src/main/java/com/google/devtools/build/lib/windows/WindowsFileSystem.java - bazel - Git at Google

 // Copyright 2016 The Bazel Authors. All rights reserved.
 //
 // Licensed 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 com.google.devtools.build.lib.windows;

 import com.google.common.annotations.VisibleForTesting;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.profiler.Profiler;
 import com.google.devtools.build.lib.profiler.ProfilerTask;
 import com.google.devtools.build.lib.util.StringEncoding;
 import com.google.devtools.build.lib.vfs.DigestHashFunction;
 import com.google.devtools.build.lib.vfs.FileStatus;
 import com.google.devtools.build.lib.vfs.JavaIoFileSystem;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.SymlinkTargetType;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.AccessDeniedException;
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.nio.file.LinkOption;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.attribute.DosFileAttributes;
 import javax.annotation.Nullable;

 /** File system implementation for Windows. */
 @ThreadSafe
 public class WindowsFileSystem extends JavaIoFileSystem {

   public static final LinkOption[] NO_OPTIONS = new LinkOption[0];
   public static final LinkOption[] NO_FOLLOW = new LinkOption[] {LinkOption.NOFOLLOW_LINKS};

   private final boolean createSymbolicLinks;

   public WindowsFileSystem(DigestHashFunction hashFunction, boolean createSymbolicLinks) {
     super(hashFunction);
     this.createSymbolicLinks = createSymbolicLinks;
   }

   @Override
   public String getFileSystemType(PathFragment path) {
     // TODO(laszlocsomor): implement this properly, i.e. actually query this information from
     // somewhere (java.nio.Filesystem? System.getProperty? implement JNI method and use WinAPI?).
     return "ntfs";
   }

   @Override
   public boolean delete(PathFragment path) throws IOException {
     long startTime = Profiler.nanoTimeMaybe();
     try {
       return WindowsFileOperations.deletePath(
           StringEncoding.internalToPlatform(path.getPathString()));
     } catch (java.nio.file.DirectoryNotEmptyException e) {
       throw new IOException(path.getPathString() + ERR_DIRECTORY_NOT_EMPTY, e);
     } catch (java.nio.file.AccessDeniedException e) {
       throw new IOException(path.getPathString() + ERR_PERMISSION_DENIED, e);
     } finally {
       profiler.logSimpleTask(startTime, ProfilerTask.VFS_DELETE, path.getPathString());
     }
   }

   @Override
   public boolean createWritableDirectory(PathFragment path) throws IOException {
     // All directories are writable on Windows.
     return createDirectory(path);
   }

   @Override
   public void createSymbolicLink(
       PathFragment linkPath, PathFragment targetFragment, SymlinkTargetType type)
       throws IOException {
     PathFragment targetPath =
         targetFragment.isAbsolute()
             ? targetFragment
             : linkPath.getParentDirectory().getRelative(targetFragment);

     FileStatus stat = statIfFound(targetPath, /* followSymlinks= */ true);
     boolean existingFile = stat != null && stat.isFile();
     boolean existingDirectory = stat != null && stat.isDirectory();

     try {
       File link = getIoFile(linkPath);
       File target = getIoFile(targetPath);

       if (!createSymbolicLinks && existingFile) {
         // If symlinks aren't enabled and the target is an existing file, fall back to a copy.
         Files.copy(target.toPath(), link.toPath());
       } else if (createSymbolicLinks
           && (existingFile || (!existingDirectory && type != SymlinkTargetType.DIRECTORY))) {
         // If symlinks are enabled and the target is not an existing or future directory, create a
         // symlink.
         WindowsFileOperations.createSymlink(link.toString(), target.toString());
       } else {
         // Otherwise, create a junction.
         WindowsFileOperations.createJunction(link.toString(), target.toString());
       }
     } catch (FileAlreadyExistsException e) {
       throw new IOException(linkPath + ERR_FILE_EXISTS, e);
     } catch (AccessDeniedException e) {
       throw new IOException(linkPath + ERR_PERMISSION_DENIED, e);
     } catch (NoSuchFileException e) {
       throw new FileNotFoundException(linkPath + ERR_NO_SUCH_FILE_OR_DIR);
     }
   }

   @Override
   public PathFragment readSymbolicLink(PathFragment path) throws IOException {
     java.nio.file.Path nioPath = getNioPath(path);
     return PathFragment.create(
         StringEncoding.platformToInternal(
             WindowsFileOperations.readSymlinkOrJunction(nioPath.toString())));
   }

   @Override
   public boolean supportsSymbolicLinksNatively(PathFragment path) {
     return false;
   }

   @Override
   public boolean isFilePathCaseSensitive() {
     return false;
   }

   @Override
   protected boolean fileIsSymbolicLink(File file) {
     try {
       if (isSymlinkOrJunction(file)) {
         return true;
       }
     } catch (IOException e) {
       // Did not work, try in another way
     }
     return super.fileIsSymbolicLink(file);
   }

   public static LinkOption[] symlinkOpts(boolean followSymlinks) {
     return followSymlinks ? NO_OPTIONS : NO_FOLLOW;
   }

   @Override
   public FileStatus stat(PathFragment path, boolean followSymlinks) throws IOException {
     File file = getIoFile(path);
     final DosFileAttributes attributes;
     try {
       attributes = getAttribs(file, followSymlinks);
     } catch (IOException e) {
       throw new FileNotFoundException(path + ERR_NO_SUCH_FILE_OR_DIR);
     }

     FileStatus status =
         new FileStatus() {
           @Nullable volatile Boolean isSymbolicLink; // null if not yet known
           volatile long lastChangeTime = -1;

           @Override
           public boolean isFile() {
             return !isSymbolicLink() && (attributes.isRegularFile() || isSpecialFile());
           }

           @Override
           public boolean isSpecialFile() {
             // attributes.isOther() returns false for symlinks but returns true for junctions.
             // Bazel treats junctions like symlinks. So let's return false here for junctions.
             // This fixes https://github.com/bazelbuild/bazel/issues/9176
             return !isSymbolicLink() && attributes.isOther();
           }

           @Override
           public boolean isDirectory() {
             return !isSymbolicLink() && attributes.isDirectory();
           }

           @Override
           public boolean isSymbolicLink() {
             if (isSymbolicLink == null) {
               isSymbolicLink = !followSymlinks && fileIsSymbolicLink(file);
             }
             return isSymbolicLink;
           }

           @Override
           public long getSize() {
             return attributes.size();
           }

           @Override
           public long getLastModifiedTime() {
             return attributes.lastModifiedTime().toMillis();
           }

           @Override
           public long getLastChangeTime() throws IOException {
             if (lastChangeTime == -1) {
               lastChangeTime =
                   WindowsFileOperations.getLastChangeTime(
                       getNioPath(path).toString(), followSymlinks);
             }
             return lastChangeTime;
           }

           @Override
           public long getNodeId() {
             // TODO(bazel-team): Consider making use of attributes.fileKey().
             return -1;
           }

           @Override
           public int getPermissions() {
             // Files on Windows are implicitly readable and executable.
             return 0555 | (attributes.isReadOnly() ? 0 : 0200);
           }
         };

     return status;
   }

   @Override
   public boolean isSymbolicLink(PathFragment path) {
     return fileIsSymbolicLink(getIoFile(path));
   }

   @Override
   public boolean isDirectory(PathFragment path, boolean followSymlinks) {
     if (!followSymlinks) {
       try {
         if (isSymlinkOrJunction(getIoFile(path))) {
           return false;
         }
       } catch (IOException e) {
         return false;
       }
     }
     return super.isDirectory(path, followSymlinks);
   }

   @Override
   public void setReadable(PathFragment path, boolean readable) {
     // Windows does not have a notion of readable files.
     // https://github.com/openjdk/jdk/blob/e52a2aeeacaeb26c801b6e31f8e67e61b1ea2de3/src/java.base/windows/native/libjava/WinNTFileSystem_md.c#L473-L476
   }

   @Override
   public void setExecutable(PathFragment path, boolean executable) {
     // Windows does not have a notion of executable files.
     // https://github.com/openjdk/jdk/blob/e52a2aeeacaeb26c801b6e31f8e67e61b1ea2de3/src/java.base/windows/native/libjava/WinNTFileSystem_md.c#L473-L476
   }

   @Override
   public void setWritable(PathFragment path, boolean writable) throws IOException {
     // Windows does not have a notion of read-only directories.
     // See https://learn.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants.
     // JavaIoFileSystem#setWritable(dir, true) would throw, so reimplement it here as a no-op.
     if (isDirectory(path, /* followSymlinks= */ true)) {
       return;
     }
     super.setWritable(path, writable);
   }

   /**
    * Returns true if the path refers to a directory junction, directory symlink, or regular symlink.
    *
    * <p>Directory junctions are symbolic links created with "mklink /J" where the target is a
    * directory or another directory junction. Directory junctions can be created without any user
    * privileges.
    *
    * <p>Directory symlinks are symbolic links created with "mklink /D" where the target is a
    * directory or another directory symlink. Note that directory symlinks can only be created by
    * Administrators.
    *
    * <p>Normal symlinks are symbolic links created with "mklink". Normal symlinks should not point
    * at directories, because even though "mklink" can create the link, it will not be a functional
    * one (the linked directory's contents cannot be listed). Only Administrators may create regular
    * symlinks.
    *
    * <p>This method returns true for all three types as long as their target is a directory (even if
    * they are dangling), though only directory junctions and directory symlinks are useful.
    */
   @VisibleForTesting
   static boolean isSymlinkOrJunction(File file) throws IOException {
     return WindowsFileOperations.isSymlinkOrJunction(file.getPath());
   }

   private static DosFileAttributes getAttribs(File file, boolean followSymlinks)
       throws IOException {
     return Files.readAttributes(
         file.toPath(), DosFileAttributes.class, symlinkOpts(followSymlinks));
   }
 }
	// Copyright 2016 The Bazel Authors. All rights reserved.
	//
	// Licensed 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 com.google.devtools.build.lib.windows;

	import com.google.common.annotations.VisibleForTesting;
	import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
	import com.google.devtools.build.lib.profiler.Profiler;
	import com.google.devtools.build.lib.profiler.ProfilerTask;
	import com.google.devtools.build.lib.util.StringEncoding;
	import com.google.devtools.build.lib.vfs.DigestHashFunction;
	import com.google.devtools.build.lib.vfs.FileStatus;
	import com.google.devtools.build.lib.vfs.JavaIoFileSystem;
	import com.google.devtools.build.lib.vfs.PathFragment;
	import com.google.devtools.build.lib.vfs.SymlinkTargetType;
	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.nio.file.AccessDeniedException;
	import java.nio.file.FileAlreadyExistsException;
	import java.nio.file.Files;
	import java.nio.file.LinkOption;
	import java.nio.file.NoSuchFileException;
	import java.nio.file.attribute.DosFileAttributes;
	import javax.annotation.Nullable;

	/** File system implementation for Windows. */
	@ThreadSafe
	public class WindowsFileSystem extends JavaIoFileSystem {

	public static final LinkOption[] NO_OPTIONS = new LinkOption[0];
	public static final LinkOption[] NO_FOLLOW = new LinkOption[] {LinkOption.NOFOLLOW_LINKS};

	private final boolean createSymbolicLinks;

	public WindowsFileSystem(DigestHashFunction hashFunction, boolean createSymbolicLinks) {
	super(hashFunction);
	this.createSymbolicLinks = createSymbolicLinks;
	}

	@Override
	public String getFileSystemType(PathFragment path) {
	// TODO(laszlocsomor): implement this properly, i.e. actually query this information from
	// somewhere (java.nio.Filesystem? System.getProperty? implement JNI method and use WinAPI?).
	return "ntfs";
	}

	@Override
	public boolean delete(PathFragment path) throws IOException {
	long startTime = Profiler.nanoTimeMaybe();
	try {
	return WindowsFileOperations.deletePath(
	StringEncoding.internalToPlatform(path.getPathString()));
	} catch (java.nio.file.DirectoryNotEmptyException e) {
	throw new IOException(path.getPathString() + ERR_DIRECTORY_NOT_EMPTY, e);
	} catch (java.nio.file.AccessDeniedException e) {
	throw new IOException(path.getPathString() + ERR_PERMISSION_DENIED, e);
	} finally {
	profiler.logSimpleTask(startTime, ProfilerTask.VFS_DELETE, path.getPathString());
	}
	}

	@Override
	public boolean createWritableDirectory(PathFragment path) throws IOException {
	// All directories are writable on Windows.
	return createDirectory(path);
	}

	@Override
	public void createSymbolicLink(
	PathFragment linkPath, PathFragment targetFragment, SymlinkTargetType type)
	throws IOException {
	PathFragment targetPath =
	targetFragment.isAbsolute()
	? targetFragment
	: linkPath.getParentDirectory().getRelative(targetFragment);

	FileStatus stat = statIfFound(targetPath, /* followSymlinks= */ true);
	boolean existingFile = stat != null && stat.isFile();
	boolean existingDirectory = stat != null && stat.isDirectory();

	try {
	File link = getIoFile(linkPath);
	File target = getIoFile(targetPath);

	if (!createSymbolicLinks && existingFile) {
	// If symlinks aren't enabled and the target is an existing file, fall back to a copy.
	Files.copy(target.toPath(), link.toPath());
	} else if (createSymbolicLinks
	&& (existingFile \|\| (!existingDirectory && type != SymlinkTargetType.DIRECTORY))) {
	// If symlinks are enabled and the target is not an existing or future directory, create a
	// symlink.
	WindowsFileOperations.createSymlink(link.toString(), target.toString());
	} else {
	// Otherwise, create a junction.
	WindowsFileOperations.createJunction(link.toString(), target.toString());
	}
	} catch (FileAlreadyExistsException e) {
	throw new IOException(linkPath + ERR_FILE_EXISTS, e);
	} catch (AccessDeniedException e) {
	throw new IOException(linkPath + ERR_PERMISSION_DENIED, e);
	} catch (NoSuchFileException e) {
	throw new FileNotFoundException(linkPath + ERR_NO_SUCH_FILE_OR_DIR);
	}
	}

	@Override
	public PathFragment readSymbolicLink(PathFragment path) throws IOException {
	java.nio.file.Path nioPath = getNioPath(path);
	return PathFragment.create(
	StringEncoding.platformToInternal(
	WindowsFileOperations.readSymlinkOrJunction(nioPath.toString())));
	}

	@Override
	public boolean supportsSymbolicLinksNatively(PathFragment path) {
	return false;
	}

	@Override
	public boolean isFilePathCaseSensitive() {
	return false;
	}

	@Override
	protected boolean fileIsSymbolicLink(File file) {
	try {
	if (isSymlinkOrJunction(file)) {
	return true;
	}
	} catch (IOException e) {
	// Did not work, try in another way
	}
	return super.fileIsSymbolicLink(file);
	}

	public static LinkOption[] symlinkOpts(boolean followSymlinks) {
	return followSymlinks ? NO_OPTIONS : NO_FOLLOW;
	}

	@Override
	public FileStatus stat(PathFragment path, boolean followSymlinks) throws IOException {
	File file = getIoFile(path);
	final DosFileAttributes attributes;
	try {
	attributes = getAttribs(file, followSymlinks);
	} catch (IOException e) {
	throw new FileNotFoundException(path + ERR_NO_SUCH_FILE_OR_DIR);
	}

	FileStatus status =
	new FileStatus() {
	@Nullable volatile Boolean isSymbolicLink; // null if not yet known
	volatile long lastChangeTime = -1;

	@Override
	public boolean isFile() {
	return !isSymbolicLink() && (attributes.isRegularFile() \|\| isSpecialFile());
	}

	@Override
	public boolean isSpecialFile() {
	// attributes.isOther() returns false for symlinks but returns true for junctions.
	// Bazel treats junctions like symlinks. So let's return false here for junctions.
	// This fixes https://github.com/bazelbuild/bazel/issues/9176
	return !isSymbolicLink() && attributes.isOther();
	}

	@Override
	public boolean isDirectory() {
	return !isSymbolicLink() && attributes.isDirectory();
	}

	@Override
	public boolean isSymbolicLink() {
	if (isSymbolicLink == null) {
	isSymbolicLink = !followSymlinks && fileIsSymbolicLink(file);
	}
	return isSymbolicLink;
	}

	@Override
	public long getSize() {
	return attributes.size();
	}

	@Override
	public long getLastModifiedTime() {
	return attributes.lastModifiedTime().toMillis();
	}

	@Override
	public long getLastChangeTime() throws IOException {
	if (lastChangeTime == -1) {
	lastChangeTime =
	WindowsFileOperations.getLastChangeTime(
	getNioPath(path).toString(), followSymlinks);
	}
	return lastChangeTime;
	}

	@Override
	public long getNodeId() {
	// TODO(bazel-team): Consider making use of attributes.fileKey().
	return -1;
	}

	@Override
	public int getPermissions() {
	// Files on Windows are implicitly readable and executable.
	return 0555 \| (attributes.isReadOnly() ? 0 : 0200);
	}
	};

	return status;
	}

	@Override
	public boolean isSymbolicLink(PathFragment path) {
	return fileIsSymbolicLink(getIoFile(path));
	}

	@Override
	public boolean isDirectory(PathFragment path, boolean followSymlinks) {
	if (!followSymlinks) {
	try {
	if (isSymlinkOrJunction(getIoFile(path))) {
	return false;
	}
	} catch (IOException e) {
	return false;
	}
	}
	return super.isDirectory(path, followSymlinks);
	}

	@Override
	public void setReadable(PathFragment path, boolean readable) {
	// Windows does not have a notion of readable files.
	// https://github.com/openjdk/jdk/blob/e52a2aeeacaeb26c801b6e31f8e67e61b1ea2de3/src/java.base/windows/native/libjava/WinNTFileSystem_md.c#L473-L476
	}

	@Override
	public void setExecutable(PathFragment path, boolean executable) {
	// Windows does not have a notion of executable files.
	// https://github.com/openjdk/jdk/blob/e52a2aeeacaeb26c801b6e31f8e67e61b1ea2de3/src/java.base/windows/native/libjava/WinNTFileSystem_md.c#L473-L476
	}

	@Override
	public void setWritable(PathFragment path, boolean writable) throws IOException {
	// Windows does not have a notion of read-only directories.
	// See https://learn.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants.
	// JavaIoFileSystem#setWritable(dir, true) would throw, so reimplement it here as a no-op.
	if (isDirectory(path, /* followSymlinks= */ true)) {
	return;
	}
	super.setWritable(path, writable);
	}

	/**
	* Returns true if the path refers to a directory junction, directory symlink, or regular symlink.
	*
	* <p>Directory junctions are symbolic links created with "mklink /J" where the target is a
	* directory or another directory junction. Directory junctions can be created without any user
	* privileges.
	*
	* <p>Directory symlinks are symbolic links created with "mklink /D" where the target is a
	* directory or another directory symlink. Note that directory symlinks can only be created by
	* Administrators.
	*
	* <p>Normal symlinks are symbolic links created with "mklink". Normal symlinks should not point
	* at directories, because even though "mklink" can create the link, it will not be a functional
	* one (the linked directory's contents cannot be listed). Only Administrators may create regular
	* symlinks.
	*
	* <p>This method returns true for all three types as long as their target is a directory (even if
	* they are dangling), though only directory junctions and directory symlinks are useful.
	*/
	@VisibleForTesting
	static boolean isSymlinkOrJunction(File file) throws IOException {
	return WindowsFileOperations.isSymlinkOrJunction(file.getPath());
	}

	private static DosFileAttributes getAttribs(File file, boolean followSymlinks)
	throws IOException {
	return Files.readAttributes(
	file.toPath(), DosFileAttributes.class, symlinkOpts(followSymlinks));
	}
	}