buffer

Convert Blob data to Raw buffer in javascript or node

由 為{幸葍}努か 提交于 2020-12-29 04:13:23
问题 I am using a plugin jsPDF which generates PDF and saves it to local file system. Now in jsPDF.js, there is some piece of code which generates pdf data in blob format as:- var blob = new Blob([array], {type: "application/pdf"}); and further saves the blob data to local file system. Now instead of saving I need to print the PDF using plugin node-printer. Here is some sample code to do so var fs = require('fs'), var dataToPrinter; fs.readFile('/home/ubuntu/test.pdf', function(err, data){

Convert Blob data to Raw buffer in javascript or node

由 ￡可爱￡侵袭症＋ 提交于 2020-12-29 04:12:55
问题 I am using a plugin jsPDF which generates PDF and saves it to local file system. Now in jsPDF.js, there is some piece of code which generates pdf data in blob format as:- var blob = new Blob([array], {type: "application/pdf"}); and further saves the blob data to local file system. Now instead of saving I need to print the PDF using plugin node-printer. Here is some sample code to do so var fs = require('fs'), var dataToPrinter; fs.readFile('/home/ubuntu/test.pdf', function(err, data){

Socket缓冲区疑问

由 為{幸葍}努か 提交于 2020-12-24 03:29:45
Socket的发送缓冲区大小为64512=63k，接收缓冲区大小为8192=8k，server端接收到client连接时启动一个线程，线程进入阻塞状态（接收第二个连接时才开始读取客户端数据），客户端程序开始读取本地文件（大于1M）往服务器发送数据，每次往输出流1k数据，发送到第80次时客户端也阻塞了，也就是前79次的数据要么已经到达服务器，要么在本地缓存，问题来了，79次*1k/次 - 客户端发送缓存63k - 服务器接收缓存8k = 8k，这8k数据在什么地方？ Server.java private static CountDownLatch latch = new CountDownLatch(1); public static void main(String[] args) throws Throwable { ServerSocket serverSocket = new ServerSocket(80); int i = 1; while (i++ <= 2)//等待两个客户端连接，第一个客户端连接将阻塞 { new Thread(new Client(serverSocket.accept())).start(); } latch.countDown(); serverSocket.close(); } static class Client implements

Buffer function for python 3+

由 寵の児 提交于 2020-12-05 06:17:12
问题 I'm trying to open a vtk window using vtk_show, but my Ipython console crashes every time i do this, apparently this is because Ipython can't display an external window, which is exactly what vtk_show does. I searched on google for a solution, but it's written for python2 (i'm using python 3.6.3). Here's the solution i found: import vtk from IPython.display import Image def vtk_show(renderer, width=400, height=300): """ Takes vtkRenderer instance and returns an IPython Image with the

Buffer function for python 3+

由 跟風遠走 提交于 2020-12-05 06:16:06
问题 I'm trying to open a vtk window using vtk_show, but my Ipython console crashes every time i do this, apparently this is because Ipython can't display an external window, which is exactly what vtk_show does. I searched on google for a solution, but it's written for python2 (i'm using python 3.6.3). Here's the solution i found: import vtk from IPython.display import Image def vtk_show(renderer, width=400, height=300): """ Takes vtkRenderer instance and returns an IPython Image with the

malloc()和calloc()

由 痞子三分冷 提交于 2020-11-17 07:15:46
malloc()和calloc() 进程对动态内存的请求被认为是不紧迫的。例如，当进程的可执行文件被装入时，进程并不一定立即对所有的代码进行访问。类似地，当进程调用malloc() 请求动态内存时，并不意味着进程很快就会访问所有获得的内存。因此一般来说，内核总是尽量推迟给用户态进程动态分配内存。 The kernel succeeds in deferring the allocation of dynamic memory to processes by using a new kind of resource. When a User Mode process asks for dynamic memory, it doesn't get additional page frames; instead, it gets the right to use a new range of linear addresses, which become part of its address space. This interval is called a "memory region." 内核使用一种资源成功实现了对进程动态内存的推迟分配。当用户态进程请求动态内存时，并没有获得请求的页框，而仅仅获得对一个新的线性地址区的使用权，而这一线性地址区间就成为进程地址空间的一部分

no buffer space available try changing

由 ◇◆丶佛笑我妖孽 提交于 2020-11-16 04:58:50
公司服务器最近几天一直报错误，大概运行一天就报如下异常。 java.net.SocketException: No buffer space available (maximum connections reached?): JVM_Bind 搞的很是郁闷，转载篇文章，貌似很全面，试试看。 一个朋友让我帮忙解决他服务器上一个JAVA应用出现的问题，我利用业务时间赶赴现场两次，终于解决了这个疑难杂症，赶紧记录下来，不求能解救曾经和我一样困惑的劳苦大众，但愿自己别忘了。 一、问题的表现 首先说明一下环境，服务器是 WINDOWS SERVER 2003，我对这个操作系统的特性不是很熟悉，只是当做普通的个人版操作系统来使用。我平时一般JAVA服务器都是安装LINUX。 数据库使用的SQL SERVER 2005，SP2。他的数据库本来是SQL SERVER 2000的，是我上周帮他做的迁移。 中间件使用RESIN 2.1.17，这是我非常喜欢和熟悉的SERVLET容器，加不加装APACHE都具有很好的WEB服务性能。 杀毒软件使用的瑞星，双网卡，硬件防火墙，什么牌子我没管。 那到底是什么问题？ 这个！ com.microsoft.sqlserver.jdbc.SQLServerException: 到主机 的 TCP/IP 连接 失败。 java.net.SocketException:
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