trunk/oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/Template.java - jackrabbit-oak - Git at Google

 /*
  * 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.jackrabbit.oak.segment;

 import static com.google.common.base.Preconditions.checkElementIndex;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static org.apache.jackrabbit.oak.api.Type.STRING;
 import static org.apache.jackrabbit.oak.plugins.memory.EmptyNodeState.MISSING_NODE;
 import static org.apache.jackrabbit.oak.segment.Segment.RECORD_ID_BYTES;
 import static org.apache.jackrabbit.oak.segment.CacheWeights.OBJECT_HEADER_SIZE;

 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;

 import com.google.common.base.Objects;
 import com.google.common.collect.Lists;
 import org.apache.jackrabbit.oak.api.PropertyState;
 import org.apache.jackrabbit.oak.api.Type;
 import org.apache.jackrabbit.oak.commons.StringUtils;
 import org.apache.jackrabbit.oak.plugins.memory.MemoryChildNodeEntry;
 import org.apache.jackrabbit.oak.spi.state.ChildNodeEntry;
 import org.apache.jackrabbit.oak.spi.state.NodeState;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 /**
  * The in-memory representation of a "hidden class" of a node; inspired by the
  * Chrome V8 Javascript engine).
  * <p>
  * Templates are always read fully in-memory.
  */
 public class Template {

     static final short ZERO_CHILD_NODES_TYPE = 0;

     static final short SINGLE_CHILD_NODE_TYPE = 1;

     static final short MANY_CHILD_NODES_TYPE = 2;

     static final String ZERO_CHILD_NODES = null;

     static final String MANY_CHILD_NODES = "";

     @NotNull
     private final SegmentReader reader;

     /**
      * The {@code jcr:primaryType} property, if present as a single-valued
      * {@code NAME} property. Otherwise {@code null}.
      */
     @Nullable
     private final PropertyState primaryType;

     /**
      * The {@code jcr:mixinTypes} property, if present as a multi-valued
      * {@code NAME} property. Otherwise {@code null}.
      */
     @Nullable
     private final PropertyState mixinTypes;

     /**
      * Templates of all the properties of a node, excluding the
      * above-mentioned {@code NAME}-valued type properties, if any.
      */
     @NotNull
     private final PropertyTemplate[] properties;

     /**
      * Name of the single child node, if the node contains just one child.
      * Otherwise {@link #ZERO_CHILD_NODES} (i.e. {@code null}) if there are
      * no children, or {@link #MANY_CHILD_NODES} if there are more than one.
      */
     @Nullable
     private final String childName;

     Template(@NotNull SegmentReader reader,
              @Nullable PropertyState primaryType,
              @Nullable PropertyState mixinTypes,
              @Nullable  PropertyTemplate[] properties,
              @Nullable String childName) {
         this.reader = checkNotNull(reader);
         this.primaryType = primaryType;
         this.mixinTypes = mixinTypes;
         if (properties != null) {
             this.properties = properties;
             Arrays.sort(this.properties);
         } else {
             this.properties = new PropertyTemplate[0];
         }
         this.childName = childName;
     }

     Template(@NotNull SegmentReader reader, @NotNull NodeState state) {
         this.reader = checkNotNull(reader);
         checkNotNull(state);
         PropertyState primary = null;
         PropertyState mixins = null;
         List<PropertyTemplate> templates = Lists.newArrayList();

         for (PropertyState property : state.getProperties()) {
             String name = property.getName();
             Type<?> type = property.getType();
             if ("jcr:primaryType".equals(name) && type == Type.NAME) {
                 primary = property;
             } else if ("jcr:mixinTypes".equals(name) && type == Type.NAMES) {
                 mixins = property;
             } else {
                 templates.add(new PropertyTemplate(property));
             }
         }

         this.primaryType = primary;
         this.mixinTypes = mixins;
         this.properties =
                 templates.toArray(new PropertyTemplate[templates.size()]);
         Arrays.sort(properties);

         long count = state.getChildNodeCount(2);
         if (count == 0) {
             childName = ZERO_CHILD_NODES;
         } else if (count == 1) {
             childName = state.getChildNodeNames().iterator().next();
             checkState(childName != null && !childName.equals(MANY_CHILD_NODES));
         } else {
             childName = MANY_CHILD_NODES;
         }
     }

     @Nullable
     PropertyState getPrimaryType() {
         return primaryType;
     }

     @Nullable
     PropertyState getMixinTypes() {
         return mixinTypes;
     }

     PropertyTemplate[] getPropertyTemplates() {
         return properties;
     }

     /**
      * Returns the template of the named property, or {@code null} if no such
      * property exists. Use the {@link #getPrimaryType()} and
      * {@link #getMixinTypes()} for accessing the JCR type properties, as
      * they don't have templates.
      *
      * @param name property name
      * @return property template, or {@code} null if not found
      */
     PropertyTemplate getPropertyTemplate(String name) {
         int hash = name.hashCode();
         int index = 0;
         while (index < properties.length
                 && properties[index].getName().hashCode() < hash) {
             index++;
         }
         while (index < properties.length
                 && properties[index].getName().hashCode() == hash) {
             if (name.equals(properties[index].getName())) {
                 return properties[index];
             }
             index++;
         }
         return null;
     }

     @Nullable
     String getChildName() {
         return childName;
     }

     SegmentPropertyState getProperty(RecordId recordId, int index) {
         checkElementIndex(index, properties.length);
         Segment segment = checkNotNull(recordId).getSegment();

         int offset = 2 * RECORD_ID_BYTES;
         if (childName != ZERO_CHILD_NODES) {
             offset += RECORD_ID_BYTES;
         }
         RecordId lid = segment.readRecordId(recordId.getRecordNumber(), offset);
         ListRecord props = new ListRecord(lid, properties.length);
         RecordId rid = props.getEntry(index);
         return reader.readProperty(rid, properties[index]);
     }

     MapRecord getChildNodeMap(RecordId recordId) {
         checkState(childName != ZERO_CHILD_NODES);
         Segment segment = recordId.getSegment();
         RecordId childNodesId = segment.readRecordId(recordId.getRecordNumber(), 2 * RECORD_ID_BYTES);
         return reader.readMap(childNodesId);
     }

     public NodeState getChildNode(String name, RecordId recordId) {
         if (childName == ZERO_CHILD_NODES) {
             return MISSING_NODE;
         } else if (childName == MANY_CHILD_NODES) {
             MapRecord map = getChildNodeMap(recordId);
             MapEntry child = map.getEntry(name);
             if (child != null) {
                 return child.getNodeState();
             } else {
                 return MISSING_NODE;
             }
         } else if (name.equals(childName)) {
             Segment segment = recordId.getSegment();
             RecordId childNodeId = segment.readRecordId(recordId.getRecordNumber(), 2 * RECORD_ID_BYTES);
             return reader.readNode(childNodeId);
         } else {
             return MISSING_NODE;
         }
     }

     Iterable<? extends ChildNodeEntry> getChildNodeEntries(RecordId recordId) {
         if (childName == ZERO_CHILD_NODES) {
             return Collections.emptyList();
         } else if (childName == MANY_CHILD_NODES) {
             MapRecord map = getChildNodeMap(recordId);
             return map.getEntries();
         } else {
             Segment segment = recordId.getSegment();
             RecordId childNodeId = segment.readRecordId(recordId.getRecordNumber(), 2 * RECORD_ID_BYTES);
             return Collections.singletonList(new MemoryChildNodeEntry(
                     childName, reader.readNode(childNodeId)));
         }
     }

     public boolean compare(RecordId thisId, RecordId thatId) {
         checkNotNull(thisId);
         checkNotNull(thatId);

         // Compare properties
         for (int i = 0; i < properties.length; i++) {
             PropertyState thisProperty = getProperty(thisId, i);
             PropertyState thatProperty = getProperty(thatId, i);
             if (!thisProperty.equals(thatProperty)) {
                 return false;
             }
         }

         // Compare child nodes
         if (childName == ZERO_CHILD_NODES) {
             return true;
         } else if (childName != MANY_CHILD_NODES) {
             NodeState thisChild = getChildNode(childName, thisId);
             NodeState thatChild = getChildNode(childName, thatId);
             return thisChild.equals(thatChild);
         } else {
             // TODO: Leverage the HAMT data structure for the comparison
             MapRecord thisMap = getChildNodeMap(thisId);
             MapRecord thatMap = getChildNodeMap(thatId);
             if (Record.fastEquals(thisMap, thatMap)) {
                 return true; // shortcut
             } else if (thisMap.size() != thatMap.size()) {
                 return false; // shortcut
             } else {
                 // TODO: can this be optimized?
                 for (MapEntry entry : thisMap.getEntries()) {
                     String name = entry.getName();
                     MapEntry thatEntry = thatMap.getEntry(name);
                     if (thatEntry == null) {
                         return false;
                     } else if (!entry.getNodeState().equals(thatEntry.getNodeState())) {
                         return false;
                     }
                 }
                 return true;
             }
         }
     }

     //------------------------------------------------------------< Object >--

     @Override
     public boolean equals(Object object) {
         if (this == object) {
             return true;
         } else if (object instanceof Template) {
             Template that = (Template) object;
             return Objects.equal(primaryType, that.primaryType)
                     && Objects.equal(mixinTypes, that.mixinTypes)
                     && Arrays.equals(properties, that.properties)
                     && Objects.equal(childName, that.childName);
         } else {
             return false;
         }
     }

     @Override
     public int hashCode() {
         return Objects.hashCode(primaryType, mixinTypes,
                 Arrays.asList(properties), getTemplateType(), childName);
     }

     @Override
     public String toString() {
         StringBuilder builder = new StringBuilder();
         builder.append("{ ");
         if (primaryType != null) {
             builder.append(primaryType);
             builder.append(", ");
         }
         if (mixinTypes != null) {
             builder.append(mixinTypes);
             builder.append(", ");
         }
         for (PropertyTemplate property : properties) {
             builder.append(property);
             builder.append(" = ?, ");
         }
         if (childName == ZERO_CHILD_NODES) {
             builder.append("<no children>");
         } else if (childName == MANY_CHILD_NODES) {
             builder.append("<many children>");
         } else {
             builder.append(childName + " = <node>");
         }
         builder.append(" }");
         return builder.toString();
     }

     short getTemplateType() {
         if (childName == ZERO_CHILD_NODES) {
             return ZERO_CHILD_NODES_TYPE;
         } else if (childName == MANY_CHILD_NODES) {
             return MANY_CHILD_NODES_TYPE;
         } else {
             return SINGLE_CHILD_NODE_TYPE;
         }
     }

     public int estimateMemoryUsage() {
         int size = OBJECT_HEADER_SIZE;
         size += 48;
         size += StringUtils.estimateMemoryUsage(childName);
         size += estimateMemoryUsage(mixinTypes);
         size += estimateMemoryUsage(primaryType);
         for (PropertyTemplate property : properties) {
             size += property.estimateMemoryUsage();
         }
         return size;
     }

     private static int estimateMemoryUsage(PropertyState propertyState) {
         if (propertyState == null) {
             return 0;
         }
         int size = OBJECT_HEADER_SIZE;
         size += StringUtils.estimateMemoryUsage(propertyState.getName());
         for (int k = 0; k < propertyState.count(); k++) {
             String s = propertyState.getValue(STRING, k);
             size += StringUtils.estimateMemoryUsage(s);
         }
         return size;
     }

 }
	/*
	* 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.jackrabbit.oak.segment;

	import static com.google.common.base.Preconditions.checkElementIndex;
	import static com.google.common.base.Preconditions.checkNotNull;
	import static com.google.common.base.Preconditions.checkState;
	import static org.apache.jackrabbit.oak.api.Type.STRING;
	import static org.apache.jackrabbit.oak.plugins.memory.EmptyNodeState.MISSING_NODE;
	import static org.apache.jackrabbit.oak.segment.Segment.RECORD_ID_BYTES;
	import static org.apache.jackrabbit.oak.segment.CacheWeights.OBJECT_HEADER_SIZE;

	import java.util.Arrays;
	import java.util.Collections;
	import java.util.List;

	import com.google.common.base.Objects;
	import com.google.common.collect.Lists;
	import org.apache.jackrabbit.oak.api.PropertyState;
	import org.apache.jackrabbit.oak.api.Type;
	import org.apache.jackrabbit.oak.commons.StringUtils;
	import org.apache.jackrabbit.oak.plugins.memory.MemoryChildNodeEntry;
	import org.apache.jackrabbit.oak.spi.state.ChildNodeEntry;
	import org.apache.jackrabbit.oak.spi.state.NodeState;
	import org.jetbrains.annotations.NotNull;
	import org.jetbrains.annotations.Nullable;

	/**
	* The in-memory representation of a "hidden class" of a node; inspired by the
	* Chrome V8 Javascript engine).
	* <p>
	* Templates are always read fully in-memory.
	*/
	public class Template {

	static final short ZERO_CHILD_NODES_TYPE = 0;

	static final short SINGLE_CHILD_NODE_TYPE = 1;

	static final short MANY_CHILD_NODES_TYPE = 2;

	static final String ZERO_CHILD_NODES = null;

	static final String MANY_CHILD_NODES = "";

	@NotNull
	private final SegmentReader reader;

	/**
	* The {@code jcr:primaryType} property, if present as a single-valued
	* {@code NAME} property. Otherwise {@code null}.
	*/
	@Nullable
	private final PropertyState primaryType;

	/**
	* The {@code jcr:mixinTypes} property, if present as a multi-valued
	* {@code NAME} property. Otherwise {@code null}.
	*/
	@Nullable
	private final PropertyState mixinTypes;

	/**
	* Templates of all the properties of a node, excluding the
	* above-mentioned {@code NAME}-valued type properties, if any.
	*/
	@NotNull
	private final PropertyTemplate[] properties;

	/**
	* Name of the single child node, if the node contains just one child.
	* Otherwise {@link #ZERO_CHILD_NODES} (i.e. {@code null}) if there are
	* no children, or {@link #MANY_CHILD_NODES} if there are more than one.
	*/
	@Nullable
	private final String childName;

	Template(@NotNull SegmentReader reader,
	@Nullable PropertyState primaryType,
	@Nullable PropertyState mixinTypes,
	@Nullable PropertyTemplate[] properties,
	@Nullable String childName) {
	this.reader = checkNotNull(reader);
	this.primaryType = primaryType;
	this.mixinTypes = mixinTypes;
	if (properties != null) {
	this.properties = properties;
	Arrays.sort(this.properties);
	} else {
	this.properties = new PropertyTemplate[0];
	}
	this.childName = childName;
	}

	Template(@NotNull SegmentReader reader, @NotNull NodeState state) {
	this.reader = checkNotNull(reader);
	checkNotNull(state);
	PropertyState primary = null;
	PropertyState mixins = null;
	List<PropertyTemplate> templates = Lists.newArrayList();

	for (PropertyState property : state.getProperties()) {
	String name = property.getName();
	Type<?> type = property.getType();
	if ("jcr:primaryType".equals(name) && type == Type.NAME) {
	primary = property;
	} else if ("jcr:mixinTypes".equals(name) && type == Type.NAMES) {
	mixins = property;
	} else {
	templates.add(new PropertyTemplate(property));
	}
	}

	this.primaryType = primary;
	this.mixinTypes = mixins;
	this.properties =
	templates.toArray(new PropertyTemplate[templates.size()]);
	Arrays.sort(properties);

	long count = state.getChildNodeCount(2);
	if (count == 0) {
	childName = ZERO_CHILD_NODES;
	} else if (count == 1) {
	childName = state.getChildNodeNames().iterator().next();
	checkState(childName != null && !childName.equals(MANY_CHILD_NODES));
	} else {
	childName = MANY_CHILD_NODES;
	}
	}

	@Nullable
	PropertyState getPrimaryType() {
	return primaryType;
	}

	@Nullable
	PropertyState getMixinTypes() {
	return mixinTypes;
	}

	PropertyTemplate[] getPropertyTemplates() {
	return properties;
	}

	/**
	* Returns the template of the named property, or {@code null} if no such
	* property exists. Use the {@link #getPrimaryType()} and
	* {@link #getMixinTypes()} for accessing the JCR type properties, as
	* they don't have templates.
	*
	* @param name property name
	* @return property template, or {@code} null if not found
	*/
	PropertyTemplate getPropertyTemplate(String name) {
	int hash = name.hashCode();
	int index = 0;
	while (index < properties.length
	&& properties[index].getName().hashCode() < hash) {
	index++;
	}
	while (index < properties.length
	&& properties[index].getName().hashCode() == hash) {
	if (name.equals(properties[index].getName())) {
	return properties[index];
	}
	index++;
	}
	return null;
	}

	@Nullable
	String getChildName() {
	return childName;
	}

	SegmentPropertyState getProperty(RecordId recordId, int index) {
	checkElementIndex(index, properties.length);
	Segment segment = checkNotNull(recordId).getSegment();

	int offset = 2 * RECORD_ID_BYTES;
	if (childName != ZERO_CHILD_NODES) {
	offset += RECORD_ID_BYTES;
	}
	RecordId lid = segment.readRecordId(recordId.getRecordNumber(), offset);
	ListRecord props = new ListRecord(lid, properties.length);
	RecordId rid = props.getEntry(index);
	return reader.readProperty(rid, properties[index]);
	}

	MapRecord getChildNodeMap(RecordId recordId) {
	checkState(childName != ZERO_CHILD_NODES);
	Segment segment = recordId.getSegment();
	RecordId childNodesId = segment.readRecordId(recordId.getRecordNumber(), 2 * RECORD_ID_BYTES);
	return reader.readMap(childNodesId);
	}

	public NodeState getChildNode(String name, RecordId recordId) {
	if (childName == ZERO_CHILD_NODES) {
	return MISSING_NODE;
	} else if (childName == MANY_CHILD_NODES) {
	MapRecord map = getChildNodeMap(recordId);
	MapEntry child = map.getEntry(name);
	if (child != null) {
	return child.getNodeState();
	} else {
	return MISSING_NODE;
	}
	} else if (name.equals(childName)) {
	Segment segment = recordId.getSegment();
	RecordId childNodeId = segment.readRecordId(recordId.getRecordNumber(), 2 * RECORD_ID_BYTES);
	return reader.readNode(childNodeId);
	} else {
	return MISSING_NODE;
	}
	}

	Iterable<? extends ChildNodeEntry> getChildNodeEntries(RecordId recordId) {
	if (childName == ZERO_CHILD_NODES) {
	return Collections.emptyList();
	} else if (childName == MANY_CHILD_NODES) {
	MapRecord map = getChildNodeMap(recordId);
	return map.getEntries();
	} else {
	Segment segment = recordId.getSegment();
	RecordId childNodeId = segment.readRecordId(recordId.getRecordNumber(), 2 * RECORD_ID_BYTES);
	return Collections.singletonList(new MemoryChildNodeEntry(
	childName, reader.readNode(childNodeId)));
	}
	}

	public boolean compare(RecordId thisId, RecordId thatId) {
	checkNotNull(thisId);
	checkNotNull(thatId);

	// Compare properties
	for (int i = 0; i < properties.length; i++) {
	PropertyState thisProperty = getProperty(thisId, i);
	PropertyState thatProperty = getProperty(thatId, i);
	if (!thisProperty.equals(thatProperty)) {
	return false;
	}
	}

	// Compare child nodes
	if (childName == ZERO_CHILD_NODES) {
	return true;
	} else if (childName != MANY_CHILD_NODES) {
	NodeState thisChild = getChildNode(childName, thisId);
	NodeState thatChild = getChildNode(childName, thatId);
	return thisChild.equals(thatChild);
	} else {
	// TODO: Leverage the HAMT data structure for the comparison
	MapRecord thisMap = getChildNodeMap(thisId);
	MapRecord thatMap = getChildNodeMap(thatId);
	if (Record.fastEquals(thisMap, thatMap)) {
	return true; // shortcut
	} else if (thisMap.size() != thatMap.size()) {
	return false; // shortcut
	} else {
	// TODO: can this be optimized?
	for (MapEntry entry : thisMap.getEntries()) {
	String name = entry.getName();
	MapEntry thatEntry = thatMap.getEntry(name);
	if (thatEntry == null) {
	return false;
	} else if (!entry.getNodeState().equals(thatEntry.getNodeState())) {
	return false;
	}
	}
	return true;
	}
	}
	}

	//------------------------------------------------------------< Object >--

	@Override
	public boolean equals(Object object) {
	if (this == object) {
	return true;
	} else if (object instanceof Template) {
	Template that = (Template) object;
	return Objects.equal(primaryType, that.primaryType)
	&& Objects.equal(mixinTypes, that.mixinTypes)
	&& Arrays.equals(properties, that.properties)
	&& Objects.equal(childName, that.childName);
	} else {
	return false;
	}
	}

	@Override
	public int hashCode() {
	return Objects.hashCode(primaryType, mixinTypes,
	Arrays.asList(properties), getTemplateType(), childName);
	}

	@Override
	public String toString() {
	StringBuilder builder = new StringBuilder();
	builder.append("{ ");
	if (primaryType != null) {
	builder.append(primaryType);
	builder.append(", ");
	}
	if (mixinTypes != null) {
	builder.append(mixinTypes);
	builder.append(", ");
	}
	for (PropertyTemplate property : properties) {
	builder.append(property);
	builder.append(" = ?, ");
	}
	if (childName == ZERO_CHILD_NODES) {
	builder.append("<no children>");
	} else if (childName == MANY_CHILD_NODES) {
	builder.append("<many children>");
	} else {
	builder.append(childName + " = <node>");
	}
	builder.append(" }");
	return builder.toString();
	}

	short getTemplateType() {
	if (childName == ZERO_CHILD_NODES) {
	return ZERO_CHILD_NODES_TYPE;
	} else if (childName == MANY_CHILD_NODES) {
	return MANY_CHILD_NODES_TYPE;
	} else {
	return SINGLE_CHILD_NODE_TYPE;
	}
	}

	public int estimateMemoryUsage() {
	int size = OBJECT_HEADER_SIZE;
	size += 48;
	size += StringUtils.estimateMemoryUsage(childName);
	size += estimateMemoryUsage(mixinTypes);
	size += estimateMemoryUsage(primaryType);
	for (PropertyTemplate property : properties) {
	size += property.estimateMemoryUsage();
	}
	return size;
	}

	private static int estimateMemoryUsage(PropertyState propertyState) {
	if (propertyState == null) {
	return 0;
	}
	int size = OBJECT_HEADER_SIZE;
	size += StringUtils.estimateMemoryUsage(propertyState.getName());
	for (int k = 0; k < propertyState.count(); k++) {
	String s = propertyState.getValue(STRING, k);
	size += StringUtils.estimateMemoryUsage(s);
	}
	return size;
	}

	}