| Index: third_party/protobuf/java/src/main/java/com/google/protobuf/LazyField.java
|
| ===================================================================
|
| --- third_party/protobuf/java/src/main/java/com/google/protobuf/LazyField.java (revision 0)
|
| +++ third_party/protobuf/java/src/main/java/com/google/protobuf/LazyField.java (revision 0)
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| @@ -0,0 +1,216 @@
|
| +// Protocol Buffers - Google's data interchange format
|
| +// Copyright 2008 Google Inc. All rights reserved.
|
| +// http://code.google.com/p/protobuf/
|
| +//
|
| +// Redistribution and use in source and binary forms, with or without
|
| +// modification, are permitted provided that the following conditions are
|
| +// met:
|
| +//
|
| +// * Redistributions of source code must retain the above copyright
|
| +// notice, this list of conditions and the following disclaimer.
|
| +// * Redistributions in binary form must reproduce the above
|
| +// copyright notice, this list of conditions and the following disclaimer
|
| +// in the documentation and/or other materials provided with the
|
| +// distribution.
|
| +// * Neither the name of Google Inc. nor the names of its
|
| +// contributors may be used to endorse or promote products derived from
|
| +// this software without specific prior written permission.
|
| +//
|
| +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
| +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
| +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
| +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
| +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
| +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
| +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
| +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
| +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
| +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
| +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
| +
|
| +package com.google.protobuf;
|
| +
|
| +import java.io.IOException;
|
| +import java.util.Iterator;
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| +import java.util.Map.Entry;
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| +
|
| +/**
|
| + * LazyField encapsulates the logic of lazily parsing message fields. It stores
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| + * the message in a ByteString initially and then parse it on-demand.
|
| + *
|
| + * LazyField is thread-compatible e.g. concurrent read are safe, however,
|
| + * synchronizations are needed under read/write situations.
|
| + *
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| + * Now LazyField is only used to lazily load MessageSet.
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| + * TODO(xiangl): Use LazyField to lazily load all messages.
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| + *
|
| + * @author xiangl@google.com (Xiang Li)
|
| + */
|
| +class LazyField {
|
| +
|
| + final private MessageLite defaultInstance;
|
| + final private ExtensionRegistryLite extensionRegistry;
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| +
|
| + // Mutable because it is initialized lazily.
|
| + private ByteString bytes;
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| + private volatile MessageLite value;
|
| + private volatile boolean isDirty = false;
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| +
|
| + public LazyField(MessageLite defaultInstance,
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| + ExtensionRegistryLite extensionRegistry, ByteString bytes) {
|
| + this.defaultInstance = defaultInstance;
|
| + this.extensionRegistry = extensionRegistry;
|
| + this.bytes = bytes;
|
| + }
|
| +
|
| + public MessageLite getValue() {
|
| + ensureInitialized();
|
| + return value;
|
| + }
|
| +
|
| + /**
|
| + * LazyField is not thread-safe for write access. Synchronizations are needed
|
| + * under read/write situations.
|
| + */
|
| + public MessageLite setValue(MessageLite value) {
|
| + MessageLite originalValue = this.value;
|
| + this.value = value;
|
| + bytes = null;
|
| + isDirty = true;
|
| + return originalValue;
|
| + }
|
| +
|
| + /**
|
| + * Due to the optional field can be duplicated at the end of serialized
|
| + * bytes, which will make the serialized size changed after LazyField
|
| + * parsed. Be careful when using this method.
|
| + */
|
| + public int getSerializedSize() {
|
| + if (isDirty) {
|
| + return value.getSerializedSize();
|
| + }
|
| + return bytes.size();
|
| + }
|
| +
|
| + public ByteString toByteString() {
|
| + if (!isDirty) {
|
| + return bytes;
|
| + }
|
| + synchronized (this) {
|
| + if (!isDirty) {
|
| + return bytes;
|
| + }
|
| + bytes = value.toByteString();
|
| + isDirty = false;
|
| + return bytes;
|
| + }
|
| + }
|
| +
|
| + @Override
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| + public int hashCode() {
|
| + ensureInitialized();
|
| + return value.hashCode();
|
| + }
|
| +
|
| + @Override
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| + public boolean equals(Object obj) {
|
| + ensureInitialized();
|
| + return value.equals(obj);
|
| + }
|
| +
|
| + @Override
|
| + public String toString() {
|
| + ensureInitialized();
|
| + return value.toString();
|
| + }
|
| +
|
| + private void ensureInitialized() {
|
| + if (value != null) {
|
| + return;
|
| + }
|
| + synchronized (this) {
|
| + if (value != null) {
|
| + return;
|
| + }
|
| + try {
|
| + if (bytes != null) {
|
| + value = defaultInstance.getParserForType()
|
| + .parseFrom(bytes, extensionRegistry);
|
| + }
|
| + } catch (IOException e) {
|
| + // TODO(xiangl): Refactory the API to support the exception thrown from
|
| + // lazily load messages.
|
| + }
|
| + }
|
| + }
|
| +
|
| + // ====================================================
|
| +
|
| + /**
|
| + * LazyEntry and LazyIterator are used to encapsulate the LazyField, when
|
| + * users iterate all fields from FieldSet.
|
| + */
|
| + static class LazyEntry<K> implements Entry<K, Object> {
|
| + private Entry<K, LazyField> entry;
|
| +
|
| + private LazyEntry(Entry<K, LazyField> entry) {
|
| + this.entry = entry;
|
| + }
|
| +
|
| + @Override
|
| + public K getKey() {
|
| + return entry.getKey();
|
| + }
|
| +
|
| + @Override
|
| + public Object getValue() {
|
| + LazyField field = entry.getValue();
|
| + if (field == null) {
|
| + return null;
|
| + }
|
| + return field.getValue();
|
| + }
|
| +
|
| + public LazyField getField() {
|
| + return entry.getValue();
|
| + }
|
| +
|
| + @Override
|
| + public Object setValue(Object value) {
|
| + if (!(value instanceof MessageLite)) {
|
| + throw new IllegalArgumentException(
|
| + "LazyField now only used for MessageSet, "
|
| + + "and the value of MessageSet must be an instance of MessageLite");
|
| + }
|
| + return entry.getValue().setValue((MessageLite) value);
|
| + }
|
| + }
|
| +
|
| + static class LazyIterator<K> implements Iterator<Entry<K, Object>> {
|
| + private Iterator<Entry<K, Object>> iterator;
|
| +
|
| + public LazyIterator(Iterator<Entry<K, Object>> iterator) {
|
| + this.iterator = iterator;
|
| + }
|
| +
|
| + @Override
|
| + public boolean hasNext() {
|
| + return iterator.hasNext();
|
| + }
|
| +
|
| + @SuppressWarnings("unchecked")
|
| + @Override
|
| + public Entry<K, Object> next() {
|
| + Entry<K, ?> entry = iterator.next();
|
| + if (entry.getValue() instanceof LazyField) {
|
| + return new LazyEntry<K>((Entry<K, LazyField>) entry);
|
| + }
|
| + return (Entry<K, Object>) entry;
|
| + }
|
| +
|
| + @Override
|
| + public void remove() {
|
| + iterator.remove();
|
| + }
|
| + }
|
| +}
|
|
|
| Property changes on: third_party/protobuf/java/src/main/java/com/google/protobuf/LazyField.java
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
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