1 /*
2 * Copyright (c) 2000, 2016, 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 jdk.internal.misc.SharedSecrets;
31 import jdk.internal.misc.JavaIOFileDescriptorAccess;
32 import sun.security.action.GetPropertyAction;
33
34 class FileDispatcherImpl extends FileDispatcher {
35
36 private static final JavaIOFileDescriptorAccess fdAccess =
37 SharedSecrets.getJavaIOFileDescriptorAccess();
38
39 // set to true if fast file transmission (TransmitFile) is enabled
40 private static final boolean fastFileTransfer;
41
42 FileDispatcherImpl() { }
43
44 @Override
45 boolean needsPositionLock() {
46 return true;
47 }
48
49 int read(FileDescriptor fd, long address, int len)
50 throws IOException
51 {
52 return read0(fd, address, len);
53 }
54
55 int pread(FileDescriptor fd, long address, int len, long position)
56 throws IOException
57 {
58 return pread0(fd, address, len, position);
59 }
60
61 long readv(FileDescriptor fd, long address, int len) throws IOException {
62 return readv0(fd, address, len);
63 }
64
65 int write(FileDescriptor fd, long address, int len) throws IOException {
66 return write0(fd, address, len, fdAccess.getAppend(fd));
67 }
68
69 int pwrite(FileDescriptor fd, long address, int len, long position)
70 throws IOException
71 {
72 return pwrite0(fd, address, len, position);
73 }
74
75 long writev(FileDescriptor fd, long address, int len) throws IOException {
76 return writev0(fd, address, len, fdAccess.getAppend(fd));
77 }
78
79 int force(FileDescriptor fd, boolean metaData) throws IOException {
80 return force0(fd, metaData);
81 }
82
83 int truncate(FileDescriptor fd, long size) throws IOException {
84 return truncate0(fd, size);
85 }
86
87 int allocate(FileDescriptor fd, long size) throws IOException {
88 // truncate0() works for extending and truncating file size
89 return truncate0(fd, size);
90 }
91
92 long size(FileDescriptor fd) throws IOException {
93 return size0(fd);
94 }
95
96 int lock(FileDescriptor fd, boolean blocking, long pos, long size,
97 boolean shared) throws IOException
98 {
99 return lock0(fd, blocking, pos, size, shared);
100 }
101
102 void release(FileDescriptor fd, long pos, long size) throws IOException {
103 release0(fd, pos, size);
104 }
105
106 void close(FileDescriptor fd) throws IOException {
107 close0(fd);
108 }
109
110 FileDescriptor duplicateForMapping(FileDescriptor fd) throws IOException {
111 // on Windows we need to keep a handle to the file
112 FileDescriptor result = new FileDescriptor();
113 long handle = duplicateHandle(fdAccess.getHandle(fd));
114 fdAccess.setHandle(result, handle);
115 return result;
116 }
117
118 boolean canTransferToDirectly(java.nio.channels.SelectableChannel sc) {
119 return fastFileTransfer && sc.isBlocking();
120 }
121
122 boolean transferToDirectlyNeedsPositionLock() {
123 return true;
124 }
125
126 static boolean isFastFileTransferRequested() {
127 String fileTransferProp = GetPropertyAction
128 .privilegedGetProperty("jdk.nio.enableFastFileTransfer");
129 boolean enable;
130 if ("".equals(fileTransferProp)) {
131 enable = true;
132 } else {
133 enable = Boolean.parseBoolean(fileTransferProp);
134 }
135 return enable;
136 }
137
138 static {
139 IOUtil.load();
140 fastFileTransfer = isFastFileTransferRequested();
141 }
142
143 //-- Native methods
144
145 static native int read0(FileDescriptor fd, long address, int len)
146 throws IOException;
147
148 static native int pread0(FileDescriptor fd, long address, int len,
149 long position) throws IOException;
150
151 static native long readv0(FileDescriptor fd, long address, int len)
152 throws IOException;
153
154 static native int write0(FileDescriptor fd, long address, int len, boolean append)
155 throws IOException;
156
157 static native int pwrite0(FileDescriptor fd, long address, int len,
158 long position) throws IOException;
159
160 static native long writev0(FileDescriptor fd, long address, int len, boolean append)
161 throws IOException;
162
163 static native int force0(FileDescriptor fd, boolean metaData)
164 throws IOException;
165
166 static native int truncate0(FileDescriptor fd, long size)
167 throws IOException;
168
169 static native long size0(FileDescriptor fd) throws IOException;
170
171 static native int lock0(FileDescriptor fd, boolean blocking, long pos,
172 long size, boolean shared) throws IOException;
173
174 static native void release0(FileDescriptor fd, long pos, long size)
175 throws IOException;
176
177 static native void close0(FileDescriptor fd) throws IOException;
178
179 static native void closeByHandle(long fd) throws IOException;
180
181 static native long duplicateHandle(long fd) throws IOException;
182 }