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1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 //     * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 //     * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 //     * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31 package com.google.protobuf;
32 
33 import java.io.IOException;
34 import java.util.Iterator;
35 import java.util.Map.Entry;
36 
37 /** Schema used for proto2 messages using message_set_wireformat. */
38 final class MessageSetSchema<T> implements Schema<T> {
39   private final MessageLite defaultInstance;
40   private final UnknownFieldSchema<?, ?> unknownFieldSchema;
41   private final boolean hasExtensions;
42   private final ExtensionSchema<?> extensionSchema;
43 
MessageSetSchema( UnknownFieldSchema<?, ?> unknownFieldSchema, ExtensionSchema<?> extensionSchema, MessageLite defaultInstance)44   private MessageSetSchema(
45       UnknownFieldSchema<?, ?> unknownFieldSchema,
46       ExtensionSchema<?> extensionSchema,
47       MessageLite defaultInstance) {
48     this.unknownFieldSchema = unknownFieldSchema;
49     this.hasExtensions = extensionSchema.hasExtensions(defaultInstance);
50     this.extensionSchema = extensionSchema;
51     this.defaultInstance = defaultInstance;
52   }
53 
newSchema( UnknownFieldSchema<?, ?> unknownFieldSchema, ExtensionSchema<?> extensionSchema, MessageLite defaultInstance)54   static <T> MessageSetSchema<T> newSchema(
55       UnknownFieldSchema<?, ?> unknownFieldSchema,
56       ExtensionSchema<?> extensionSchema,
57       MessageLite defaultInstance) {
58     return new MessageSetSchema<T>(unknownFieldSchema, extensionSchema, defaultInstance);
59   }
60 
61   @SuppressWarnings("unchecked")
62   @Override
newInstance()63   public T newInstance() {
64     // TODO(b/248560713) decide if we're keeping support for Full in schema classes and handle this
65     // better.
66     if (defaultInstance instanceof GeneratedMessageLite) {
67       return (T) ((GeneratedMessageLite<?, ?>) defaultInstance).newMutableInstance();
68     } else {
69       return (T) defaultInstance.newBuilderForType().buildPartial();
70     }
71   }
72 
73   @Override
equals(T message, T other)74   public boolean equals(T message, T other) {
75     Object messageUnknown = unknownFieldSchema.getFromMessage(message);
76     Object otherUnknown = unknownFieldSchema.getFromMessage(other);
77     if (!messageUnknown.equals(otherUnknown)) {
78       return false;
79     }
80     if (hasExtensions) {
81       FieldSet<?> messageExtensions = extensionSchema.getExtensions(message);
82       FieldSet<?> otherExtensions = extensionSchema.getExtensions(other);
83       return messageExtensions.equals(otherExtensions);
84     }
85     return true;
86   }
87 
88   @Override
hashCode(T message)89   public int hashCode(T message) {
90     int hashCode = unknownFieldSchema.getFromMessage(message).hashCode();
91     if (hasExtensions) {
92       FieldSet<?> extensions = extensionSchema.getExtensions(message);
93       hashCode = (hashCode * 53) + extensions.hashCode();
94     }
95     return hashCode;
96   }
97 
98   @Override
mergeFrom(T message, T other)99   public void mergeFrom(T message, T other) {
100     SchemaUtil.mergeUnknownFields(unknownFieldSchema, message, other);
101     if (hasExtensions) {
102       SchemaUtil.mergeExtensions(extensionSchema, message, other);
103     }
104   }
105 
106   @SuppressWarnings("unchecked")
107   @Override
writeTo(T message, Writer writer)108   public void writeTo(T message, Writer writer) throws IOException {
109     FieldSet<?> extensions = extensionSchema.getExtensions(message);
110     Iterator<?> iterator = extensions.iterator();
111     while (iterator.hasNext()) {
112       Entry<?, ?> extension = (Entry<?, ?>) iterator.next();
113       FieldSet.FieldDescriptorLite<?> fd = (FieldSet.FieldDescriptorLite<?>) extension.getKey();
114       if (fd.getLiteJavaType() != WireFormat.JavaType.MESSAGE || fd.isRepeated() || fd.isPacked()) {
115         throw new IllegalStateException("Found invalid MessageSet item.");
116       }
117       if (extension instanceof LazyField.LazyEntry) {
118         writer.writeMessageSetItem(
119             fd.getNumber(), ((LazyField.LazyEntry) extension).getField().toByteString());
120       } else {
121         writer.writeMessageSetItem(fd.getNumber(), extension.getValue());
122       }
123     }
124     writeUnknownFieldsHelper(unknownFieldSchema, message, writer);
125   }
126 
127   /**
128    * A helper method for wildcard capture of {@code unknownFieldSchema}. See:
129    * https://docs.oracle.com/javase/tutorial/java/generics/capture.html
130    */
writeUnknownFieldsHelper( UnknownFieldSchema<UT, UB> unknownFieldSchema, T message, Writer writer)131   private <UT, UB> void writeUnknownFieldsHelper(
132       UnknownFieldSchema<UT, UB> unknownFieldSchema, T message, Writer writer) throws IOException {
133     unknownFieldSchema.writeAsMessageSetTo(unknownFieldSchema.getFromMessage(message), writer);
134   }
135 
136   @SuppressWarnings("ReferenceEquality")
137   @Override
mergeFrom( T message, byte[] data, int position, int limit, ArrayDecoders.Registers registers)138   public void mergeFrom(
139       T message, byte[] data, int position, int limit, ArrayDecoders.Registers registers)
140       throws IOException {
141     // TODO(b/248560713) decide if we're keeping support for Full in schema classes and handle this
142     // better.
143     UnknownFieldSetLite unknownFields = ((GeneratedMessageLite) message).unknownFields;
144     if (unknownFields == UnknownFieldSetLite.getDefaultInstance()) {
145       unknownFields = UnknownFieldSetLite.newInstance();
146       ((GeneratedMessageLite) message).unknownFields = unknownFields;
147     }
148     final FieldSet<GeneratedMessageLite.ExtensionDescriptor> extensions =
149         ((GeneratedMessageLite.ExtendableMessage<?, ?>) message).ensureExtensionsAreMutable();
150     GeneratedMessageLite.GeneratedExtension<?, ?> extension = null;
151     while (position < limit) {
152       position = ArrayDecoders.decodeVarint32(data, position, registers);
153       final int startTag = registers.int1;
154       if (startTag != WireFormat.MESSAGE_SET_ITEM_TAG) {
155         if (WireFormat.getTagWireType(startTag) == WireFormat.WIRETYPE_LENGTH_DELIMITED) {
156           extension =
157               (GeneratedMessageLite.GeneratedExtension<?, ?>) extensionSchema.findExtensionByNumber(
158                   registers.extensionRegistry, defaultInstance,
159                   WireFormat.getTagFieldNumber(startTag));
160           if (extension != null) {
161             position =
162                 ArrayDecoders.decodeMessageField(
163                     Protobuf.getInstance().schemaFor(
164                         extension.getMessageDefaultInstance().getClass()),
165                     data, position, limit, registers);
166             extensions.setField(extension.descriptor, registers.object1);
167           } else {
168             position =
169                 ArrayDecoders.decodeUnknownField(
170                     startTag, data, position, limit, unknownFields, registers);
171           }
172         } else {
173           position = ArrayDecoders.skipField(startTag, data, position, limit, registers);
174         }
175         continue;
176       }
177 
178       int typeId = 0;
179       ByteString rawBytes = null;
180 
181       while (position < limit) {
182         position = ArrayDecoders.decodeVarint32(data, position, registers);
183         final int tag = registers.int1;
184         final int number = WireFormat.getTagFieldNumber(tag);
185         final int wireType = WireFormat.getTagWireType(tag);
186         switch (number) {
187           case WireFormat.MESSAGE_SET_TYPE_ID:
188             if (wireType == WireFormat.WIRETYPE_VARINT) {
189               position = ArrayDecoders.decodeVarint32(data, position, registers);
190               typeId = registers.int1;
191               // TODO(b/248560713) decide if we're keeping support for Full in schema classes and
192               // handle this better.
193               extension =
194                   (GeneratedMessageLite.GeneratedExtension<?, ?>)
195                       extensionSchema.findExtensionByNumber(
196                           registers.extensionRegistry, defaultInstance, typeId);
197               continue;
198             }
199             break;
200           case WireFormat.MESSAGE_SET_MESSAGE:
201             if (extension != null) {
202               position = ArrayDecoders.decodeMessageField(
203                   Protobuf.getInstance().schemaFor(
204                       extension.getMessageDefaultInstance().getClass()),
205                   data, position, limit, registers);
206               extensions.setField(extension.descriptor, registers.object1);
207               continue;
208             } else {
209               if (wireType == WireFormat.WIRETYPE_LENGTH_DELIMITED) {
210                 position = ArrayDecoders.decodeBytes(data, position, registers);
211                 rawBytes = (ByteString) registers.object1;
212                 continue;
213               }
214               break;
215             }
216           default:
217             break;
218         }
219         if (tag == WireFormat.MESSAGE_SET_ITEM_END_TAG) {
220           break;
221         }
222         position = ArrayDecoders.skipField(tag, data, position, limit, registers);
223       }
224 
225       if (rawBytes != null) {
226         unknownFields.storeField(
227             WireFormat.makeTag(typeId, WireFormat.WIRETYPE_LENGTH_DELIMITED), rawBytes);
228       }
229     }
230     if (position != limit) {
231       throw InvalidProtocolBufferException.parseFailure();
232     }
233   }
234 
235   @Override
mergeFrom(T message, Reader reader, ExtensionRegistryLite extensionRegistry)236   public void mergeFrom(T message, Reader reader, ExtensionRegistryLite extensionRegistry)
237       throws IOException {
238     mergeFromHelper(unknownFieldSchema, extensionSchema, message, reader, extensionRegistry);
239   }
240 
241   /**
242    * A helper method for wildcard capture of {@code unknownFieldSchema}. See:
243    * https://docs.oracle.com/javase/tutorial/java/generics/capture.html
244    */
245   @SuppressWarnings("unchecked")
mergeFromHelper( UnknownFieldSchema<UT, UB> unknownFieldSchema, ExtensionSchema<ET> extensionSchema, T message, Reader reader, ExtensionRegistryLite extensionRegistry)246   private <UT, UB, ET extends FieldSet.FieldDescriptorLite<ET>> void mergeFromHelper(
247       UnknownFieldSchema<UT, UB> unknownFieldSchema,
248       ExtensionSchema<ET> extensionSchema,
249       T message,
250       Reader reader,
251       ExtensionRegistryLite extensionRegistry)
252       throws IOException {
253     UB unknownFields = unknownFieldSchema.getBuilderFromMessage(message);
254     FieldSet<ET> extensions = extensionSchema.getMutableExtensions(message);
255     try {
256       while (true) {
257         final int number = reader.getFieldNumber();
258         if (number == Reader.READ_DONE) {
259           return;
260         }
261         if (parseMessageSetItemOrUnknownField(
262             reader,
263             extensionRegistry,
264             extensionSchema,
265             extensions,
266             unknownFieldSchema,
267             unknownFields)) {
268           continue;
269         }
270         // Done reading.
271         return;
272       }
273     } finally {
274       unknownFieldSchema.setBuilderToMessage(message, unknownFields);
275     }
276   }
277 
278   @Override
makeImmutable(T message)279   public void makeImmutable(T message) {
280     unknownFieldSchema.makeImmutable(message);
281     extensionSchema.makeImmutable(message);
282   }
283 
284   private <UT, UB, ET extends FieldSet.FieldDescriptorLite<ET>>
parseMessageSetItemOrUnknownField( Reader reader, ExtensionRegistryLite extensionRegistry, ExtensionSchema<ET> extensionSchema, FieldSet<ET> extensions, UnknownFieldSchema<UT, UB> unknownFieldSchema, UB unknownFields)285       boolean parseMessageSetItemOrUnknownField(
286           Reader reader,
287           ExtensionRegistryLite extensionRegistry,
288           ExtensionSchema<ET> extensionSchema,
289           FieldSet<ET> extensions,
290           UnknownFieldSchema<UT, UB> unknownFieldSchema,
291           UB unknownFields)
292           throws IOException {
293     int startTag = reader.getTag();
294     if (startTag != WireFormat.MESSAGE_SET_ITEM_TAG) {
295       if (WireFormat.getTagWireType(startTag) == WireFormat.WIRETYPE_LENGTH_DELIMITED) {
296         Object extension =
297             extensionSchema.findExtensionByNumber(
298                 extensionRegistry, defaultInstance, WireFormat.getTagFieldNumber(startTag));
299         if (extension != null) {
300           extensionSchema.parseLengthPrefixedMessageSetItem(
301               reader, extension, extensionRegistry, extensions);
302           return true;
303         } else {
304           return unknownFieldSchema.mergeOneFieldFrom(unknownFields, reader);
305         }
306       } else {
307         return reader.skipField();
308       }
309     }
310 
311     // The wire format for MessageSet is:
312     //   message MessageSet {
313     //     repeated group Item = 1 {
314     //       required int32 typeId = 2;
315     //       required bytes message = 3;
316     //     }
317     //   }
318     // "typeId" is the extension's field number.  The extension can only be
319     // a message type, where "message" contains the encoded bytes of that
320     // message.
321     //
322     // In practice, we will probably never see a MessageSet item in which
323     // the message appears before the type ID, or where either field does not
324     // appear exactly once.  However, in theory such cases are valid, so we
325     // should be prepared to accept them.
326 
327     int typeId = 0;
328     ByteString rawBytes = null; // If we encounter "message" before "typeId"
329     Object extension = null;
330 
331     // Read bytes from input, if we get it's type first then parse it eagerly,
332     // otherwise we store the raw bytes in a local variable.
333     loop:
334     while (true) {
335       final int number = reader.getFieldNumber();
336       if (number == Reader.READ_DONE) {
337         break;
338       }
339 
340       final int tag = reader.getTag();
341       if (tag == WireFormat.MESSAGE_SET_TYPE_ID_TAG) {
342         typeId = reader.readUInt32();
343         extension =
344             extensionSchema.findExtensionByNumber(extensionRegistry, defaultInstance, typeId);
345         continue;
346       } else if (tag == WireFormat.MESSAGE_SET_MESSAGE_TAG) {
347         if (extension != null) {
348           extensionSchema.parseLengthPrefixedMessageSetItem(
349               reader, extension, extensionRegistry, extensions);
350           continue;
351         }
352         // We haven't seen a type ID yet or we want parse message lazily.
353         rawBytes = reader.readBytes();
354         continue;
355       } else {
356         if (!reader.skipField()) {
357           break loop; // End of group
358         }
359       }
360     }
361 
362     if (reader.getTag() != WireFormat.MESSAGE_SET_ITEM_END_TAG) {
363       throw InvalidProtocolBufferException.invalidEndTag();
364     }
365 
366     // If there are any rawBytes left, it means the message content appears before the type ID.
367     if (rawBytes != null) {
368       if (extension != null) { // We known the type
369         // TODO(xiaofeng): Instead of reading into a temporary ByteString, maybe there is a way
370         // to read directly from Reader to the submessage?
371         extensionSchema.parseMessageSetItem(rawBytes, extension, extensionRegistry, extensions);
372       } else {
373         unknownFieldSchema.addLengthDelimited(unknownFields, typeId, rawBytes);
374       }
375     }
376     return true;
377   }
378 
379   @Override
isInitialized(T message)380   public final boolean isInitialized(T message) {
381     FieldSet<?> extensions = extensionSchema.getExtensions(message);
382     return extensions.isInitialized();
383   }
384 
385   @Override
getSerializedSize(T message)386   public int getSerializedSize(T message) {
387     int size = 0;
388 
389     size += getUnknownFieldsSerializedSize(unknownFieldSchema, message);
390 
391     if (hasExtensions) {
392       size += extensionSchema.getExtensions(message).getMessageSetSerializedSize();
393     }
394 
395     return size;
396   }
397 
getUnknownFieldsSerializedSize( UnknownFieldSchema<UT, UB> schema, T message)398   private <UT, UB> int getUnknownFieldsSerializedSize(
399       UnknownFieldSchema<UT, UB> schema, T message) {
400     UT unknowns = schema.getFromMessage(message);
401     return schema.getSerializedSizeAsMessageSet(unknowns);
402   }
403 }
404