src/java.base/macosx/classes/sun/nio/fs/BsdFileAttributeViews.java - master - githubmirror/panama-vector

src/java.base/macosx/classes/sun/nio/fs/BsdFileAttributeViews.java
202 строки8 KB
Brian Burkhalter
8344078: Remove security manager dependency in java.nio
18 ноя 2024, 22:17
18 ноя 2024, 22:17922b12f
/*
 * Copyright (c) 2022, 2024, Oracle and/or its affiliates. All rights reserved.
 * 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.nio.fs;

import java.io.IOException;
import java.nio.file.attribute.FileTime;
import java.util.concurrent.TimeUnit;
import static sun.nio.fs.BsdNativeDispatcher.*;
import static sun.nio.fs.UnixConstants.ELOOP;
import static sun.nio.fs.UnixConstants.ENXIO;
import static sun.nio.fs.UnixNativeDispatcher.futimens;
import static sun.nio.fs.UnixNativeDispatcher.utimensat;

class BsdFileAttributeViews {
    //
    // Use the futimens(2)/utimensat(2) system calls to set the access and
    // modification times, and setattrlist(2) to set the creation time.
    //
    private static void setTimes(UnixPath path, FileTime lastModifiedTime,
                                 FileTime lastAccessTime, FileTime createTime,
                                 boolean followLinks) throws IOException
    {
        // null => don't change
        if (lastModifiedTime == null && lastAccessTime == null &&
            createTime == null) {
            // no effect
            return;
        }

        // use a file descriptor if possible to avoid a race due to accessing
        // a path more than once as the file at that path could change.
        // if path is a symlink, then the open should fail with ELOOP and
        // the path will be used instead of the file descriptor.
        int fd = -1;
        try {
            fd = path.openForAttributeAccess(followLinks);
        } catch (UnixException x) {
            if (!(x.errno() == ENXIO || (x.errno() == ELOOP))) {
                x.rethrowAsIOException(path);
            }
        }

        try {
            // not all volumes support setattrlist(2), so set the last
            // modified and last access times use futimens(2)/utimensat(2)
            if (lastModifiedTime != null || lastAccessTime != null) {
                // if not changing both attributes then need existing attributes
                if (lastModifiedTime == null || lastAccessTime == null) {
                    try {
                        UnixFileAttributes attrs = fd >= 0 ?
                            UnixFileAttributes.get(fd) :
                            UnixFileAttributes.get(path, followLinks);
                        if (lastModifiedTime == null)
                            lastModifiedTime = attrs.lastModifiedTime();
                        if (lastAccessTime == null)
                            lastAccessTime = attrs.lastAccessTime();
                    } catch (UnixException x) {
                        x.rethrowAsIOException(path);
                    }
                }

                // update times
                long modValue = lastModifiedTime.to(TimeUnit.NANOSECONDS);
                long accessValue= lastAccessTime.to(TimeUnit.NANOSECONDS);

                boolean retry = false;
                int flags = followLinks ? 0 : UnixConstants.AT_SYMLINK_NOFOLLOW;
                try {
                    if (fd >= 0)
                        futimens(fd, accessValue, modValue);
                    else
                        utimensat(UnixConstants.AT_FDCWD, path, accessValue,
                                  modValue, flags);
                } catch (UnixException x) {
                    // if futimens/utimensat 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(path);
                    }
                }
                if (retry) {
                    if (modValue < 0L) modValue = 0L;
                    if (accessValue < 0L) accessValue= 0L;
                    try {
                        if (fd >= 0)
                            futimens(fd, accessValue, modValue);
                        else
                            utimensat(UnixConstants.AT_FDCWD, path, accessValue,
                                      modValue, flags);
                    } catch (UnixException x) {
                        x.rethrowAsIOException(path);
                    }
                }
            }

            // set the creation time using setattrlist(2)
            if (createTime != null) {
                long createValue = createTime.to(TimeUnit.NANOSECONDS);
                int commonattr = UnixConstants.ATTR_CMN_CRTIME;
                try {
                    if (fd >= 0)
                        fsetattrlist(fd, commonattr, 0L, 0L, createValue,
                                     followLinks ? 0 : UnixConstants.FSOPT_NOFOLLOW);
                    else
                        setattrlist(path, commonattr, 0L, 0L, createValue,
                                    followLinks ? 0 : UnixConstants.FSOPT_NOFOLLOW);
                } catch (UnixException x) {
                    x.rethrowAsIOException(path);
                }
            }
        } finally {
            close(fd, e -> null);
        }
    }

    static class Basic extends UnixFileAttributeViews.Basic {
        Basic(UnixPath file, boolean followLinks) {
            super(file, followLinks);
        }

        @Override
        public void setTimes(FileTime lastModifiedTime,
                             FileTime lastAccessTime,
                             FileTime createTime) throws IOException
        {
            BsdFileAttributeViews.setTimes(file, lastModifiedTime,
                                           lastAccessTime, createTime,
                                           followLinks);
        }
    }

    static class Posix extends UnixFileAttributeViews.Posix {
        Posix(UnixPath file, boolean followLinks) {
            super(file, followLinks);
        }

        @Override
        public void setTimes(FileTime lastModifiedTime,
                             FileTime lastAccessTime,
                             FileTime createTime) throws IOException
        {
            BsdFileAttributeViews.setTimes(file, lastModifiedTime,
                                           lastAccessTime, createTime,
                                           followLinks);
        }
    }

    static class Unix extends UnixFileAttributeViews.Unix {
        Unix(UnixPath file, boolean followLinks) {
            super(file, followLinks);
        }

        @Override
        public void setTimes(FileTime lastModifiedTime,
                             FileTime lastAccessTime,
                             FileTime createTime) throws IOException
        {
            BsdFileAttributeViews.setTimes(file, lastModifiedTime,
                                           lastAccessTime, createTime,
                                           followLinks);
        }
    }

    static Basic createBasicView(UnixPath file, boolean followLinks) {
        return new Basic(file, followLinks);
    }

    static Posix createPosixView(UnixPath file, boolean followLinks) {
        return new Posix(file, followLinks);
    }

    static Unix createUnixView(UnixPath file, boolean followLinks) {
        return new Unix(file, followLinks);
    }
}