0,0 → 1,169 |
// 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.util.Collections; |
import java.util.HashMap; |
import java.util.Map; |
|
/** |
* Equivalent to {@link ExtensionRegistry} but supports only "lite" types. |
* <p> |
* If all of your types are lite types, then you only need to use |
* {@code ExtensionRegistryLite}. Similarly, if all your types are regular |
* types, then you only need {@link ExtensionRegistry}. Typically it does not |
* make sense to mix the two, since if you have any regular types in your |
* program, you then require the full runtime and lose all the benefits of |
* the lite runtime, so you might as well make all your types be regular types. |
* However, in some cases (e.g. when depending on multiple third-patry libraries |
* where one uses lite types and one uses regular), you may find yourself |
* wanting to mix the two. In this case things get more complicated. |
* <p> |
* There are three factors to consider: Whether the type being extended is |
* lite, whether the embedded type (in the case of a message-typed extension) |
* is lite, and whether the extension itself is lite. Since all three are |
* declared in different files, they could all be different. Here are all |
* the combinations and which type of registry to use: |
* <pre> |
* Extended type Inner type Extension Use registry |
* ======================================================================= |
* lite lite lite ExtensionRegistryLite |
* lite regular lite ExtensionRegistry |
* regular regular regular ExtensionRegistry |
* all other combinations not supported |
* </pre> |
* <p> |
* Note that just as regular types are not allowed to contain lite-type fields, |
* they are also not allowed to contain lite-type extensions. This is because |
* regular types must be fully accessible via reflection, which in turn means |
* that all the inner messages must also support reflection. On the other hand, |
* since regular types implement the entire lite interface, there is no problem |
* with embedding regular types inside lite types. |
* |
* @author kenton@google.com Kenton Varda |
*/ |
public class ExtensionRegistryLite { |
/** Construct a new, empty instance. */ |
public static ExtensionRegistryLite newInstance() { |
return new ExtensionRegistryLite(); |
} |
|
/** Get the unmodifiable singleton empty instance. */ |
public static ExtensionRegistryLite getEmptyRegistry() { |
return EMPTY; |
} |
|
/** Returns an unmodifiable view of the registry. */ |
public ExtensionRegistryLite getUnmodifiable() { |
return new ExtensionRegistryLite(this); |
} |
|
/** |
* Find an extension by containing type and field number. |
* |
* @return Information about the extension if found, or {@code null} |
* otherwise. |
*/ |
@SuppressWarnings("unchecked") |
public <ContainingType extends MessageLite> |
GeneratedMessageLite.GeneratedExtension<ContainingType, ?> |
findLiteExtensionByNumber( |
final ContainingType containingTypeDefaultInstance, |
final int fieldNumber) { |
return (GeneratedMessageLite.GeneratedExtension<ContainingType, ?>) |
extensionsByNumber.get( |
new ObjectIntPair(containingTypeDefaultInstance, fieldNumber)); |
} |
|
/** Add an extension from a lite generated file to the registry. */ |
public final void add( |
final GeneratedMessageLite.GeneratedExtension<?, ?> extension) { |
extensionsByNumber.put( |
new ObjectIntPair(extension.getContainingTypeDefaultInstance(), |
extension.getNumber()), |
extension); |
} |
|
// ================================================================= |
// Private stuff. |
|
// Constructors are package-private so that ExtensionRegistry can subclass |
// this. |
|
ExtensionRegistryLite() { |
this.extensionsByNumber = |
new HashMap<ObjectIntPair, |
GeneratedMessageLite.GeneratedExtension<?, ?>>(); |
} |
|
ExtensionRegistryLite(ExtensionRegistryLite other) { |
if (other == EMPTY) { |
this.extensionsByNumber = Collections.emptyMap(); |
} else { |
this.extensionsByNumber = |
Collections.unmodifiableMap(other.extensionsByNumber); |
} |
} |
|
private final Map<ObjectIntPair, |
GeneratedMessageLite.GeneratedExtension<?, ?>> |
extensionsByNumber; |
|
private ExtensionRegistryLite(boolean empty) { |
this.extensionsByNumber = Collections.emptyMap(); |
} |
private static final ExtensionRegistryLite EMPTY = |
new ExtensionRegistryLite(true); |
|
/** A (Object, int) pair, used as a map key. */ |
private static final class ObjectIntPair { |
private final Object object; |
private final int number; |
|
ObjectIntPair(final Object object, final int number) { |
this.object = object; |
this.number = number; |
} |
|
@Override |
public int hashCode() { |
return System.identityHashCode(object) * ((1 << 16) - 1) + number; |
} |
@Override |
public boolean equals(final Object obj) { |
if (!(obj instanceof ObjectIntPair)) { |
return false; |
} |
final ObjectIntPair other = (ObjectIntPair)obj; |
return object == other.object && number == other.number; |
} |
} |
} |