Package org.eclipse.jgit.util

Class FS.FileStoreAttributes

  • Enclosing class:
    FS
    public static final class FS.FileStoreAttributes
extends java.lang.Object
    Attributes of FileStores on this system
    Since:
    5.1.9

    • Field Detail

      • UNDEFINED_DURATION

        private static final java.time.Duration UNDEFINED_DURATION
        Marker to detect undefined values when reading from the config file.

      • FALLBACK_TIMESTAMP_RESOLUTION

        public static final java.time.Duration FALLBACK_TIMESTAMP_RESOLUTION
        Fallback filesystem timestamp resolution. The worst case timestamp resolution on FAT filesystems is 2 seconds.

        Must be at least 1 second.

      • FALLBACK_FILESTORE_ATTRIBUTES

        public static final FS.FileStoreAttributes FALLBACK_FILESTORE_ATTRIBUTES
        Fallback FileStore attributes used when we can't measure the filesystem timestamp resolution. The last modified time granularity of FAT filesystems is 2 seconds.

      • ONE_MICROSECOND

        private static final long ONE_MICROSECOND

      • ONE_MILLISECOND

        private static final long ONE_MILLISECOND

      • ONE_SECOND

        private static final long ONE_SECOND

      • MINIMUM_RESOLUTION_NANOS

        private static final long MINIMUM_RESOLUTION_NANOS
        Minimum file system timestamp resolution granularity to check, in nanoseconds. Should be a positive power of ten smaller than ONE_SECOND. Must be strictly greater than zero, i.e., minimum value is 1 nanosecond.

        Currently set to 1 microsecond, but could also be lower still.

      • JAVA_VERSION_PREFIX

        private static final java.lang.String JAVA_VERSION_PREFIX

      • FALLBACK_MIN_RACY_INTERVAL

        private static final java.time.Duration FALLBACK_MIN_RACY_INTERVAL

      • attributeCache

        private static final java.util.Map<java.nio.file.FileStore,​FS.FileStoreAttributes> attributeCache

      • background

        private static final java.util.concurrent.atomic.AtomicBoolean background

      • locks

        private static final java.util.Map<java.nio.file.FileStore,​java.util.concurrent.locks.Lock> locks

      • threadNumber

        private static final java.util.concurrent.atomic.AtomicInteger threadNumber

      • FUTURE_RUNNER

        private static final java.util.concurrent.Executor FUTURE_RUNNER
        Don't use the default thread factory of the ForkJoinPool for the CompletableFuture; it runs without any privileges, which causes trouble if a SecurityManager is present.

        Instead use normal daemon threads. They'll belong to the SecurityManager's thread group, or use the one of the calling thread, as appropriate.

        See Also:
        Executors.newCachedThreadPool()

      • SAVE_RUNNER

        private static final java.util.concurrent.Executor SAVE_RUNNER
        Use a separate executor with at most one thread to synchronize writing to the config. We write asynchronously since the config itself might be on a different file system, which might otherwise lead to locking problems.

        Writing the config must not use a daemon thread, otherwise we may leave an inconsistent state on disk when the JVM shuts down. Use a small keep-alive time to avoid delays on shut-down.

      • fsTimestampResolution

        @NonNull
private final java.time.Duration fsTimestampResolution

      • minimalRacyInterval

        private java.time.Duration minimalRacyInterval

    • Constructor Detail

      • FileStoreAttributes

        public FileStoreAttributes​(@NonNull
                           java.time.Duration fsTimestampResolution)
        Construct a FileStoreAttributeCache entry for the given filesystem timestamp resolution
        Parameters:
        fsTimestampResolution -

    • Method Detail

      • setBackground

        public static void setBackground​(boolean async)
        Whether FileStore attributes should be determined asynchronously
        Parameters:
        async - whether FileStore attributes should be determined asynchronously. If false access to cached attributes may block for some seconds for the first call per FileStore
        Since:
        5.6.2

      • configureAttributesPathCache

        public static void configureAttributesPathCache​(int maxSize,
                                                float purgeFactor)
        Configures size and purge factor of the path-based cache for file system attributes. Caching of file system attributes avoids recurring lookup of @{code FileStore} of files which may be expensive on some platforms.
        Parameters:
        maxSize - maximum size of the cache, default is 100
        purgeFactor - when the size of the map reaches maxSize the oldest entries will be purged to free up some space for new entries, purgeFactor is the fraction of maxSize to purge when this happens
        Since:
        5.1.9

      • get

        public static FS.FileStoreAttributes get​(java.nio.file.Path path)
        Get the FileStoreAttributes for the given FileStore
        Parameters:
        path - file residing in the FileStore to get attributes for
        Returns:
        FileStoreAttributes for the given path.

      • getFileStoreAttributes

        private static FS.FileStoreAttributes getFileStoreAttributes​(java.nio.file.Path dir)

      • measureMinimalRacyInterval

        private static java.time.Duration measureMinimalRacyInterval​(java.nio.file.Path dir)

      • write

        private static void write​(java.nio.file.Path p,
                          java.lang.String body)
                   throws java.io.IOException
        Throws:
        java.io.IOException

      • read

        private static java.lang.String read​(java.nio.file.Path p)
                              throws java.io.IOException
        Throws:
        java.io.IOException

      • measureFsTimestampResolution

        private static java.util.Optional<java.time.Duration> measureFsTimestampResolution​(java.nio.file.FileStore s,
                                                                                   java.nio.file.Path dir)

      • getFsResolution

        private static java.time.Duration getFsResolution​(java.nio.file.FileStore s,
                                                  java.nio.file.Path dir,
                                                  java.nio.file.Path probe)
                                           throws java.io.IOException
        Throws:
        java.io.IOException

      • measureClockResolution

        private static java.time.Duration measureClockResolution()

      • deleteProbe

        private static void deleteProbe​(java.nio.file.Path probe)

      • readFromConfig

        private static java.util.Optional<FS.FileStoreAttributes> readFromConfig​(java.nio.file.FileStore s)

      • getConfigKey

        private static java.lang.String getConfigKey​(java.nio.file.FileStore s)

      • getUnit

        private static java.util.concurrent.TimeUnit getUnit​(long nanos)

      • getMinimalRacyInterval

        public java.time.Duration getMinimalRacyInterval()
        Returns:
        the measured minimal interval after a file has been modified in which we cannot rely on lastModified to detect modifications

      • getFsTimestampResolution

        @NonNull
public java.time.Duration getFsTimestampResolution()
        Returns:
        the measured filesystem timestamp resolution

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object