1 /* 2 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.nio.ch; 27 28 import java.io.FileDescriptor; 29 import java.io.IOException; 30 import java.security.PrivilegedAction; 31 import sun.misc.SharedSecrets; 32 import sun.misc.JavaIOFileDescriptorAccess; 33 34 class FileDispatcherImpl extends FileDispatcher { 35 36 // set to true if fast file transmission (TransmitFile) is enabled 37 private static final boolean fastFileTransfer; 38 39 /** 40 * Indicates if the dispatcher should first advance the file position 41 * to the end of file when writing. 42 */ 43 private final boolean append; 44 45 FileDispatcherImpl(boolean append) { 46 this.append = append; 47 } 48 49 FileDispatcherImpl() { 50 this(false); 51 } 52 53 @Override 54 boolean needsPositionLock() { 55 return true; 56 } 57 58 int read(FileDescriptor fd, long address, int len) 59 throws IOException 60 { 61 return read0(fd, address, len); 62 } 63 64 int pread(FileDescriptor fd, long address, int len, long position) 65 throws IOException 66 { 67 return pread0(fd, address, len, position); 68 } 69 70 long readv(FileDescriptor fd, long address, int len) throws IOException { 71 return readv0(fd, address, len); 72 } 73 74 int write(FileDescriptor fd, long address, int len) throws IOException { 75 return write0(fd, address, len, append); 76 } 77 78 int pwrite(FileDescriptor fd, long address, int len, long position) 79 throws IOException 80 { 81 return pwrite0(fd, address, len, position); 82 } 83 84 long writev(FileDescriptor fd, long address, int len) throws IOException { 85 return writev0(fd, address, len, append); 86 } 87 88 // Added parameter writable for AIX platform port (not used on Windows). 89 int force(FileDescriptor fd, boolean metaData, boolean writable) throws IOException { 90 return force0(fd, metaData); 91 } 92 93 int truncate(FileDescriptor fd, long size) throws IOException { 94 return truncate0(fd, size); 95 } 96 97 long size(FileDescriptor fd) throws IOException { 98 return size0(fd); 99 } 100 101 int lock(FileDescriptor fd, boolean blocking, long pos, long size, 102 boolean shared) throws IOException 103 { 104 return lock0(fd, blocking, pos, size, shared); 105 } 106 107 void release(FileDescriptor fd, long pos, long size) throws IOException { 108 release0(fd, pos, size); 109 } 110 111 void close(FileDescriptor fd) throws IOException { 112 close0(fd); 113 } 114 115 FileDescriptor duplicateForMapping(FileDescriptor fd) throws IOException { 116 // on Windows we need to keep a handle to the file 117 JavaIOFileDescriptorAccess fdAccess = 118 SharedSecrets.getJavaIOFileDescriptorAccess(); 119 FileDescriptor result = new FileDescriptor(); 120 long handle = duplicateHandle(fdAccess.getHandle(fd)); 121 fdAccess.setHandle(result, handle); 122 return result; 123 } 124 125 boolean canTransferToDirectly(java.nio.channels.SelectableChannel sc) { 126 return fastFileTransfer && sc.isBlocking(); 127 } 128 129 boolean transferToDirectlyNeedsPositionLock() { 130 return true; 131 } 132 133 static boolean isFastFileTransferRequested() { 134 String fileTransferProp = java.security.AccessController.doPrivileged( 135 new PrivilegedAction<String>() { 136 @Override 137 public String run() { 138 return System.getProperty("jdk.nio.enableFastFileTransfer"); 139 } 140 }); 141 boolean enable; 142 if ("".equals(fileTransferProp)) { 143 enable = true; 144 } else { 145 enable = Boolean.parseBoolean(fileTransferProp); 146 } 147 return enable; 148 } 149 150 static { 151 IOUtil.load(); 152 fastFileTransfer = isFastFileTransferRequested(); 153 } 154 155 //-- Native methods 156 157 static native int read0(FileDescriptor fd, long address, int len) 158 throws IOException; 159 160 static native int pread0(FileDescriptor fd, long address, int len, 161 long position) throws IOException; 162 163 static native long readv0(FileDescriptor fd, long address, int len) 164 throws IOException; 165 166 static native int write0(FileDescriptor fd, long address, int len, boolean append) 167 throws IOException; 168 169 static native int pwrite0(FileDescriptor fd, long address, int len, 170 long position) throws IOException; 171 172 static native long writev0(FileDescriptor fd, long address, int len, boolean append) 173 throws IOException; 174 175 static native int force0(FileDescriptor fd, boolean metaData) 176 throws IOException; 177 178 static native int truncate0(FileDescriptor fd, long size) 179 throws IOException; 180 181 static native long size0(FileDescriptor fd) throws IOException; 182 183 static native int lock0(FileDescriptor fd, boolean blocking, long pos, 184 long size, boolean shared) throws IOException; 185 186 static native void release0(FileDescriptor fd, long pos, long size) 187 throws IOException; 188 189 static native void close0(FileDescriptor fd) throws IOException; 190 191 static native void closeByHandle(long fd) throws IOException; 192 193 static native long duplicateHandle(long fd) throws IOException; 194 }