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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 // 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 
38 #include <climits>
39 #include <cstdint>
40 #include <string>
41 
42 #include <google/protobuf/stubs/logging.h>
43 #include <google/protobuf/stubs/common.h>
44 #include <google/protobuf/stubs/stringprintf.h>
45 #include <google/protobuf/parse_context.h>
46 #include <google/protobuf/io/coded_stream.h>
47 #include <google/protobuf/io/zero_copy_stream.h>
48 #include <google/protobuf/io/zero_copy_stream_impl.h>
49 #include <google/protobuf/io/zero_copy_stream_impl_lite.h>
50 #include <google/protobuf/arena.h>
51 #include <google/protobuf/generated_message_table_driven.h>
52 #include <google/protobuf/generated_message_util.h>
53 #include <google/protobuf/repeated_field.h>
54 #include <google/protobuf/stubs/strutil.h>
55 #include <google/protobuf/stubs/stl_util.h>
56 #include <google/protobuf/stubs/mutex.h>
57 
58 #include <google/protobuf/port_def.inc>
59 
60 namespace google {
61 namespace protobuf {
62 
InitializationErrorString() const63 std::string MessageLite::InitializationErrorString() const {
64   return "(cannot determine missing fields for lite message)";
65 }
66 
DebugString() const67 std::string MessageLite::DebugString() const {
68   std::uintptr_t address = reinterpret_cast<std::uintptr_t>(this);
69   return StrCat("MessageLite at 0x", strings::Hex(address));
70 }
71 
72 namespace {
73 
74 // When serializing, we first compute the byte size, then serialize the message.
75 // If serialization produces a different number of bytes than expected, we
76 // call this function, which crashes.  The problem could be due to a bug in the
77 // protobuf implementation but is more likely caused by concurrent modification
78 // of the message.  This function attempts to distinguish between the two and
79 // provide a useful error message.
ByteSizeConsistencyError(size_t byte_size_before_serialization,size_t byte_size_after_serialization,size_t bytes_produced_by_serialization,const MessageLite & message)80 void ByteSizeConsistencyError(size_t byte_size_before_serialization,
81                               size_t byte_size_after_serialization,
82                               size_t bytes_produced_by_serialization,
83                               const MessageLite& message) {
84   GOOGLE_CHECK_EQ(byte_size_before_serialization, byte_size_after_serialization)
85       << message.GetTypeName()
86       << " was modified concurrently during serialization.";
87   GOOGLE_CHECK_EQ(bytes_produced_by_serialization, byte_size_before_serialization)
88       << "Byte size calculation and serialization were inconsistent.  This "
89          "may indicate a bug in protocol buffers or it may be caused by "
90          "concurrent modification of "
91       << message.GetTypeName() << ".";
92   GOOGLE_LOG(FATAL) << "This shouldn't be called if all the sizes are equal.";
93 }
94 
InitializationErrorMessage(const char * action,const MessageLite & message)95 std::string InitializationErrorMessage(const char* action,
96                                        const MessageLite& message) {
97   // Note:  We want to avoid depending on strutil in the lite library, otherwise
98   //   we'd use:
99   //
100   // return strings::Substitute(
101   //   "Can't $0 message of type \"$1\" because it is missing required "
102   //   "fields: $2",
103   //   action, message.GetTypeName(),
104   //   message.InitializationErrorString());
105 
106   std::string result;
107   result += "Can't ";
108   result += action;
109   result += " message of type \"";
110   result += message.GetTypeName();
111   result += "\" because it is missing required fields: ";
112   result += message.InitializationErrorString();
113   return result;
114 }
115 
as_string_view(const void * data,int size)116 inline StringPiece as_string_view(const void* data, int size) {
117   return StringPiece(static_cast<const char*>(data), size);
118 }
119 
120 // Returns true of all required fields are present / have values.
CheckFieldPresence(const internal::ParseContext & ctx,const MessageLite & msg,MessageLite::ParseFlags parse_flags)121 inline bool CheckFieldPresence(const internal::ParseContext& ctx,
122                                const MessageLite& msg,
123                                MessageLite::ParseFlags parse_flags) {
124   if (PROTOBUF_PREDICT_FALSE((parse_flags & MessageLite::kMergePartial) != 0)) {
125     return true;
126   }
127   return msg.IsInitializedWithErrors();
128 }
129 
130 }  // namespace
131 
LogInitializationErrorMessage() const132 void MessageLite::LogInitializationErrorMessage() const {
133   GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *this);
134 }
135 
136 namespace internal {
137 
138 template <bool aliasing>
MergeFromImpl(StringPiece input,MessageLite * msg,MessageLite::ParseFlags parse_flags)139 bool MergeFromImpl(StringPiece input, MessageLite* msg,
140                    MessageLite::ParseFlags parse_flags) {
141   const char* ptr;
142   internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
143                              aliasing, &ptr, input);
144   ptr = msg->_InternalParse(ptr, &ctx);
145   // ctx has an explicit limit set (length of string_view).
146   if (PROTOBUF_PREDICT_TRUE(ptr && ctx.EndedAtLimit())) {
147     return CheckFieldPresence(ctx, *msg, parse_flags);
148   }
149   return false;
150 }
151 
152 template <bool aliasing>
MergeFromImpl(io::ZeroCopyInputStream * input,MessageLite * msg,MessageLite::ParseFlags parse_flags)153 bool MergeFromImpl(io::ZeroCopyInputStream* input, MessageLite* msg,
154                    MessageLite::ParseFlags parse_flags) {
155   const char* ptr;
156   internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
157                              aliasing, &ptr, input);
158   ptr = msg->_InternalParse(ptr, &ctx);
159   // ctx has no explicit limit (hence we end on end of stream)
160   if (PROTOBUF_PREDICT_TRUE(ptr && ctx.EndedAtEndOfStream())) {
161     return CheckFieldPresence(ctx, *msg, parse_flags);
162   }
163   return false;
164 }
165 
166 template <bool aliasing>
MergeFromImpl(BoundedZCIS input,MessageLite * msg,MessageLite::ParseFlags parse_flags)167 bool MergeFromImpl(BoundedZCIS input, MessageLite* msg,
168                    MessageLite::ParseFlags parse_flags) {
169   const char* ptr;
170   internal::ParseContext ctx(io::CodedInputStream::GetDefaultRecursionLimit(),
171                              aliasing, &ptr, input.zcis, input.limit);
172   ptr = msg->_InternalParse(ptr, &ctx);
173   if (PROTOBUF_PREDICT_FALSE(!ptr)) return false;
174   ctx.BackUp(ptr);
175   if (PROTOBUF_PREDICT_TRUE(ctx.EndedAtLimit())) {
176     return CheckFieldPresence(ctx, *msg, parse_flags);
177   }
178   return false;
179 }
180 
181 template bool MergeFromImpl<false>(StringPiece input, MessageLite* msg,
182                                    MessageLite::ParseFlags parse_flags);
183 template bool MergeFromImpl<true>(StringPiece input, MessageLite* msg,
184                                   MessageLite::ParseFlags parse_flags);
185 template bool MergeFromImpl<false>(io::ZeroCopyInputStream* input,
186                                    MessageLite* msg,
187                                    MessageLite::ParseFlags parse_flags);
188 template bool MergeFromImpl<true>(io::ZeroCopyInputStream* input,
189                                   MessageLite* msg,
190                                   MessageLite::ParseFlags parse_flags);
191 template bool MergeFromImpl<false>(BoundedZCIS input, MessageLite* msg,
192                                    MessageLite::ParseFlags parse_flags);
193 template bool MergeFromImpl<true>(BoundedZCIS input, MessageLite* msg,
194                                   MessageLite::ParseFlags parse_flags);
195 
196 }  // namespace internal
197 
New(Arena * arena) const198 MessageLite* MessageLite::New(Arena* arena) const {
199   MessageLite* message = New();
200   if (arena != NULL) {
201     arena->Own(message);
202   }
203   return message;
204 }
205 
206 class ZeroCopyCodedInputStream : public io::ZeroCopyInputStream {
207  public:
ZeroCopyCodedInputStream(io::CodedInputStream * cis)208   ZeroCopyCodedInputStream(io::CodedInputStream* cis) : cis_(cis) {}
Next(const void ** data,int * size)209   bool Next(const void** data, int* size) final {
210     if (!cis_->GetDirectBufferPointer(data, size)) return false;
211     cis_->Skip(*size);
212     return true;
213   }
BackUp(int count)214   void BackUp(int count) final { cis_->Advance(-count); }
Skip(int count)215   bool Skip(int count) final { return cis_->Skip(count); }
ByteCount() const216   int64_t ByteCount() const final { return 0; }
217 
aliasing_enabled()218   bool aliasing_enabled() { return cis_->aliasing_enabled_; }
219 
220  private:
221   io::CodedInputStream* cis_;
222 };
223 
MergeFromImpl(io::CodedInputStream * input,MessageLite::ParseFlags parse_flags)224 bool MessageLite::MergeFromImpl(io::CodedInputStream* input,
225                                 MessageLite::ParseFlags parse_flags) {
226   ZeroCopyCodedInputStream zcis(input);
227   const char* ptr;
228   internal::ParseContext ctx(input->RecursionBudget(), zcis.aliasing_enabled(),
229                              &ptr, &zcis);
230   // MergePartialFromCodedStream allows terminating the wireformat by 0 or
231   // end-group tag. Leaving it up to the caller to verify correct ending by
232   // calling LastTagWas on input. We need to maintain this behavior.
233   ctx.TrackCorrectEnding();
234   ctx.data().pool = input->GetExtensionPool();
235   ctx.data().factory = input->GetExtensionFactory();
236   ptr = _InternalParse(ptr, &ctx);
237   if (PROTOBUF_PREDICT_FALSE(!ptr)) return false;
238   ctx.BackUp(ptr);
239   if (!ctx.EndedAtEndOfStream()) {
240     GOOGLE_DCHECK(ctx.LastTag() != 1);  // We can't end on a pushed limit.
241     if (ctx.IsExceedingLimit(ptr)) return false;
242     input->SetLastTag(ctx.LastTag());
243   } else {
244     input->SetConsumed();
245   }
246   return CheckFieldPresence(ctx, *this, parse_flags);
247 }
248 
MergePartialFromCodedStream(io::CodedInputStream * input)249 bool MessageLite::MergePartialFromCodedStream(io::CodedInputStream* input) {
250   return MergeFromImpl(input, kMergePartial);
251 }
252 
MergeFromCodedStream(io::CodedInputStream * input)253 bool MessageLite::MergeFromCodedStream(io::CodedInputStream* input) {
254   return MergeFromImpl(input, kMerge);
255 }
256 
ParseFromCodedStream(io::CodedInputStream * input)257 bool MessageLite::ParseFromCodedStream(io::CodedInputStream* input) {
258   Clear();
259   return MergeFromImpl(input, kParse);
260 }
261 
ParsePartialFromCodedStream(io::CodedInputStream * input)262 bool MessageLite::ParsePartialFromCodedStream(io::CodedInputStream* input) {
263   Clear();
264   return MergeFromImpl(input, kParsePartial);
265 }
266 
ParseFromZeroCopyStream(io::ZeroCopyInputStream * input)267 bool MessageLite::ParseFromZeroCopyStream(io::ZeroCopyInputStream* input) {
268   return ParseFrom<kParse>(input);
269 }
270 
ParsePartialFromZeroCopyStream(io::ZeroCopyInputStream * input)271 bool MessageLite::ParsePartialFromZeroCopyStream(
272     io::ZeroCopyInputStream* input) {
273   return ParseFrom<kParsePartial>(input);
274 }
275 
ParseFromFileDescriptor(int file_descriptor)276 bool MessageLite::ParseFromFileDescriptor(int file_descriptor) {
277   io::FileInputStream input(file_descriptor);
278   return ParseFromZeroCopyStream(&input) && input.GetErrno() == 0;
279 }
280 
ParsePartialFromFileDescriptor(int file_descriptor)281 bool MessageLite::ParsePartialFromFileDescriptor(int file_descriptor) {
282   io::FileInputStream input(file_descriptor);
283   return ParsePartialFromZeroCopyStream(&input) && input.GetErrno() == 0;
284 }
285 
ParseFromIstream(std::istream * input)286 bool MessageLite::ParseFromIstream(std::istream* input) {
287   io::IstreamInputStream zero_copy_input(input);
288   return ParseFromZeroCopyStream(&zero_copy_input) && input->eof();
289 }
290 
ParsePartialFromIstream(std::istream * input)291 bool MessageLite::ParsePartialFromIstream(std::istream* input) {
292   io::IstreamInputStream zero_copy_input(input);
293   return ParsePartialFromZeroCopyStream(&zero_copy_input) && input->eof();
294 }
295 
MergePartialFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input,int size)296 bool MessageLite::MergePartialFromBoundedZeroCopyStream(
297     io::ZeroCopyInputStream* input, int size) {
298   return ParseFrom<kMergePartial>(internal::BoundedZCIS{input, size});
299 }
300 
MergeFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input,int size)301 bool MessageLite::MergeFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
302                                                  int size) {
303   return ParseFrom<kMerge>(internal::BoundedZCIS{input, size});
304 }
305 
ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input,int size)306 bool MessageLite::ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
307                                                  int size) {
308   return ParseFrom<kParse>(internal::BoundedZCIS{input, size});
309 }
310 
ParsePartialFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input,int size)311 bool MessageLite::ParsePartialFromBoundedZeroCopyStream(
312     io::ZeroCopyInputStream* input, int size) {
313   return ParseFrom<kParsePartial>(internal::BoundedZCIS{input, size});
314 }
315 
ParseFromString(const std::string & data)316 bool MessageLite::ParseFromString(const std::string& data) {
317   return ParseFrom<kParse>(data);
318 }
319 
ParsePartialFromString(const std::string & data)320 bool MessageLite::ParsePartialFromString(const std::string& data) {
321   return ParseFrom<kParsePartial>(data);
322 }
323 
ParseFromArray(const void * data,int size)324 bool MessageLite::ParseFromArray(const void* data, int size) {
325   return ParseFrom<kParse>(as_string_view(data, size));
326 }
327 
ParsePartialFromArray(const void * data,int size)328 bool MessageLite::ParsePartialFromArray(const void* data, int size) {
329   return ParseFrom<kParsePartial>(as_string_view(data, size));
330 }
331 
MergeFromString(const std::string & data)332 bool MessageLite::MergeFromString(const std::string& data) {
333   return ParseFrom<kMerge>(data);
334 }
335 
336 
337 // ===================================================================
338 
SerializeToArrayImpl(const MessageLite & msg,uint8 * target,int size)339 inline uint8* SerializeToArrayImpl(const MessageLite& msg, uint8* target,
340                                    int size) {
341   constexpr bool debug = false;
342   if (debug) {
343     // Force serialization to a stream with a block size of 1, which forces
344     // all writes to the stream to cross buffers triggering all fallback paths
345     // in the unittests when serializing to string / array.
346     io::ArrayOutputStream stream(target, size, 1);
347     uint8* ptr;
348     io::EpsCopyOutputStream out(
349         &stream, io::CodedOutputStream::IsDefaultSerializationDeterministic(),
350         &ptr);
351     ptr = msg._InternalSerialize(ptr, &out);
352     out.Trim(ptr);
353     GOOGLE_DCHECK(!out.HadError() && stream.ByteCount() == size);
354     return target + size;
355   } else {
356     io::EpsCopyOutputStream out(
357         target, size,
358         io::CodedOutputStream::IsDefaultSerializationDeterministic());
359     auto res = msg._InternalSerialize(target, &out);
360     GOOGLE_DCHECK(target + size == res);
361     return res;
362   }
363 }
364 
SerializeWithCachedSizesToArray(uint8 * target) const365 uint8* MessageLite::SerializeWithCachedSizesToArray(uint8* target) const {
366   // We only optimize this when using optimize_for = SPEED.  In other cases
367   // we just use the CodedOutputStream path.
368   return SerializeToArrayImpl(*this, target, GetCachedSize());
369 }
370 
SerializeToCodedStream(io::CodedOutputStream * output) const371 bool MessageLite::SerializeToCodedStream(io::CodedOutputStream* output) const {
372   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
373   return SerializePartialToCodedStream(output);
374 }
375 
SerializePartialToCodedStream(io::CodedOutputStream * output) const376 bool MessageLite::SerializePartialToCodedStream(
377     io::CodedOutputStream* output) const {
378   const size_t size = ByteSizeLong();  // Force size to be cached.
379   if (size > INT_MAX) {
380     GOOGLE_LOG(ERROR) << GetTypeName()
381                << " exceeded maximum protobuf size of 2GB: " << size;
382     return false;
383   }
384 
385   int original_byte_count = output->ByteCount();
386   SerializeWithCachedSizes(output);
387   if (output->HadError()) {
388     return false;
389   }
390   int final_byte_count = output->ByteCount();
391 
392   if (final_byte_count - original_byte_count != size) {
393     ByteSizeConsistencyError(size, ByteSizeLong(),
394                              final_byte_count - original_byte_count, *this);
395   }
396 
397   return true;
398 }
399 
SerializeToZeroCopyStream(io::ZeroCopyOutputStream * output) const400 bool MessageLite::SerializeToZeroCopyStream(
401     io::ZeroCopyOutputStream* output) const {
402   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
403   return SerializePartialToZeroCopyStream(output);
404 }
405 
SerializePartialToZeroCopyStream(io::ZeroCopyOutputStream * output) const406 bool MessageLite::SerializePartialToZeroCopyStream(
407     io::ZeroCopyOutputStream* output) const {
408   const size_t size = ByteSizeLong();  // Force size to be cached.
409   if (size > INT_MAX) {
410     GOOGLE_LOG(ERROR) << GetTypeName()
411                << " exceeded maximum protobuf size of 2GB: " << size;
412     return false;
413   }
414 
415   uint8* target;
416   io::EpsCopyOutputStream stream(
417       output, io::CodedOutputStream::IsDefaultSerializationDeterministic(),
418       &target);
419   target = _InternalSerialize(target, &stream);
420   stream.Trim(target);
421   if (stream.HadError()) return false;
422   return true;
423 }
424 
SerializeToFileDescriptor(int file_descriptor) const425 bool MessageLite::SerializeToFileDescriptor(int file_descriptor) const {
426   io::FileOutputStream output(file_descriptor);
427   return SerializeToZeroCopyStream(&output) && output.Flush();
428 }
429 
SerializePartialToFileDescriptor(int file_descriptor) const430 bool MessageLite::SerializePartialToFileDescriptor(int file_descriptor) const {
431   io::FileOutputStream output(file_descriptor);
432   return SerializePartialToZeroCopyStream(&output) && output.Flush();
433 }
434 
SerializeToOstream(std::ostream * output) const435 bool MessageLite::SerializeToOstream(std::ostream* output) const {
436   {
437     io::OstreamOutputStream zero_copy_output(output);
438     if (!SerializeToZeroCopyStream(&zero_copy_output)) return false;
439   }
440   return output->good();
441 }
442 
SerializePartialToOstream(std::ostream * output) const443 bool MessageLite::SerializePartialToOstream(std::ostream* output) const {
444   io::OstreamOutputStream zero_copy_output(output);
445   return SerializePartialToZeroCopyStream(&zero_copy_output);
446 }
447 
AppendToString(std::string * output) const448 bool MessageLite::AppendToString(std::string* output) const {
449   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
450   return AppendPartialToString(output);
451 }
452 
AppendPartialToString(std::string * output) const453 bool MessageLite::AppendPartialToString(std::string* output) const {
454   size_t old_size = output->size();
455   size_t byte_size = ByteSizeLong();
456   if (byte_size > INT_MAX) {
457     GOOGLE_LOG(ERROR) << GetTypeName()
458                << " exceeded maximum protobuf size of 2GB: " << byte_size;
459     return false;
460   }
461 
462   STLStringResizeUninitialized(output, old_size + byte_size);
463   uint8* start =
464       reinterpret_cast<uint8*>(io::mutable_string_data(output) + old_size);
465   SerializeToArrayImpl(*this, start, byte_size);
466   return true;
467 }
468 
SerializeToString(std::string * output) const469 bool MessageLite::SerializeToString(std::string* output) const {
470   output->clear();
471   return AppendToString(output);
472 }
473 
SerializePartialToString(std::string * output) const474 bool MessageLite::SerializePartialToString(std::string* output) const {
475   output->clear();
476   return AppendPartialToString(output);
477 }
478 
SerializeToArray(void * data,int size) const479 bool MessageLite::SerializeToArray(void* data, int size) const {
480   GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
481   return SerializePartialToArray(data, size);
482 }
483 
SerializePartialToArray(void * data,int size) const484 bool MessageLite::SerializePartialToArray(void* data, int size) const {
485   const size_t byte_size = ByteSizeLong();
486   if (byte_size > INT_MAX) {
487     GOOGLE_LOG(ERROR) << GetTypeName()
488                << " exceeded maximum protobuf size of 2GB: " << byte_size;
489     return false;
490   }
491   if (size < byte_size) return false;
492   uint8* start = reinterpret_cast<uint8*>(data);
493   SerializeToArrayImpl(*this, start, byte_size);
494   return true;
495 }
496 
SerializeAsString() const497 std::string MessageLite::SerializeAsString() const {
498   // If the compiler implements the (Named) Return Value Optimization,
499   // the local variable 'output' will not actually reside on the stack
500   // of this function, but will be overlaid with the object that the
501   // caller supplied for the return value to be constructed in.
502   std::string output;
503   if (!AppendToString(&output)) output.clear();
504   return output;
505 }
506 
SerializePartialAsString() const507 std::string MessageLite::SerializePartialAsString() const {
508   std::string output;
509   if (!AppendPartialToString(&output)) output.clear();
510   return output;
511 }
512 
513 
514 namespace internal {
515 
516 template <>
NewFromPrototype(const MessageLite * prototype,Arena * arena)517 MessageLite* GenericTypeHandler<MessageLite>::NewFromPrototype(
518     const MessageLite* prototype, Arena* arena) {
519   return prototype->New(arena);
520 }
521 template <>
Merge(const MessageLite & from,MessageLite * to)522 void GenericTypeHandler<MessageLite>::Merge(const MessageLite& from,
523                                             MessageLite* to) {
524   to->CheckTypeAndMergeFrom(from);
525 }
526 template <>
Merge(const std::string & from,std::string * to)527 void GenericTypeHandler<std::string>::Merge(const std::string& from,
528                                             std::string* to) {
529   *to = from;
530 }
531 
532 }  // namespace internal
533 
534 
535 // ===================================================================
536 // Shutdown support.
537 
538 namespace internal {
539 
540 struct ShutdownData {
~ShutdownDatagoogle::protobuf::internal::ShutdownData541   ~ShutdownData() {
542     std::reverse(functions.begin(), functions.end());
543     for (auto pair : functions) pair.first(pair.second);
544   }
545 
getgoogle::protobuf::internal::ShutdownData546   static ShutdownData* get() {
547     static auto* data = new ShutdownData;
548     return data;
549   }
550 
551   std::vector<std::pair<void (*)(const void*), const void*>> functions;
552   Mutex mutex;
553 };
554 
RunZeroArgFunc(const void * arg)555 static void RunZeroArgFunc(const void* arg) {
556   void (*func)() = reinterpret_cast<void (*)()>(const_cast<void*>(arg));
557   func();
558 }
559 
OnShutdown(void (* func)())560 void OnShutdown(void (*func)()) {
561   OnShutdownRun(RunZeroArgFunc, reinterpret_cast<void*>(func));
562 }
563 
OnShutdownRun(void (* f)(const void *),const void * arg)564 void OnShutdownRun(void (*f)(const void*), const void* arg) {
565   auto shutdown_data = ShutdownData::get();
566   MutexLock lock(&shutdown_data->mutex);
567   shutdown_data->functions.push_back(std::make_pair(f, arg));
568 }
569 
570 }  // namespace internal
571 
ShutdownProtobufLibrary()572 void ShutdownProtobufLibrary() {
573   // This function should be called only once, but accepts multiple calls.
574   static bool is_shutdown = false;
575   if (!is_shutdown) {
576     delete internal::ShutdownData::get();
577     is_shutdown = true;
578   }
579 }
580 
581 
582 }  // namespace protobuf
583 }  // namespace google
584