JDK14/Java14源码在线阅读
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.nio.fs;
import java.nio.file.*;
import java.nio.file.attribute.*;
import java.util.*;
import java.util.concurrent.TimeUnit;
import java.io.IOException;
import static sun.nio.fs.UnixNativeDispatcher.*;
class UnixFileAttributeViews {
static class Basic extends AbstractBasicFileAttributeView {
protected final UnixPath file;
protected final boolean followLinks;
Basic(UnixPath file, boolean followLinks) {
this.file = file;
this.followLinks = followLinks;
}
@Override
public BasicFileAttributes readAttributes() throws IOException {
file.checkRead();
try {
UnixFileAttributes attrs =
UnixFileAttributes.get(file, followLinks);
return attrs.asBasicFileAttributes();
} catch (UnixException x) {
x.rethrowAsIOException(file);
return null; // keep compiler happy
}
}
@Override
public void setTimes(FileTime lastModifiedTime,
FileTime lastAccessTime,
FileTime createTime) throws IOException
{
// null => don't change
if (lastModifiedTime == null && lastAccessTime == null) {
// no effect
return;
}
// permission check
file.checkWrite();
boolean haveFd = false;
boolean useFutimes = false;
boolean useFutimens = false;
boolean useLutimes = false;
int fd = -1;
try {
if (!followLinks) {
useLutimes = lutimesSupported() &&
UnixFileAttributes.get(file, false).isSymbolicLink();
}
if (!useLutimes) {
fd = file.openForAttributeAccess(followLinks);
if (fd != -1) {
haveFd = true;
if (!(useFutimens = futimensSupported())) {
useFutimes = futimesSupported();
}
}
}
} catch (UnixException x) {
if (!(x.errno() == UnixConstants.ENXIO ||
(x.errno() == UnixConstants.ELOOP && useLutimes))) {
x.rethrowAsIOException(file);
}
}
try {
// assert followLinks || !UnixFileAttributes.get(fd).isSymbolicLink();
// if not changing both attributes then need existing attributes
if (lastModifiedTime == null || lastAccessTime == null) {
try {
UnixFileAttributes attrs = haveFd ?
UnixFileAttributes.get(fd) :
UnixFileAttributes.get(file, followLinks);
if (lastModifiedTime == null)
lastModifiedTime = attrs.lastModifiedTime();
if (lastAccessTime == null)
lastAccessTime = attrs.lastAccessTime();
} catch (UnixException x) {
x.rethrowAsIOException(file);
}
}
// update times
TimeUnit timeUnit = useFutimens ?
TimeUnit.NANOSECONDS : TimeUnit.MICROSECONDS;
long modValue = lastModifiedTime.to(timeUnit);
long accessValue= lastAccessTime.to(timeUnit);
boolean retry = false;
try {
if (useFutimens) {
futimens(fd, accessValue, modValue);
} else if (useFutimes) {
futimes(fd, accessValue, modValue);
} else if (useLutimes) {
lutimes(file, accessValue, modValue);
} else {
utimes(file, accessValue, modValue);
}
} catch (UnixException x) {
// if futimes/utimes fails with EINVAL and one/both of the times is
// negative then we adjust the value to the epoch and retry.
if (x.errno() == UnixConstants.EINVAL &&
(modValue < 0L || accessValue < 0L)) {
retry = true;
} else {
x.rethrowAsIOException(file);
}
}
if (retry) {
if (modValue < 0L) modValue = 0L;
if (accessValue < 0L) accessValue= 0L;
try {
if (useFutimens) {
futimens(fd, accessValue, modValue);
} else if (useFutimes) {
futimes(fd, accessValue, modValue);
} else if (useLutimes) {
lutimes(file, accessValue, modValue);
} else {
utimes(file, accessValue, modValue);
}
} catch (UnixException x) {
x.rethrowAsIOException(file);
}
}
} finally {
close(fd);
}
}
}
private static class Posix extends Basic implements PosixFileAttributeView {
private static final String PERMISSIONS_NAME = "permissions";
private static final String OWNER_NAME = "owner";
private static final String GROUP_NAME = "group";
// the names of the posix attributes (includes basic)
static final Set<String> posixAttributeNames =
Util.newSet(basicAttributeNames, PERMISSIONS_NAME, OWNER_NAME, GROUP_NAME);
Posix(UnixPath file, boolean followLinks) {
super(file, followLinks);
}
final void checkReadExtended() {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
file.checkRead();
sm.checkPermission(new RuntimePermission("accessUserInformation"));
}
}
final void checkWriteExtended() {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
file.checkWrite();
sm.checkPermission(new RuntimePermission("accessUserInformation"));
}
}
@Override
public String name() {
return "posix";
}
@Override
@SuppressWarnings("unchecked")
public void setAttribute(String attribute, Object value)
throws IOException
{
if (attribute.equals(PERMISSIONS_NAME)) {
setPermissions((Set<PosixFilePermission>)value);
return;
}
if (attribute.equals(OWNER_NAME)) {
setOwner((UserPrincipal)value);
return;
}
if (attribute.equals(GROUP_NAME)) {
setGroup((GroupPrincipal)value);
return;
}
super.setAttribute(attribute, value);
}
/**
* Invoked by readAttributes or sub-classes to add all matching posix
* attributes to the builder
*/
final void addRequestedPosixAttributes(PosixFileAttributes attrs,
AttributesBuilder builder)
{
addRequestedBasicAttributes(attrs, builder);
if (builder.match(PERMISSIONS_NAME))
builder.add(PERMISSIONS_NAME, attrs.permissions());
if (builder.match(OWNER_NAME))
builder.add(OWNER_NAME, attrs.owner());
if (builder.match(GROUP_NAME))
builder.add(GROUP_NAME, attrs.group());
}
@Override
public Map<String,Object> readAttributes(String[] requested)
throws IOException
{
AttributesBuilder builder =
AttributesBuilder.create(posixAttributeNames, requested);
PosixFileAttributes attrs = readAttributes();
addRequestedPosixAttributes(attrs, builder);
return builder.unmodifiableMap();
}
@Override
public UnixFileAttributes readAttributes() throws IOException {
checkReadExtended();
try {
return UnixFileAttributes.get(file, followLinks);
} catch (UnixException x) {
x.rethrowAsIOException(file);
return null; // keep compiler happy
}
}
// chmod
final void setMode(int mode) throws IOException {
checkWriteExtended();
try {
if (followLinks) {
chmod(file, mode);
} else {
int fd = file.openForAttributeAccess(false);
try {
fchmod(fd, mode);
} finally {
close(fd);
}
}
} catch (UnixException x) {
x.rethrowAsIOException(file);
}
}
// chown
final void setOwners(int uid, int gid) throws IOException {
checkWriteExtended();
try {
if (followLinks) {
chown(file, uid, gid);
} else {
lchown(file, uid, gid);
}
} catch (UnixException x) {
x.rethrowAsIOException(file);
}
}
@Override
public void setPermissions(Set<PosixFilePermission> perms)
throws IOException
{
setMode(UnixFileModeAttribute.toUnixMode(perms));
}
@Override
public void setOwner(UserPrincipal owner)
throws IOException
{
if (owner == null)
throw new NullPointerException("'owner' is null");
if (!(owner instanceof UnixUserPrincipals.User))
throw new ProviderMismatchException();
if (owner instanceof UnixUserPrincipals.Group)
throw new IOException("'owner' parameter can't be a group");
int uid = ((UnixUserPrincipals.User)owner).uid();
setOwners(uid, -1);
}
@Override
public UserPrincipal getOwner() throws IOException {
return readAttributes().owner();
}
@Override
public void setGroup(GroupPrincipal group)
throws IOException
{
if (group == null)
throw new NullPointerException("'owner' is null");
if (!(group instanceof UnixUserPrincipals.Group))
throw new ProviderMismatchException();
int gid = ((UnixUserPrincipals.Group)group).gid();
setOwners(-1, gid);
}
}
private static class Unix extends Posix {
private static final String MODE_NAME = "mode";
private static final String INO_NAME = "ino";
private static final String DEV_NAME = "dev";
private static final String RDEV_NAME = "rdev";
private static final String NLINK_NAME = "nlink";
private static final String UID_NAME = "uid";
private static final String GID_NAME = "gid";
private static final String CTIME_NAME = "ctime";
// the names of the unix attributes (including posix)
static final Set<String> unixAttributeNames =
Util.newSet(posixAttributeNames,
MODE_NAME, INO_NAME, DEV_NAME, RDEV_NAME,
NLINK_NAME, UID_NAME, GID_NAME, CTIME_NAME);
Unix(UnixPath file, boolean followLinks) {
super(file, followLinks);
}
@Override
public String name() {
return "unix";
}
@Override
public void setAttribute(String attribute, Object value)
throws IOException
{
if (attribute.equals(MODE_NAME)) {
setMode((Integer)value);
return;
}
if (attribute.equals(UID_NAME)) {
setOwners((Integer)value, -1);
return;
}
if (attribute.equals(GID_NAME)) {
setOwners(-1, (Integer)value);
return;
}
super.setAttribute(attribute, value);
}
@Override
public Map<String,Object> readAttributes(String[] requested)
throws IOException
{
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