/*
* 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.mongomk;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import org.apache.jackrabbit.mk.api.MicroKernelException;
import org.apache.jackrabbit.mongomk.UpdateOp.Operation;
import org.apache.jackrabbit.mongomk.util.Utils;
/**
* Emulates a MongoDB store (possibly consisting of multiple shards and
* replicas).
*/
public class MemoryDocumentStore implements DocumentStore {
/**
* The 'nodes' collection.
*/
private ConcurrentSkipListMap<String, Map<String, Object>> nodes =
new ConcurrentSkipListMap<String, Map<String, Object>>();
/**
* The 'clusterNodes' collection.
*/
private ConcurrentSkipListMap<String, Map<String, Object>> clusterNodes =
new ConcurrentSkipListMap<String, Map<String, Object>>();
public Map<String, Object> find(Collection collection, String key, int maxCacheAge) {
return find(collection, key);
}
public Map<String, Object> find(Collection collection, String key) {
ConcurrentSkipListMap<String, Map<String, Object>> map = getMap(collection);
Map<String, Object> n = map.get(key);
if (n == null) {
return null;
}
Map<String, Object> copy = Utils.newMap();
synchronized (n) {
Utils.deepCopyMap(n, copy);
}
return copy;
}
@Nonnull
public List<Map<String, Object>> query(Collection collection, String fromKey, String toKey, int limit) {
ConcurrentSkipListMap<String, Map<String, Object>> map = getMap(collection);
ConcurrentNavigableMap<String, Map<String, Object>> sub = map.subMap(fromKey, toKey);
ArrayList<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
for (Map<String, Object> n : sub.values()) {
Map<String, Object> copy = Utils.newMap();
synchronized (n) {
Utils.deepCopyMap(n, copy);
}
list.add(copy);
if (list.size() > limit) {
break;
}
}
return list;
}
public void remove(Collection collection, String path) {
getMap(collection).remove(path);
}
/**
* Get the in-memory map for this collection.
*
* @param collection the collection
* @return the map
*/
private ConcurrentSkipListMap<String, Map<String, Object>> getMap(Collection collection) {
switch (collection) {
case NODES:
return nodes;
case CLUSTER_NODES:
return clusterNodes;
default:
throw new IllegalArgumentException(collection.name());
}
}
@CheckForNull
private Map<String, Object> internalCreateOrUpdate(Collection collection,
UpdateOp update,
boolean checkConditions) {
ConcurrentSkipListMap<String, Map<String, Object>> map = getMap(collection);
Map<String, Object> n;
Map<String, Object> oldNode;
// get the node if it's there
oldNode = n = map.get(update.key);
if (n == null) {
if (!update.isNew) {
throw new MicroKernelException("Document does not exist: " + update.key);
}
// for a new node, add it (without synchronization)
n = Utils.newMap();
oldNode = map.putIfAbsent(update.key, n);
if (oldNode != null) {
// somebody else added it at the same time
n = oldNode;
}
}
synchronized (n) {
if (checkConditions && !checkConditions(n, update)) {
return null;
}
if (oldNode != null) {
// clone the old node
// (document level operations are synchronized)
Map<String, Object> oldNode2 = Utils.newMap();
Utils.deepCopyMap(oldNode, oldNode2);
oldNode = oldNode2;
}
// to return the new document:
// update the document
// (document level operations are synchronized)
applyChanges(n, update);
}
return oldNode;
}
@Nonnull
@Override
public Map<String, Object> createOrUpdate(Collection collection,
UpdateOp update)
throws MicroKernelException {
return internalCreateOrUpdate(collection, update, false);
}
@Override
public Map<String, Object> findAndUpdate(Collection collection,
UpdateOp update)
throws MicroKernelException {
return internalCreateOrUpdate(collection, update, true);
}
private static boolean checkConditions(Map<String, Object> target,
UpdateOp update) {
for (Map.Entry<String, Operation> change : update.changes.entrySet()) {
Operation op = change.getValue();
if (op.type == Operation.Type.CONTAINS_MAP_ENTRY) {
String k = change.getKey();
String[] kv = k.split("\\.");
Object value = target.get(kv[0]);
if (value == null) {
if (Boolean.TRUE.equals(op.value)) {
return false;
}
} else {
if (value instanceof java.util.Collection) {
java.util.Collection<?> col = (java.util.Collection<?>) value;
if (Boolean.TRUE.equals(op.value)) {
if (!col.contains(kv[1])) {
return false;
}
} else {
if (col.contains(kv[1])) {
return false;
}
}
} else {
return false;
}
}
}
}
return true;
}
/**
* Apply the changes to the in-memory map.
*
* @param target the target map
* @param update the changes to apply
*/
public static void applyChanges(Map<String, Object> target, UpdateOp update) {
for (Entry<String, Operation> e : update.changes.entrySet()) {
String k = e.getKey();
String[] kv = k.split("\\.");
Operation op = e.getValue();
switch (op.type) {
case SET: {
target.put(k, op.value);
break;
}
case INCREMENT: {
Object old = target.get(k);
Long x = (Long) op.value;
if (old == null) {
old = 0L;
}
target.put(k, ((Long) old) + x);
break;
}
case SET_MAP_ENTRY: {
Object old = target.get(kv[0]);
@SuppressWarnings("unchecked")
Map<String, Object> m = (Map<String, Object>) old;
if (m == null) {
m = Utils.newMap();
target.put(kv[0], m);
}
m.put(kv[1], op.value);
break;
}
case REMOVE_MAP_ENTRY: {
Object old = target.get(kv[0]);
@SuppressWarnings("unchecked")
Map<String, Object> m = (Map<String, Object>) old;
if (m != null) {
m.remove(kv[1]);
}
break;
}
case SET_MAP: {
Object old = target.get(kv[0]);
@SuppressWarnings("unchecked")
Map<String, Object> m = (Map<String, Object>) old;
if (m == null) {
m = Utils.newMap();
target.put(kv[0], m);
}
m.put(kv[1], op.value);
break;
}
case CONTAINS_MAP_ENTRY:
// no effect
break;
}
}
}
@Override
public boolean create(Collection collection, List<UpdateOp> updateOps) {
ConcurrentSkipListMap<String, Map<String, Object>> map = getMap(collection);
for (UpdateOp op : updateOps) {
if (map.containsKey(op.key)) {
return false;
}
}
for (UpdateOp op : updateOps) {
createOrUpdate(collection, op);
}
return true;
}
public String toString() {
StringBuilder buff = new StringBuilder();
buff.append("Nodes:\n");
for (String p : nodes.keySet()) {
buff.append("Path: ").append(p).append('\n');
Map<String, Object> e = nodes.get(p);
for (String prop : e.keySet()) {
buff.append(prop).append('=').append(e.get(prop)).append('\n');
}
buff.append("\n");
}
return buff.toString();
}
@Override
public void invalidateCache() {
// there is no cache, so nothing to invalidate
}
@Override
public void dispose() {
// ignore
}
@Override
public boolean isCached(Collection collection, String key) {
return false;
}
@Override
public void invalidateCache(Collection collection, String key) {
// ignore
}
}