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package org.mule.util.store; |
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import org.mule.api.store.ObjectAlreadyExistsException; |
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import org.mule.api.store.ObjectDoesNotExistException; |
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import org.mule.api.store.ObjectStoreException; |
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import org.mule.config.i18n.CoreMessages; |
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import java.io.Serializable; |
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import java.util.Iterator; |
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import java.util.Map; |
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import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentSkipListMap; |
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import edu.emory.mathcs.backport.java.util.concurrent.TimeUnit; |
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public class InMemoryObjectStore<T extends Serializable> extends AbstractMonitoredObjectStore<T> |
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{ |
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protected ConcurrentSkipListMap store; |
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public InMemoryObjectStore() |
36 | 0 | { |
37 | 0 | this.store = new ConcurrentSkipListMap(); |
38 | 0 | } |
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public boolean contains(Serializable key) throws ObjectStoreException |
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{ |
45 | 0 | if (key == null) |
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{ |
47 | 0 | throw new ObjectStoreException(CoreMessages.objectIsNull("id")); |
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} |
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|
50 | 0 | synchronized (store) |
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{ |
52 | 0 | return store.values().contains(new StoredObject<T>(key, null)); |
53 | 0 | } |
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} |
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public void store(Serializable id, T value) throws ObjectStoreException |
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{ |
61 | 0 | if (id == null) |
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{ |
63 | 0 | throw new ObjectStoreException(CoreMessages.objectIsNull("id")); |
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} |
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|
68 | 0 | StoredObject<T> obj = new StoredObject<T>(id, value); |
69 | 0 | synchronized (store) |
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{ |
71 | 0 | if (store.values().contains(obj)) |
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{ |
73 | 0 | throw new ObjectAlreadyExistsException(); |
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} |
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|
76 | 0 | boolean written = false; |
77 | 0 | while (!written) |
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{ |
79 | 0 | Long key = Long.valueOf(System.nanoTime()); |
80 | 0 | written = (store.put(key, obj) == null); |
81 | 0 | } |
82 | 0 | } |
83 | 0 | } |
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@SuppressWarnings("unchecked") |
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public T retrieve(Serializable key) throws ObjectStoreException |
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{ |
91 | 0 | synchronized (store) |
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{ |
93 | 0 | Map.Entry<?, ?> entry = findEntry(key); |
94 | 0 | if (entry != null) |
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{ |
96 | 0 | StoredObject object = (StoredObject) entry.getValue(); |
97 | 0 | return (T)object.getItem(); |
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} |
99 | 0 | } |
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|
101 | 0 | throw new ObjectDoesNotExistException(CoreMessages.objectNotFound(key)); |
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} |
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@SuppressWarnings("unchecked") |
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private Map.Entry<?, ?> findEntry(Serializable key) |
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{ |
107 | 0 | Iterator<?> entryIterator = store.entrySet().iterator(); |
108 | 0 | while (entryIterator.hasNext()) |
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{ |
110 | 0 | Map.Entry<?, ?> entry = (Map.Entry<?, ?>) entryIterator.next(); |
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|
112 | 0 | StoredObject object = (StoredObject) entry.getValue(); |
113 | 0 | if (object.getId().equals(key)) |
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{ |
115 | 0 | return entry; |
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} |
117 | 0 | } |
118 | 0 | return null; |
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} |
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@SuppressWarnings("unchecked") |
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public T remove(Serializable key) throws ObjectStoreException |
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{ |
124 | 0 | synchronized (store) |
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{ |
126 | 0 | Map.Entry<?, ?> entry = findEntry(key); |
127 | 0 | if (entry != null) |
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{ |
129 | 0 | StoredObject removedObject = (StoredObject) store.remove(entry.getKey()); |
130 | 0 | return (T)removedObject.getItem(); |
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} |
132 | 0 | } |
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134 | 0 | throw new ObjectDoesNotExistException(CoreMessages.objectNotFound(key)); |
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} |
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@Override |
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public void expire() |
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{ |
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141 | 0 | int currentSize = store.size(); |
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144 | 0 | currentSize = trimToMaxSize(currentSize); |
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|
147 | 0 | if ((entryTTL > 0) && (currentSize != 0)) |
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{ |
149 | 0 | final long now = System.nanoTime(); |
150 | 0 | int expiredEntries = 0; |
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Map.Entry<?, ?> oldestEntry; |
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purge: |
154 | 0 | while ((oldestEntry = store.firstEntry()) != null) |
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{ |
156 | 0 | Long oldestKey = (Long) oldestEntry.getKey(); |
157 | 0 | long oldestKeyValue = oldestKey.longValue(); |
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|
159 | 0 | if (TimeUnit.NANOSECONDS.toMillis(now - oldestKeyValue) >= entryTTL) |
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{ |
161 | 0 | store.remove(oldestKey); |
162 | 0 | expiredEntries++; |
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} |
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else |
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{ |
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break purge; |
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} |
168 | 0 | } |
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170 | 0 | if (logger.isDebugEnabled()) |
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{ |
172 | 0 | logger.debug("Expired " + expiredEntries + " old entries"); |
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} |
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} |
175 | 0 | } |
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private int trimToMaxSize(int currentSize) |
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{ |
179 | 0 | if (maxEntries < 0) |
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{ |
181 | 0 | return currentSize; |
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} |
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|
184 | 0 | int excess = (currentSize - maxEntries); |
185 | 0 | if (excess > 0) |
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{ |
187 | 0 | while (currentSize > maxEntries) |
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{ |
189 | 0 | store.pollFirstEntry(); |
190 | 0 | currentSize--; |
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} |
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193 | 0 | if (logger.isDebugEnabled()) |
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{ |
195 | 0 | logger.debug("Expired " + excess + " excess entries"); |
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} |
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} |
198 | 0 | return currentSize; |
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} |
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@Override |
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public String toString() |
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{ |
204 | 0 | return getClass().getSimpleName() + " " + store; |
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} |
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protected static class StoredObject<T> |
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{ |
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private Serializable id; |
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private T item; |
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public StoredObject(Serializable id, T item) |
216 | 0 | { |
217 | 0 | this.id = id; |
218 | 0 | this.item = item; |
219 | 0 | } |
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public Serializable getId() |
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{ |
223 | 0 | return id; |
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} |
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public T getItem() |
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{ |
228 | 0 | return item; |
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} |
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@Override |
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@SuppressWarnings("unchecked") |
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public boolean equals(Object o) |
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{ |
235 | 0 | if (this == o) |
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{ |
237 | 0 | return true; |
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} |
239 | 0 | if (o == null || getClass() != o.getClass()) |
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{ |
241 | 0 | return false; |
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} |
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|
244 | 0 | StoredObject that = (StoredObject) o; |
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|
246 | 0 | if (!id.equals(that.id)) |
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{ |
248 | 0 | return false; |
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} |
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|
251 | 0 | return true; |
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} |
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@Override |
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public int hashCode() |
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{ |
257 | 0 | return id.hashCode(); |
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} |
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@Override |
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public String toString() |
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{ |
263 | 0 | final StringBuffer sb = new StringBuffer(); |
264 | 0 | sb.append("StoredObject"); |
265 | 0 | sb.append("{id='").append(id).append('\''); |
266 | 0 | sb.append(", item=").append(item); |
267 | 0 | sb.append('}'); |
268 | 0 | return sb.toString(); |
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} |
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} |
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} |