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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * 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).
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package sun.nio.fs;

import sun.nio.cs.UTF_8;

import jdk.internal.util.StaticProperty;

import java.nio.file.*;
import java.nio.file.attribute.*;
import java.nio.channels.*;
import java.util.*;
import java.io.IOException;
import java.security.AccessController;
import java.security.PrivilegedAction;

Base implementation of FileStore for Unix/like implementations.
/** * Base implementation of FileStore for Unix/like implementations. */
abstract class UnixFileStore extends FileStore { // original path of file that identified file system private final UnixPath file; // device ID private final long dev; // entry in the mount tab private final UnixMountEntry entry; // return the device ID where the given file resides private static long devFor(UnixPath file) throws IOException { try { return UnixFileAttributes.get(file, true).dev(); } catch (UnixException x) { x.rethrowAsIOException(file); return 0L; // keep compiler happy } } UnixFileStore(UnixPath file) throws IOException { this.file = file; this.dev = devFor(file); this.entry = findMountEntry(); } UnixFileStore(UnixFileSystem fs, UnixMountEntry entry) throws IOException { this.file = new UnixPath(fs, entry.dir()); this.dev = (entry.dev() == 0L) ? devFor(this.file) : entry.dev(); this.entry = entry; }
Find the mount entry for the file store
/** * Find the mount entry for the file store */
abstract UnixMountEntry findMountEntry() throws IOException; UnixPath file() { return file; } long dev() { return dev; } UnixMountEntry entry() { return entry; } @Override public String name() { return entry.name(); } @Override public String type() { return entry.fstype(); } @Override public boolean isReadOnly() { return entry.isReadOnly(); } // uses statvfs to read the file system information private UnixFileStoreAttributes readAttributes() throws IOException { try { return UnixFileStoreAttributes.get(file); } catch (UnixException x) { x.rethrowAsIOException(file); return null; // keep compile happy } } @Override public long getTotalSpace() throws IOException { UnixFileStoreAttributes attrs = readAttributes(); try { return Math.multiplyExact(attrs.blockSize(), attrs.totalBlocks()); } catch (ArithmeticException ignore) { return Long.MAX_VALUE; } } @Override public long getUsableSpace() throws IOException { UnixFileStoreAttributes attrs = readAttributes(); try { return Math.multiplyExact(attrs.blockSize(), attrs.availableBlocks()); } catch (ArithmeticException ignore) { return Long.MAX_VALUE; } } @Override public long getUnallocatedSpace() throws IOException { UnixFileStoreAttributes attrs = readAttributes(); try { return Math.multiplyExact(attrs.blockSize(), attrs.freeBlocks()); } catch (ArithmeticException ignore) { return Long.MAX_VALUE; } } @Override public long getBlockSize() throws IOException { UnixFileStoreAttributes attrs = readAttributes(); return attrs.blockSize(); } @Override public <V extends FileStoreAttributeView> V getFileStoreAttributeView(Class<V> view) { if (view == null) throw new NullPointerException(); return (V) null; } @Override public Object getAttribute(String attribute) throws IOException { if (attribute.equals("totalSpace")) return getTotalSpace(); if (attribute.equals("usableSpace")) return getUsableSpace(); if (attribute.equals("unallocatedSpace")) return getUnallocatedSpace(); throw new UnsupportedOperationException("'" + attribute + "' not recognized"); } @Override public boolean supportsFileAttributeView(Class<? extends FileAttributeView> type) { if (type == null) throw new NullPointerException(); if (type == BasicFileAttributeView.class) return true; if (type == PosixFileAttributeView.class || type == FileOwnerAttributeView.class) { // lookup fstypes.properties FeatureStatus status = checkIfFeaturePresent("posix"); // assume supported if UNKNOWN return (status != FeatureStatus.NOT_PRESENT); } return false; } @Override public boolean supportsFileAttributeView(String name) { if (name.equals("basic") || name.equals("unix")) return true; if (name.equals("posix")) return supportsFileAttributeView(PosixFileAttributeView.class); if (name.equals("owner")) return supportsFileAttributeView(FileOwnerAttributeView.class); return false; } @Override public boolean equals(Object ob) { if (ob == this) return true; if (!(ob instanceof UnixFileStore)) return false; UnixFileStore other = (UnixFileStore)ob; return (this.dev == other.dev) && Arrays.equals(this.entry.dir(), other.entry.dir()) && this.entry.name().equals(other.entry.name()); } @Override public int hashCode() { return (int)(dev ^ (dev >>> 32)) ^ Arrays.hashCode(entry.dir()); } @Override public String toString() { StringBuilder sb = new StringBuilder(Util.toString(entry.dir())); sb.append(" ("); sb.append(entry.name()); sb.append(")"); return sb.toString(); } // -- fstypes.properties -- private static final Object loadLock = new Object(); private static volatile Properties props; enum FeatureStatus { PRESENT, NOT_PRESENT, UNKNOWN; }
Returns status to indicate if file system supports a given feature
/** * Returns status to indicate if file system supports a given feature */
FeatureStatus checkIfFeaturePresent(String feature) { if (props == null) { synchronized (loadLock) { if (props == null) { props = AccessController.doPrivileged( new PrivilegedAction<>() { @Override public Properties run() { return loadProperties(); }}); } } } String value = props.getProperty(type()); if (value != null) { String[] values = value.split("\\s"); for (String s: values) { s = s.trim().toLowerCase(); if (s.equals(feature)) { return FeatureStatus.PRESENT; } if (s.startsWith("no")) { s = s.substring(2); if (s.equals(feature)) { return FeatureStatus.NOT_PRESENT; } } } } return FeatureStatus.UNKNOWN; } private static Properties loadProperties() { Properties result = new Properties(); String fstypes = StaticProperty.javaHome() + "/lib/fstypes.properties"; Path file = Path.of(fstypes); try { try (ReadableByteChannel rbc = Files.newByteChannel(file)) { result.load(Channels.newReader(rbc, UTF_8.INSTANCE)); } } catch (IOException x) { } return result; } }