fn_virtualfilestats. It is very possible that there are no proper indexes on the system and there are lots of table scans and heap scans. Creating proper index can reduce the IO bandwidth considerably. If SQL Server can use appropriate cover index instead of clustered index, it can significantly reduce lots of CPU, Memory and IO (considering cover index has much lesser columns than cluster table and all other it depends conditions). You can refer to the two articles’ links below previously written by me that talk about how to optimize indexes. Create Missing Indexes Drop Unused Indexes Updating statistics can help the Query Optimizer to render optimal plan, which can only be either directly or indirectly. I have seen that updating statistics with full scan (again, if your database is huge and you cannot do this – never mind!) can provide optimal information to SQL Server optimizer leading to efficient plan. Checking Memory Related Perfmon Counters SQLServer: Memory Manager\Memory Grants Pending (Consistent higher value than 0-2) SQLServer: Memory Manager\Memory Grants Outstanding (Consistent higher value, Benchmark) SQLServer: Buffer Manager\Buffer Hit Cache Ratio (Higher is better, greater than 90% for usually smooth running system) SQLServer: Buffer Manager\Page Life Expectancy (Consistent lower value than 300 seconds) Memory: Available Mbytes (Information only) Memory: Page Faults/sec (Benchmark only) Memory: Pages/sec (Benchmark only) Checking Disk Related Perfmon Counters Average Disk sec/Read (Consistent higher value than 4-8 millisecond is not good) Average Disk sec/Write (Consistent higher value than 4-8 millisecond is not good) Average Disk Read/Write Queue Length (Consistent higher value than benchmark is not good) Note: The information presented here is from my experience and there is no way that I claim it to be accurate. I suggest reading Book OnLine for further clarification. All of the discussions of Wait Stats in this blog is generic and varies from system to system. It is recommended that you test this on a development server before implementing it to a production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • Driver error when using multiple shaders

    - by Jinxi
    I'm using 3 different shaders: a tessellation shader to use the tessellation feature of DirectX11 :) a regular shader to show how it would look without tessellation and a text shader to display debug-info such as FPS, model count etc. All of these shaders are initialized at the beginning. Using the keyboard, I can switch between the tessellation shader and regular shader to render the scene. Additionally, I also want to be able toggle the display of debug-info using the text shader. Since implementing the tessellation shader the text shader doesn't work anymore. When I activate the DebugText (rendered using the text-shader) my screens go black for a while, and Windows displays the following message: Display Driver stopped responding and has recovered This happens with either of the two shaders used to render the scene. Additionally: I can start the application using the regular shader to render the scene and then switch to the tessellation shader. If I try to switch back to the regular shader I get the same error as with the text shader. What am I doing wrong when switching between shaders? What am I doing wrong when displaying text at the same time? What file can I post to help you help me? :) thx P.S. I already checked if my keyinputs interrupt at the wrong time (during render or so..), but that seems to be ok Testing Procedure Regular Shader without text shader Add text shader to Regular Shader by keyinput (works now, I built the text shader back to only vertex and pixel shader) (somthing with the z buffer is stil wrong...) Remove text shader, then change shader to Tessellation Shader by key input Then if I add the Text Shader or switch back to the Regular Shader Switching/Render Shader Here the code snipet from the Renderer.cpp where I choose the Shader according to the boolean "m_useTessellationShader": if(m_useTessellationShader) { // Render the model using the tesselation shader ecResult = m_ShaderManager->renderTessellationShader(m_D3D->getDeviceContext(), meshes[lod_level]->getIndexCount(), worldMatrix, viewMatrix, projectionMatrix, textures, texturecount, m_Light->getDirection(), m_Light->getAmbientColor(), m_Light->getDiffuseColor(), (D3DXVECTOR3)m_Camera->getPosition(), TESSELLATION_AMOUNT); } else { // todo: loaded model depends on distance to camera // Render the model using the light shader. ecResult = m_ShaderManager->renderShader(m_D3D->getDeviceContext(), meshes[lod_level]->getIndexCount(), lod_level, textures, texturecount, m_Light->getDirection(), m_Light->getAmbientColor(), m_Light->getDiffuseColor(), worldMatrix, viewMatrix, projectionMatrix); } And here the code snipet from the Mesh.cpp where I choose the Typology according to the boolean "useTessellationShader": // RenderBuffers is called from the Render function. The purpose of this function is to set the vertex buffer and index buffer as active on the input assembler in the GPU. Once the GPU has an active vertex buffer it can then use the shader to render that buffer. void Mesh::renderBuffers(ID3D11DeviceContext* deviceContext, bool useTessellationShader) { unsigned int stride; unsigned int offset; // Set vertex buffer stride and offset. stride = sizeof(VertexType); offset = 0; // Set the vertex buffer to active in the input assembler so it can be rendered. deviceContext->IASetVertexBuffers(0, 1, &m_vertexBuffer, &stride, &offset); // Set the index buffer to active in the input assembler so it can be rendered. deviceContext->IASetIndexBuffer(m_indexBuffer, DXGI_FORMAT_R32_UINT, 0); // Check which Shader is used to set the appropriate Topology // Set the type of primitive that should be rendered from this vertex buffer, in this case triangles. if(useTessellationShader) { deviceContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_3_CONTROL_POINT_PATCHLIST); }else{ deviceContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST); } return; } RenderShader Could there be a problem using sometimes only vertex and pixel shader and after switching using vertex, hull, domain and pixel shader? Here a little overview of my architecture: TextClass: uses font.vs and font.ps deviceContext-VSSetShader(m_vertexShader, NULL, 0); deviceContext-PSSetShader(m_pixelShader, NULL, 0); deviceContext-PSSetSamplers(0, 1, &m_sampleState); RegularShader: uses vertex.vs and pixel.ps deviceContext-VSSetShader(m_vertexShader, NULL, 0); deviceContext-PSSetShader(m_pixelShader, NULL, 0); deviceContext-PSSetSamplers(0, 1, &m_sampleState); TessellationShader: uses tessellation.vs, tessellation.hs, tessellation.ds, tessellation.ps deviceContext-VSSetShader(m_vertexShader, NULL, 0); deviceContext-HSSetShader(m_hullShader, NULL, 0); deviceContext-DSSetShader(m_domainShader, NULL, 0); deviceContext-PSSetShader(m_pixelShader, NULL, 0); deviceContext-PSSetSamplers(0, 1, &m_sampleState); ClearState I'd like to switch between 2 shaders and it seems they have different context parameters, right? In clearstate methode it says it resets following params to NULL: I found following in my Direct3D Class: depth-stencil state - m_deviceContext-OMSetDepthStencilState rasterizer state - m_deviceContext-RSSetState(m_rasterState); blend state - m_device-CreateBlendState viewports - m_deviceContext-RSSetViewports(1, &viewport); I found following in every Shader Class: input/output resource slots - deviceContext-PSSetShaderResources shaders - deviceContext-VSSetShader to - deviceContext-PSSetShader input layouts - device-CreateInputLayout sampler state - device-CreateSamplerState These two I didn't understand, where can I find them? predications - ? scissor rectangles - ? Do I need to store them all localy so I can switch between them, because it doesn't feel right to reinitialize the Direct3d and the Shaders by every switch (key input)?!

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  • How to detect when video is buffering?

    - by Leon
    Hi guys, my question today deals with Flash AS3 video buffering. (Streaming or Progressive) I want to be able to detect when the video is being buffered, so I can display some sort of animation letting the user know to wait just a little longer. Currently my video will start up, hold on frame 1 for 3-4 secs then play. Kinda giving the impression that the video is paused or broken :( Update Thanks to iandisme I believe I'm faced in the right direction now. NetStatusEvent from livedocs. It seems to me that the key status to be working in is "NetStream.Buffer.Empty" so I added some code in there to see if this would trigger my animation or a trace statement. No luck yet, however when the Buffer is full it will trigger my code :/ Maybe my video is always somewhere between Buffer.Empty and Buffer.Full that's why it won't trigger any code when I test case for Buffer.Empty? Current Code public function netStatusHandler(event:NetStatusEvent):void { // handles net status events switch (event.info.code) { case "NetStream.Buffer.Empty": trace("¤¤¤ Buffering!"); //<- never traces addChild(bufferLoop); //<- doesn't execute break; case "NetStream.Buffer.Full": trace("¤¤¤ FULL!"); //<- trace works here removeChild(bufferLoop); //<- so does any other code break; case "NetStream.Buffer.Flush": trace("¤¤¤ FLUSH!"); //Not sure if this is important break } }

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  • Ruby Design Problem for SQL Bulk Inserter

    - by crunchyt
    This is a Ruby design problem. How can I make a reusable flat file parser that can perform different data scrubbing operations per call, return the emitted results from each scrubbing operation to the caller and perform bulk SQL insertions? Now, before anyone gets narky/concerned, I have written this code already in a very unDRY fashion. Which is why I am asking any Ruby rockstars our there for some assitance. Basically, everytime I want to perform this logic, I create two nested loops, with custom processing in between, buffer each processed line to an array, and output to the DB as a bulk insert when the buffer size limit is reached. Although I have written lots of helpers, the main pattern is being copy pasted everytime. Not very DRY! Here is a Ruby/Pseudo code example of what I am repeating. lines_from_file.each do |line| line.match(/some regex/).each do |sub_str| # Process substring into useful format # EG1: Simple gsub() call # EG2: Custom function call to do complex scrubbing # and matching, emitting results to array # EG3: Loop to match opening/closing/nested brackets # or other delimiters and emit results to array end # Add processed lines to a buffer as SQL insert statement @buffer << PREPARED INSERT STATEMENT # Flush buffer when "buffer size limit reached" or "end of file" if sql_buffer_full || last_line_reached @dbc.insert(SQL INSERTS FROM BUFFER) @buffer = nil end end I am familiar with Proc/Lambda functions. However, because I want to pass two separate procs to the one function, I am not sure how to proceed. I have some idea about how to solve this, but I would really like to see what the real Rubyists suggest? Over to you. Thanks in advance :D

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  • Is There a Better Way to Feed Different Parameters into Functions with If-Statements?

    - by FlowofSoul
    I've been teaching myself Python for a little while now, and I've never programmed before. I just wrote a basic backup program that writes out the progress of each individual file while it is copying. I wrote a function that determines buffer size so that smaller files are copied with a smaller buffer, and bigger files are copied with a bigger buffer. The way I have the code set up now doesn't seem very efficient, as there is an if loop that then leads to another if loops, creating four options, and they all just call the same function with different parameters. import os import sys def smartcopy(filestocopy, dest_path, show_progress = False): """Determines what buffer size to use with copy() Setting show_progress to True calls back display_progress()""" #filestocopy is a list of dictionaries for the files needed to be copied #dictionaries are used as the fullpath, st_mtime, and size are needed if len(filestocopy.keys()) == 0: return None #Determines average file size for which buffer to use average_size = 0 for key in filestocopy.keys(): average_size += int(filestocopy[key]['size']) average_size = average_size/len(filestocopy.keys()) #Smaller buffer for smaller files if average_size < 1024*10000: #Buffer sizes determined by informal tests on my laptop if show_progress: for key in filestocopy.keys(): #dest_path+key is the destination path, as the key is the relative path #and the dest_path is the top level folder copy(filestocopy[key]['fullpath'], dest_path+key, callback = lambda pos, total: display_progress(pos, total, key)) else: for key in filestocopy.keys(): copy(filestocopy[key]['fullpath'], dest_path+key, callback = None) #Bigger buffer for bigger files else: if show_progress: for key in filestocopy.keys(): copy(filestocopy[key]['fullpath'], dest_path+key, 1024*2600, callback = lambda pos, total: display_progress(pos, total, key)) else: for key in filestocopy.keys(): copy(filestocopy[key]['fullpath'], dest_path+key, 1024*2600) def display_progress(pos, total, filename): percent = round(float(pos)/float(total)*100,2) if percent <= 100: sys.stdout.write(filename + ' - ' + str(percent)+'% \r') else: percent = 100 sys.stdout.write(filename + ' - Completed \n') Is there a better way to accomplish what I'm doing? Sorry if the code is commented poorly or hard to follow. I didn't want to ask someone to read through all 120 lines of my poorly written code, so I just isolated the two functions. Thanks for any help.

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  • What used the linux memory? Low cache, low buffer, not a VM

    - by Jason
    First of all, yes, I have read LinuxAteMyRAM, which doesn't explain my situation. # free -tm total used free shared buffers cached Mem: 48149 43948 4200 0 4 75 -/+ buffers/cache: 43868 4280 Swap: 38287 0 38287 Total: 86436 43948 42488 # As shown above, the -/+ buffers/cache: line shows indicates the used memory rate is very high. However, from output of top, I don't see any process used more than 100MB of memory. So, what used the memory? PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 28078 root 18 0 327m 92m 10m S 0 0.2 0:25.06 java 31416 root 16 0 250m 28m 20m S 0 0.1 25:54.59 ResourceMonitor 21598 root -98 0 26552 25m 8316 S 0 0.1 80:49.54 had 24580 root 16 0 24152 10m 760 S 0 0.0 1:25.87 rsyncd 4956 root 16 0 62588 10m 3132 S 0 0.0 12:36.54 vxconfigd 26703 root 16 0 139m 7120 2900 S 1 0.0 4359:39 hrmonitor 21873 root 15 0 18764 4684 2152 S 0 0.0 30:07.56 MountAgent 21883 root 15 0 13736 4280 2172 S 0 0.0 25:25.09 SybaseAgent 21878 root 15 0 18548 4172 2000 S 0 0.0 52:33.46 NICAgent 21887 root 15 0 12660 4056 2168 S 0 0.0 25:07.80 SybaseBkAgent 17798 root 25 0 10652 4048 1160 S 0 0.0 0:00.04 vxconfigbackupd This is an x86_64 machine (not a common-brand server) running x84_64 Linux, not a container in a virtual machine. Kernel (uname -a): Linux 2.6.16.60-0.99.1-smp #1 SMP Fri Oct 12 14:24:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux Content of /proc/meminfo: MemTotal: 49304856 kB MemFree: 4066708 kB Buffers: 35688 kB Cached: 132588 kB SwapCached: 0 kB Active: 26536644 kB Inactive: 17296272 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 49304856 kB LowFree: 4066708 kB SwapTotal: 39206624 kB SwapFree: 39206528 kB Dirty: 200 kB Writeback: 0 kB AnonPages: 249592 kB Mapped: 52712 kB Slab: 1049464 kB CommitLimit: 63859052 kB Committed_AS: 659384 kB PageTables: 3412 kB VmallocTotal: 34359738367 kB VmallocUsed: 478420 kB VmallocChunk: 34359259695 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 Hugepagesize: 2048 kB df reports no large consumption of memory from tmpfs filesystems.

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  • Why does async BeginReceiveFrom never time out on a raw socket?

    - by James Hugard
    Writing an asynchronous Ping using Raw Sockets in F#, to enable parallel requests using as few threads as possible. Not using "System.Net.NetworkInformation.Ping", because it appears to allocate one thread per request. Am also interested in using F# async workflows. The synchronous version below correctly times out when the target host does not exist/respond, but the asynchronous version hangs. Both work when the host does respond. Not sure if this is a .NET issue, or an F# one... Any ideas? (note: the process must run as Admin to allow Raw Socket access) This throws a timeout: let result = Ping.Ping ( IPAddress.Parse( "192.168.33.22" ), 1000 ) However, this hangs: let result = Ping.AsyncPing ( IPAddress.Parse( "192.168.33.22" ), 1000 ) |> Async.RunSynchronously Here's the code... module Ping open System open System.Net open System.Net.Sockets open System.Threading //---- ICMP Packet Classes type IcmpMessage (t : byte) = let mutable m_type = t let mutable m_code = 0uy let mutable m_checksum = 0us member this.Type with get() = m_type member this.Code with get() = m_code member this.Checksum = m_checksum abstract Bytes : byte array default this.Bytes with get() = [| m_type m_code byte(m_checksum) byte(m_checksum >>> 8) |] member this.GetChecksum() = let mutable sum = 0ul let bytes = this.Bytes let mutable i = 0 // Sum up uint16s while i < bytes.Length - 1 do sum <- sum + uint32(BitConverter.ToUInt16( bytes, i )) i <- i + 2 // Add in last byte, if an odd size buffer if i <> bytes.Length then sum <- sum + uint32(bytes.[i]) // Shuffle the bits sum <- (sum >>> 16) + (sum &&& 0xFFFFul) sum <- sum + (sum >>> 16) sum <- ~~~sum uint16(sum) member this.UpdateChecksum() = m_checksum <- this.GetChecksum() type InformationMessage (t : byte) = inherit IcmpMessage(t) let mutable m_identifier = 0us let mutable m_sequenceNumber = 0us member this.Identifier = m_identifier member this.SequenceNumber = m_sequenceNumber override this.Bytes with get() = Array.append (base.Bytes) [| byte(m_identifier) byte(m_identifier >>> 8) byte(m_sequenceNumber) byte(m_sequenceNumber >>> 8) |] type EchoMessage() = inherit InformationMessage( 8uy ) let mutable m_data = Array.create 32 32uy do base.UpdateChecksum() member this.Data with get() = m_data and set(d) = m_data <- d this.UpdateChecksum() override this.Bytes with get() = Array.append (base.Bytes) (this.Data) //---- Synchronous Ping let Ping (host : IPAddress, timeout : int ) = let mutable ep = new IPEndPoint( host, 0 ) let socket = new Socket( AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.SendTimeout, timeout ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, timeout ) let packet = EchoMessage() let mutable buffer = packet.Bytes try if socket.SendTo( buffer, ep ) <= 0 then raise (SocketException()) buffer <- Array.create (buffer.Length + 20) 0uy let mutable epr = ep :> EndPoint if socket.ReceiveFrom( buffer, &epr ) <= 0 then raise (SocketException()) finally socket.Close() buffer //---- Entensions to the F# Async class to allow up to 5 paramters (not just 3) type Async with static member FromBeginEnd(arg1,arg2,arg3,arg4,beginAction,endAction,?cancelAction): Async<'T> = Async.FromBeginEnd((fun (iar,state) -> beginAction(arg1,arg2,arg3,arg4,iar,state)), endAction, ?cancelAction=cancelAction) static member FromBeginEnd(arg1,arg2,arg3,arg4,arg5,beginAction,endAction,?cancelAction): Async<'T> = Async.FromBeginEnd((fun (iar,state) -> beginAction(arg1,arg2,arg3,arg4,arg5,iar,state)), endAction, ?cancelAction=cancelAction) //---- Extensions to the Socket class to provide async SendTo and ReceiveFrom type System.Net.Sockets.Socket with member this.AsyncSendTo( buffer, offset, size, socketFlags, remoteEP ) = Async.FromBeginEnd( buffer, offset, size, socketFlags, remoteEP, this.BeginSendTo, this.EndSendTo ) member this.AsyncReceiveFrom( buffer, offset, size, socketFlags, remoteEP ) = Async.FromBeginEnd( buffer, offset, size, socketFlags, remoteEP, this.BeginReceiveFrom, (fun asyncResult -> this.EndReceiveFrom(asyncResult, remoteEP) ) ) //---- Asynchronous Ping let AsyncPing (host : IPAddress, timeout : int ) = async { let ep = IPEndPoint( host, 0 ) use socket = new Socket( AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.SendTimeout, timeout ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, timeout ) let packet = EchoMessage() let outbuffer = packet.Bytes try let! result = socket.AsyncSendTo( outbuffer, 0, outbuffer.Length, SocketFlags.None, ep ) if result <= 0 then raise (SocketException()) let epr = ref (ep :> EndPoint) let inbuffer = Array.create (outbuffer.Length + 256) 0uy let! result = socket.AsyncReceiveFrom( inbuffer, 0, inbuffer.Length, SocketFlags.None, epr ) if result <= 0 then raise (SocketException()) return inbuffer finally socket.Close() }

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  • How to detect a timeout when using asynchronous Socket.BeginReceive?

    - by James Hugard
    Writing an asynchronous Ping using Raw Sockets in F#, to enable parallel requests using as few threads as possible. Not using "System.Net.NetworkInformation.Ping", because it appears to allocate one thread per request. Am also interested in using F# async workflows. The synchronous version below correctly times out when the target host does not exist/respond, but the asynchronous version hangs. Both work when the host does respond. Not sure if this is a .NET issue, or an F# one... Any ideas? (note: the process must run as Admin to allow Raw Socket access) This throws a timeout: let result = Ping.Ping ( IPAddress.Parse( "192.168.33.22" ), 1000 ) However, this hangs: let result = Ping.AsyncPing ( IPAddress.Parse( "192.168.33.22" ), 1000 ) |> Async.RunSynchronously Here's the code... module Ping open System open System.Net open System.Net.Sockets open System.Threading //---- ICMP Packet Classes type IcmpMessage (t : byte) = let mutable m_type = t let mutable m_code = 0uy let mutable m_checksum = 0us member this.Type with get() = m_type member this.Code with get() = m_code member this.Checksum = m_checksum abstract Bytes : byte array default this.Bytes with get() = [| m_type m_code byte(m_checksum) byte(m_checksum >>> 8) |] member this.GetChecksum() = let mutable sum = 0ul let bytes = this.Bytes let mutable i = 0 // Sum up uint16s while i < bytes.Length - 1 do sum <- sum + uint32(BitConverter.ToUInt16( bytes, i )) i <- i + 2 // Add in last byte, if an odd size buffer if i <> bytes.Length then sum <- sum + uint32(bytes.[i]) // Shuffle the bits sum <- (sum >>> 16) + (sum &&& 0xFFFFul) sum <- sum + (sum >>> 16) sum <- ~~~sum uint16(sum) member this.UpdateChecksum() = m_checksum <- this.GetChecksum() type InformationMessage (t : byte) = inherit IcmpMessage(t) let mutable m_identifier = 0us let mutable m_sequenceNumber = 0us member this.Identifier = m_identifier member this.SequenceNumber = m_sequenceNumber override this.Bytes with get() = Array.append (base.Bytes) [| byte(m_identifier) byte(m_identifier >>> 8) byte(m_sequenceNumber) byte(m_sequenceNumber >>> 8) |] type EchoMessage() = inherit InformationMessage( 8uy ) let mutable m_data = Array.create 32 32uy do base.UpdateChecksum() member this.Data with get() = m_data and set(d) = m_data <- d this.UpdateChecksum() override this.Bytes with get() = Array.append (base.Bytes) (this.Data) //---- Synchronous Ping let Ping (host : IPAddress, timeout : int ) = let mutable ep = new IPEndPoint( host, 0 ) let socket = new Socket( AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.SendTimeout, timeout ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, timeout ) let packet = EchoMessage() let mutable buffer = packet.Bytes try if socket.SendTo( buffer, ep ) <= 0 then raise (SocketException()) buffer <- Array.create (buffer.Length + 20) 0uy let mutable epr = ep :> EndPoint if socket.ReceiveFrom( buffer, &epr ) <= 0 then raise (SocketException()) finally socket.Close() buffer //---- Entensions to the F# Async class to allow up to 5 paramters (not just 3) type Async with static member FromBeginEnd(arg1,arg2,arg3,arg4,beginAction,endAction,?cancelAction): Async<'T> = Async.FromBeginEnd((fun (iar,state) -> beginAction(arg1,arg2,arg3,arg4,iar,state)), endAction, ?cancelAction=cancelAction) static member FromBeginEnd(arg1,arg2,arg3,arg4,arg5,beginAction,endAction,?cancelAction): Async<'T> = Async.FromBeginEnd((fun (iar,state) -> beginAction(arg1,arg2,arg3,arg4,arg5,iar,state)), endAction, ?cancelAction=cancelAction) //---- Extensions to the Socket class to provide async SendTo and ReceiveFrom type System.Net.Sockets.Socket with member this.AsyncSendTo( buffer, offset, size, socketFlags, remoteEP ) = Async.FromBeginEnd( buffer, offset, size, socketFlags, remoteEP, this.BeginSendTo, this.EndSendTo ) member this.AsyncReceiveFrom( buffer, offset, size, socketFlags, remoteEP ) = Async.FromBeginEnd( buffer, offset, size, socketFlags, remoteEP, this.BeginReceiveFrom, (fun asyncResult -> this.EndReceiveFrom(asyncResult, remoteEP) ) ) //---- Asynchronous Ping let AsyncPing (host : IPAddress, timeout : int ) = async { let ep = IPEndPoint( host, 0 ) use socket = new Socket( AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.SendTimeout, timeout ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, timeout ) let packet = EchoMessage() let outbuffer = packet.Bytes try let! result = socket.AsyncSendTo( outbuffer, 0, outbuffer.Length, SocketFlags.None, ep ) if result <= 0 then raise (SocketException()) let epr = ref (ep :> EndPoint) let inbuffer = Array.create (outbuffer.Length + 256) 0uy let! result = socket.AsyncReceiveFrom( inbuffer, 0, inbuffer.Length, SocketFlags.None, epr ) if result <= 0 then raise (SocketException()) return inbuffer finally socket.Close() }

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  • Why does BeginReceiveFrom never time out?

    - by James Hugard
    I am writing an asynchronous Ping using Raw Sockets in F#, to enable parallel requests using as few threads as possible ("System.Net.NetworkInformation.Ping" appears to use one thread per request, but have not tested this... also am interested in using F# async workflows). The synchronous version below correctly times out when the target host does not exist/respond, but the asynchronous version hangs. Both work when the host does respond... Any ideas? (note: the process must run as Admin for this code to work) This throws a timeout: let result = Ping.Ping ( IPAddress.Parse( "192.168.33.22" ), 1000 ) However, this hangs: let result = Ping.PingAsync ( IPAddress.Parse( "192.168.33.22" ), 1000 ) |> Async.RunSynchronously Here's the code... module Ping open System open System.Net open System.Net.Sockets open System.Threading //---- ICMP Packet Classes type IcmpMessage (t : byte) = let mutable m_type = t let mutable m_code = 0uy let mutable m_checksum = 0us member this.Type with get() = m_type member this.Code with get() = m_code member this.Checksum = m_checksum abstract Bytes : byte array default this.Bytes with get() = [| m_type m_code byte(m_checksum) byte(m_checksum >>> 8) |] member this.GetChecksum() = let mutable sum = 0ul let bytes = this.Bytes let mutable i = 0 // Sum up uint16s while i < bytes.Length - 1 do sum <- sum + uint32(BitConverter.ToUInt16( bytes, i )) i <- i + 2 // Add in last byte, if an odd size buffer if i <> bytes.Length then sum <- sum + uint32(bytes.[i]) // Shuffle the bits sum <- (sum >>> 16) + (sum &&& 0xFFFFul) sum <- sum + (sum >>> 16) sum <- ~~~sum uint16(sum) member this.UpdateChecksum() = m_checksum <- this.GetChecksum() type InformationMessage (t : byte) = inherit IcmpMessage(t) let mutable m_identifier = 0us let mutable m_sequenceNumber = 0us member this.Identifier = m_identifier member this.SequenceNumber = m_sequenceNumber override this.Bytes with get() = Array.append (base.Bytes) [| byte(m_identifier) byte(m_identifier >>> 8) byte(m_sequenceNumber) byte(m_sequenceNumber >>> 8) |] type EchoMessage() = inherit InformationMessage( 8uy ) let mutable m_data = Array.create 32 32uy do base.UpdateChecksum() member this.Data with get() = m_data and set(d) = m_data <- d this.UpdateChecksum() override this.Bytes with get() = Array.append (base.Bytes) (this.Data) //---- Synchronous Ping let Ping (host : IPAddress, timeout : int ) = let mutable ep = new IPEndPoint( host, 0 ) let socket = new Socket( AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.SendTimeout, timeout ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, timeout ) let packet = EchoMessage() let mutable buffer = packet.Bytes try if socket.SendTo( buffer, ep ) <= 0 then raise (SocketException()) buffer <- Array.create (buffer.Length + 20) 0uy let mutable epr = ep :> EndPoint if socket.ReceiveFrom( buffer, &epr ) <= 0 then raise (SocketException()) finally socket.Close() buffer //---- Entensions to the F# Async class to allow up to 5 paramters (not just 3) type Async with static member FromBeginEnd(arg1,arg2,arg3,arg4,beginAction,endAction,?cancelAction): Async<'T> = Async.FromBeginEnd((fun (iar,state) -> beginAction(arg1,arg2,arg3,arg4,iar,state)), endAction, ?cancelAction=cancelAction) static member FromBeginEnd(arg1,arg2,arg3,arg4,arg5,beginAction,endAction,?cancelAction): Async<'T> = Async.FromBeginEnd((fun (iar,state) -> beginAction(arg1,arg2,arg3,arg4,arg5,iar,state)), endAction, ?cancelAction=cancelAction) //---- Extensions to the Socket class to provide async SendTo and ReceiveFrom type System.Net.Sockets.Socket with member this.AsyncSendTo( buffer, offset, size, socketFlags, remoteEP ) = Async.FromBeginEnd( buffer, offset, size, socketFlags, remoteEP, this.BeginSendTo, this.EndSendTo ) member this.AsyncReceiveFrom( buffer, offset, size, socketFlags, remoteEP ) = Async.FromBeginEnd( buffer, offset, size, socketFlags, remoteEP, this.BeginReceiveFrom, (fun asyncResult -> this.EndReceiveFrom(asyncResult, remoteEP) ) ) //---- Asynchronous Ping let PingAsync (host : IPAddress, timeout : int ) = async { let ep = IPEndPoint( host, 0 ) use socket = new Socket( AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.SendTimeout, timeout ) socket.SetSocketOption( SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, timeout ) let packet = EchoMessage() let outbuffer = packet.Bytes try let! result = socket.AsyncSendTo( outbuffer, 0, outbuffer.Length, SocketFlags.None, ep ) if result <= 0 then raise (SocketException()) let epr = ref (ep :> EndPoint) let inbuffer = Array.create (outbuffer.Length + 256) 0uy let! result = socket.AsyncReceiveFrom( inbuffer, 0, inbuffer.Length, SocketFlags.None, epr ) if result <= 0 then raise (SocketException()) return inbuffer finally socket.Close() }

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  • Overloading operator>> to a char buffer in C++ - can I tell the stream length?

    - by exscape
    I'm on a custom C++ crash course. I've known the basics for many years, but I'm currently trying to refresh my memory and learn more. To that end, as my second task (after writing a stack class based on linked lists), I'm writing my own string class. It's gone pretty smoothly until now; I want to overload operator that I can do stuff like cin my_string;. The problem is that I don't know how to read the istream properly (or perhaps the problem is that I don't know streams...). I tried a while (!stream.eof()) loop that .read()s 128 bytes at a time, but as one might expect, it stops only on EOF. I want it to read to a newline, like you get with cin to a std::string. My string class has an alloc(size_t new_size) function that (re)allocates memory, and an append(const char *) function that does that part, but I obviously need to know the amount of memory to allocate before I can write to the buffer. Any advice on how to implement this? I tried getting the istream length with seekg() and tellg(), to no avail (it returns -1), and as I said looping until EOF (doesn't stop reading at a newline) reading one chunk at a time.

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  • Write to memory buffer instead of file with libjpeg?

    - by Richard Knop
    I have found this function which uses libjpeg to write to a file: int write_jpeg_file( char *filename ) { struct jpeg_compress_struct cinfo; struct jpeg_error_mgr jerr; /* this is a pointer to one row of image data */ JSAMPROW row_pointer[1]; FILE *outfile = fopen( filename, "wb" ); if ( !outfile ) { printf("Error opening output jpeg file %s\n!", filename ); return -1; } cinfo.err = jpeg_std_error( &jerr ); jpeg_create_compress(&cinfo); jpeg_stdio_dest(&cinfo, outfile); /* Setting the parameters of the output file here */ cinfo.image_width = width; cinfo.image_height = height; cinfo.input_components = bytes_per_pixel; cinfo.in_color_space = color_space; /* default compression parameters, we shouldn't be worried about these */ jpeg_set_defaults( &cinfo ); /* Now do the compression .. */ jpeg_start_compress( &cinfo, TRUE ); /* like reading a file, this time write one row at a time */ while( cinfo.next_scanline < cinfo.image_height ) { row_pointer[0] = &raw_image[ cinfo.next_scanline * cinfo.image_width * cinfo.input_components]; jpeg_write_scanlines( &cinfo, row_pointer, 1 ); } /* similar to read file, clean up after we're done compressing */ jpeg_finish_compress( &cinfo ); jpeg_destroy_compress( &cinfo ); fclose( outfile ); /* success code is 1! */ return 1; } I would actually need to write the jpeg compressed image just to memory buffer, without saving it to a file, to save time. Could somebody give me an example how to do it? I have been searching the web for a while but the documentation is very rare if any and examples are also difficult to come by.

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  • No Buffer Space available(maximum connection reached?) Form Postgres EDB Driver

    - by Listening.Platform
    We are facing an exception while connecting to database through our java application. The stack trace is as follows com.edb.util.PSQLException: The connection attempt failed. at com.edb.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:189) at com.edb.core.ConnectionFactory.openConnection(ConnectionFactory.java:64) at com.edb.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:161) at com.edb.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30) at com.edb.jdbc3.Jdbc3Connection.<init>(Jdbc3Connection.java:24) at com.edb.Driver.makeConnection(Driver.java:391) at com.edb.Driver.connect(Driver.java:266) at java.sql.DriverManager.getConnection(Unknown Source) at java.sql.DriverManager.getConnection(Unknown Source) ... 12 more Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(Unknown Source) at java.net.PlainSocketImpl.connectToAddress(Unknown Source) at java.net.PlainSocketImpl.connect(Unknown Source) at java.net.SocksSocketImpl.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.<init>(Unknown Source) at java.net.Socket.<init>(Unknown Source) at com.edb.core.PGStream.<init>(PGStream.java:70) at com.edb.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:115) ... 20 more When the error occured we were not able to connect to internet and DB and had to reboot the system. But the error occured again after 3 days at same code i.e while connecting to DB. We checked TCP connections using netstat. But there were not many TCP connections i.e it has not reached the max limit. Our application has multiple long running Java processes that pools the DB connections (not more than 60) and keeps it alive for firing the next query (as it has to poll the DB every 2 seconds). Some of the queries in our application are joining large tables (10 million records) to get the related data. We are using following System and applications Windows 2003 server SP2 Java 1.6 Postgres Plus Advanced server 8.4 Database edb-jdbc14.jar driver for connection DB from Java We have used the default configuration of Postgres DB except increasing the connection to 120 from 100. Has anybody encountred the same error with postgres edb driver? Can anybody help us finding the solution?

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  • Java algorithm for normalizing audio

    - by Marty Pitt
    I'm trying to normalize an audio file of speech. Specifically, where an audio file contains peaks in volume, I'm trying to level it out, so the quiet sections are louder, and the peaks are quieter. I know very little about audio manipulation, beyond what I've learnt from working on this task. Also, my math is embarrassingly weak. I've done some research, and the Xuggle site provides a sample which shows reducing the volume using the following code: (full version here) @Override public void onAudioSamples(IAudioSamplesEvent event) { // get the raw audio byes and adjust it's value ShortBuffer buffer = event.getAudioSamples().getByteBuffer().asShortBuffer(); for (int i = 0; i < buffer.limit(); ++i) buffer.put(i, (short)(buffer.get(i) * mVolume)); super.onAudioSamples(event); } Here, they modify the bytes in getAudioSamples() by a constant of mVolume. Building on this approach, I've attempted a normalisation modifies the bytes in getAudioSamples() to a normalised value, considering the max/min in the file. (See below for details). I have a simple filter to leave "silence" alone (ie., anything below a value). I'm finding that the output file is very noisy (ie., the quality is seriously degraded). I assume that the error is either in my normalisation algorithim, or the way I manipulate the bytes. However, I'm unsure of where to go next. Here's an abridged version of what I'm currently doing. Step 1: Find peaks in file: Reads the full audio file, and finds this highest and lowest values of buffer.get() for all AudioSamples @Override public void onAudioSamples(IAudioSamplesEvent event) { IAudioSamples audioSamples = event.getAudioSamples(); ShortBuffer buffer = audioSamples.getByteBuffer().asShortBuffer(); short min = Short.MAX_VALUE; short max = Short.MIN_VALUE; for (int i = 0; i < buffer.limit(); ++i) { short value = buffer.get(i); min = (short) Math.min(min, value); max = (short) Math.max(max, value); } // assign of min/max ommitted for brevity. super.onAudioSamples(event); } Step 2: Normalize all values: In a loop similar to step1, replace the buffer with normalized values, calling: buffer.put(i, normalize(buffer.get(i)); public short normalize(short value) { if (isBackgroundNoise(value)) return value; short rawMin = // min from step1 short rawMax = // max from step1 short targetRangeMin = 1000; short targetRangeMax = 8000; int abs = Math.abs(value); double a = (abs - rawMin) * (targetRangeMax - targetRangeMin); double b = (rawMax - rawMin); double result = targetRangeMin + ( a/b ); // Copy the sign of value to result. result = Math.copySign(result,value); return (short) result; } Questions: Is this a valid approach for attempting to normalize an audio file? Is my math in normalize() valid? Why would this cause the file to become noisy, where a similar approach in the demo code doesn't?

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  • How to set buffer size in client-server app using sockets?

    - by nelly
    First of all i am new to networking so i may say dumb thing in here. Considering a client-server application using sockets(.net with c# if that matters). The client sends some data, the server process it and sends back a string. The client sends some other data, the serve process it, queries the db and sends back several hundreds of items from the database The client sends some other type of data and the server notifies some other clients . My question is how to set the buffer size correctly for reading/writing operation. Should i do something like this: byte[] buff = new byte[client.ReceiveBufferSize] ? I am thinking of something like this: Client sends data to the server(and the server will follow the same pattern) byte[] bytesToSend=new byte[2048] //2048 to be standard for any command send by the client bytes 0..1 ->command type bytes 1..2047 ->command parameters byte[] bytesToReceive=new byte[8]/byte[64]/byte[8192] //switch(command type) But..what is happening when a client is notified by the server without sending data? What is the correct way to accomplish what i am trying to do? Thanks for reading.

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