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/*
 * Copyright 2017-2019 ObjectBox Ltd. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.objectbox;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Callable;

import javax.annotation.Nullable;
import javax.annotation.concurrent.ThreadSafe;

import io.objectbox.annotation.Backlink;
import io.objectbox.annotation.Id;
import io.objectbox.annotation.apihint.Beta;
import io.objectbox.annotation.apihint.Experimental;
import io.objectbox.annotation.apihint.Internal;
import io.objectbox.exception.DbException;
import io.objectbox.internal.CallWithHandle;
import io.objectbox.internal.IdGetter;
import io.objectbox.internal.ReflectionCache;
import io.objectbox.query.QueryBuilder;
import io.objectbox.query.QueryCondition;
import io.objectbox.relation.RelationInfo;
import io.objectbox.relation.ToMany;
import io.objectbox.relation.ToOne;

/**
 * A Box to put and get Objects of a specific Entity class.
 * 

* Thread-safe. */ @ThreadSafe @SuppressWarnings("WeakerAccess,UnusedReturnValue,unused") public class Box { private final BoxStore store; private final Class entityClass; /** Set when running inside TX */ final ThreadLocal> activeTxCursor = new ThreadLocal<>(); private final ThreadLocal> threadLocalReader = new ThreadLocal<>(); private final IdGetter idGetter; private EntityInfo entityInfo; private volatile Field boxStoreField; Box(BoxStore store, Class entityClass) { this.store = store; this.entityClass = entityClass; idGetter = store.getEntityInfo(entityClass).getIdGetter(); } Cursor getReader() { Cursor cursor = getActiveTxCursor(); if (cursor != null) { return cursor; } else { cursor = threadLocalReader.get(); if (cursor != null) { Transaction tx = cursor.tx; if (tx.isClosed() || !tx.isRecycled()) { throw new IllegalStateException("Illegal reader TX state"); } tx.renew(); cursor.renew(); } else { cursor = store.beginReadTx().createCursor(entityClass); threadLocalReader.set(cursor); } } return cursor; } Cursor getActiveTxCursor() { Transaction activeTx = store.activeTx.get(); if (activeTx != null) { if (activeTx.isClosed()) { throw new IllegalStateException("Active TX is closed"); } Cursor cursor = activeTxCursor.get(); if (cursor == null || cursor.getTx().isClosed()) { cursor = activeTx.createCursor(entityClass); activeTxCursor.set(cursor); } return cursor; } return null; } Cursor getWriter() { Cursor cursor = getActiveTxCursor(); if (cursor != null) { return cursor; } else { Transaction tx = store.beginTx(); try { return tx.createCursor(entityClass); } catch (RuntimeException e) { tx.close(); throw e; } } } void commitWriter(Cursor cursor) { // NOP if TX is ongoing if (activeTxCursor.get() == null) { cursor.close(); cursor.getTx().commitAndClose(); } } void releaseWriter(Cursor cursor) { // NOP if TX is ongoing if (activeTxCursor.get() == null) { Transaction tx = cursor.getTx(); if (!tx.isClosed()) { cursor.close(); tx.abort(); tx.close(); } } } void releaseReader(Cursor cursor) { // NOP if TX is ongoing if (activeTxCursor.get() == null) { Transaction tx = cursor.getTx(); if (tx.isClosed() || tx.isRecycled() || !tx.isReadOnly()) { throw new IllegalStateException("Illegal reader TX state"); } tx.recycle(); } } /** * Like {@link BoxStore#closeThreadResources()}, but limited to only this Box. *

* Rule of thumb: prefer {@link BoxStore#closeThreadResources()} unless you know that your thread only interacted * with this Box. */ public void closeThreadResources() { Cursor cursor = threadLocalReader.get(); if (cursor != null) { cursor.close(); cursor.getTx().close(); // a read TX is always started when the threadLocalReader is set threadLocalReader.remove(); } } void txCommitted(Transaction tx) { // Thread local readers will be renewed on next get, so we do not need clean them up Cursor cursor = activeTxCursor.get(); if (cursor != null) { activeTxCursor.remove(); cursor.close(); } } /** * Called by {@link BoxStore#callInReadTx(Callable)} - does not throw so caller does not need try/finally. */ void readTxFinished(Transaction tx) { Cursor cursor = activeTxCursor.get(); if (cursor != null && cursor.getTx() == tx) { activeTxCursor.remove(); cursor.close(); } } /** Used by tests */ int getPropertyId(String propertyName) { Cursor reader = getReader(); try { return reader.getPropertyId(propertyName); } finally { releaseReader(reader); } } @Internal public long getId(T entity) { return idGetter.getId(entity); } /** * Get the stored object for the given ID. * * @return null if not found */ public T get(long id) { Cursor reader = getReader(); try { return reader.get(id); } finally { releaseReader(reader); } } /** * Get the stored objects for the given IDs. * * @return null if not found */ public List get(Iterable ids) { ArrayList list = new ArrayList<>(); Cursor reader = getReader(); try { for (Long id : ids) { T entity = reader.get(id); if (entity != null) { list.add(entity); } } } finally { releaseReader(reader); } return list; } /** * Get the stored objects for the given IDs. * * @return null if not found */ public List get(long[] ids) { ArrayList list = new ArrayList<>(ids.length); Cursor reader = getReader(); try { for (Long id : ids) { T entity = reader.get(id); if (entity != null) { list.add(entity); } } } finally { releaseReader(reader); } return list; } /** * Get the stored objects for the given IDs as a Map with IDs as keys, and entities as values. * IDs for which no entity is found will be put in the map with null values. * * @return null if not found */ public Map getMap(Iterable ids) { HashMap map = new HashMap<>(); Cursor reader = getReader(); try { for (Long id : ids) { map.put(id, reader.get(id)); } } finally { releaseReader(reader); } return map; } /** * Returns the count of all stored objects in this box. */ public long count() { return count(0); } /** * Returns the count of all stored objects in this box or the given maxCount, whichever is lower. * * @param maxCount maximum value to count or 0 (zero) to have no maximum limit */ public long count(long maxCount) { Cursor reader = getReader(); try { return reader.count(maxCount); } finally { releaseReader(reader); } } /** Returns true if no objects are in this box. */ public boolean isEmpty() { return count(1) == 0; } /** * Returns all stored Objects in this Box. * * @return since 2.4 the returned list is always mutable (before an empty result list was immutable) */ public List getAll() { ArrayList list = new ArrayList<>(); Cursor cursor = getReader(); try { for (T object = cursor.first(); object != null; object = cursor.next()) { list.add(object); } return list; } finally { releaseReader(cursor); } } /** * Check if an object with the given ID exists in the database. * This is more efficient than a {@link #get(long)} and comparing against null. * * @return true if an object with the given ID was found, false otherwise. * @since 2.7 */ public boolean contains(long id) { Cursor reader = getReader(); try { return reader.seek(id); } finally { releaseReader(reader); } } /** * Puts the given object and returns its (new) ID. *

* This means that if its {@link Id @Id} property is 0 or null, it is inserted as a new object and assigned the next * available ID. For example, if there is an object with ID 1 and another with ID 100, it will be assigned ID 101. * The new ID is also set on the given object before this returns. *

* If instead the object has an assigned ID set, if an object with the same ID exists it is updated. Otherwise, it * is inserted with that ID. *

* If the ID was not assigned before an {@link IllegalArgumentException} is thrown. *

* When the object contains {@link ToOne} or {@link ToMany} relations, they are created (or updated) to point to the * (new) target objects. The target objects themselves are typically not updated or removed. To do so, put or remove * them using their {@link Box}. However, for convenience, if a target object is new, it will be inserted and * assigned an ID in its Box before creating or updating the relation. Also, for ToMany relations based on a * {@link Backlink} the target objects are updated (to store changes in the linked ToOne or ToMany relation). *

* Performance note: if you want to put several objects, consider {@link #put(Collection)}, {@link #put(Object[])}, * {@link BoxStore#runInTx(Runnable)}, etc. instead. */ public long put(T entity) { Cursor cursor = getWriter(); try { long key = cursor.put(entity); commitWriter(cursor); return key; } finally { releaseWriter(cursor); } } /** * Puts the given entities in a box using a single transaction. *

* See {@link #put(Object)} for more details. */ @SafeVarargs // Not using T... as Object[], no ClassCastException expected. public final void put(@Nullable T... entities) { if (entities == null || entities.length == 0) { return; } Cursor cursor = getWriter(); try { for (T entity : entities) { cursor.put(entity); } commitWriter(cursor); } finally { releaseWriter(cursor); } } /** * Puts the given entities in a box using a single transaction. *

* See {@link #put(Object)} for more details. * * @param entities It is fine to pass null or an empty collection: * this case is handled efficiently without overhead. */ public void put(@Nullable Collection entities) { if (entities == null || entities.isEmpty()) { return; } Cursor cursor = getWriter(); try { for (T entity : entities) { cursor.put(entity); } commitWriter(cursor); } finally { releaseWriter(cursor); } } /** * Puts the given entities in a box in batches using a separate transaction for each batch. *

* See {@link #put(Object)} for more details. * * @param entities It is fine to pass null or an empty collection: * this case is handled efficiently without overhead. * @param batchSize Number of entities that will be put in one transaction. Must be 1 or greater. */ public void putBatched(@Nullable Collection entities, int batchSize) { if (batchSize < 1) { throw new IllegalArgumentException("Batch size must be 1 or greater but was " + batchSize); } if (entities == null) { return; } Iterator iterator = entities.iterator(); while (iterator.hasNext()) { Cursor cursor = getWriter(); try { int number = 0; while (number++ < batchSize && iterator.hasNext()) { cursor.put(iterator.next()); } commitWriter(cursor); } finally { releaseWriter(cursor); } } } /** * Removes (deletes) the object with the given ID. *

* If the object is part of a relation, it will be removed from that relation as well. * * @return true if the object did exist and was removed, otherwise false. */ public boolean remove(long id) { Cursor cursor = getWriter(); boolean removed; try { removed = cursor.deleteEntity(id); commitWriter(cursor); } finally { releaseWriter(cursor); } return removed; } /** * Like {@link #remove(long)}, but removes multiple objects in a single transaction. */ public void remove(@Nullable long... ids) { if (ids == null || ids.length == 0) { return; } Cursor cursor = getWriter(); try { for (long key : ids) { cursor.deleteEntity(key); } commitWriter(cursor); } finally { releaseWriter(cursor); } } /** * @deprecated use {@link #removeByIds(Collection)} instead. */ @Deprecated public void removeByKeys(@Nullable Collection ids) { removeByIds(ids); } /** * Like {@link #remove(long)}, but removes multiple objects in a single transaction. */ public void removeByIds(@Nullable Collection ids) { if (ids == null || ids.isEmpty()) { return; } Cursor cursor = getWriter(); try { for (long key : ids) { cursor.deleteEntity(key); } commitWriter(cursor); } finally { releaseWriter(cursor); } } /** * Like {@link #remove(long)}, but obtains the ID from the {@link Id @Id} property of the given object instead. */ public boolean remove(T object) { Cursor cursor = getWriter(); boolean removed; try { long id = cursor.getId(object); removed = cursor.deleteEntity(id); commitWriter(cursor); } finally { releaseWriter(cursor); } return removed; } /** * Like {@link #remove(Object)}, but removes multiple objects in a single transaction. */ @SafeVarargs // Not using T... as Object[], no ClassCastException expected. @SuppressWarnings("Duplicates") // Detected duplicate has different type public final void remove(@Nullable T... objects) { if (objects == null || objects.length == 0) { return; } Cursor cursor = getWriter(); try { for (T entity : objects) { long key = cursor.getId(entity); cursor.deleteEntity(key); } commitWriter(cursor); } finally { releaseWriter(cursor); } } /** * Like {@link #remove(Object)}, but removes multiple objects in a single transaction. */ @SuppressWarnings("Duplicates") // Detected duplicate has different type public void remove(@Nullable Collection objects) { if (objects == null || objects.isEmpty()) { return; } Cursor cursor = getWriter(); try { for (T entity : objects) { long key = cursor.getId(entity); cursor.deleteEntity(key); } commitWriter(cursor); } finally { releaseWriter(cursor); } } /** * Like {@link #remove(long)}, but removes all objects in a single transaction. */ public void removeAll() { Cursor cursor = getWriter(); try { cursor.deleteAll(); commitWriter(cursor); } finally { releaseWriter(cursor); } } /** * WARNING: this method should generally be avoided as it is not transactional and thus may leave the DB in an * inconsistent state. It may be the a last resort option to recover from a full DB. * Like removeAll(), it removes all objects, returns the count of objects removed. * Logs progress using warning log level. */ @Experimental public long panicModeRemoveAll() { return store.panicModeRemoveAllObjects(getEntityInfo().getEntityId()); } /** * Create a query with no conditions. * * @see #query(QueryCondition) */ public QueryBuilder query() { return new QueryBuilder<>(this, store.getNativeStore(), store.getDbName(entityClass)); } /** * Applies the given query conditions and returns the builder for further customization, such as result order. * Build the condition using the properties from your entity underscore classes. *

* An example with a nested OR condition: *

     * # Java
     * box.query(User_.name.equal("Jane")
     *         .and(User_.age.less(12)
     *                 .or(User_.status.equal("child"))));
     *
     * # Kotlin
     * box.query(User_.name.equal("Jane")
     *         and (User_.age.less(12)
     *         or User_.status.equal("child")))
     * 
* This method is a shortcut for {@code query().apply(condition)}. * * @see QueryBuilder#apply(QueryCondition) */ public QueryBuilder query(QueryCondition queryCondition) { return query().apply(queryCondition); } public BoxStore getStore() { return store; } public synchronized EntityInfo getEntityInfo() { if (entityInfo == null) { Cursor reader = getReader(); try { entityInfo = reader.getEntityInfo(); } finally { releaseReader(reader); } } return entityInfo; } @Beta public void attach(T entity) { if (boxStoreField == null) { try { boxStoreField = ReflectionCache.getInstance().getField(entityClass, "__boxStore"); } catch (Exception e) { throw new DbException("Entity cannot be attached - only active entities with relationships support " + "attaching (class has no __boxStore field(?)) : " + entityClass, e); } } try { boxStoreField.set(entity, store); } catch (IllegalAccessException e) { throw new RuntimeException(e); } } // Sketching future API extension private boolean isChanged(T entity) { return false; } // Sketching future API extension private boolean putIfChanged(T entity) { return false; } public Class getEntityClass() { return entityClass; } @Internal public List internalGetBacklinkEntities(int entityId, Property relationIdProperty, long key) { Cursor reader = getReader(); try { return reader.getBacklinkEntities(entityId, relationIdProperty, key); } finally { releaseReader(reader); } } @Internal public List internalGetRelationEntities(int sourceEntityId, int relationId, long key, boolean backlink) { Cursor reader = getReader(); try { return reader.getRelationEntities(sourceEntityId, relationId, key, backlink); } finally { releaseReader(reader); } } @Internal public long[] internalGetRelationIds(int sourceEntityId, int relationId, long key, boolean backlink) { Cursor reader = getReader(); try { return reader.getRelationIds(sourceEntityId, relationId, key, backlink); } finally { releaseReader(reader); } } /** * Given a ToMany relation and the ID of a source entity gets the target entities of the relation from their box, * for example {@code orderBox.getRelationEntities(Customer_.orders, customer.getId())}. */ public List getRelationEntities(RelationInfo relationInfo, long id) { return internalGetRelationEntities(relationInfo.sourceInfo.getEntityId(), relationInfo.relationId, id, false); } /** * Given a ToMany relation and the ID of a target entity gets all source entities pointing to this target entity, * for example {@code customerBox.getRelationEntities(Customer_.orders, order.getId())}. */ public List getRelationBacklinkEntities(RelationInfo relationInfo, long id) { return internalGetRelationEntities(relationInfo.sourceInfo.getEntityId(), relationInfo.relationId, id, true); } /** * Like {@link #getRelationEntities(RelationInfo, long)}, but only returns the IDs of the target entities. */ public long[] getRelationIds(RelationInfo relationInfo, long id) { return internalGetRelationIds(relationInfo.sourceInfo.getEntityId(), relationInfo.relationId, id, false); } /** * Like {@link #getRelationBacklinkEntities(RelationInfo, long)}, but only returns the IDs of the source entities. */ public long[] getRelationBacklinkIds(RelationInfo relationInfo, long id) { return internalGetRelationIds(relationInfo.sourceInfo.getEntityId(), relationInfo.relationId, id, true); } @Internal public RESULT internalCallWithReaderHandle(CallWithHandle task) { Cursor reader = getReader(); try { return task.call(reader.internalHandle()); } finally { releaseReader(reader); } } @Internal public RESULT internalCallWithWriterHandle(CallWithHandle task) { Cursor writer = getWriter(); RESULT result; try { result = task.call(writer.internalHandle()); commitWriter(writer); } finally { releaseWriter(writer); } return result; } public String getReaderDebugInfo() { Cursor reader = getReader(); try { return reader + " with " + reader.getTx() + "; store's commit count: " + getStore().commitCount; } finally { releaseReader(reader); } } }




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