Package org.apache.cayenne.access
Class IncrementalFaultList<E>
java.lang.Object
org.apache.cayenne.access.IncrementalFaultList<E>
- All Implemented Interfaces:
Serializable
,Iterable<E>
,Collection<E>
,List<E>
,SequencedCollection<E>
A synchronized list that serves as a container of Persistent objects. It is returned
when a paged query is performed by DataContext. On creation, only the first
"page" is fully resolved, for the rest of the objects only their ObjectIds
are read. Pages following the first page are resolved on demand only. On
access to an element, the list would ensure that this element as well as all
its siblings on the same page are fully resolved.
The list can hold DataRows or Persistent objects. Attempts to add any other object types will result in an exception.
Performance note: certain operations like toArray
would trigger
full list fetch.
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionprotected final DataContext
protected final List
protected final int
Stores a hint allowing to distinguish data rows from unfetched ids when the query fetches data rows.protected int
Defines the upper limit on the size of fetches.protected final QueryMetadata
protected final int
protected final ObjEntity
protected int
-
Method Summary
Modifier and TypeMethodDescriptionvoid
boolean
boolean
addAll
(int index, Collection<? extends E> c) boolean
addAll
(Collection<? extends E> c) void
clear()
boolean
boolean
containsAll
(Collection<?> c) void
Sets initial data (i.e.protected void
Deprecated, for removal: This API element is subject to removal in a future version.since 5.0, does nothingget
(int index) Returns the dataContext.int
Get the upper bound on the number of records to resolve in one round trip to the database.int
Returns the pageSize.int
Returns a total number of objects that are not resolved yet.int
boolean
isEmpty()
iterator()
Return an iterator for this list.int
Returns a list iterator for this list.listIterator
(int index) Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list.int
pageIndex
(int elementIndex) Returns zero-based index of the virtual "page" for a given array element index.remove
(int index) boolean
boolean
removeAll
(Collection<?> c) void
Will resolve all unread objects.protected void
resolveInterval
(int fromIndex, int toIndex) Resolves a sublist of objects starting atfromIndex
up to but not includingtoIndex
.boolean
retainAll
(Collection<?> c) void
setMaxFetchSize
(int fetchSize) int
size()
subList
(int fromIndex, int toIndex) Object[]
toArray()
<T> T[]
toArray
(T[] a) Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream, toArray
Methods inherited from interface java.util.List
addFirst, addLast, equals, getFirst, getLast, hashCode, removeFirst, removeLast, replaceAll, reversed, sort, spliterator
-
Field Details
-
pageSize
protected final int pageSize -
elements
-
dataContext
-
rootEntity
-
unfetchedObjects
protected volatile int unfetchedObjects -
idWidth
protected final int idWidthStores a hint allowing to distinguish data rows from unfetched ids when the query fetches data rows. -
metadata
-
maxFetchSize
protected int maxFetchSizeDefines the upper limit on the size of fetches. This is needed to avoid where clause size limitations.
-
-
Method Details
-
fillIn
@Deprecated(since="5.0", forRemoval=true) protected void fillIn(Query query, List<Object> elementsList) Deprecated, for removal: This API element is subject to removal in a future version.since 5.0, does nothingPerforms initialization of the list of objects. Only the first page is fully resolved. For the rest of the list, only ObjectIds are read.- Since:
- 3.0
-
fillIn
Sets initial data (i.e. list of ObjectIds) for this FaultList- Parameters:
elementsList
- initial data to fill this list with- Since:
- 5.0
-
resolveAll
public void resolveAll()Will resolve all unread objects. -
resolveInterval
protected void resolveInterval(int fromIndex, int toIndex) Resolves a sublist of objects starting atfromIndex
up to but not includingtoIndex
. Internally performs bound checking and trims indexes accordingly. -
pageIndex
public int pageIndex(int elementIndex) Returns zero-based index of the virtual "page" for a given array element index. -
getMaxFetchSize
public int getMaxFetchSize()Get the upper bound on the number of records to resolve in one round trip to the database. This setting governs the size/complexity of the where clause generated to retrieve the next page of records. If the fetch size is less than the page size, then multiple fetches will be made to resolve a page. -
setMaxFetchSize
public void setMaxFetchSize(int fetchSize) -
getDataContext
Returns the dataContext.- Returns:
- DataContext
-
getPageSize
public int getPageSize()Returns the pageSize.- Returns:
- int
-
listIterator
Returns a list iterator for this list. Persistent objects are resolved a page (according to getPageSize()) at a time as necessary - when retrieved with next() or previous().- Specified by:
listIterator
in interfaceList<E>
-
listIterator
Returns a list iterator of the elements in this list (in proper sequence), starting at the specified position in this list. The specified index indicates the first element that would be returned by an initial call to the next method. An initial call to the previous method would return the element with the specified index minus one. Persistent objects are resolved a page at a time (according to getPageSize()) as necessary - when retrieved with next() or previous().- Specified by:
listIterator
in interfaceList<E>
-
iterator
Return an iterator for this list. Persistent objects are resolved a page (according to getPageSize()) at a time as necessary - when retrieved with next(). -
add
-
add
-
addAll
-
addAll
-
clear
public void clear() -
contains
-
containsAll
- Specified by:
containsAll
in interfaceCollection<E>
- Specified by:
containsAll
in interfaceList<E>
- See Also:
-
get
-
indexOf
-
isEmpty
public boolean isEmpty() -
lastIndexOf
- Specified by:
lastIndexOf
in interfaceList<E>
-
remove
-
remove
-
removeAll
-
retainAll
-
set
-
size
public int size() -
subList
-
toArray
-
toArray
public <T> T[] toArray(T[] a) -
getUnfetchedObjects
public int getUnfetchedObjects()Returns a total number of objects that are not resolved yet.
-