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1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // http://code.google.com/p/protobuf/
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 // Authors: wink@google.com (Wink Saville),
32 //          kenton@google.com (Kenton Varda)
33 //  Based on original Protocol Buffers design by
34 //  Sanjay Ghemawat, Jeff Dean, and others.
35 
36 #include <google/protobuf/message_lite.h>
37 #include <string>
38 #include <google/protobuf/stubs/common.h>
39 #include <google/protobuf/io/coded_stream.h>
40 #include <google/protobuf/io/zero_copy_stream_impl.h>
41 #include <google/protobuf/stubs/stl_util-inl.h>
42 
43 namespace google {
44 namespace protobuf {
45 
~MessageLite()46 MessageLite::~MessageLite() {}
47 
InitializationErrorString() const48 string MessageLite::InitializationErrorString() const {
49   return "(cannot determine missing fields for lite message)";
50 }
51 
52 namespace {
53 
54 // When serializing, we first compute the byte size, then serialize the message.
55 // If serialization produces a different number of bytes than expected, we
56 // call this function, which crashes.  The problem could be due to a bug in the
57 // protobuf implementation but is more likely caused by concurrent modification
58 // of the message.  This function attempts to distinguish between the two and
59 // provide a useful error message.
ByteSizeConsistencyError(int byte_size_before_serialization,int byte_size_after_serialization,int bytes_produced_by_serialization)60 void ByteSizeConsistencyError(int byte_size_before_serialization,
61                               int byte_size_after_serialization,
62                               int bytes_produced_by_serialization) {
63   GOOGLE_CHECK_EQ(byte_size_before_serialization, byte_size_after_serialization)
64       << "Protocol message was modified concurrently during serialization.";
65   GOOGLE_CHECK_EQ(bytes_produced_by_serialization, byte_size_before_serialization)
66       << "Byte size calculation and serialization were inconsistent.  This "
67          "may indicate a bug in protocol buffers or it may be caused by "
68          "concurrent modification of the message.";
69   GOOGLE_LOG(FATAL) << "This shouldn't be called if all the sizes are equal.";
70 }
71 
InitializationErrorMessage(const char * action,const MessageLite & message)72 string InitializationErrorMessage(const char* action,
73                                   const MessageLite& message) {
74   // Note:  We want to avoid depending on strutil in the lite library, otherwise
75   //   we'd use:
76   //
77   // return strings::Substitute(
78   //   "Can't $0 message of type \"$1\" because it is missing required "
79   //   "fields: $2",
80   //   action, message.GetTypeName(),
81   //   message.InitializationErrorString());
82 
83   string result;
84   result += "Can't ";
85   result += action;
86   result += " message of type \"";
87   result += message.GetTypeName();
88   result += "\" because it is missing required fields: ";
89   result += message.InitializationErrorString();
90   return result;
91 }
92 
93 // Several of the Parse methods below just do one thing and then call another
94 // method.  In a naive implementation, we might have ParseFromString() call
95 // ParseFromArray() which would call ParseFromZeroCopyStream() which would call
96 // ParseFromCodedStream() which would call MergeFromCodedStream() which would
97 // call MergePartialFromCodedStream().  However, when parsing very small
98 // messages, every function call introduces significant overhead.  To avoid
99 // this without reproducing code, we use these forced-inline helpers.
100 //
101 // Note:  GCC only allows GOOGLE_ATTRIBUTE_ALWAYS_INLINE on declarations, not
102 //   definitions.
103 inline bool InlineMergeFromCodedStream(io::CodedInputStream* input,
104                                        MessageLite* message)
105                                        GOOGLE_ATTRIBUTE_ALWAYS_INLINE;
106 inline bool InlineParseFromCodedStream(io::CodedInputStream* input,
107                                        MessageLite* message)
108                                        GOOGLE_ATTRIBUTE_ALWAYS_INLINE;
109 inline bool InlineParsePartialFromCodedStream(io::CodedInputStream* input,
110                                               MessageLite* message)
111                                               GOOGLE_ATTRIBUTE_ALWAYS_INLINE;
112 inline bool InlineParseFromArray(const void* data, int size,
113                                  MessageLite* message)
114                                  GOOGLE_ATTRIBUTE_ALWAYS_INLINE;
115 inline bool InlineParsePartialFromArray(const void* data, int size,
116                                         MessageLite* message)
117                                         GOOGLE_ATTRIBUTE_ALWAYS_INLINE;
118 
InlineMergeFromCodedStream(io::CodedInputStream * input,MessageLite * message)119 bool InlineMergeFromCodedStream(io::CodedInputStream* input,
120                                 MessageLite* message) {
121   if (!message->MergePartialFromCodedStream(input)) return false;
122   if (!message->IsInitialized()) {
123     GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *message);
124     return false;
125   }
126   return true;
127 }
128 
InlineParseFromCodedStream(io::CodedInputStream * input,MessageLite * message)129 bool InlineParseFromCodedStream(io::CodedInputStream* input,
130                                 MessageLite* message) {
131   message->Clear();
132   return InlineMergeFromCodedStream(input, message);
133 }
134 
InlineParsePartialFromCodedStream(io::CodedInputStream * input,MessageLite * message)135 bool InlineParsePartialFromCodedStream(io::CodedInputStream* input,
136                                        MessageLite* message) {
137   message->Clear();
138   return message->MergePartialFromCodedStream(input);
139 }
140 
InlineParseFromArray(const void * data,int size,MessageLite * message)141 bool InlineParseFromArray(const void* data, int size, MessageLite* message) {
142   io::CodedInputStream input(reinterpret_cast<const uint8*>(data), size);
143   return InlineParseFromCodedStream(&input, message) &&
144          input.ConsumedEntireMessage();
145 }
146 
InlineParsePartialFromArray(const void * data,int size,MessageLite * message)147 bool InlineParsePartialFromArray(const void* data, int size,
148                                  MessageLite* message) {
149   io::CodedInputStream input(reinterpret_cast<const uint8*>(data), size);
150   return InlineParsePartialFromCodedStream(&input, message) &&
151          input.ConsumedEntireMessage();
152 }
153 
154 }  // namespace
155 
MergeFromCodedStream(io::CodedInputStream * input)156 bool MessageLite::MergeFromCodedStream(io::CodedInputStream* input) {
157   return InlineMergeFromCodedStream(input, this);
158 }
159 
ParseFromCodedStream(io::CodedInputStream * input)160 bool MessageLite::ParseFromCodedStream(io::CodedInputStream* input) {
161   return InlineParseFromCodedStream(input, this);
162 }
163 
ParsePartialFromCodedStream(io::CodedInputStream * input)164 bool MessageLite::ParsePartialFromCodedStream(io::CodedInputStream* input) {
165   return InlineParsePartialFromCodedStream(input, this);
166 }
167 
ParseFromZeroCopyStream(io::ZeroCopyInputStream * input)168 bool MessageLite::ParseFromZeroCopyStream(io::ZeroCopyInputStream* input) {
169   io::CodedInputStream decoder(input);
170   return ParseFromCodedStream(&decoder) && decoder.ConsumedEntireMessage();
171 }
172 
ParsePartialFromZeroCopyStream(io::ZeroCopyInputStream * input)173 bool MessageLite::ParsePartialFromZeroCopyStream(
174     io::ZeroCopyInputStream* input) {
175   io::CodedInputStream decoder(input);
176   return ParsePartialFromCodedStream(&decoder) &&
177          decoder.ConsumedEntireMessage();
178 }
179 
ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input,int size)180 bool MessageLite::ParseFromBoundedZeroCopyStream(
181     io::ZeroCopyInputStream* input, int size) {
182   io::CodedInputStream decoder(input);
183   decoder.PushLimit(size);
184   return ParseFromCodedStream(&decoder) &&
185          decoder.ConsumedEntireMessage() &&
186          decoder.BytesUntilLimit() == 0;
187 }
188 
ParsePartialFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input,int size)189 bool MessageLite::ParsePartialFromBoundedZeroCopyStream(
190     io::ZeroCopyInputStream* input, int size) {
191   io::CodedInputStream decoder(input);
192   decoder.PushLimit(size);
193   return ParsePartialFromCodedStream(&decoder) &&
194          decoder.ConsumedEntireMessage() &&
195          decoder.BytesUntilLimit() == 0;
196 }
197 
ParseFromString(const string & data)198 bool MessageLite::ParseFromString(const string& data) {
199   return InlineParseFromArray(data.data(), data.size(), this);
200 }
201 
ParsePartialFromString(const string & data)202 bool MessageLite::ParsePartialFromString(const string& data) {
203   return InlineParsePartialFromArray(data.data(), data.size(), this);
204 }
205 
ParseFromArray(const void * data,int size)206 bool MessageLite::ParseFromArray(const void* data, int size) {
207   return InlineParseFromArray(data, size, this);
208 }
209 
ParsePartialFromArray(const void * data,int size)210 bool MessageLite::ParsePartialFromArray(const void* data, int size) {
211   return InlineParsePartialFromArray(data, size, this);
212 }
213 
214 
215 // ===================================================================
216 
SerializeWithCachedSizesToArray(uint8 * target) const217 uint8* MessageLite::SerializeWithCachedSizesToArray(uint8* target) const {
218   // We only optimize this when using optimize_for = SPEED.  In other cases
219   // we just use the CodedOutputStream path.
220   int size = GetCachedSize();
221   io::ArrayOutputStream out(target, size);
222   io::CodedOutputStream coded_out(&out);
223   SerializeWithCachedSizes(&coded_out);
224   GOOGLE_CHECK(!coded_out.HadError());
225   return target + size;
226 }
227 
SerializeToCodedStream(io::CodedOutputStream * output) const228 bool MessageLite::SerializeToCodedStream(io::CodedOutputStream* output) const {
229   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
230   return SerializePartialToCodedStream(output);
231 }
232 
SerializePartialToCodedStream(io::CodedOutputStream * output) const233 bool MessageLite::SerializePartialToCodedStream(
234     io::CodedOutputStream* output) const {
235   const int size = ByteSize();  // Force size to be cached.
236   uint8* buffer = output->GetDirectBufferForNBytesAndAdvance(size);
237   if (buffer != NULL) {
238     uint8* end = SerializeWithCachedSizesToArray(buffer);
239     if (end - buffer != size) {
240       ByteSizeConsistencyError(size, ByteSize(), end - buffer);
241     }
242     return true;
243   } else {
244     int original_byte_count = output->ByteCount();
245     SerializeWithCachedSizes(output);
246     if (output->HadError()) {
247       return false;
248     }
249     int final_byte_count = output->ByteCount();
250 
251     if (final_byte_count - original_byte_count != size) {
252       ByteSizeConsistencyError(size, ByteSize(),
253                                final_byte_count - original_byte_count);
254     }
255 
256     return true;
257   }
258 }
259 
SerializeToZeroCopyStream(io::ZeroCopyOutputStream * output) const260 bool MessageLite::SerializeToZeroCopyStream(
261     io::ZeroCopyOutputStream* output) const {
262   io::CodedOutputStream encoder(output);
263   return SerializeToCodedStream(&encoder);
264 }
265 
SerializePartialToZeroCopyStream(io::ZeroCopyOutputStream * output) const266 bool MessageLite::SerializePartialToZeroCopyStream(
267     io::ZeroCopyOutputStream* output) const {
268   io::CodedOutputStream encoder(output);
269   return SerializePartialToCodedStream(&encoder);
270 }
271 
AppendToString(string * output) const272 bool MessageLite::AppendToString(string* output) const {
273   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
274   return AppendPartialToString(output);
275 }
276 
AppendPartialToString(string * output) const277 bool MessageLite::AppendPartialToString(string* output) const {
278   int old_size = output->size();
279   int byte_size = ByteSize();
280   STLStringResizeUninitialized(output, old_size + byte_size);
281   uint8* start = reinterpret_cast<uint8*>(string_as_array(output) + old_size);
282   uint8* end = SerializeWithCachedSizesToArray(start);
283   if (end - start != byte_size) {
284     ByteSizeConsistencyError(byte_size, ByteSize(), end - start);
285   }
286   return true;
287 }
288 
SerializeToString(string * output) const289 bool MessageLite::SerializeToString(string* output) const {
290   output->clear();
291   return AppendToString(output);
292 }
293 
SerializePartialToString(string * output) const294 bool MessageLite::SerializePartialToString(string* output) const {
295   output->clear();
296   return AppendPartialToString(output);
297 }
298 
SerializeToArray(void * data,int size) const299 bool MessageLite::SerializeToArray(void* data, int size) const {
300   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
301   return SerializePartialToArray(data, size);
302 }
303 
SerializePartialToArray(void * data,int size) const304 bool MessageLite::SerializePartialToArray(void* data, int size) const {
305   int byte_size = ByteSize();
306   if (size < byte_size) return false;
307   uint8* start = reinterpret_cast<uint8*>(data);
308   uint8* end = SerializeWithCachedSizesToArray(start);
309   if (end - start != byte_size) {
310     ByteSizeConsistencyError(byte_size, ByteSize(), end - start);
311   }
312   return true;
313 }
314 
SerializeAsString() const315 string MessageLite::SerializeAsString() const {
316   // If the compiler implements the (Named) Return Value Optimization,
317   // the local variable 'result' will not actually reside on the stack
318   // of this function, but will be overlaid with the object that the
319   // caller supplied for the return value to be constructed in.
320   string output;
321   if (!AppendToString(&output))
322     output.clear();
323   return output;
324 }
325 
SerializePartialAsString() const326 string MessageLite::SerializePartialAsString() const {
327   string output;
328   if (!AppendPartialToString(&output))
329     output.clear();
330   return output;
331 }
332 
333 }  // namespace protobuf
334 }  // namespace google
335