Package org.eclipse.aether.internal.impl.synccontext.named

Class HashingNameMapper

  • All Implemented Interfaces:
    NameMapper
    public class HashingNameMapper
extends java.lang.Object
implements NameMapper
    Wrapping NameMapper, that wraps another NameMapper and hashes resulting strings. It makes use of fact that (proper) Hash will create unique fixed length string for each different input string (so injection still stands). This mapper produces file system friendly names. Supports different "depths" (0-4 inclusive) where the name will contain 0 to 4 level deep directories.

    This mapper is usable in any scenario, but intent was to produce more "compact" name mapper for file locking.

    Since:
    1.9.0

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String CONFIG_PROP_DEPTH
      The depth how many levels should adapter create.
      static int DEFAULT_DEPTH  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean isFileSystemFriendly()
      Returns true if lock names returned by this lock name mapper are file system friendly, can be used as file names and paths.
      java.util.Collection<org.eclipse.aether.named.NamedLockKey> nameLocks​(org.eclipse.aether.RepositorySystemSession session, java.util.Collection<? extends org.eclipse.aether.artifact.Artifact> artifacts, java.util.Collection<? extends org.eclipse.aether.metadata.Metadata> metadatas)
      Creates (opaque) names for passed in artifacts and metadata.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • isFileSystemFriendly

        public boolean isFileSystemFriendly()
        Description copied from interface: NameMapper
        Returns true if lock names returned by this lock name mapper are file system friendly, can be used as file names and paths.

        Note: The fact that name mapper is "file system friendly" means ONLY that names it produces CAN be used as file names and paths. Still, it does not mean they will work with ANY file based locking, as for example FileLockNamedLockFactory expects names as string encoded URIs. The only name mapper doing it is BasedirNameMapper.

        Specified by:
        isFileSystemFriendly in interface NameMapper

      • nameLocks

        public java.util.Collection<org.eclipse.aether.named.NamedLockKey> nameLocks​(org.eclipse.aether.RepositorySystemSession session,
                                                                             java.util.Collection<? extends org.eclipse.aether.artifact.Artifact> artifacts,
                                                                             java.util.Collection<? extends org.eclipse.aether.metadata.Metadata> metadatas)
        Description copied from interface: NameMapper
        Creates (opaque) names for passed in artifacts and metadata. Returned collection has max size of sum of the passed in artifacts and metadata collections, or less. If an empty collection is returned, there will be no locking happening. Never returns null. The resulting collection MUST BE "stable" (always sorted by same criteria) to avoid deadlocks by acquiring locks in same order, essentially disregarding the order of the input collections.

        There is no requirement of any kind of "parity" between input element count (sum of two collections, that is) and output collection size, just the returned upper size limit is defined (sum of the passed in two collections size). If returned collection is empty, no locking will happen, if single element, one lock will be used, if two then two named locks will be used etc.

        Note: name mapper must not use same string for artifacts and metadata, so even the simplest possible implementation like StaticNameMapper uses two different static strings.

        Specified by:
        nameLocks in interface NameMapper