com.opendatagroup.hadrian.shared
Returns the item with a given name at substructure path if it exists or an exception if there are any errors.
Returns the item with a given name at substructure path if it exists or an exception if there are any errors.
Blocks during initialization, but never afterward. If a put, update, or remove is in progress, get returns the old version of the item; it does not wait for a new version to be provided.
name of the object to extract (could be a cell or an item of a pool)
sequence of array indexes, map keys, and record field names to extract
a tagged union (Scala Either) of Left(exception object) or Right(result at the end of the path)
Replaces or adds an item with a given name at substructure path, returning value if there are no errors or an exception otherwise.
Replaces or adds an item with a given name at substructure path, returning value if there are no errors or an exception otherwise.
Blocks during initialization and during any other update (put, update, or remove). Blocking is at the granularity of a particular item: if another item (with another name) is being updated, this function does not wait.
put is a special case of update in which initialValue is value and updator is a function that ignores the input and returns value.
name of the object to replace (could be a cell or an item of a pool)
sequence of array indexes, map keys, and record field names to dig down to before replacing
a tagged union (Scala Either) of Left(exception object) or Right(new value at the end of the path)
Removes an item with a given name.
Removes an item with a given name.
Blocks during initialization and during any other update (put, update, or remove). Blocking is at the granularity of a particular item: if another item (with another name) is being updated, this function does not wait.
name of the object to replace (could be a cell or an item of a pool)
old value
Block updates and return a snapshot of the SharedMap at a point in time.
Replaces or adds an item with a given name at substructure path with an updator function (if it exists) or an initialValue (if it does not), returning the new value if there are no errors or an exception otherwise.
Replaces or adds an item with a given name at substructure path with an updator function (if it exists) or an initialValue (if it does not), returning the new value if there are no errors or an exception otherwise.
Blocks during initialization and during any other update (put, update, or remove). Blocking is at the granularity of a particular item: if another item (with another name) is being updated, this function does not wait.
name of the object to replace (could be a cell or an item of a pool)
sequence of array indexes, map keys, and record field names to dig down to before replacing
value to use it the object does not yet exist
function to apply to an existing object to get a new value
a tagged union (Scala Either) of Left(exception object) or Right(new value at the end of the path)
Methods like get, put, etc.
Methods like get, put, etc. should wait for initialize to finish. Concrete implementations should call blockUntilInitialized first to ensure that the SharedMap is past the initialization stage.
The first time a SharedMap is built, it may need to set up many names at once and ensure that all of these names are installed before any further access.
The first time a SharedMap is built, it may need to set up many names at once and ensure that all of these names are installed before any further access. This function provides a way to do that.
initialize only takes effect the first time it is called. After that, it is strictly pass-through.
An abstract class for shared memory whose update granularity is one item in the map.
Make subclasses of this class for sharing data in different circumstances, such as data shared among JVM processes or among compute nodes in a network, using databases, etc.
The
SharedState/SharedMappolicy is:initializefirst, and all other methods block untilinitializeis done.getnever blocks (afterinitializeis done), returning whatever version of an item is available when it is called. (Aput,update, orremovemight be in progress, butgetdoes not wait for the new version.)putreplaces one item in the map with a prefabricated alternative, blocking if that item is being modified (put,update, orremove) by another thread.putdoes not block if other items in the map are being modified. If apathis provided, theputonly changes a part of the item, but the whole item blocks.updatereplaces one item in the map with anupdatorfunction, which transforms an old value into a new value. The same blocking rules apply as forput, including apathfor modifying substructures. A prefabricatedinitialValuemust be provided in casenamedoes not yet exist in the map: theinitialValueis inserted, rather than evaluating theupdatorfunction.removeremoves one item from the map, following the same blocking rules asput.