pcidescriptors.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 121 行

/*
 * $Id: PCIDescriptors.java,v 1.1 2003/11/25 11:41:21 epr Exp $
 */
package org.jnode.driver.pci;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;

import org.apache.log4j.Logger;

/**
 * @author epr
 */
public class PCIDescriptors {
	
	/** My logger */
	private final Logger log = Logger.getLogger(getClass());
	private final HashMap vendors;
	private static final PCIDescriptors instance = new PCIDescriptors();
	
	private PCIDescriptors() {
		try {
			vendors = readDevices();
		} catch (IOException ex) {
			throw new ExceptionInInitializerError(ex);
		}
	}
	
	/**
	 * Gets my single instance
	 */
	public static PCIDescriptors getInstance() {
		return instance;
	}
	
	/**
	 * Gets the descriptor of the vendor with the given ID.
	 * @param vendorId
	 */
	public VendorDescriptor findVendor(int vendorId) {
		VendorDescriptor result;
		result = (VendorDescriptor)vendors.get(new Integer(vendorId));
		if (result == null) {
			result = new VendorDescriptor(vendorId, "? (" + vendorId + ")");
		}
		return result;
	}
	
	private HashMap readDevices() 
	throws IOException {
		log.debug("Loading PCI device info");
		InputStream is = ClassLoader.getSystemResourceAsStream("org/jnode/driver/pci/pci.ids");
		InputStreamReader isr = new InputStreamReader(is);
		BufferedReader in = new BufferedReader(isr);
		HashMap vendors = new HashMap();
		VendorDescriptor lastVendor = null;
		DeviceDescriptor lastDevice = null;
		
		String line;
		
		while ((line = in.readLine()) != null) {
			line = stripComment(line);
			
			if (line.length() > 0) {
				int tabs = countTabs(line);
				line = line.trim();
				if (tabs == 0) {
					// Vendor ID
					lastVendor = parseVendor(line);
					vendors.put(new Integer(lastVendor.getId()), lastVendor);
				} else if (tabs == 1) {
					// Device 
					lastDevice = parseDevice(line);
					lastVendor.addDevice(lastDevice);
				} else {
					// Subclass
				}
			}
			
		}
		
		return vendors;
	}
	
	private VendorDescriptor parseVendor(String line) {
		int idx = line.indexOf(' ');
		int id = Integer.parseInt(line.substring(0, idx), 16);
		return new VendorDescriptor(id, line.substring(idx+1).trim());
	}
	
	private DeviceDescriptor parseDevice(String line) {
		int idx = line.indexOf(' ');
		int id = Integer.parseInt(line.substring(0, idx), 16);
		return new DeviceDescriptor(id, line.substring(idx+1).trim());
	}
	
	private String stripComment(String line) {
		int idx = line.indexOf('#');
		if (idx >= 0) {
			line = line.substring(0, idx);
		}
		return line;
	}
	
	private int countTabs(String line) {
		final int len = line.length();
		int count = 0;
		for (int i = 0; i < len; i++) {
			if (line.charAt(i) == '\t') {
				count++;
			} else {
				return count;
			}
		}
		return count;
	}
}