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

Class DiscriminatingNameMapper

java.lang.Object

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

All Implemented Interfaces:

NameMapper

public class DiscriminatingNameMapper
extends java.lang.Object
implements NameMapper

Wrapping NameMapper, that wraps another NameMapper and adds a "discriminator" as prefix, that makes lock names unique including the hostname and local repository (by default). The discriminator may be passed in via RepositorySystemSession or is automatically calculated based on the local hostname and repository path. The implementation retains order of collection elements as it got it from NameMapper.nameLocks(RepositorySystemSession, Collection, Collection) method.

The default setup wraps GAVNameMapper, but manually may be created any instance needed.

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	CONFIG_PROP_DISCRIMINATOR	Configuration property to pass in discriminator, if needed.
static java.lang.String	CONFIG_PROP_HOSTNAME	Configuration property to pass in hostname, if needed.

Constructor Summary

Constructors

Constructor	Description
DiscriminatingNameMapper(NameMapper delegate)

Method Summary

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

Field Detail

CONFIG_PROP_DISCRIMINATOR

public static final java.lang.String CONFIG_PROP_DISCRIMINATOR

Configuration property to pass in discriminator, if needed. If not present, it is auto-calculated.

Since:

1.7.0

See Also:

Constant Field Values

CONFIG_PROP_HOSTNAME

public static final java.lang.String CONFIG_PROP_HOSTNAME

Configuration property to pass in hostname, if needed. If not present, hostname as reported by system will be used.

Since:

1.7.0

See Also:

Constant Field Values

Constructor Detail

DiscriminatingNameMapper

public DiscriminatingNameMapper(NameMapper delegate)

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