/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.openjpa.kernel;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.commons.lang.StringUtils;
import org.apache.openjpa.conf.OpenJPAConfiguration;
import org.apache.openjpa.lib.rop.EagerResultList;
import org.apache.openjpa.lib.rop.ListResultObjectProvider;
import org.apache.openjpa.lib.rop.ResultList;
import org.apache.openjpa.lib.rop.ResultObjectProvider;
import org.apache.openjpa.lib.rop.SimpleResultList;
import org.apache.openjpa.lib.rop.WindowResultList;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.meta.ClassMetaData;
import org.apache.openjpa.meta.FetchGroup;
import org.apache.openjpa.meta.FieldMetaData;
import org.apache.openjpa.meta.JavaTypes;
import org.apache.openjpa.util.ImplHelper;
import org.apache.openjpa.util.InternalException;
import org.apache.openjpa.util.NoTransactionException;
import org.apache.openjpa.util.UserException;
/**
* Allows configuration and optimization of how objects are loaded from
* the data store.
*
* @since 0.3.0
* @author Abe White
* @author Pinaki Poddar
* @nojavadoc
*/
public class FetchConfigurationImpl
implements FetchConfiguration, Cloneable {
private static final Localizer _loc = Localizer.forPackage
(FetchConfigurationImpl.class);
/**
* Configurable state shared throughout a traversal chain.
*/
protected static class ConfigurationState
implements Serializable
{
public transient StoreContext ctx = null;
public int fetchBatchSize = 0;
public int maxFetchDepth = 1;
public boolean queryCache = true;
public int flushQuery = 0;
public int lockTimeout = -1;
public int readLockLevel = LOCK_NONE;
public int writeLockLevel = LOCK_NONE;
public Set fetchGroups = null;
public Set fields = null;
public Set rootClasses;
public Set rootInstances;
public Map hints = null;
}
private final ConfigurationState _state;
private FetchConfigurationImpl _parent;
private String _fromField;
private Class _fromType;
private String _directRelationOwner;
private boolean _load = true;
private int _availableRecursion;
private int _availableDepth;
public FetchConfigurationImpl() {
this(null);
}
protected FetchConfigurationImpl(ConfigurationState state) {
_state = (state == null) ? new ConfigurationState() : state;
_availableDepth = _state.maxFetchDepth;
}
public StoreContext getContext() {
return _state.ctx;
}
public void setContext(StoreContext ctx) {
// can't reset non-null context to another context
if (ctx != null && _state.ctx != null && ctx != _state.ctx)
throw new InternalException();
_state.ctx = ctx;
if (ctx == null)
return;
// initialize to conf info
OpenJPAConfiguration conf = ctx.getConfiguration();
setFetchBatchSize(conf.getFetchBatchSize());
setFlushBeforeQueries(conf.getFlushBeforeQueriesConstant());
clearFetchGroups();
addFetchGroups(Arrays.asList(conf.getFetchGroupsList()));
setMaxFetchDepth(conf.getMaxFetchDepth());
}
/**
* Clone this instance.
*/
public Object clone() {
FetchConfigurationImpl clone = newInstance(null);
clone._state.ctx = _state.ctx;
clone._parent = _parent;
clone._fromField = _fromField;
clone._fromType = _fromType;
clone._directRelationOwner = _directRelationOwner;
clone._load = _load;
clone._availableRecursion = _availableRecursion;
clone._availableDepth = _availableDepth;
clone.copy(this);
return clone;
}
/**
* Return a new hollow instance.
*/
protected FetchConfigurationImpl newInstance(ConfigurationState state) {
return new FetchConfigurationImpl(state);
}
public void copy(FetchConfiguration fetch) {
setFetchBatchSize(fetch.getFetchBatchSize());
setMaxFetchDepth(fetch.getMaxFetchDepth());
setQueryCacheEnabled(fetch.getQueryCacheEnabled());
setFlushBeforeQueries(fetch.getFlushBeforeQueries());
setLockTimeout(fetch.getLockTimeout());
clearFetchGroups();
addFetchGroups(fetch.getFetchGroups());
clearFields();
addFields(fetch.getFields());
// don't use setters because require active transaction
_state.readLockLevel = fetch.getReadLockLevel();
_state.writeLockLevel = fetch.getWriteLockLevel();
}
public int getFetchBatchSize() {
return _state.fetchBatchSize;
}
public FetchConfiguration setFetchBatchSize(int fetchBatchSize) {
if (fetchBatchSize == DEFAULT && _state.ctx != null)
fetchBatchSize = _state.ctx.getConfiguration().getFetchBatchSize();
if (fetchBatchSize != DEFAULT)
_state.fetchBatchSize = fetchBatchSize;
return this;
}
public int getMaxFetchDepth() {
return _state.maxFetchDepth;
}
public FetchConfiguration setMaxFetchDepth(int depth) {
if (depth == DEFAULT && _state.ctx != null)
depth = _state.ctx.getConfiguration().getMaxFetchDepth();
if (depth != DEFAULT)
{
_state.maxFetchDepth = depth;
if (_parent == null)
_availableDepth = depth;
}
return this;
}
public boolean getQueryCacheEnabled() {
return _state.queryCache;
}
public FetchConfiguration setQueryCacheEnabled(boolean cache) {
_state.queryCache = cache;
return this;
}
public int getFlushBeforeQueries() {
return _state.flushQuery;
}
public FetchConfiguration setFlushBeforeQueries(int flush) {
if (flush == DEFAULT && _state.ctx != null)
_state.flushQuery = _state.ctx.getConfiguration().
getFlushBeforeQueriesConstant();
else if (flush != DEFAULT)
_state.flushQuery = flush;
return this;
}
public Set getFetchGroups() {
return (_state.fetchGroups == null) ? Collections.EMPTY_SET
: _state.fetchGroups;
}
public boolean hasFetchGroup(String group) {
return _state.fetchGroups != null
&& (_state.fetchGroups.contains(group)
|| _state.fetchGroups.contains(FetchGroup.NAME_ALL));
}
public FetchConfiguration addFetchGroup(String name) {
if (StringUtils.isEmpty(name))
throw new UserException(_loc.get("null-fg"));
lock();
try {
if (_state.fetchGroups == null)
_state.fetchGroups = new HashSet();
_state.fetchGroups.add(name);
} finally {
unlock();
}
return this;
}
public FetchConfiguration addFetchGroups(Collection groups) {
if (groups == null || groups.isEmpty())
return this;
for (Iterator itr = groups.iterator(); itr.hasNext();)
addFetchGroup((String) itr.next());
return this;
}
public FetchConfiguration removeFetchGroup(String group) {
lock();
try {
if (_state.fetchGroups != null)
_state.fetchGroups.remove(group);
} finally {
unlock();
}
return this;
}
public FetchConfiguration removeFetchGroups(Collection groups) {
lock();
try {
if (_state.fetchGroups != null)
_state.fetchGroups.removeAll(groups);
} finally {
unlock();
}
return this;
}
public FetchConfiguration clearFetchGroups() {
lock();
try {
if (_state.fetchGroups != null)
_state.fetchGroups.clear();
} finally {
unlock();
}
return this;
}
public FetchConfiguration resetFetchGroups() {
clearFetchGroups();
if (_state.ctx != null)
addFetchGroups(Arrays.asList(_state.ctx.getConfiguration().
getFetchGroupsList()));
return this;
}
public Set getFields() {
return (_state.fields == null) ? Collections.EMPTY_SET : _state.fields;
}
public boolean hasField(String field) {
return _state.fields != null && _state.fields.contains(field);
}
public FetchConfiguration addField(String field) {
if (StringUtils.isEmpty(field))
throw new UserException(_loc.get("null-field"));
lock();
try {
if (_state.fields == null)
_state.fields = new HashSet();
_state.fields.add(field);
} finally {
unlock();
}
return this;
}
public FetchConfiguration addFields(Collection fields) {
if (fields == null || fields.isEmpty())
return this;
lock();
try {
if (_state.fields == null)
_state.fields = new HashSet();
_state.fields.addAll(fields);
} finally {
unlock();
}
return this;
}
public FetchConfiguration removeField(String field) {
lock();
try {
if (_state.fields != null)
_state.fields.remove(field);
} finally {
unlock();
}
return this;
}
public FetchConfiguration removeFields(Collection fields) {
lock();
try {
if (_state.fields != null)
_state.fields.removeAll(fields);
} finally {
unlock();
}
return this;
}
public FetchConfiguration clearFields() {
lock();
try {
if (_state.fields != null)
_state.fields.clear();
} finally {
unlock();
}
return this;
}
public int getLockTimeout() {
return _state.lockTimeout;
}
public FetchConfiguration setLockTimeout(int timeout) {
if (timeout == DEFAULT && _state.ctx != null)
_state.lockTimeout = _state.ctx.getConfiguration().getLockTimeout();
else if (timeout != DEFAULT)
_state.lockTimeout = timeout;
return this;
}
public int getReadLockLevel() {
return _state.readLockLevel;
}
public FetchConfiguration setReadLockLevel(int level) {
if (_state.ctx == null)
return this;
lock();
try {
assertActiveTransaction();
if (level == DEFAULT)
_state.readLockLevel = _state.ctx.getConfiguration().
getReadLockLevelConstant();
else
_state.readLockLevel = level;
} finally {
unlock();
}
return this;
}
public int getWriteLockLevel() {
return _state.writeLockLevel;
}
public FetchConfiguration setWriteLockLevel(int level) {
if (_state.ctx == null)
return this;
lock();
try {
assertActiveTransaction();
if (level == DEFAULT)
_state.writeLockLevel = _state.ctx.getConfiguration().
getWriteLockLevelConstant();
else
_state.writeLockLevel = level;
} finally {
unlock();
}
return this;
}
public ResultList newResultList(ResultObjectProvider rop) {
if (rop instanceof ListResultObjectProvider)
return new SimpleResultList(rop);
if (_state.fetchBatchSize < 0)
return new EagerResultList(rop);
if (rop.supportsRandomAccess())
return new SimpleResultList(rop);
return new WindowResultList(rop);
}
/**
* Throw an exception if no transaction is active.
*/
private void assertActiveTransaction() {
if (_state.ctx != null && !_state.ctx.isActive())
throw new NoTransactionException(_loc.get("not-active"));
}
public void setHint(String name, Object value) {
lock();
try {
if (_state.hints == null)
_state.hints = new HashMap();
_state.hints.put(name, value);
} finally {
unlock();
}
}
public Object getHint(String name) {
return (_state.hints == null) ? null : _state.hints.get(name);
}
public Set getRootClasses() {
return (_state.rootClasses == null) ? Collections.EMPTY_SET
: _state.rootClasses;
}
public FetchConfiguration setRootClasses(Collection classes) {
lock();
try {
if (_state.rootClasses != null)
_state.rootClasses.clear();
if (classes != null && !classes.isEmpty()) {
if (_state.rootClasses == null)
_state.rootClasses = new HashSet(classes);
else
_state.rootClasses.addAll(classes);
}
} finally {
unlock();
}
return this;
}
public Set getRootInstances() {
return (_state.rootInstances == null) ? Collections.EMPTY_SET
: _state.rootInstances;
}
public FetchConfiguration setRootInstances(Collection instances) {
lock();
try {
if (_state.rootInstances != null)
_state.rootInstances.clear();
if (instances != null && !instances.isEmpty()) {
if (_state.rootInstances == null)
_state.rootInstances = new HashSet(instances);
else
_state.rootInstances.addAll(instances);
}
} finally {
unlock();
}
return this;
}
public void lock() {
if (_state.ctx != null)
_state.ctx.lock();
}
public void unlock() {
if (_state.ctx != null)
_state.ctx.unlock();
}
/////////////
// Traversal
/////////////
public int requiresFetch(FieldMetaData fm) {
if (!includes(fm))
return FETCH_NONE;
Class type = getRelationType(fm);
if (type == null)
return FETCH_LOAD;
if (_availableDepth == 0)
return FETCH_NONE;
// we can skip calculating recursion depth if this is a top-level conf:
// the field is in our fetch groups, so can't possibly not select
if (_parent == null)
return FETCH_LOAD;
int rdepth = getAvailableRecursionDepth(fm, type, false);
if (rdepth != FetchGroup.DEPTH_INFINITE && rdepth <= 0)
return FETCH_NONE;
if (StringUtils.equals(_directRelationOwner, fm.getFullName()))
return FETCH_REF;
return FETCH_LOAD;
}
public boolean requiresLoad() {
return _load;
}
public FetchConfiguration traverse(FieldMetaData fm) {
Class type = getRelationType(fm);
if (type == null)
return this;
FetchConfigurationImpl clone = newInstance(_state);
clone._parent = this;
clone._availableDepth = reduce(_availableDepth);
clone._fromField = fm.getFullName(false);
clone._fromType = type;
clone._availableRecursion = getAvailableRecursionDepth(fm, type, true);
if (StringUtils.equals(_directRelationOwner, fm.getFullName()))
clone._load = false;
else
clone._load = _load;
FieldMetaData owner = fm.getMappedByMetaData();
if (owner != null && owner.getTypeCode() == JavaTypes.PC)
clone._directRelationOwner = owner.getFullName();
return clone;
}
/**
* Whether our configuration state includes the given field.
*/
private boolean includes(FieldMetaData fmd) {
if ((fmd.isInDefaultFetchGroup()
&& hasFetchGroup(FetchGroup.NAME_DEFAULT))
|| hasFetchGroup(FetchGroup.NAME_ALL)
|| hasField(fmd.getFullName(false)))
return true;
String[] fgs = fmd.getCustomFetchGroups();
for (int i = 0; i < fgs.length; i++)
if (hasFetchGroup(fgs[i]))
return true;
return false;
}
/**
* Return the available recursion depth via the given field for the
* given type.
*
* @param traverse whether we're traversing the field
*/
private int getAvailableRecursionDepth(FieldMetaData fm, Class type,
boolean traverse) {
// see if there's a previous limit
int avail = Integer.MIN_VALUE;
for (FetchConfigurationImpl f = this; f != null; f = f._parent) {
if (ImplHelper.isAssignable(f._fromType, type)) {
avail = f._availableRecursion;
if (traverse)
avail = reduce(avail);
break;
}
}
if (avail == 0)
return 0;
// calculate fetch groups max
ClassMetaData meta = fm.getDefiningMetaData();
int max = Integer.MIN_VALUE;
if (fm.isInDefaultFetchGroup())
max = meta.getFetchGroup(FetchGroup.NAME_DEFAULT).
getRecursionDepth(fm);
String[] groups = fm.getCustomFetchGroups();
int cur;
for (int i = 0; max != FetchGroup.DEPTH_INFINITE
&& i < groups.length; i++) {
// ignore custom groups that are inactive in this configuration
if (!this.hasFetchGroup(groups[i])) continue;
cur = meta.getFetchGroup(groups[i]).getRecursionDepth(fm);
if (cur == FetchGroup.DEPTH_INFINITE || cur > max)
max = cur;
}
// reduce max if we're traversing a self-type relation
if (traverse && max != Integer.MIN_VALUE
&& ImplHelper.isAssignable(meta.getDescribedType(), type))
max = reduce(max);
// take min/defined of previous avail and fetch group max
if (avail == Integer.MIN_VALUE && max == Integer.MIN_VALUE) {
int def = FetchGroup.RECURSION_DEPTH_DEFAULT;
return (traverse && ImplHelper.isAssignable(
meta.getDescribedType(), type)) ? def - 1 : def;
}
if (avail == Integer.MIN_VALUE || avail == FetchGroup.DEPTH_INFINITE)
return max;
if (max == Integer.MIN_VALUE || max == FetchGroup.DEPTH_INFINITE)
return avail;
return Math.min(max, avail);
}
/**
* Return the relation type of the given field.
*/
private static Class getRelationType(FieldMetaData fm) {
if (fm.isDeclaredTypePC())
return fm.getDeclaredType();
if (fm.getElement().isDeclaredTypePC())
return fm.getElement().getDeclaredType();
if (fm.getKey().isDeclaredTypePC())
return fm.getKey().getDeclaredType();
return null;
}
/**
* Reduce the given logical depth by 1.
*/
private static int reduce(int d) {
if (d == 0)
return 0;
if (d != FetchGroup.DEPTH_INFINITE)
d--;
return d;
}
/////////////////
// Debug methods
/////////////////
FetchConfiguration getParent() {
return _parent;
}
boolean isRoot() {
return _parent == null;
}
FetchConfiguration getRoot() {
return (isRoot()) ? this : _parent.getRoot();
}
int getAvailableFetchDepth() {
return _availableDepth;
}
int getAvailableRecursionDepth() {
return _availableRecursion;
}
String getTraversedFromField() {
return _fromField;
}
Class getTraversedFromType() {
return _fromType;
}
List getPath() {
if (isRoot())
return Collections.EMPTY_LIST;
return trackPath(new ArrayList());
}
List trackPath(List path) {
if (_parent != null)
_parent.trackPath(path);
path.add(this);
return path;
}
public String toString() {
return "FetchConfiguration@" + System.identityHashCode(this)
+ " (" + _availableDepth + ")" + getPathString();
}
private String getPathString()
{
List path = getPath();
if (path.isEmpty())
return "";
StringBuffer buf = new StringBuffer().append (": ");
for (Iterator itr = path.iterator(); itr.hasNext();) {
buf.append(((FetchConfigurationImpl) itr.next()).
getTraversedFromField());
if (itr.hasNext())
buf.append("->");
}
return buf.toString();
}
}