flush

问题 My client is a web browser, and sending request to myserver using this url: http://localhost This is the server side code. The problem lies in the run method of the ServingThread class. class ServingThread implements Runnable{ private Socket socket ; public ServingThread(Socket socket){ this.socket = socket ; System.out.println("Receives a new browser request from " + socket + "\n\n"); } public void run() { PrintWriter out = null ; try { String str = "" ; out = new PrintWriter( socket

问题 I understand the theory behind BufferedOutputStream . Bytes are written to a buffer array until it is full, and then written (flushed) to the underlying stream - the idea being that it is faster than writing byte-by-byte as there are fewer OS calls. However, from looking at the implementation of the BufferedOutputStream class and methods (BufferedOutputStream.java), it seems that ultimately, the bytes from the buffer are just written byte-by-byte. I think this is the case because: In

问题 By definition taken from: http://www.cplusplus.com/reference/iostream/ostream/flush/ , it is not clear why the function exists, and for what purpose you would use it for. Why not call flush(), every time your write to the stream? 回答1: In all likelihood, the word flush comes from exactly what you'd flush in real-life. A toilet... So let's try a toilet analogy: Flushing every time a new one drops into the bowl is very time-consuming and a complete waste of water. That's a big problem today

问题 I am using RavenDb embedded. As a part of my intergration tests I want to check objects are persisted. When I SaveChanges on an object, then retrieve it, it cannot be found unless I dispose my connection. This does not work for me, as no files are returned using (var session = _dataDocumentStore.Instance.OpenSession()) { session.Store(file); session.SaveChanges(); } .... using (var session = _dataDocumentStore.Instance.OpenSession() ) { return session.Query<File>().ToList(); } I created a

问题 I am writing a C program in which I need to flush my memory. I would like know if there is any UNIX system command to flush the CPU cache. This is a requirement for my project which involves calculating the time taken for my logic. I have read about the cacheflush(char *s, int a, int b) function but I am not sure as to whether it will be suitable and what to pass in the parameters. 回答1: I take it you mean "CPU cache", not memory cache The link above is good: the suggestion "write a lot of

问题 I'm on MacOSX. In the logger part of my application, I'm dumping data to a file. suppose I have a globally declared std::ofstream outFile("log"); and in my logging code I have: outFile << "......." ; outFile.flush(); Now, suppose my code crashes after the flush() happens; Is the stuff written to outFile before the flush() guaranteed to be written to disk (note that I don't call a close() ). Thanks! 回答1: From the C++ runtime's point of view, it should have been written to disk. From an OS

问题 I have read this about the switch between read and write operations(and vice-versa) for files opened for update using fopen() (LINK) "For files open for update (those which include a "+" sign), on which both input and output operations are allowed, the stream should be flushed (fflush) or repositioned (fseek, fsetpos, rewind) between either a writing operation followed by a reading operation or a reading operation which did not reach the end-of-file followed by a writing operation." There are

问题 In Python, and in general - does a close() operation on a file object imply a flush() operation? 回答1: Yes. It uses the underlying close() function which does that for you (source). 回答2: NB: close() and flush() won't ensure that the data is actually secure on the disk. It just ensures that the OS has the data == that it isn't buffered inside the process. You can try sync or fsync to get the data written to the disk. 回答3: Yes, in Python 3 this is finally in the official documentation, but is

问题 I am not sure whether I need to call Flush() on the used objects if I write something like this: using (FileStream...) using (CryptoStream...) using (BinaryWriter...) { // do something } Are they always automatically flushed? When does the using statement flush them and when it doesn’t (if that can happen)? 回答1: As soon as you leave the using block’s scope, the stream is closed and disposed. The Close() calls the Flush(), so you should not need to call it manually. 回答2: It varies, Stream by

问题 I have emacs + sbcl + slime installed. I have this function defined (defun jugar () (let* ((nodoActual *nodo-inicial*) (estadoActual (nodo-estado nodoActual)) (timeStart nil) (timeEnd nil) ) (loop while (not (es-estado-final estadoActual)) do (setf *hojas* 0) (setf timeStart (get-universal-time)) (setf nodoActual (decision-minimax nodoActual *profundidad* timeStart)) (setf timeEnd (get-universal-time)) (setf estadoActual (nodo-estado nodoActual)) (imprime-en-fichero estadoActual) (format t