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 // Defines MessageLite, the abstract interface implemented by all (lite
37 // and non-lite) protocol message objects.
38
39 #ifndef GOOGLE_PROTOBUF_MESSAGE_LITE_H__
40 #define GOOGLE_PROTOBUF_MESSAGE_LITE_H__
41
42 #include <climits>
43 #include <string>
44
45 #include <google/protobuf/stubs/common.h>
46 #include <google/protobuf/stubs/logging.h>
47 #include <google/protobuf/io/coded_stream.h>
48 #include <google/protobuf/arena.h>
49 #include <google/protobuf/metadata_lite.h>
50 #include <google/protobuf/stubs/once.h>
51 #include <google/protobuf/port.h>
52 #include <google/protobuf/stubs/strutil.h>
53
54
55 #include <google/protobuf/port_def.inc>
56
57 #ifdef SWIG
58 #error "You cannot SWIG proto headers"
59 #endif
60
61 namespace google {
62 namespace protobuf {
63
64 template <typename T>
65 class RepeatedPtrField;
66
67 namespace io {
68
69 class CodedInputStream;
70 class CodedOutputStream;
71 class ZeroCopyInputStream;
72 class ZeroCopyOutputStream;
73
74 } // namespace io
75 namespace internal {
76
77 // See parse_context.h for explanation
78 class ParseContext;
79
80 class RepeatedPtrFieldBase;
81 class WireFormatLite;
82 class WeakFieldMap;
83
84 // We compute sizes as size_t but cache them as int. This function converts a
85 // computed size to a cached size. Since we don't proceed with serialization
86 // if the total size was > INT_MAX, it is not important what this function
87 // returns for inputs > INT_MAX. However this case should not error or
88 // GOOGLE_CHECK-fail, because the full size_t resolution is still returned from
89 // ByteSizeLong() and checked against INT_MAX; we can catch the overflow
90 // there.
ToCachedSize(size_t size)91 inline int ToCachedSize(size_t size) { return static_cast<int>(size); }
92
93 // We mainly calculate sizes in terms of size_t, but some functions that
94 // compute sizes return "int". These int sizes are expected to always be
95 // positive. This function is more efficient than casting an int to size_t
96 // directly on 64-bit platforms because it avoids making the compiler emit a
97 // sign extending instruction, which we don't want and don't want to pay for.
FromIntSize(int size)98 inline size_t FromIntSize(int size) {
99 // Convert to unsigned before widening so sign extension is not necessary.
100 return static_cast<unsigned int>(size);
101 }
102
103 // For cases where a legacy function returns an integer size. We GOOGLE_DCHECK()
104 // that the conversion will fit within an integer; if this is false then we
105 // are losing information.
ToIntSize(size_t size)106 inline int ToIntSize(size_t size) {
107 GOOGLE_DCHECK_LE(size, static_cast<size_t>(INT_MAX));
108 return static_cast<int>(size);
109 }
110
111 // This type wraps a variable whose constructor and destructor are explicitly
112 // called. It is particularly useful for a global variable, without its
113 // constructor and destructor run on start and end of the program lifetime.
114 // This circumvents the initial construction order fiasco, while keeping
115 // the address of the empty string a compile time constant.
116 //
117 // Pay special attention to the initialization state of the object.
118 // 1. The object is "uninitialized" to begin with.
119 // 2. Call Construct() or DefaultConstruct() only if the object is
120 // uninitialized. After the call, the object becomes "initialized".
121 // 3. Call get() and get_mutable() only if the object is initialized.
122 // 4. Call Destruct() only if the object is initialized.
123 // After the call, the object becomes uninitialized.
124 template <typename T>
125 class ExplicitlyConstructed {
126 public:
DefaultConstruct()127 void DefaultConstruct() { new (&union_) T(); }
128
129 template <typename... Args>
Construct(Args &&...args)130 void Construct(Args&&... args) {
131 new (&union_) T(std::forward<Args>(args)...);
132 }
133
Destruct()134 void Destruct() { get_mutable()->~T(); }
135
get()136 constexpr const T& get() const { return reinterpret_cast<const T&>(union_); }
get_mutable()137 T* get_mutable() { return reinterpret_cast<T*>(&union_); }
138
139 private:
140 // Prefer c++14 aligned_storage, but for compatibility this will do.
141 union AlignedUnion {
142 char space[sizeof(T)];
143 int64 align_to_int64;
144 void* align_to_ptr;
145 } union_;
146 };
147
148 // Default empty string object. Don't use this directly. Instead, call
149 // GetEmptyString() to get the reference.
150 PROTOBUF_EXPORT extern ExplicitlyConstructed<std::string>
151 fixed_address_empty_string;
152
153
GetEmptyStringAlreadyInited()154 PROTOBUF_EXPORT inline const std::string& GetEmptyStringAlreadyInited() {
155 return fixed_address_empty_string.get();
156 }
157
158 PROTOBUF_EXPORT size_t StringSpaceUsedExcludingSelfLong(const std::string& str);
159
160 } // namespace internal
161
162 // Interface to light weight protocol messages.
163 //
164 // This interface is implemented by all protocol message objects. Non-lite
165 // messages additionally implement the Message interface, which is a
166 // subclass of MessageLite. Use MessageLite instead when you only need
167 // the subset of features which it supports -- namely, nothing that uses
168 // descriptors or reflection. You can instruct the protocol compiler
169 // to generate classes which implement only MessageLite, not the full
170 // Message interface, by adding the following line to the .proto file:
171 //
172 // option optimize_for = LITE_RUNTIME;
173 //
174 // This is particularly useful on resource-constrained systems where
175 // the full protocol buffers runtime library is too big.
176 //
177 // Note that on non-constrained systems (e.g. servers) when you need
178 // to link in lots of protocol definitions, a better way to reduce
179 // total code footprint is to use optimize_for = CODE_SIZE. This
180 // will make the generated code smaller while still supporting all the
181 // same features (at the expense of speed). optimize_for = LITE_RUNTIME
182 // is best when you only have a small number of message types linked
183 // into your binary, in which case the size of the protocol buffers
184 // runtime itself is the biggest problem.
185 //
186 // Users must not derive from this class. Only the protocol compiler and
187 // the internal library are allowed to create subclasses.
188 class PROTOBUF_EXPORT MessageLite {
189 public:
MessageLite()190 inline MessageLite() {}
191 virtual ~MessageLite() = default;
192
193 // Basic Operations ------------------------------------------------
194
195 // Get the name of this message type, e.g. "foo.bar.BazProto".
196 virtual std::string GetTypeName() const = 0;
197
198 // Construct a new instance of the same type. Ownership is passed to the
199 // caller.
200 virtual MessageLite* New() const = 0;
201
202 // Construct a new instance on the arena. Ownership is passed to the caller
203 // if arena is a NULL. Default implementation for backwards compatibility.
204 virtual MessageLite* New(Arena* arena) const;
205
206 // Get the arena, if any, associated with this message. Virtual method
207 // required for generic operations but most arena-related operations should
208 // use the GetArena() generated-code method. Default implementation
209 // to reduce code size by avoiding the need for per-type implementations
210 // when types do not implement arena support.
GetArena()211 Arena* GetArena() const { return _internal_metadata_.arena(); }
212
213 // Get a pointer that may be equal to this message's arena, or may not be.
214 // If the value returned by this method is equal to some arena pointer, then
215 // this message is on that arena; however, if this message is on some arena,
216 // this method may or may not return that arena's pointer. As a tradeoff,
217 // this method may be more efficient than GetArena(). The intent is to allow
218 // underlying representations that use e.g. tagged pointers to sometimes
219 // store the arena pointer directly, and sometimes in a more indirect way,
220 // and allow a fastpath comparison against the arena pointer when it's easy
221 // to obtain.
GetMaybeArenaPointer()222 void* GetMaybeArenaPointer() const {
223 return _internal_metadata_.raw_arena_ptr();
224 }
225
226 // Clear all fields of the message and set them to their default values.
227 // Clear() avoids freeing memory, assuming that any memory allocated
228 // to hold parts of the message will be needed again to hold the next
229 // message. If you actually want to free the memory used by a Message,
230 // you must delete it.
231 virtual void Clear() = 0;
232
233 // Quickly check if all required fields have values set.
234 virtual bool IsInitialized() const = 0;
235
236 // This is not implemented for Lite messages -- it just returns "(cannot
237 // determine missing fields for lite message)". However, it is implemented
238 // for full messages. See message.h.
239 virtual std::string InitializationErrorString() const;
240
241 // If |other| is the exact same class as this, calls MergeFrom(). Otherwise,
242 // results are undefined (probably crash).
243 virtual void CheckTypeAndMergeFrom(const MessageLite& other) = 0;
244
245 // These methods return a human-readable summary of the message. Note that
246 // since the MessageLite interface does not support reflection, there is very
247 // little information that these methods can provide. They are shadowed by
248 // methods of the same name on the Message interface which provide much more
249 // information. The methods here are intended primarily to facilitate code
250 // reuse for logic that needs to interoperate with both full and lite protos.
251 //
252 // The format of the returned string is subject to change, so please do not
253 // assume it will remain stable over time.
254 std::string DebugString() const;
ShortDebugString()255 std::string ShortDebugString() const { return DebugString(); }
256 // MessageLite::DebugString is already Utf8 Safe. This is to add compatibility
257 // with Message.
Utf8DebugString()258 std::string Utf8DebugString() const { return DebugString(); }
259
260 // Parsing ---------------------------------------------------------
261 // Methods for parsing in protocol buffer format. Most of these are
262 // just simple wrappers around MergeFromCodedStream(). Clear() will be
263 // called before merging the input.
264
265 // Fill the message with a protocol buffer parsed from the given input
266 // stream. Returns false on a read error or if the input is in the wrong
267 // format. A successful return does not indicate the entire input is
268 // consumed, ensure you call ConsumedEntireMessage() to check that if
269 // applicable.
270 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParseFromCodedStream(
271 io::CodedInputStream* input);
272 // Like ParseFromCodedStream(), but accepts messages that are missing
273 // required fields.
274 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParsePartialFromCodedStream(
275 io::CodedInputStream* input);
276 // Read a protocol buffer from the given zero-copy input stream. If
277 // successful, the entire input will be consumed.
278 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParseFromZeroCopyStream(
279 io::ZeroCopyInputStream* input);
280 // Like ParseFromZeroCopyStream(), but accepts messages that are missing
281 // required fields.
282 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParsePartialFromZeroCopyStream(
283 io::ZeroCopyInputStream* input);
284 // Parse a protocol buffer from a file descriptor. If successful, the entire
285 // input will be consumed.
286 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParseFromFileDescriptor(
287 int file_descriptor);
288 // Like ParseFromFileDescriptor(), but accepts messages that are missing
289 // required fields.
290 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParsePartialFromFileDescriptor(
291 int file_descriptor);
292 // Parse a protocol buffer from a C++ istream. If successful, the entire
293 // input will be consumed.
294 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParseFromIstream(std::istream* input);
295 // Like ParseFromIstream(), but accepts messages that are missing
296 // required fields.
297 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParsePartialFromIstream(
298 std::istream* input);
299 // Read a protocol buffer from the given zero-copy input stream, expecting
300 // the message to be exactly "size" bytes long. If successful, exactly
301 // this many bytes will have been consumed from the input.
302 bool MergePartialFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
303 int size);
304 // Like ParseFromBoundedZeroCopyStream(), but accepts messages that are
305 // missing required fields.
306 bool MergeFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input, int size);
307 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParseFromBoundedZeroCopyStream(
308 io::ZeroCopyInputStream* input, int size);
309 // Like ParseFromBoundedZeroCopyStream(), but accepts messages that are
310 // missing required fields.
311 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParsePartialFromBoundedZeroCopyStream(
312 io::ZeroCopyInputStream* input, int size);
313 // Parses a protocol buffer contained in a string. Returns true on success.
314 // This function takes a string in the (non-human-readable) binary wire
315 // format, matching the encoding output by MessageLite::SerializeToString().
316 // If you'd like to convert a human-readable string into a protocol buffer
317 // object, see google::protobuf::TextFormat::ParseFromString().
318 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParseFromString(
319 const std::string& data);
320 // Like ParseFromString(), but accepts messages that are missing
321 // required fields.
322 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParsePartialFromString(
323 const std::string& data);
324 // Parse a protocol buffer contained in an array of bytes.
325 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParseFromArray(const void* data,
326 int size);
327 // Like ParseFromArray(), but accepts messages that are missing
328 // required fields.
329 PROTOBUF_ATTRIBUTE_REINITIALIZES bool ParsePartialFromArray(const void* data,
330 int size);
331
332
333 // Reads a protocol buffer from the stream and merges it into this
334 // Message. Singular fields read from the what is
335 // already in the Message and repeated fields are appended to those
336 // already present.
337 //
338 // It is the responsibility of the caller to call input->LastTagWas()
339 // (for groups) or input->ConsumedEntireMessage() (for non-groups) after
340 // this returns to verify that the message's end was delimited correctly.
341 //
342 // ParseFromCodedStream() is implemented as Clear() followed by
343 // MergeFromCodedStream().
344 bool MergeFromCodedStream(io::CodedInputStream* input);
345
346 // Like MergeFromCodedStream(), but succeeds even if required fields are
347 // missing in the input.
348 //
349 // MergeFromCodedStream() is just implemented as MergePartialFromCodedStream()
350 // followed by IsInitialized().
351 bool MergePartialFromCodedStream(io::CodedInputStream* input);
352
353 // Merge a protocol buffer contained in a string.
354 bool MergeFromString(const std::string& data);
355
356
357 // Serialization ---------------------------------------------------
358 // Methods for serializing in protocol buffer format. Most of these
359 // are just simple wrappers around ByteSize() and SerializeWithCachedSizes().
360
361 // Write a protocol buffer of this message to the given output. Returns
362 // false on a write error. If the message is missing required fields,
363 // this may GOOGLE_CHECK-fail.
364 bool SerializeToCodedStream(io::CodedOutputStream* output) const;
365 // Like SerializeToCodedStream(), but allows missing required fields.
366 bool SerializePartialToCodedStream(io::CodedOutputStream* output) const;
367 // Write the message to the given zero-copy output stream. All required
368 // fields must be set.
369 bool SerializeToZeroCopyStream(io::ZeroCopyOutputStream* output) const;
370 // Like SerializeToZeroCopyStream(), but allows missing required fields.
371 bool SerializePartialToZeroCopyStream(io::ZeroCopyOutputStream* output) const;
372 // Serialize the message and store it in the given string. All required
373 // fields must be set.
374 bool SerializeToString(std::string* output) const;
375 // Like SerializeToString(), but allows missing required fields.
376 bool SerializePartialToString(std::string* output) const;
377 // Serialize the message and store it in the given byte array. All required
378 // fields must be set.
379 bool SerializeToArray(void* data, int size) const;
380 // Like SerializeToArray(), but allows missing required fields.
381 bool SerializePartialToArray(void* data, int size) const;
382
383 // Make a string encoding the message. Is equivalent to calling
384 // SerializeToString() on a string and using that. Returns the empty
385 // string if SerializeToString() would have returned an error.
386 // Note: If you intend to generate many such strings, you may
387 // reduce heap fragmentation by instead re-using the same string
388 // object with calls to SerializeToString().
389 std::string SerializeAsString() const;
390 // Like SerializeAsString(), but allows missing required fields.
391 std::string SerializePartialAsString() const;
392
393 // Serialize the message and write it to the given file descriptor. All
394 // required fields must be set.
395 bool SerializeToFileDescriptor(int file_descriptor) const;
396 // Like SerializeToFileDescriptor(), but allows missing required fields.
397 bool SerializePartialToFileDescriptor(int file_descriptor) const;
398 // Serialize the message and write it to the given C++ ostream. All
399 // required fields must be set.
400 bool SerializeToOstream(std::ostream* output) const;
401 // Like SerializeToOstream(), but allows missing required fields.
402 bool SerializePartialToOstream(std::ostream* output) const;
403
404 // Like SerializeToString(), but appends to the data to the string's
405 // existing contents. All required fields must be set.
406 bool AppendToString(std::string* output) const;
407 // Like AppendToString(), but allows missing required fields.
408 bool AppendPartialToString(std::string* output) const;
409
410
411 // Computes the serialized size of the message. This recursively calls
412 // ByteSizeLong() on all embedded messages.
413 //
414 // ByteSizeLong() is generally linear in the number of fields defined for the
415 // proto.
416 virtual size_t ByteSizeLong() const = 0;
417
418 // Legacy ByteSize() API.
419 PROTOBUF_DEPRECATED_MSG("Please use ByteSizeLong() instead")
ByteSize()420 int ByteSize() const { return internal::ToIntSize(ByteSizeLong()); }
421
422 // Serializes the message without recomputing the size. The message must not
423 // have changed since the last call to ByteSize(), and the value returned by
424 // ByteSize must be non-negative. Otherwise the results are undefined.
SerializeWithCachedSizes(io::CodedOutputStream * output)425 void SerializeWithCachedSizes(io::CodedOutputStream* output) const {
426 output->SetCur(_InternalSerialize(output->Cur(), output->EpsCopy()));
427 }
428
429 // Functions below here are not part of the public interface. It isn't
430 // enforced, but they should be treated as private, and will be private
431 // at some future time. Unfortunately the implementation of the "friend"
432 // keyword in GCC is broken at the moment, but we expect it will be fixed.
433
434 // Like SerializeWithCachedSizes, but writes directly to *target, returning
435 // a pointer to the byte immediately after the last byte written. "target"
436 // must point at a byte array of at least ByteSize() bytes. Whether to use
437 // deterministic serialization, e.g., maps in sorted order, is determined by
438 // CodedOutputStream::IsDefaultSerializationDeterministic().
439 uint8* SerializeWithCachedSizesToArray(uint8* target) const;
440
441 // Returns the result of the last call to ByteSize(). An embedded message's
442 // size is needed both to serialize it (because embedded messages are
443 // length-delimited) and to compute the outer message's size. Caching
444 // the size avoids computing it multiple times.
445 //
446 // ByteSize() does not automatically use the cached size when available
447 // because this would require invalidating it every time the message was
448 // modified, which would be too hard and expensive. (E.g. if a deeply-nested
449 // sub-message is changed, all of its parents' cached sizes would need to be
450 // invalidated, which is too much work for an otherwise inlined setter
451 // method.)
452 virtual int GetCachedSize() const = 0;
453
_InternalParse(const char *,internal::ParseContext *)454 virtual const char* _InternalParse(const char* /*ptr*/,
455 internal::ParseContext* /*ctx*/) {
456 return nullptr;
457 }
458
459 protected:
460 template <typename T>
CreateMaybeMessage(Arena * arena)461 static T* CreateMaybeMessage(Arena* arena) {
462 return Arena::CreateMaybeMessage<T>(arena);
463 }
464
MessageLite(Arena * arena)465 inline explicit MessageLite(Arena* arena) : _internal_metadata_(arena) {}
466
467 internal::InternalMetadata _internal_metadata_;
468
469 public:
470 enum ParseFlags {
471 kMerge = 0,
472 kParse = 1,
473 kMergePartial = 2,
474 kParsePartial = 3,
475 kMergeWithAliasing = 4,
476 kParseWithAliasing = 5,
477 kMergePartialWithAliasing = 6,
478 kParsePartialWithAliasing = 7
479 };
480
481 template <ParseFlags flags, typename T>
482 bool ParseFrom(const T& input);
483
484 // Fast path when conditions match (ie. non-deterministic)
485 // uint8* _InternalSerialize(uint8* ptr) const;
486 virtual uint8* _InternalSerialize(uint8* ptr,
487 io::EpsCopyOutputStream* stream) const = 0;
488
489 // Identical to IsInitialized() except that it logs an error message.
IsInitializedWithErrors()490 bool IsInitializedWithErrors() const {
491 if (IsInitialized()) return true;
492 LogInitializationErrorMessage();
493 return false;
494 }
495
496 private:
497 // TODO(gerbens) make this a pure abstract function
InternalGetTable()498 virtual const void* InternalGetTable() const { return NULL; }
499
500 friend class internal::WireFormatLite;
501 friend class Message;
502 friend class internal::WeakFieldMap;
503
504 void LogInitializationErrorMessage() const;
505
506 bool MergeFromImpl(io::CodedInputStream* input, ParseFlags parse_flags);
507
508 GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MessageLite);
509 };
510
511 namespace internal {
512
513 template <bool alias>
514 bool MergeFromImpl(StringPiece input, MessageLite* msg,
515 MessageLite::ParseFlags parse_flags);
516 extern template bool MergeFromImpl<false>(StringPiece input,
517 MessageLite* msg,
518 MessageLite::ParseFlags parse_flags);
519 extern template bool MergeFromImpl<true>(StringPiece input,
520 MessageLite* msg,
521 MessageLite::ParseFlags parse_flags);
522
523 template <bool alias>
524 bool MergeFromImpl(io::ZeroCopyInputStream* input, MessageLite* msg,
525 MessageLite::ParseFlags parse_flags);
526 extern template bool MergeFromImpl<false>(io::ZeroCopyInputStream* input,
527 MessageLite* msg,
528 MessageLite::ParseFlags parse_flags);
529 extern template bool MergeFromImpl<true>(io::ZeroCopyInputStream* input,
530 MessageLite* msg,
531 MessageLite::ParseFlags parse_flags);
532
533 struct BoundedZCIS {
534 io::ZeroCopyInputStream* zcis;
535 int limit;
536 };
537
538 template <bool alias>
539 bool MergeFromImpl(BoundedZCIS input, MessageLite* msg,
540 MessageLite::ParseFlags parse_flags);
541 extern template bool MergeFromImpl<false>(BoundedZCIS input, MessageLite* msg,
542 MessageLite::ParseFlags parse_flags);
543 extern template bool MergeFromImpl<true>(BoundedZCIS input, MessageLite* msg,
544 MessageLite::ParseFlags parse_flags);
545
546 template <typename T>
547 struct SourceWrapper;
548
549 template <bool alias, typename T>
MergeFromImpl(const SourceWrapper<T> & input,MessageLite * msg,MessageLite::ParseFlags parse_flags)550 bool MergeFromImpl(const SourceWrapper<T>& input, MessageLite* msg,
551 MessageLite::ParseFlags parse_flags) {
552 return input.template MergeInto<alias>(msg, parse_flags);
553 }
554
555 } // namespace internal
556
557 template <MessageLite::ParseFlags flags, typename T>
ParseFrom(const T & input)558 bool MessageLite::ParseFrom(const T& input) {
559 if (flags & kParse) Clear();
560 constexpr bool alias = (flags & kMergeWithAliasing) != 0;
561 return internal::MergeFromImpl<alias>(input, this, flags);
562 }
563
564 // ===================================================================
565 // Shutdown support.
566
567
568 // Shut down the entire protocol buffers library, deleting all static-duration
569 // objects allocated by the library or by generated .pb.cc files.
570 //
571 // There are two reasons you might want to call this:
572 // * You use a draconian definition of "memory leak" in which you expect
573 // every single malloc() to have a corresponding free(), even for objects
574 // which live until program exit.
575 // * You are writing a dynamically-loaded library which needs to clean up
576 // after itself when the library is unloaded.
577 //
578 // It is safe to call this multiple times. However, it is not safe to use
579 // any other part of the protocol buffers library after
580 // ShutdownProtobufLibrary() has been called. Furthermore this call is not
581 // thread safe, user needs to synchronize multiple calls.
582 PROTOBUF_EXPORT void ShutdownProtobufLibrary();
583
584 namespace internal {
585
586 // Register a function to be called when ShutdownProtocolBuffers() is called.
587 PROTOBUF_EXPORT void OnShutdown(void (*func)());
588 // Run an arbitrary function on an arg
589 PROTOBUF_EXPORT void OnShutdownRun(void (*f)(const void*), const void* arg);
590
591 template <typename T>
OnShutdownDelete(T * p)592 T* OnShutdownDelete(T* p) {
593 OnShutdownRun([](const void* pp) { delete static_cast<const T*>(pp); }, p);
594 return p;
595 }
596
597 } // namespace internal
598 } // namespace protobuf
599 } // namespace google
600
601 #include <google/protobuf/port_undef.inc>
602
603 #endif // GOOGLE_PROTOBUF_MESSAGE_LITE_H__
604