queue

问题 I am currently struggle to find a solution for implement a specific kind of queue, which require the following traits: All queue must respect the order that job were added. The whole queue will have a concurrency of 1, which means that there will only be one job execute at a time per queue , not worker. There will be more than a few thousand queue like this. It need to be distributed and be able to scale (example if I add a worker) Basically it is a single process FIFO queue, and this is

问题 Following this question: How do I retrieve a list or number of jobs from a printer queue? I'm still stuck on how to target a specific printer of which I currently only know the name using the LocalPrintServer class. The application is supposed to print to several machines at once and all printspoolers need to be monitored separately. Can anyone provide me with a code snippet that shows how I can instantiate a LocalPrintServer object using only the name of the printer? Thanks in advance! Edit:

问题 The current Go library doesn't provide the queue container. To implement a simple queue, I use circle array as the underlying data structure. It follows algorithms mentioned in TAOCP: Insert Y into queue X: X[R]<-Y; R<-(R+1)%M; if R=F then OVERFLOW. Delete Y from queue X: if F=R then UNDERFLOW; Y<-X[F]; F<-(F+1) % M. F: Front, R: Rear, M: Array length. Following is the code: package main import ( "fmt" ) type Queue struct { len int head, tail int q []int } func New(n int) *Queue { return

问题 I'm putting several tasks into a task queue and would like to know when the specific tasks are done. I haven't found anything in the API about call backs, or checking the status of a task, so I thought I'd see what other people do, or if there's a work around (or official) way to check. I don't care about individual tasks, if it helps, I'm putting 6 different tasks in, and want to know when all 6 are complete. Thanks! 回答1: The new REST/JSON task queue API will let you do this. http://code

问题 What is the difference when creating these two objects Queue<String> test = new LinkedList<String>(); and List<String> test2 = new LinkedList<String>(); What are the actual differences between test and test2 ? Are both of them LinkedList ? Are there performance differences or reasons to use one over the other? 回答1: The two statements you've written each construct a LinkedList<String> object to hold a list of strings, then assign it to a variable. The difference is in the type of the variable.

问题 What is the basic difference between stream processing and traditional message processing? As people say that kafka is good choice for stream processing but essentially kafka is a messaging framework similar to ActivMQ, RabbitMQ etc. Why do we generally not say that ActiveMQ is good for stream processing as well. Is it the speed at which messages are consumed by the consumer determines if it is a stream? 回答1: In traditional message processing, you apply simple computations on the messages --

问题 I was wondering if you can push an address onto a queue instead of its contents. For example I have a 2d array and I'm moving around it. I want to keep track of the spots I've been in and I don't necessarily care about the contents of those spots. 回答1: Yes, you just have to declare queue as queue of pointers, for example " int* " or whatever type you are using. Here's the code: #include <iostream> #include <queue> using namespace std; int main() { ios_base::sync_with_stdio(0); int a = 3, b =

问题 I've got my code working, it's not pretty but it doe's the job :) Now I want to write a piece of code that stops the data from being loaded if there is 19 or more pieces of data in the text file and then display a message saying Invalid input for example. I'm not sure how to do this so any help would be appreciated. package stackandqueue; import java.util.*; import java.util.Stack; import java.util.Queue; import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io

问题 This question already has answers here : Strange code in java.util.concurrent.LinkedBlockingQueue (4 answers) Closed last year . I'm a little confused by the structure of the Node class in OpenJDK's implementation of LinkedBlockingQueue (in java.util.concurrent). I've reproduced the description of the node class below: static class Node<E> { E item; /** * One of: * - the real successor Node * - this Node, meaning the successor is head.next * - null, meaning there is no successor (this is the

问题 How do I make the print_queue work properly in java? This is my own implementation of queue. Using Iterator() works fine, except it prints numbers in random order. package data_structures_java ; import java.util.Iterator; import java.util.PriorityQueue ; import java.util.* ; public class Queue_implementation { PriorityQueue<Integer> actual_queue ; public Queue_implementation(){ actual_queue = new PriorityQueue<Integer>() ; } public void add(int num){ actual_queue.add(num) ; } public int