| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package org.netbeans.modules.masterfs.watcher.linux; |
| |
| import org.netbeans.modules.masterfs.providers.Notifier; |
| import com.sun.jna.Library; |
| import com.sun.jna.Native; |
| import com.sun.jna.NativeLibrary; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.ByteOrder; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| import org.openide.util.lookup.ServiceProvider; |
| |
| /** |
| * A {@link Notifier} implementation based on Linux inotify mechanism. |
| * |
| * @author nenik |
| */ |
| @ServiceProvider(service=Notifier.class, position=500) |
| public final class LinuxNotifier extends Notifier<LinuxNotifier.LKey> { |
| private static final Logger LOG = Logger.getLogger(LinuxNotifier.class.getName()); |
| |
| private static interface InotifyImpl extends Library { |
| public int inotify_init(); |
| public int inotify_init1(int flags); |
| public int close(int fd); |
| public int read(int fd, ByteBuffer buff, int count); |
| public int inotify_add_watch(int fd, String pathname, int mask); |
| public int inotify_rm_watch(int fd, int wd); |
| |
| public static final int O_CLOEXEC = 02000000; //0x80000 |
| |
| // Masks |
| public static final int IN_ACCESS = 0x0001; /* File was accessed */ |
| public static final int IN_MODIFY = 0x0002; /* File was modified */ |
| public static final int IN_ATTRIB = 0x0004; /* Metadata changed */ |
| public static final int IN_CLOSE_WRITE = 0x0008; /* Writtable file was closed */ |
| public static final int IN_CLOSE_NOWRITE = 0x0010; /* Unwrittable file closed */ |
| public static final int IN_OPEN = 0x0020; /* File was opened */ |
| public static final int IN_MOVED_FROM = 0x0040; /* File was moved from X */ |
| public static final int IN_MOVED_TO = 0x0080; /* File was moved to Y */ |
| public static final int IN_CREATE = 0x0100; /* Subfile was created */ |
| public static final int IN_DELETE = 0x0200; /* Subfile was deleted */ |
| public static final int IN_DELETE_SELF = 0x0400; /* Self was deleted */ |
| public static final int IN_MOVE_SELF = 0x0800; /* Self was moved */ |
| |
| // additional event masks |
| public static final int IN_UNMOUNT = 0x2000; /* Backing fs was unmounted */ |
| public static final int IN_Q_OVERFLOW = 0x4000; /* Event queued overflowed */ |
| public static final int IN_IGNORED = 0x8000; /* File was ignored */ |
| |
| } |
| |
| final InotifyImpl IMPL; |
| private int fd; |
| private final ByteBuffer buff = ByteBuffer.allocateDirect(4096); |
| |
| // An array would serve nearly as well |
| private final Map<Integer, LKey> map = new HashMap<Integer, LKey>(); |
| |
| public LinuxNotifier() { |
| IMPL = Native.load("c", InotifyImpl.class); |
| } |
| |
| private String getString(int maxLen) { |
| if (maxLen < 1) return null; // no name field |
| byte[] temp = new byte[maxLen]; |
| buff.get(temp); |
| return Native.toString(temp); |
| } |
| |
| @Override public String nextEvent() throws IOException { |
| String path; |
| while (true) { |
| path = nextEventPath(); |
| if (path == null || !path.isEmpty()) { |
| return path; |
| } |
| } |
| } |
| |
| /** |
| * @return Path for the next event, null in case of queue overflow, or empty |
| * string if the event should be ignored. |
| */ |
| public String nextEventPath() throws IOException { |
| /* inotify event structure layout: |
| * int wd; // Watch descriptor |
| * uint32_t mask; // Mask of events |
| * uint32_t cookie;// Unique cookie associating related events (for rename(2)) |
| * uint32_t len; // Size of name field |
| * char name[];// Optional null-terminated name |
| */ |
| while (buff.remaining() < 16 || buff.remaining() < 16 + buff.getInt(buff.position() + 12)) { |
| buff.compact(); |
| int len = IMPL.read(fd, buff, buff.remaining()); |
| |
| if (len <= 0) { |
| // lazily get a thread local errno |
| int errno = NativeLibrary.getInstance("c").getFunction("errno").getInt(0); |
| if (errno == 4) { // EINTR |
| buff.flip(); |
| continue; // restart the I/O |
| } else { |
| throw new IOException("error reading from inotify: " + errno); |
| } |
| } |
| buff.position(buff.position() + len); |
| buff.flip(); |
| } |
| |
| // now we have enough data in the buffer |
| int wd = buff.getInt(); |
| int mask = buff.getInt(); |
| int cookie = buff.getInt(); |
| int len = buff.getInt(); |
| String name = getString(len); // ignore |
| |
| if ((mask & InotifyImpl.IN_IGNORED) == InotifyImpl.IN_IGNORED) { |
| return ""; // #235632 //NOI18N |
| } |
| LKey key = map.get(wd); |
| if (key == null) { /* wd == -1 -> Queue overflow */ |
| return null; |
| } |
| |
| return key.path; |
| } |
| |
| static class LKey { |
| int id; |
| String path; |
| |
| public LKey(int id, String path) { |
| this.id = id; |
| this.path = path; |
| } |
| |
| @Override |
| public String toString() { |
| return "LKey[" + id + " - '" + path + "']"; |
| } |
| } |
| |
| @Override |
| protected void start() throws IOException { |
| buff.position(buff.capacity()); // make the buffer empty |
| buff.order(ByteOrder.nativeOrder()); |
| fd = IMPL.inotify_init1(InotifyImpl.O_CLOEXEC); |
| if (fd < 0) { |
| LOG.log( |
| Level.INFO, "Linux kernel {0} returned {1} from inotify_init1", |
| new Object[]{System.getProperty("os.version"), fd}); |
| fd = IMPL.inotify_init(); |
| LOG.log(Level.INFO, "Trying inotify_init: {0}", fd); |
| } |
| if (fd < 0) { |
| throw new IOException("inotify_init failed: " + fd); |
| } |
| } |
| |
| @Override public LKey addWatch(String path) throws IOException { |
| // what if the file doesn't exist? |
| int id = IMPL.inotify_add_watch(fd, path, |
| InotifyImpl.IN_CREATE | InotifyImpl.IN_MOVED_TO | |
| InotifyImpl.IN_DELETE | InotifyImpl.IN_MOVED_FROM | |
| InotifyImpl.IN_MODIFY | InotifyImpl.IN_ATTRIB); |
| //XXX handle error return value (-1) |
| LOG.log(Level.FINEST, "addWatch{0} res: {1}", new Object[]{path, id}); |
| if (id <= 0) { |
| // 28 == EINOSPC |
| int errno = NativeLibrary.getInstance("c").getFunction("errno").getInt(0); // NOI18N |
| throw new IOException("addWatch on " + path + " errno: " + errno); // NOI18N |
| } |
| |
| LKey newKey = map.get(id); |
| if (newKey == null) { |
| newKey = new LKey(id, path); |
| map.put(id, newKey); |
| } |
| return newKey; |
| } |
| |
| @Override public void removeWatch(LKey lkey) { |
| map.remove(lkey.id); |
| IMPL.inotify_rm_watch(fd, lkey.id); |
| } |
| } |