/*
* Copyright 2017 Google Inc.
*
* 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 com.google.firebase.database.snapshot;
import com.google.firebase.database.collection.ImmutableSortedMap;
import com.google.firebase.database.collection.LLRBNode;
import com.google.firebase.database.core.Path;
import com.google.firebase.database.utilities.Utilities;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/** User: greg Date: 5/16/13 Time: 4:47 PM */
public class ChildrenNode implements Node {
public static final Comparator<ChildKey> NAME_ONLY_COMPARATOR =
new Comparator<ChildKey>() {
@Override
public int compare(ChildKey o1, ChildKey o2) {
return o1.compareTo(o2);
}
};
private final ImmutableSortedMap<ChildKey, Node> children;
private final Node priority;
private String lazyHash = null;
protected ChildrenNode() {
this.children = ImmutableSortedMap.Builder.emptyMap(NAME_ONLY_COMPARATOR);
this.priority = PriorityUtilities.NullPriority();
}
protected ChildrenNode(ImmutableSortedMap<ChildKey, Node> children, Node priority) {
if (children.isEmpty() && !priority.isEmpty()) {
throw new IllegalArgumentException("Can't create empty ChildrenNode with priority!");
}
this.priority = priority;
this.children = children;
}
private static void addIndentation(StringBuilder builder, int indentation) {
for (int i = 0; i < indentation; i++) {
builder.append(" ");
}
}
@Override
public boolean hasChild(ChildKey name) {
return !this.getImmediateChild(name).isEmpty();
}
@Override
public boolean isEmpty() {
return children.isEmpty();
}
@Override
public int getChildCount() {
return children.size();
}
@Override
public Object getValue() {
return getValue(false);
}
@Override
public Object getValue(boolean useExportFormat) {
if (isEmpty()) {
return null;
}
int numKeys = 0;
int maxKey = 0;
boolean allIntegerKeys = true;
Map<String, Object> result = new HashMap<>();
for (Map.Entry<ChildKey, Node> entry : children) {
String key = entry.getKey().asString();
result.put(key, entry.getValue().getValue(useExportFormat));
numKeys++;
// If we already found a string key, don't bother with any of this
if (allIntegerKeys) {
if (key.length() > 1 && key.charAt(0) == '0') {
allIntegerKeys = false;
} else {
Integer keyAsInt = Utilities.tryParseInt(key);
if (keyAsInt != null && keyAsInt >= 0) {
if (keyAsInt > maxKey) {
maxKey = keyAsInt;
}
} else {
allIntegerKeys = false;
}
}
}
}
if (!useExportFormat && allIntegerKeys && maxKey < 2 * numKeys) {
// convert to an array
List<Object> arrayResult = new ArrayList<>(maxKey + 1);
for (int i = 0; i <= maxKey; ++i) {
// Map.get will return null for non-existent values, so we don't have to worry about
// filling them in manually
arrayResult.add(result.get("" + i));
}
return arrayResult;
} else {
if (useExportFormat && !priority.isEmpty()) {
result.put(".priority", priority.getValue());
}
return result;
}
}
@Override
public ChildKey getPredecessorChildKey(ChildKey childKey) {
return this.children.getPredecessorKey(childKey);
}
@Override
public ChildKey getSuccessorChildKey(ChildKey childKey) {
return this.children.getSuccessorKey(childKey);
}
@Override
public String getHashRepresentation(HashVersion version) {
if (version != HashVersion.V1) {
throw new IllegalArgumentException("Hashes on children nodes only supported for V1");
}
final StringBuilder toHash = new StringBuilder();
if (!priority.isEmpty()) {
toHash.append("priority:");
toHash.append(priority.getHashRepresentation(HashVersion.V1));
toHash.append(":");
}
List<NamedNode> nodes = new ArrayList<>();
boolean sawPriority = false;
for (NamedNode node : this) {
nodes.add(node);
sawPriority = sawPriority || !node.getNode().getPriority().isEmpty();
}
if (sawPriority) {
Collections.sort(nodes, PriorityIndex.getInstance());
}
for (NamedNode node : nodes) {
String hashString = node.getNode().getHash();
if (!hashString.equals("")) {
toHash.append(":");
toHash.append(node.getName().asString());
toHash.append(":");
toHash.append(hashString);
}
}
return toHash.toString();
}
@Override
public String getHash() {
if (this.lazyHash == null) {
String hashString = getHashRepresentation(HashVersion.V1);
this.lazyHash = hashString.isEmpty() ? "" : Utilities.sha1HexDigest(hashString);
}
return this.lazyHash;
}
@Override
public boolean isLeafNode() {
return false;
}
@Override
public Node getPriority() {
return priority;
}
@Override
public Node updatePriority(Node priority) {
if (this.children.isEmpty()) {
return EmptyNode.Empty();
} else {
return new ChildrenNode(this.children, priority);
}
}
@Override
public Node getImmediateChild(ChildKey name) {
// Hack to treat priority as a regular child
if (name.isPriorityChildName() && !this.priority.isEmpty()) {
return this.priority;
} else if (children.containsKey(name)) {
return children.get(name);
} else {
return EmptyNode.Empty();
}
}
@Override
public Node getChild(Path path) {
ChildKey front = path.getFront();
if (front == null) {
return this;
} else {
return getImmediateChild(front).getChild(path.popFront());
}
}
public void forEachChild(final ChildVisitor visitor) {
forEachChild(visitor, /*includePriority=*/ false);
}
public void forEachChild(final ChildVisitor visitor, boolean includePriority) {
if (!includePriority || this.getPriority().isEmpty()) {
children.inOrderTraversal(visitor);
} else {
children.inOrderTraversal(
new LLRBNode.NodeVisitor<ChildKey, Node>() {
boolean passedPriorityKey = false;
@Override
public void visitEntry(ChildKey key, Node value) {
if (!passedPriorityKey && key.compareTo(ChildKey.getPriorityKey()) > 0) {
passedPriorityKey = true;
visitor.visitChild(ChildKey.getPriorityKey(), getPriority());
}
visitor.visitChild(key, value);
}
});
}
}
public ChildKey getFirstChildKey() {
return children.getMinKey();
}
public ChildKey getLastChildKey() {
return children.getMaxKey();
}
@Override
public Node updateChild(Path path, Node newChildNode) {
ChildKey front = path.getFront();
if (front == null) {
return newChildNode;
} else if (front.isPriorityChildName()) {
assert PriorityUtilities.isValidPriority(newChildNode);
return updatePriority(newChildNode);
} else {
Node newImmediateChild = getImmediateChild(front).updateChild(path.popFront(), newChildNode);
return updateImmediateChild(front, newImmediateChild);
}
}
@Override
public Iterator<NamedNode> iterator() {
return new NamedNodeIterator(children.iterator());
}
@Override
public Iterator<NamedNode> reverseIterator() {
return new NamedNodeIterator(children.reverseIterator());
}
@Override
public Node updateImmediateChild(ChildKey key, Node newChildNode) {
if (key.isPriorityChildName()) {
return updatePriority(newChildNode);
} else {
ImmutableSortedMap<ChildKey, Node> newChildren = children;
if (newChildren.containsKey(key)) {
newChildren = newChildren.remove(key);
}
if (!newChildNode.isEmpty()) {
newChildren = newChildren.insert(key, newChildNode);
}
if (newChildren.isEmpty()) {
// Ignore priorities on empty nodes
return EmptyNode.Empty();
} else {
return new ChildrenNode(newChildren, this.priority);
}
}
}
@Override
public int compareTo(Node o) {
if (this.isEmpty()) {
if (o.isEmpty()) {
return 0;
} else {
return -1;
}
} else if (o.isLeafNode()) {
// Children nodes are greater than all leaf nodes
return 1;
} else if (o.isEmpty()) {
return 1;
} else if (o == Node.MAX_NODE) {
return -1;
} else {
// Must be another Children node
return 0;
}
}
@Override
public boolean equals(Object otherObj) {
if (otherObj == null) {
return false;
}
if (otherObj == this) {
return true;
}
if (!(otherObj instanceof ChildrenNode)) {
return false;
}
ChildrenNode other = (ChildrenNode) otherObj;
if (!this.getPriority().equals(other.getPriority())) {
return false;
} else if (this.children.size() != other.children.size()) {
return false;
} else {
Iterator<Map.Entry<ChildKey, Node>> thisIterator = this.children.iterator();
Iterator<Map.Entry<ChildKey, Node>> otherIterator = other.children.iterator();
while (thisIterator.hasNext() && otherIterator.hasNext()) {
Map.Entry<ChildKey, Node> thisNameNode = thisIterator.next();
Map.Entry<ChildKey, Node> otherNamedNode = otherIterator.next();
if (!thisNameNode.getKey().equals(otherNamedNode.getKey())
|| !thisNameNode.getValue().equals(otherNamedNode.getValue())) {
return false;
}
}
if (thisIterator.hasNext() || otherIterator.hasNext()) {
throw new IllegalStateException("Something went wrong internally.");
}
return true;
}
}
@Override
public int hashCode() {
int hashCode = 0;
for (NamedNode entry : this) {
hashCode = 31 * hashCode + entry.getName().hashCode();
hashCode = 17 * hashCode + entry.getNode().hashCode();
}
return hashCode;
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
toString(builder, 0);
return builder.toString();
}
private void toString(StringBuilder builder, int indentation) {
if (this.children.isEmpty() && this.priority.isEmpty()) {
builder.append("{ }");
} else {
builder.append("{\n");
for (Map.Entry<ChildKey, Node> childEntry : this.children) {
addIndentation(builder, indentation + 2);
builder.append(childEntry.getKey().asString());
builder.append("=");
if (childEntry.getValue() instanceof ChildrenNode) {
ChildrenNode childrenNode = (ChildrenNode) childEntry.getValue();
childrenNode.toString(builder, indentation + 2);
} else {
builder.append(childEntry.getValue().toString());
}
builder.append("\n");
}
if (!this.priority.isEmpty()) {
addIndentation(builder, indentation + 2);
builder.append(".priority=");
builder.append(this.priority.toString());
builder.append("\n");
}
addIndentation(builder, indentation);
builder.append("}");
}
}
private static class NamedNodeIterator implements Iterator<NamedNode> {
private final Iterator<Map.Entry<ChildKey, Node>> iterator;
public NamedNodeIterator(Iterator<Map.Entry<ChildKey, Node>> iterator) {
this.iterator = iterator;
}
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public NamedNode next() {
Map.Entry<ChildKey, Node> entry = iterator.next();
return new NamedNode(entry.getKey(), entry.getValue());
}
@Override
public void remove() {
iterator.remove();
}
}
public abstract static class ChildVisitor extends LLRBNode.NodeVisitor<ChildKey, Node> {
@Override
public void visitEntry(ChildKey key, Node value) {
visitChild(key, value);
}
public abstract void visitChild(ChildKey name, Node child);
}
}