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SnappyData store based off Pivotal GemFireXD
/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* 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. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.internal.cache;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import com.gemstone.gemfire.CopyHelper;
import com.gemstone.gemfire.DataSerializer;
import com.gemstone.gemfire.cache.Region;
import com.gemstone.gemfire.internal.DataSerializableFixedID;
import com.gemstone.gemfire.internal.LogWriterImpl;
import com.gemstone.gemfire.internal.cache.lru.LRUEntry;
import com.gemstone.gemfire.internal.i18n.LocalizedStrings;
import com.gemstone.gemfire.internal.shared.Version;
import com.gemstone.gemfire.pdx.PdxInstance;
/**
* The first time someone asks this instance for its Object it will deserialize
* the bytes and from then on keep a reference to the deserialized form.
* So it "prefers deserialization".
* @author Eric Zoerner
*
*/
public final class VMCachedDeserializable implements CachedDeserializable, DataSerializableFixedID {
/** The cached value */
private volatile Object value;
private int valueSize; // only set in constructor or fromData
/**
* +PER_OBJECT_OVERHEAD for VMCachedDeserializable object
* +4 for value field
* +4 for valueSize field
*/
static final int MEM_OVERHEAD = PER_OBJECT_OVERHEAD + 4 + 4;
/**
* zero-arg constructor for serialization only
*/
public VMCachedDeserializable() {
}
/**
* Creates a new instance of VMCachedDeserializable.
*
* Note that, in general, instances of this class should be obtained
* via {@link CachedDeserializableFactory}.
*/
VMCachedDeserializable(byte[] serializedValue) {
if (serializedValue == null)
throw new NullPointerException(LocalizedStrings.VMCachedDeserializable_VALUE_MUST_NOT_BE_NULL.toLocalizedString());
this.value = serializedValue;
this.valueSize = CachedDeserializableFactory.getByteSize(serializedValue);
}
VMCachedDeserializable(VMCachedDeserializable cd) {
this.value = cd.value;
this.valueSize = cd.valueSize;
}
/**
* Create a new instance with an object and it's size.
* Note the caller decides if objectSize is the memory size or the serialized size.
* @param object
* @param objectSize
*/
public VMCachedDeserializable(Object object, int objectSize) {
this.value = object;
this.valueSize = objectSize;
}
public Object getDeserializedValue(Region r, RegionEntry re) {
Object v = this.value;
if (v instanceof byte[]) {
// com.gemstone.gemfire.internal.cache.GemFireCache.getInstance().getLogger().info("DEBUG getDeserializedValue r=" + r + " re=" + re, new RuntimeException("STACK"));
LRUEntry le = null;
if (re != null) {
assert r != null;
if (re instanceof LRUEntry) {
le = (LRUEntry)re;
}
}
if (le != null) {
if (r instanceof PartitionedRegion) {
r = ((PartitionedRegion)r).getBucketRegion(re.getKeyCopy());
}
boolean callFinish = false;
AbstractLRURegionMap lruMap = null;
if (r != null) { // fix for bug 44795
lruMap = (AbstractLRURegionMap)((LocalRegion)r).getRegionMap();
}
boolean threadAlreadySynced = Thread.holdsLock(le);
boolean isCacheListenerInvoked = re.isCacheListenerInvocationInProgress();
synchronized (le) {
v = this.value;
if (!(v instanceof byte[])) return v;
v = EntryEventImpl.deserialize((byte[])v);
if (threadAlreadySynced && !isCacheListenerInvoked) {
// to fix bug 43355 and 43409 don't change the value form
// if the thread that called us was already synced.
return v;
}
if (!(v instanceof PdxInstance)) {
this.value = v;
if (lruMap != null) {
callFinish = lruMap.beginChangeValueForm(le, this, v);
}
}
}
if (callFinish && !isCacheListenerInvoked) {
lruMap.finishChangeValueForm();
}
} else {
// we sync on this so we will only do one deserialize
synchronized (this) {
v = this.value;
if (!(v instanceof byte[])) return v;
v = EntryEventImpl.deserialize((byte[])v);
if (!(v instanceof PdxInstance)) {
this.value = v;
}
// ObjectSizer os = null;
// if (r != null) {
// EvictionAttributes ea = r.getAttributes().getEvictionAttributes();
// if (ea != null) {
// os = ea.getObjectSizer();
// }
// int vSize = CachedDeserializableFactory.calcMemSize(v, os, false, false);
// if (vSize != -1) {
// int oldSize = this.valueSize;
// this.valueSize = vSize;
// if (r instanceof BucketRegion) {
// BucketRegion br = (BucketRegion)r;
// br.updateBucketMemoryStats(vSize - oldSize);
// }
// // @todo do we need to update some lru stats since the size changed?
// }
// // If vSize == -1 then leave valueSize as is which is the serialized size.
}
}
}
return v;
}
public Object getDeserializedForReading() {
Object v = this.value;
if (v instanceof byte[]) {
return EntryEventImpl.deserialize((byte[])v);
} else {
return v;
}
}
public Object getDeserializedWritableCopy(Region r, RegionEntry re) {
Object v = this.value;
if (v instanceof byte[]) {
Object result = EntryEventImpl.deserialize((byte[])v);
if (CopyHelper.isWellKnownImmutableInstance(result, result.getClass())
&& !(result instanceof PdxInstance)) {
// Since it is immutable go ahead and change the form
// since we can return the immutable instance each time.
result = getDeserializedValue(r, re);
}
return result;
} else {
return CopyHelper.copy(v);
}
}
/**
* Return the serialized value as a byte[]
*/
public byte[] getSerializedValue() {
Object v = this.value;
if (v instanceof byte[])
return (byte[])v;
return EntryEventImpl.serialize(v);
}
/**
* Return current value regardless of whether it is serialized or
* deserialized: if it was serialized than it is a byte[], otherwise
* it is not a byte[].
*/
public Object getValue() {
return this.value;
}
public int getSizeInBytes() {
return MEM_OVERHEAD + this.valueSize;
}
public int getValueSizeInBytes() {
return valueSize;
}
public int getDSFID() {
return VM_CACHED_DESERIALIZABLE;
}
public void fromData(DataInput in) throws IOException, ClassNotFoundException {
// fix for bug 38309
byte[] bytes = DataSerializer.readByteArray(in);
this.valueSize = bytes.length;
this.value = bytes;
}
public void toData(DataOutput out) throws IOException {
// fix for bug 38309
DataSerializer.writeObjectAsByteArray(getValue(), out);
}
String getShortClassName() {
String cname = getClass().getName();
return cname.substring(getClass().getPackage().getName().length()+1);
}
@Override
public String toString() {
return getShortClassName() + '@' + this.hashCode();
}
public void writeValueAsByteArray(DataOutput out) throws IOException {
toData(out);
}
public void fillSerializedValue(BytesAndBitsForCompactor wrapper, byte userBits)
{
Object v = this.value;
if (v instanceof byte[]) {
wrapper.setData((byte[])v, userBits, ((byte[])v).length, false /* Not Reusable as it refers to underlying value*/);
}else {
EntryEventImpl.fillSerializedValue(wrapper, v, userBits);
}
}
public String getStringForm() {
try {
return LogWriterImpl.forceToString(getDeserializedForReading());
} catch (RuntimeException ex) {
return "Could not convert object to string because " + ex;
}
}
@Override
public Version[] getSerializationVersions() {
return null;
}
}