melin melin

Docker Hub 镜像加速器

国内从 Docker Hub 拉取镜像有时会遇到困难，此时可以配置镜像加速器。

Dockerized 实践 https://github.com/y0ngb1n/dockerized

	##服务代码

	```python
	#!/usr/bin/env python2
	#coding=utf-8

	import tornado.ioloop

	import tornado.web
	from tornado.escape import json_encode

	/* BTrace Script Template */
	import com.sun.btrace.annotations.*;
	import static com.sun.btrace.BTraceUtils.*;
	import java.lang.reflect.Field;

	@BTrace
	public class TracingScript {

	/*
	* 获取方参数、返回值信息；获取方法调用时间

	public class ArrayQueueSemaphore implements Queue {
	private final Semaphore notFull = new Semaphore(10);
	private final Semaphore notEmpty = new Semaphore(0);
	private final ReentrantLock lock = new ReentrantLock();

	private final String[] connections = new String[10];
	int putIndex, takeIndex, count;

	public void put(String e) throws InterruptedException {
	notFull.acquire();

	package com.github.melin.concurrnt.future;

	import java.util.concurrent.CompletableFuture;
	import java.util.concurrent.Executor;
	import java.util.concurrent.Executors;
	import java.util.concurrent.TimeUnit;
	import java.util.function.BiFunction;
	import java.util.function.Consumer;
	import java.util.function.Function;
	import java.util.function.Supplier;

	1. Send HTTP GET Request

	String url = "http://www.google.com/search?q=httpClient";

	HttpClient client = HttpClientBuilder.create().build();
	HttpGet request = new HttpGet(url);

	// add request header
	request.addHeader("User-Agent", USER_AGENT);
	HttpResponse response = client.execute(request);

	1、ByteBuf支持同时读写操作，包含writerIndex和readerIndex两个变量，如果readerIndex值超过writerIndex，将会抛出IndexOutOfBoundsException错误。
	2、ByteBuf支持head buffer（jvm堆中）和direct buffer，堆外分配buffer成本更高。
	3、使用ByteBuffer实例：
	ByteBuf heapBuf = ...;
	if (heapBuf.hasArray()) { #1
	byte[] array = heapBuf.array(); #2
	int offset = heapBuf.arrayOffset() + heapBuf.position(); #3
	int length = heapBuf.readableBytes(); #4
	YourImpl.method(array, offset, length); #5
	}

	ChannelInboundHandlerAdapter
	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) {
	System.out.println(ìServer received: ì + msg);
	ctx.write(msg) #2
	}
	@Override
	public void channelReadComplete(ChannelHandlerContext ctx) {
	ctx.writeAndFlush(Unpooled.EMPTY_BUFFER)
	.addListener(ChannelFutureListener.CLOSE); #3

	import java.io.*;
	import java.util.*;
	import sun.jvm.hotspot.memory.*;
	import sun.jvm.hotspot.oops.*;
	import sun.jvm.hotspot.debugger.*;
	import sun.jvm.hotspot.runtime.*;
	import sun.jvm.hotspot.tools.*;
	import sun.jvm.hotspot.utilities.*;

	public class DirectMemorySize extends Tool {