package net.loyin.util.performance;

import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.lang.management.ManagementFactory;

import com.sun.management.OperatingSystemMXBean;

public class MonitorServiceImpl implements IMonitorService {
	// 可以设置长些，防止读到运行此次系统检查时的cpu占用率，就不准了
	private static final int CPUTIME = 5000;

	private static final int PERCENT = 100;

	private static final int FAULTLENGTH = 10;

	
	/**
	 * 获得当前的监控对象.
	 * 
	 * @return 返回构造好的监控对象
	 * @throws Exception
	 * @author amg * Creation date: 2008-4-25 - 上午10:45:08
	 */
	public MonitorInfoBean getMonitorInfoBean() throws Exception {
		int kb = 1024;

		// 可使用内存
		long totalMemory = Runtime.getRuntime().totalMemory() / kb;
		// 剩余内存
		long freeMemory = Runtime.getRuntime().freeMemory() / kb;
		// 最大可使用内存
		long maxMemory = Runtime.getRuntime().maxMemory() / kb;

		OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory
				.getOperatingSystemMXBean();

		// 操作系统
		String osName = System.getProperty("os.name");
		// 总的物理内存
		long totalMemorySize = osmxb.getTotalPhysicalMemorySize() / kb;
		// 剩余的物理内存
		long freePhysicalMemorySize = osmxb.getFreePhysicalMemorySize() / kb;
		// 已使用的物理内存
		long usedMemory = (osmxb.getTotalPhysicalMemorySize() - osmxb
				.getFreePhysicalMemorySize()) / kb;

		// 获得线程总数
		ThreadGroup parentThread;
		for (parentThread = Thread.currentThread().getThreadGroup(); parentThread
				.getParent() != null; parentThread = parentThread.getParent())
			;
		int totalThread = parentThread.activeCount();

		double cpuRatio = 0;
		if (osName.toLowerCase().startsWith("windows")) {
			cpuRatio = this.getCpuRatioForWindows();
		}

		// 构造返回对象
		MonitorInfoBean infoBean = new MonitorInfoBean();
		infoBean.setFreeMemory(freeMemory);
		infoBean.setFreePhysicalMemorySize(freePhysicalMemorySize);
		infoBean.setMaxMemory(maxMemory);
		infoBean.setOsName(osName);
		infoBean.setTotalMemory(totalMemory);
		infoBean.setTotalMemorySize(totalMemorySize);
		infoBean.setTotalThread(totalThread);
		infoBean.setUsedMemory(usedMemory);
		infoBean.setCpuRatio(cpuRatio);
		return infoBean;
	}

	
	/**
	 * 获得CPU使用率.
	 * 
	 * @return 返回cpu使用率
	 * @author amg * Creation date: 2008-4-25 - 下午06:05:11
	 */
	private double getCpuRatioForWindows() {
		try {
			String procCmd = System.getenv("windir")
					+ "\\system32\\wbem\\wmic.exe process get Caption,CommandLine,"
					+ "KernelModeTime,ReadOperationCount,ThreadCount,UserModeTime,WriteOperationCount";
			// 取进程信息
			long[] c0 = readCpu(Runtime.getRuntime().exec(procCmd));
			Thread.sleep(CPUTIME);
			long[] c1 = readCpu(Runtime.getRuntime().exec(procCmd));
			if (c0 != null && c1 != null) {
				long idletime = c1[0] - c0[0];
				long busytime = c1[1] - c0[1];
				return Double.valueOf(
						PERCENT * (busytime) / (busytime + idletime))
						.doubleValue();
			} else {
				return 0.0;
			}
		} catch (Exception ex) {
			ex.printStackTrace();
			return 0.0;
		}
	}

	
	/**
	 * 读取CPU信息.
	 * 
	 * @param proc
	 * @return
	 * @author amg * Creation date: 2008-4-25 - 下午06:10:14
	 */
	private long[] readCpu(final Process proc) {
		long[] retn = new long[2];
		try {
			proc.getOutputStream().close();
			InputStreamReader ir = new InputStreamReader(proc.getInputStream());
			LineNumberReader input = new LineNumberReader(ir);
			String line = input.readLine();
			if (line == null || line.length() < FAULTLENGTH) {
				return null;
			}
			int capidx = line.indexOf("Caption");
			int cmdidx = line.indexOf("CommandLine");
			int rocidx = line.indexOf("ReadOperationCount");
			int umtidx = line.indexOf("UserModeTime");
			int kmtidx = line.indexOf("KernelModeTime");
			int wocidx = line.indexOf("WriteOperationCount");
			long idletime = 0;
//			long kneltime = 0;
//			long usertime = 0;
			while ((line = input.readLine()) != null) {
				if (line.length() < wocidx) {
					continue;
				}
				// 字段出现顺序：Caption,CommandLine,KernelModeTime,ReadOperationCount,
				// ThreadCount,UserModeTime,WriteOperation
				String caption = Bytes.substring(line, capidx, cmdidx - 1)
						.trim();
				String cmd = Bytes.substring(line, cmdidx, kmtidx - 1).trim();
				if (cmd.indexOf("wmic.exe") >= 0) {
					continue;
				}
				// log.info("line="+line);
				if (caption.equals("System Idle Process")
						|| caption.equals("System")) {
					idletime += Long.valueOf(
							Bytes.substring(line, kmtidx, rocidx - 1).trim())
							.longValue();
					idletime += Long.valueOf(
							Bytes.substring(line, umtidx, wocidx - 1).trim())
							.longValue();
					continue;
				}

				/*kneltime += Long.valueOf(
						Bytes.substring(line, kmtidx, rocidx - 1).trim())
						.longValue();
				usertime += Long.valueOf(
						Bytes.substring(line, umtidx, wocidx - 1).trim())
						.longValue();*/
			}
			retn[0] = idletime;
			retn[1] = 0;//kneltime + usertime;
			return retn;
		} catch (Exception ex) {
			ex.printStackTrace();
		} finally {
			try {
				proc.getInputStream().close();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return null;
	}

	
	/**
	 * 测试方法.
	 * 
	 * @param args
	 * @throws Exception
	 * @author amg * Creation date: 2008-4-30 - 下午04:47:29
	 */
	public static void main(String[] args) throws Exception {
		IMonitorService service = new MonitorServiceImpl();
		MonitorInfoBean monitorInfo = service.getMonitorInfoBean();
		System.out.println("cpu占有率=" + monitorInfo.getCpuRatio());

		System.out.println("可使用内存=" + monitorInfo.getTotalMemory());
		System.out.println("剩余内存=" + monitorInfo.getFreeMemory());
		System.out.println("最大可使用内存=" + monitorInfo.getMaxMemory());

		System.out.println("操作系统=" + monitorInfo.getOsName());
		System.out.println("总的物理内存=" + monitorInfo.getTotalMemorySize() + "kb");
		System.out.println("剩余的物理内存=" + monitorInfo.getFreeMemory() + "kb");
		System.out.println("已使用的物理内存=" + monitorInfo.getUsedMemory() + "kb");
		System.out.println("线程总数=" + monitorInfo.getTotalThread() + "kb");
	}
}
