• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 //
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file or at
6 // https://developers.google.com/open-source/licenses/bsd
7 
8 // Author: kenton@google.com (Kenton Varda)
9 //  Based on original Protocol Buffers design by
10 //  Sanjay Ghemawat, Jeff Dean, and others.
11 //
12 // This file contains the CodedInputStream and CodedOutputStream classes,
13 // which wrap a ZeroCopyInputStream or ZeroCopyOutputStream, respectively,
14 // and allow you to read or write individual pieces of data in various
15 // formats.  In particular, these implement the varint encoding for
16 // integers, a simple variable-length encoding in which smaller numbers
17 // take fewer bytes.
18 //
19 // Typically these classes will only be used internally by the protocol
20 // buffer library in order to encode and decode protocol buffers.  Clients
21 // of the library only need to know about this class if they wish to write
22 // custom message parsing or serialization procedures.
23 //
24 // CodedOutputStream example:
25 //   // Write some data to "myfile".  First we write a 4-byte "magic number"
26 //   // to identify the file type, then write a length-prefixed string.  The
27 //   // string is composed of a varint giving the length followed by the raw
28 //   // bytes.
29 //   int fd = open("myfile", O_CREAT | O_WRONLY);
30 //   ZeroCopyOutputStream* raw_output = new FileOutputStream(fd);
31 //   CodedOutputStream* coded_output = new CodedOutputStream(raw_output);
32 //
33 //   int magic_number = 1234;
34 //   char text[] = "Hello world!";
35 //   coded_output->WriteLittleEndian32(magic_number);
36 //   coded_output->WriteVarint32(strlen(text));
37 //   coded_output->WriteRaw(text, strlen(text));
38 //
39 //   delete coded_output;
40 //   delete raw_output;
41 //   close(fd);
42 //
43 // CodedInputStream example:
44 //   // Read a file created by the above code.
45 //   int fd = open("myfile", O_RDONLY);
46 //   ZeroCopyInputStream* raw_input = new FileInputStream(fd);
47 //   CodedInputStream* coded_input = new CodedInputStream(raw_input);
48 //
49 //   coded_input->ReadLittleEndian32(&magic_number);
50 //   if (magic_number != 1234) {
51 //     cerr << "File not in expected format." << endl;
52 //     return;
53 //   }
54 //
55 //   uint32_t size;
56 //   coded_input->ReadVarint32(&size);
57 //
58 //   char* text = new char[size + 1];
59 //   coded_input->ReadRaw(buffer, size);
60 //   text[size] = '\0';
61 //
62 //   delete coded_input;
63 //   delete raw_input;
64 //   close(fd);
65 //
66 //   cout << "Text is: " << text << endl;
67 //   delete [] text;
68 //
69 // For those who are interested, varint encoding is defined as follows:
70 //
71 // The encoding operates on unsigned integers of up to 64 bits in length.
72 // Each byte of the encoded value has the format:
73 // * bits 0-6: Seven bits of the number being encoded.
74 // * bit 7: Zero if this is the last byte in the encoding (in which
75 //   case all remaining bits of the number are zero) or 1 if
76 //   more bytes follow.
77 // The first byte contains the least-significant 7 bits of the number, the
78 // second byte (if present) contains the next-least-significant 7 bits,
79 // and so on.  So, the binary number 1011000101011 would be encoded in two
80 // bytes as "10101011 00101100".
81 //
82 // In theory, varint could be used to encode integers of any length.
83 // However, for practicality we set a limit at 64 bits.  The maximum encoded
84 // length of a number is thus 10 bytes.
85 
86 #ifndef GOOGLE_PROTOBUF_IO_CODED_STREAM_H__
87 #define GOOGLE_PROTOBUF_IO_CODED_STREAM_H__
88 
89 #include <assert.h>
90 
91 #include <atomic>
92 #include <climits>
93 #include <cstddef>
94 #include <cstdint>
95 #include <cstring>
96 #include <limits>
97 #include <string>
98 #include <type_traits>
99 #include <utility>
100 
101 #if defined(_MSC_VER) && _MSC_VER >= 1300 && !defined(__INTEL_COMPILER)
102 // If MSVC has "/RTCc" set, it will complain about truncating casts at
103 // runtime.  This file contains some intentional truncating casts.
104 #pragma runtime_checks("c", off)
105 #endif
106 
107 #include "absl/log/absl_log.h"  // Replace with vlog_is_on.h after Abseil LTS 20240722
108 
109 #include "absl/log/absl_check.h"
110 #include "absl/numeric/bits.h"
111 #include "absl/strings/cord.h"
112 #include "absl/strings/string_view.h"
113 #include "google/protobuf/endian_pb.h"
114 
115 // Must be included last.
116 #include "google/protobuf/port_def.inc"
117 
118 namespace google {
119 namespace protobuf {
120 
121 class DescriptorPool;
122 class MessageFactory;
123 class ZeroCopyCodedInputStream;
124 
125 namespace internal {
126 void MapTestForceDeterministic();
127 class EpsCopyByteStream;
128 }  // namespace internal
129 
130 namespace io {
131 
132 // Defined in this file.
133 class CodedInputStream;
134 class CodedOutputStream;
135 
136 // Defined in other files.
137 class ZeroCopyInputStream;   // zero_copy_stream.h
138 class ZeroCopyOutputStream;  // zero_copy_stream.h
139 
140 // Class which reads and decodes binary data which is composed of varint-
141 // encoded integers and fixed-width pieces.  Wraps a ZeroCopyInputStream.
142 // Most users will not need to deal with CodedInputStream.
143 //
144 // Most methods of CodedInputStream that return a bool return false if an
145 // underlying I/O error occurs or if the data is malformed.  Once such a
146 // failure occurs, the CodedInputStream is broken and is no longer useful.
147 // After a failure, callers also should assume writes to "out" args may have
148 // occurred, though nothing useful can be determined from those writes.
149 class PROTOBUF_EXPORT CodedInputStream {
150  public:
151   // Create a CodedInputStream that reads from the given ZeroCopyInputStream.
152   explicit CodedInputStream(ZeroCopyInputStream* input);
153 
154   // Create a CodedInputStream that reads from the given flat array.  This is
155   // faster than using an ArrayInputStream.  PushLimit(size) is implied by
156   // this constructor.
157   explicit CodedInputStream(const uint8_t* buffer, int size);
158   CodedInputStream(const CodedInputStream&) = delete;
159   CodedInputStream& operator=(const CodedInputStream&) = delete;
160 
161   // Destroy the CodedInputStream and position the underlying
162   // ZeroCopyInputStream at the first unread byte.  If an error occurred while
163   // reading (causing a method to return false), then the exact position of
164   // the input stream may be anywhere between the last value that was read
165   // successfully and the stream's byte limit.
166   ~CodedInputStream();
167 
168   // Return true if this CodedInputStream reads from a flat array instead of
169   // a ZeroCopyInputStream.
170   inline bool IsFlat() const;
171 
172   // Skips a number of bytes.  Returns false if an underlying read error
173   // occurs.
174   inline bool Skip(int count);
175 
176   // Sets *data to point directly at the unread part of the CodedInputStream's
177   // underlying buffer, and *size to the size of that buffer, but does not
178   // advance the stream's current position.  This will always either produce
179   // a non-empty buffer or return false.  If the caller consumes any of
180   // this data, it should then call Skip() to skip over the consumed bytes.
181   // This may be useful for implementing external fast parsing routines for
182   // types of data not covered by the CodedInputStream interface.
183   bool GetDirectBufferPointer(const void** data, int* size);
184 
185   // Like GetDirectBufferPointer, but this method is inlined, and does not
186   // attempt to Refresh() if the buffer is currently empty.
187   PROTOBUF_ALWAYS_INLINE
188   void GetDirectBufferPointerInline(const void** data, int* size);
189 
190   // Read raw bytes, copying them into the given buffer.
191   bool ReadRaw(void* buffer, int size);
192 
193   // Like ReadRaw, but reads into a string.
194   bool ReadString(std::string* buffer, int size);
195 
196   // Like ReadString(), but reads to a Cord.
197   bool ReadCord(absl::Cord* output, int size);
198 
199 
200   // Read a 16-bit little-endian integer.
201   bool ReadLittleEndian16(uint16_t* value);
202   // Read a 32-bit little-endian integer.
203   bool ReadLittleEndian32(uint32_t* value);
204   // Read a 64-bit little-endian integer.
205   bool ReadLittleEndian64(uint64_t* value);
206 
207   // These methods read from an externally provided buffer. The caller is
208   // responsible for ensuring that the buffer has sufficient space.
209   // Read a 16-bit little-endian integer.
210   static const uint8_t* ReadLittleEndian16FromArray(const uint8_t* buffer,
211                                                     uint16_t* value);
212   // Read a 32-bit little-endian integer.
213   static const uint8_t* ReadLittleEndian32FromArray(const uint8_t* buffer,
214                                                     uint32_t* value);
215   // Read a 64-bit little-endian integer.
216   static const uint8_t* ReadLittleEndian64FromArray(const uint8_t* buffer,
217                                                     uint64_t* value);
218 
219   // Read an unsigned integer with Varint encoding, truncating to 32 bits.
220   // Reading a 32-bit value is equivalent to reading a 64-bit one and casting
221   // it to uint32_t, but may be more efficient.
222   bool ReadVarint32(uint32_t* value);
223   // Read an unsigned integer with Varint encoding.
224   bool ReadVarint64(uint64_t* value);
225 
226   // Reads a varint off the wire into an "int". This should be used for reading
227   // sizes off the wire (sizes of strings, submessages, bytes fields, etc).
228   //
229   // The value from the wire is interpreted as unsigned.  If its value exceeds
230   // the representable value of an integer on this platform, instead of
231   // truncating we return false. Truncating (as performed by ReadVarint32()
232   // above) is an acceptable approach for fields representing an integer, but
233   // when we are parsing a size from the wire, truncating the value would result
234   // in us misparsing the payload.
235   bool ReadVarintSizeAsInt(int* value);
236 
237   // Read a tag.  This calls ReadVarint32() and returns the result, or returns
238   // zero (which is not a valid tag) if ReadVarint32() fails.  Also, ReadTag
239   // (but not ReadTagNoLastTag) updates the last tag value, which can be checked
240   // with LastTagWas().
241   //
242   // Always inline because this is only called in one place per parse loop
243   // but it is called for every iteration of said loop, so it should be fast.
244   // GCC doesn't want to inline this by default.
ReadTag()245   PROTOBUF_ALWAYS_INLINE uint32_t ReadTag() {
246     return last_tag_ = ReadTagNoLastTag();
247   }
248 
249   PROTOBUF_ALWAYS_INLINE uint32_t ReadTagNoLastTag();
250 
251   // This usually a faster alternative to ReadTag() when cutoff is a manifest
252   // constant.  It does particularly well for cutoff >= 127.  The first part
253   // of the return value is the tag that was read, though it can also be 0 in
254   // the cases where ReadTag() would return 0.  If the second part is true
255   // then the tag is known to be in [0, cutoff].  If not, the tag either is
256   // above cutoff or is 0.  (There's intentional wiggle room when tag is 0,
257   // because that can arise in several ways, and for best performance we want
258   // to avoid an extra "is tag == 0?" check here.)
259   PROTOBUF_ALWAYS_INLINE
ReadTagWithCutoff(uint32_t cutoff)260   std::pair<uint32_t, bool> ReadTagWithCutoff(uint32_t cutoff) {
261     std::pair<uint32_t, bool> result = ReadTagWithCutoffNoLastTag(cutoff);
262     last_tag_ = result.first;
263     return result;
264   }
265 
266   PROTOBUF_ALWAYS_INLINE
267   std::pair<uint32_t, bool> ReadTagWithCutoffNoLastTag(uint32_t cutoff);
268 
269   // Usually returns true if calling ReadVarint32() now would produce the given
270   // value.  Will always return false if ReadVarint32() would not return the
271   // given value.  If ExpectTag() returns true, it also advances past
272   // the varint.  For best performance, use a compile-time constant as the
273   // parameter.
274   // Always inline because this collapses to a small number of instructions
275   // when given a constant parameter, but GCC doesn't want to inline by default.
276   PROTOBUF_ALWAYS_INLINE bool ExpectTag(uint32_t expected);
277 
278   // Like above, except this reads from the specified buffer. The caller is
279   // responsible for ensuring that the buffer is large enough to read a varint
280   // of the expected size. For best performance, use a compile-time constant as
281   // the expected tag parameter.
282   //
283   // Returns a pointer beyond the expected tag if it was found, or NULL if it
284   // was not.
285   PROTOBUF_ALWAYS_INLINE
286   static const uint8_t* ExpectTagFromArray(const uint8_t* buffer,
287                                            uint32_t expected);
288 
289   // Usually returns true if no more bytes can be read.  Always returns false
290   // if more bytes can be read.  If ExpectAtEnd() returns true, a subsequent
291   // call to LastTagWas() will act as if ReadTag() had been called and returned
292   // zero, and ConsumedEntireMessage() will return true.
293   bool ExpectAtEnd();
294 
295   // If the last call to ReadTag() or ReadTagWithCutoff() returned the given
296   // value, returns true.  Otherwise, returns false.
297   // ReadTagNoLastTag/ReadTagWithCutoffNoLastTag do not preserve the last
298   // returned value.
299   //
300   // This is needed because parsers for some types of embedded messages
301   // (with field type TYPE_GROUP) don't actually know that they've reached the
302   // end of a message until they see an ENDGROUP tag, which was actually part
303   // of the enclosing message.  The enclosing message would like to check that
304   // tag to make sure it had the right number, so it calls LastTagWas() on
305   // return from the embedded parser to check.
306   bool LastTagWas(uint32_t expected);
SetLastTag(uint32_t tag)307   void SetLastTag(uint32_t tag) { last_tag_ = tag; }
308 
309   // When parsing message (but NOT a group), this method must be called
310   // immediately after MergeFromCodedStream() returns (if it returns true)
311   // to further verify that the message ended in a legitimate way.  For
312   // example, this verifies that parsing did not end on an end-group tag.
313   // It also checks for some cases where, due to optimizations,
314   // MergeFromCodedStream() can incorrectly return true.
315   bool ConsumedEntireMessage();
SetConsumed()316   void SetConsumed() { legitimate_message_end_ = true; }
317 
318   // Limits ----------------------------------------------------------
319   // Limits are used when parsing length-prefixed embedded messages.
320   // After the message's length is read, PushLimit() is used to prevent
321   // the CodedInputStream from reading beyond that length.  Once the
322   // embedded message has been parsed, PopLimit() is called to undo the
323   // limit.
324 
325   // Opaque type used with PushLimit() and PopLimit().  Do not modify
326   // values of this type yourself.  The only reason that this isn't a
327   // struct with private internals is for efficiency.
328   typedef int Limit;
329 
330   // Places a limit on the number of bytes that the stream may read,
331   // starting from the current position.  Once the stream hits this limit,
332   // it will act like the end of the input has been reached until PopLimit()
333   // is called.
334   //
335   // As the names imply, the stream conceptually has a stack of limits.  The
336   // shortest limit on the stack is always enforced, even if it is not the
337   // top limit.
338   //
339   // The value returned by PushLimit() is opaque to the caller, and must
340   // be passed unchanged to the corresponding call to PopLimit().
341   Limit PushLimit(int byte_limit);
342 
343   // Pops the last limit pushed by PushLimit().  The input must be the value
344   // returned by that call to PushLimit().
345   void PopLimit(Limit limit);
346 
347   // Returns the number of bytes left until the nearest limit on the
348   // stack is hit, or -1 if no limits are in place.
349   int BytesUntilLimit() const;
350 
351   // Returns current position relative to the beginning of the input stream.
352   int CurrentPosition() const;
353 
354   // Total Bytes Limit -----------------------------------------------
355   // To prevent malicious users from sending excessively large messages
356   // and causing memory exhaustion, CodedInputStream imposes a hard limit on
357   // the total number of bytes it will read.
358 
359   // Sets the maximum number of bytes that this CodedInputStream will read
360   // before refusing to continue.  To prevent servers from allocating enormous
361   // amounts of memory to hold parsed messages, the maximum message length
362   // should be limited to the shortest length that will not harm usability.
363   // The default limit is INT_MAX (~2GB) and apps should set shorter limits
364   // if possible. An error will always be printed to stderr if the limit is
365   // reached.
366   //
367   // Note: setting a limit less than the current read position is interpreted
368   // as a limit on the current position.
369   //
370   // This is unrelated to PushLimit()/PopLimit().
371   void SetTotalBytesLimit(int total_bytes_limit);
372 
373   // The Total Bytes Limit minus the Current Position, or -1 if the total bytes
374   // limit is INT_MAX.
375   int BytesUntilTotalBytesLimit() const;
376 
377   // Recursion Limit -------------------------------------------------
378   // To prevent corrupt or malicious messages from causing stack overflows,
379   // we must keep track of the depth of recursion when parsing embedded
380   // messages and groups.  CodedInputStream keeps track of this because it
381   // is the only object that is passed down the stack during parsing.
382 
383   // Sets the maximum recursion depth.  The default is 100.
384   void SetRecursionLimit(int limit);
RecursionBudget()385   int RecursionBudget() { return recursion_budget_; }
386 
GetDefaultRecursionLimit()387   static int GetDefaultRecursionLimit() { return default_recursion_limit_; }
388 
389   // Increments the current recursion depth.  Returns true if the depth is
390   // under the limit, false if it has gone over.
391   bool IncrementRecursionDepth();
392 
393   // Decrements the recursion depth if possible.
394   void DecrementRecursionDepth();
395 
396   // Decrements the recursion depth blindly.  This is faster than
397   // DecrementRecursionDepth().  It should be used only if all previous
398   // increments to recursion depth were successful.
399   void UnsafeDecrementRecursionDepth();
400 
401   // Shorthand for make_pair(PushLimit(byte_limit), --recursion_budget_).
402   // Using this can reduce code size and complexity in some cases.  The caller
403   // is expected to check that the second part of the result is non-negative (to
404   // bail out if the depth of recursion is too high) and, if all is well, to
405   // later pass the first part of the result to PopLimit() or similar.
406   std::pair<CodedInputStream::Limit, int> IncrementRecursionDepthAndPushLimit(
407       int byte_limit);
408 
409   // Shorthand for PushLimit(ReadVarint32(&length) ? length : 0).
410   Limit ReadLengthAndPushLimit();
411 
412   // Helper that is equivalent to: {
413   //  bool result = ConsumedEntireMessage();
414   //  PopLimit(limit);
415   //  UnsafeDecrementRecursionDepth();
416   //  return result; }
417   // Using this can reduce code size and complexity in some cases.
418   // Do not use unless the current recursion depth is greater than zero.
419   bool DecrementRecursionDepthAndPopLimit(Limit limit);
420 
421   // Helper that is equivalent to: {
422   //  bool result = ConsumedEntireMessage();
423   //  PopLimit(limit);
424   //  return result; }
425   // Using this can reduce code size and complexity in some cases.
426   bool CheckEntireMessageConsumedAndPopLimit(Limit limit);
427 
428   // Extension Registry ----------------------------------------------
429   // ADVANCED USAGE:  99.9% of people can ignore this section.
430   //
431   // By default, when parsing extensions, the parser looks for extension
432   // definitions in the pool which owns the outer message's Descriptor.
433   // However, you may call SetExtensionRegistry() to provide an alternative
434   // pool instead.  This makes it possible, for example, to parse a message
435   // using a generated class, but represent some extensions using
436   // DynamicMessage.
437 
438   // Set the pool used to look up extensions.  Most users do not need to call
439   // this as the correct pool will be chosen automatically.
440   //
441   // WARNING:  It is very easy to misuse this.  Carefully read the requirements
442   //   below.  Do not use this unless you are sure you need it.  Almost no one
443   //   does.
444   //
445   // Let's say you are parsing a message into message object m, and you want
446   // to take advantage of SetExtensionRegistry().  You must follow these
447   // requirements:
448   //
449   // The given DescriptorPool must contain m->GetDescriptor().  It is not
450   // sufficient for it to simply contain a descriptor that has the same name
451   // and content -- it must be the *exact object*.  In other words:
452   //   assert(pool->FindMessageTypeByName(m->GetDescriptor()->full_name()) ==
453   //          m->GetDescriptor());
454   // There are two ways to satisfy this requirement:
455   // 1) Use m->GetDescriptor()->pool() as the pool.  This is generally useless
456   //    because this is the pool that would be used anyway if you didn't call
457   //    SetExtensionRegistry() at all.
458   // 2) Use a DescriptorPool which has m->GetDescriptor()->pool() as an
459   //    "underlay".  Read the documentation for DescriptorPool for more
460   //    information about underlays.
461   //
462   // You must also provide a MessageFactory.  This factory will be used to
463   // construct Message objects representing extensions.  The factory's
464   // GetPrototype() MUST return non-NULL for any Descriptor which can be found
465   // through the provided pool.
466   //
467   // If the provided factory might return instances of protocol-compiler-
468   // generated (i.e. compiled-in) types, or if the outer message object m is
469   // a generated type, then the given factory MUST have this property:  If
470   // GetPrototype() is given a Descriptor which resides in
471   // DescriptorPool::generated_pool(), the factory MUST return the same
472   // prototype which MessageFactory::generated_factory() would return.  That
473   // is, given a descriptor for a generated type, the factory must return an
474   // instance of the generated class (NOT DynamicMessage).  However, when
475   // given a descriptor for a type that is NOT in generated_pool, the factory
476   // is free to return any implementation.
477   //
478   // The reason for this requirement is that generated sub-objects may be
479   // accessed via the standard (non-reflection) extension accessor methods,
480   // and these methods will down-cast the object to the generated class type.
481   // If the object is not actually of that type, the results would be undefined.
482   // On the other hand, if an extension is not compiled in, then there is no
483   // way the code could end up accessing it via the standard accessors -- the
484   // only way to access the extension is via reflection.  When using reflection,
485   // DynamicMessage and generated messages are indistinguishable, so it's fine
486   // if these objects are represented using DynamicMessage.
487   //
488   // Using DynamicMessageFactory on which you have called
489   // SetDelegateToGeneratedFactory(true) should be sufficient to satisfy the
490   // above requirement.
491   //
492   // If either pool or factory is NULL, both must be NULL.
493   //
494   // Note that this feature is ignored when parsing "lite" messages as they do
495   // not have descriptors.
496   void SetExtensionRegistry(const DescriptorPool* pool,
497                             MessageFactory* factory);
498 
499   // Get the DescriptorPool set via SetExtensionRegistry(), or NULL if no pool
500   // has been provided.
501   const DescriptorPool* GetExtensionPool();
502 
503   // Get the MessageFactory set via SetExtensionRegistry(), or NULL if no
504   // factory has been provided.
505   MessageFactory* GetExtensionFactory();
506 
507  private:
508   const uint8_t* buffer_;
509   const uint8_t* buffer_end_;  // pointer to the end of the buffer.
510   ZeroCopyInputStream* input_;
511   int total_bytes_read_;  // total bytes read from input_, including
512                           // the current buffer
513 
514   // If total_bytes_read_ surpasses INT_MAX, we record the extra bytes here
515   // so that we can BackUp() on destruction.
516   int overflow_bytes_;
517 
518   // LastTagWas() stuff.
519   uint32_t last_tag_;  // result of last ReadTag() or ReadTagWithCutoff().
520 
521   // This is set true by ReadTag{Fallback/Slow}() if it is called when exactly
522   // at EOF, or by ExpectAtEnd() when it returns true.  This happens when we
523   // reach the end of a message and attempt to read another tag.
524   bool legitimate_message_end_;
525 
526   // See EnableAliasing().
527   bool aliasing_enabled_;
528 
529   // If true, set eager parsing mode to override lazy fields.
530   bool force_eager_parsing_;
531 
532   // Limits
533   Limit current_limit_;  // if position = -1, no limit is applied
534 
535   // For simplicity, if the current buffer crosses a limit (either a normal
536   // limit created by PushLimit() or the total bytes limit), buffer_size_
537   // only tracks the number of bytes before that limit.  This field
538   // contains the number of bytes after it.  Note that this implies that if
539   // buffer_size_ == 0 and buffer_size_after_limit_ > 0, we know we've
540   // hit a limit.  However, if both are zero, it doesn't necessarily mean
541   // we aren't at a limit -- the buffer may have ended exactly at the limit.
542   int buffer_size_after_limit_;
543 
544   // Maximum number of bytes to read, period.  This is unrelated to
545   // current_limit_.  Set using SetTotalBytesLimit().
546   int total_bytes_limit_;
547 
548   // Current recursion budget, controlled by IncrementRecursionDepth() and
549   // similar.  Starts at recursion_limit_ and goes down: if this reaches
550   // -1 we are over budget.
551   int recursion_budget_;
552   // Recursion depth limit, set by SetRecursionLimit().
553   int recursion_limit_;
554 
555   // See SetExtensionRegistry().
556   const DescriptorPool* extension_pool_;
557   MessageFactory* extension_factory_;
558 
559   // Private member functions.
560 
561   // Fallback when Skip() goes past the end of the current buffer.
562   bool SkipFallback(int count, int original_buffer_size);
563 
564   // Advance the buffer by a given number of bytes.
565   void Advance(int amount);
566 
567   // Back up input_ to the current buffer position.
568   void BackUpInputToCurrentPosition();
569 
570   // Recomputes the value of buffer_size_after_limit_.  Must be called after
571   // current_limit_ or total_bytes_limit_ changes.
572   void RecomputeBufferLimits();
573 
574   // Writes an error message saying that we hit total_bytes_limit_.
575   void PrintTotalBytesLimitError();
576 
577   // Called when the buffer runs out to request more data.  Implies an
578   // Advance(BufferSize()).
579   bool Refresh();
580 
581   // When parsing varints, we optimize for the common case of small values, and
582   // then optimize for the case when the varint fits within the current buffer
583   // piece. The Fallback method is used when we can't use the one-byte
584   // optimization. The Slow method is yet another fallback when the buffer is
585   // not large enough. Making the slow path out-of-line speeds up the common
586   // case by 10-15%. The slow path is fairly uncommon: it only triggers when a
587   // message crosses multiple buffers.  Note: ReadVarint32Fallback() and
588   // ReadVarint64Fallback() are called frequently and generally not inlined, so
589   // they have been optimized to avoid "out" parameters.  The former returns -1
590   // if it fails and the uint32_t it read otherwise.  The latter has a bool
591   // indicating success or failure as part of its return type.
592   int64_t ReadVarint32Fallback(uint32_t first_byte_or_zero);
593   int ReadVarintSizeAsIntFallback();
594   std::pair<uint64_t, bool> ReadVarint64Fallback();
595   bool ReadVarint32Slow(uint32_t* value);
596   bool ReadVarint64Slow(uint64_t* value);
597   int ReadVarintSizeAsIntSlow();
598   bool ReadLittleEndian16Fallback(uint16_t* value);
599   bool ReadLittleEndian32Fallback(uint32_t* value);
600   bool ReadLittleEndian64Fallback(uint64_t* value);
601 
602   // Fallback/slow methods for reading tags. These do not update last_tag_,
603   // but will set legitimate_message_end_ if we are at the end of the input
604   // stream.
605   uint32_t ReadTagFallback(uint32_t first_byte_or_zero);
606   uint32_t ReadTagSlow();
607   bool ReadStringFallback(std::string* buffer, int size);
608 
609   // Return the size of the buffer.
610   int BufferSize() const;
611 
612   static const int kDefaultTotalBytesLimit = INT_MAX;
613 
614   static int default_recursion_limit_;  // 100 by default.
615 
616   friend class google::protobuf::ZeroCopyCodedInputStream;
617   friend class google::protobuf::internal::EpsCopyByteStream;
618 };
619 
620 // EpsCopyOutputStream wraps a ZeroCopyOutputStream and exposes a new stream,
621 // which has the property you can write kSlopBytes (16 bytes) from the current
622 // position without bounds checks. The cursor into the stream is managed by
623 // the user of the class and is an explicit parameter in the methods. Careful
624 // use of this class, ie. keep ptr a local variable, eliminates the need to
625 // for the compiler to sync the ptr value between register and memory.
626 class PROTOBUF_EXPORT EpsCopyOutputStream {
627  public:
628   enum { kSlopBytes = 16 };
629 
630   // Initialize from a stream.
EpsCopyOutputStream(ZeroCopyOutputStream * stream,bool deterministic,uint8_t ** pp)631   EpsCopyOutputStream(ZeroCopyOutputStream* stream, bool deterministic,
632                       uint8_t** pp)
633       : end_(buffer_),
634         stream_(stream),
635         is_serialization_deterministic_(deterministic) {
636     *pp = buffer_;
637   }
638 
639   // Only for array serialization. No overflow protection, end_ will be the
640   // pointed to the end of the array. When using this the total size is already
641   // known, so no need to maintain the slop region.
EpsCopyOutputStream(void * data,int size,bool deterministic)642   EpsCopyOutputStream(void* data, int size, bool deterministic)
643       : end_(static_cast<uint8_t*>(data) + size),
644         buffer_end_(nullptr),
645         stream_(nullptr),
646         is_serialization_deterministic_(deterministic) {}
647 
648   // Initialize from stream but with the first buffer already given (eager).
EpsCopyOutputStream(void * data,int size,ZeroCopyOutputStream * stream,bool deterministic,uint8_t ** pp)649   EpsCopyOutputStream(void* data, int size, ZeroCopyOutputStream* stream,
650                       bool deterministic, uint8_t** pp)
651       : stream_(stream), is_serialization_deterministic_(deterministic) {
652     *pp = SetInitialBuffer(data, size);
653   }
654 
655   // Flush everything that's written into the underlying ZeroCopyOutputStream
656   // and trims the underlying stream to the location of ptr.
657   uint8_t* Trim(uint8_t* ptr);
658 
659   // After this it's guaranteed you can safely write kSlopBytes to ptr. This
660   // will never fail! The underlying stream can produce an error. Use HadError
661   // to check for errors.
EnsureSpace(uint8_t * ptr)662   PROTOBUF_NODISCARD uint8_t* EnsureSpace(uint8_t* ptr) {
663     if (PROTOBUF_PREDICT_FALSE(ptr >= end_)) {
664       return EnsureSpaceFallback(ptr);
665     }
666     return ptr;
667   }
668 
WriteRaw(const void * data,int size,uint8_t * ptr)669   uint8_t* WriteRaw(const void* data, int size, uint8_t* ptr) {
670     if (PROTOBUF_PREDICT_FALSE(end_ - ptr < size)) {
671       return WriteRawFallback(data, size, ptr);
672     }
673     std::memcpy(ptr, data, static_cast<unsigned int>(size));
674     return ptr + size;
675   }
676   // Writes the buffer specified by data, size to the stream. Possibly by
677   // aliasing the buffer (ie. not copying the data). The caller is responsible
678   // to make sure the buffer is alive for the duration of the
679   // ZeroCopyOutputStream.
680 #ifndef NDEBUG
681   PROTOBUF_NOINLINE
682 #endif
WriteRawMaybeAliased(const void * data,int size,uint8_t * ptr)683   uint8_t* WriteRawMaybeAliased(const void* data, int size, uint8_t* ptr) {
684     if (aliasing_enabled_) {
685       return WriteAliasedRaw(data, size, ptr);
686     } else {
687       return WriteRaw(data, size, ptr);
688     }
689   }
690 
691   uint8_t* WriteCord(const absl::Cord& cord, uint8_t* ptr);
692 
693 #ifndef NDEBUG
694   PROTOBUF_NOINLINE
695 #endif
WriteStringMaybeAliased(uint32_t num,const std::string & s,uint8_t * ptr)696   uint8_t* WriteStringMaybeAliased(uint32_t num, const std::string& s,
697                                    uint8_t* ptr) {
698     std::ptrdiff_t size = s.size();
699     if (PROTOBUF_PREDICT_FALSE(
700             size >= 128 || end_ - ptr + 16 - TagSize(num << 3) - 1 < size)) {
701       return WriteStringMaybeAliasedOutline(num, s, ptr);
702     }
703     ptr = UnsafeVarint((num << 3) | 2, ptr);
704     *ptr++ = static_cast<uint8_t>(size);
705     std::memcpy(ptr, s.data(), size);
706     return ptr + size;
707   }
WriteBytesMaybeAliased(uint32_t num,const std::string & s,uint8_t * ptr)708   uint8_t* WriteBytesMaybeAliased(uint32_t num, const std::string& s,
709                                   uint8_t* ptr) {
710     return WriteStringMaybeAliased(num, s, ptr);
711   }
712 
713   template <typename T>
WriteString(uint32_t num,const T & s,uint8_t * ptr)714   PROTOBUF_ALWAYS_INLINE uint8_t* WriteString(uint32_t num, const T& s,
715                                               uint8_t* ptr) {
716     std::ptrdiff_t size = s.size();
717     if (PROTOBUF_PREDICT_FALSE(
718             size >= 128 || end_ - ptr + 16 - TagSize(num << 3) - 1 < size)) {
719       return WriteStringOutline(num, s, ptr);
720     }
721     ptr = UnsafeVarint((num << 3) | 2, ptr);
722     *ptr++ = static_cast<uint8_t>(size);
723     std::memcpy(ptr, s.data(), size);
724     return ptr + size;
725   }
726 
WriteString(uint32_t num,const absl::Cord & s,uint8_t * ptr)727   uint8_t* WriteString(uint32_t num, const absl::Cord& s, uint8_t* ptr) {
728     ptr = EnsureSpace(ptr);
729     ptr = WriteTag(num, 2, ptr);
730     return WriteCordOutline(s, ptr);
731   }
732 
733   template <typename T>
734 #ifndef NDEBUG
735   PROTOBUF_NOINLINE
736 #endif
WriteBytes(uint32_t num,const T & s,uint8_t * ptr)737   uint8_t* WriteBytes(uint32_t num, const T& s, uint8_t* ptr) {
738     return WriteString(num, s, ptr);
739   }
740 
741   template <typename T>
WriteInt32Packed(int num,const T & r,int size,uint8_t * ptr)742   PROTOBUF_ALWAYS_INLINE uint8_t* WriteInt32Packed(int num, const T& r,
743                                                    int size, uint8_t* ptr) {
744     return WriteVarintPacked(num, r, size, ptr, Encode64);
745   }
746   template <typename T>
WriteUInt32Packed(int num,const T & r,int size,uint8_t * ptr)747   PROTOBUF_ALWAYS_INLINE uint8_t* WriteUInt32Packed(int num, const T& r,
748                                                     int size, uint8_t* ptr) {
749     return WriteVarintPacked(num, r, size, ptr, Encode32);
750   }
751   template <typename T>
WriteSInt32Packed(int num,const T & r,int size,uint8_t * ptr)752   PROTOBUF_ALWAYS_INLINE uint8_t* WriteSInt32Packed(int num, const T& r,
753                                                     int size, uint8_t* ptr) {
754     return WriteVarintPacked(num, r, size, ptr, ZigZagEncode32);
755   }
756   template <typename T>
WriteInt64Packed(int num,const T & r,int size,uint8_t * ptr)757   PROTOBUF_ALWAYS_INLINE uint8_t* WriteInt64Packed(int num, const T& r,
758                                                    int size, uint8_t* ptr) {
759     return WriteVarintPacked(num, r, size, ptr, Encode64);
760   }
761   template <typename T>
WriteUInt64Packed(int num,const T & r,int size,uint8_t * ptr)762   PROTOBUF_ALWAYS_INLINE uint8_t* WriteUInt64Packed(int num, const T& r,
763                                                     int size, uint8_t* ptr) {
764     return WriteVarintPacked(num, r, size, ptr, Encode64);
765   }
766   template <typename T>
WriteSInt64Packed(int num,const T & r,int size,uint8_t * ptr)767   PROTOBUF_ALWAYS_INLINE uint8_t* WriteSInt64Packed(int num, const T& r,
768                                                     int size, uint8_t* ptr) {
769     return WriteVarintPacked(num, r, size, ptr, ZigZagEncode64);
770   }
771   template <typename T>
WriteEnumPacked(int num,const T & r,int size,uint8_t * ptr)772   PROTOBUF_ALWAYS_INLINE uint8_t* WriteEnumPacked(int num, const T& r, int size,
773                                                   uint8_t* ptr) {
774     return WriteVarintPacked(num, r, size, ptr, Encode64);
775   }
776 
777   template <typename T>
WriteFixedPacked(int num,const T & r,uint8_t * ptr)778   PROTOBUF_ALWAYS_INLINE uint8_t* WriteFixedPacked(int num, const T& r,
779                                                    uint8_t* ptr) {
780     ptr = EnsureSpace(ptr);
781     constexpr auto element_size = sizeof(typename T::value_type);
782     auto size = r.size() * element_size;
783     ptr = WriteLengthDelim(num, size, ptr);
784     return WriteRawLittleEndian<element_size>(r.data(), static_cast<int>(size),
785                                               ptr);
786   }
787 
788   // Returns true if there was an underlying I/O error since this object was
789   // created.
HadError()790   bool HadError() const { return had_error_; }
791 
792   // Instructs the EpsCopyOutputStream to allow the underlying
793   // ZeroCopyOutputStream to hold pointers to the original structure instead of
794   // copying, if it supports it (i.e. output->AllowsAliasing() is true).  If the
795   // underlying stream does not support aliasing, then enabling it has no
796   // affect.  For now, this only affects the behavior of
797   // WriteRawMaybeAliased().
798   //
799   // NOTE: It is caller's responsibility to ensure that the chunk of memory
800   // remains live until all of the data has been consumed from the stream.
801   void EnableAliasing(bool enabled);
802 
803   // See documentation on CodedOutputStream::SetSerializationDeterministic.
SetSerializationDeterministic(bool value)804   void SetSerializationDeterministic(bool value) {
805     is_serialization_deterministic_ = value;
806   }
807 
808   // See documentation on CodedOutputStream::IsSerializationDeterministic.
IsSerializationDeterministic()809   bool IsSerializationDeterministic() const {
810     return is_serialization_deterministic_;
811   }
812 
813   // The number of bytes written to the stream at position ptr, relative to the
814   // stream's overall position.
815   int64_t ByteCount(uint8_t* ptr) const;
816 
817 
818  private:
819   uint8_t* end_;
820   uint8_t* buffer_end_ = buffer_;
821   uint8_t buffer_[2 * kSlopBytes];
822   ZeroCopyOutputStream* stream_;
823   bool had_error_ = false;
824   bool aliasing_enabled_ = false;  // See EnableAliasing().
825   bool is_serialization_deterministic_;
826   bool skip_check_consistency = false;
827 
828   uint8_t* EnsureSpaceFallback(uint8_t* ptr);
829   inline uint8_t* Next();
830   int Flush(uint8_t* ptr);
GetSize(uint8_t * ptr)831   std::ptrdiff_t GetSize(uint8_t* ptr) const {
832     ABSL_DCHECK(ptr <= end_ + kSlopBytes);  // NOLINT
833     return end_ + kSlopBytes - ptr;
834   }
835 
Error()836   uint8_t* Error() {
837     had_error_ = true;
838     // We use the patch buffer to always guarantee space to write to.
839     end_ = buffer_ + kSlopBytes;
840     return buffer_;
841   }
842 
TagSize(uint32_t tag)843   static constexpr int TagSize(uint32_t tag) {
844     return (tag < (1 << 7))    ? 1
845            : (tag < (1 << 14)) ? 2
846            : (tag < (1 << 21)) ? 3
847            : (tag < (1 << 28)) ? 4
848                                : 5;
849   }
850 
WriteTag(uint32_t num,uint32_t wt,uint8_t * ptr)851   PROTOBUF_ALWAYS_INLINE uint8_t* WriteTag(uint32_t num, uint32_t wt,
852                                            uint8_t* ptr) {
853     ABSL_DCHECK(ptr < end_);  // NOLINT
854     return UnsafeVarint((num << 3) | wt, ptr);
855   }
856 
WriteLengthDelim(int num,uint32_t size,uint8_t * ptr)857   PROTOBUF_ALWAYS_INLINE uint8_t* WriteLengthDelim(int num, uint32_t size,
858                                                    uint8_t* ptr) {
859     ptr = WriteTag(num, 2, ptr);
860     return UnsafeWriteSize(size, ptr);
861   }
862 
863   uint8_t* WriteRawFallback(const void* data, int size, uint8_t* ptr);
864 
865   uint8_t* WriteAliasedRaw(const void* data, int size, uint8_t* ptr);
866 
867   uint8_t* WriteStringMaybeAliasedOutline(uint32_t num, const std::string& s,
868                                           uint8_t* ptr);
869   uint8_t* WriteStringOutline(uint32_t num, const std::string& s, uint8_t* ptr);
870   uint8_t* WriteStringOutline(uint32_t num, absl::string_view s, uint8_t* ptr);
871   uint8_t* WriteCordOutline(const absl::Cord& c, uint8_t* ptr);
872 
873   template <typename T, typename E>
WriteVarintPacked(int num,const T & r,int size,uint8_t * ptr,const E & encode)874   PROTOBUF_ALWAYS_INLINE uint8_t* WriteVarintPacked(int num, const T& r,
875                                                     int size, uint8_t* ptr,
876                                                     const E& encode) {
877     ptr = EnsureSpace(ptr);
878     ptr = WriteLengthDelim(num, size, ptr);
879     auto it = r.data();
880     auto end = it + r.size();
881     do {
882       ptr = EnsureSpace(ptr);
883       ptr = UnsafeVarint(encode(*it++), ptr);
884     } while (it < end);
885     return ptr;
886   }
887 
Encode32(uint32_t v)888   static uint32_t Encode32(uint32_t v) { return v; }
Encode64(uint64_t v)889   static uint64_t Encode64(uint64_t v) { return v; }
ZigZagEncode32(int32_t v)890   static uint32_t ZigZagEncode32(int32_t v) {
891     return (static_cast<uint32_t>(v) << 1) ^ static_cast<uint32_t>(v >> 31);
892   }
ZigZagEncode64(int64_t v)893   static uint64_t ZigZagEncode64(int64_t v) {
894     return (static_cast<uint64_t>(v) << 1) ^ static_cast<uint64_t>(v >> 63);
895   }
896 
897   template <typename T>
UnsafeVarint(T value,uint8_t * ptr)898   PROTOBUF_ALWAYS_INLINE static uint8_t* UnsafeVarint(T value, uint8_t* ptr) {
899     static_assert(std::is_unsigned<T>::value,
900                   "Varint serialization must be unsigned");
901     while (PROTOBUF_PREDICT_FALSE(value >= 0x80)) {
902       *ptr = static_cast<uint8_t>(value | 0x80);
903       value >>= 7;
904       ++ptr;
905     }
906     *ptr++ = static_cast<uint8_t>(value);
907     return ptr;
908   }
909 
UnsafeWriteSize(uint32_t value,uint8_t * ptr)910   PROTOBUF_ALWAYS_INLINE static uint8_t* UnsafeWriteSize(uint32_t value,
911                                                          uint8_t* ptr) {
912     while (PROTOBUF_PREDICT_FALSE(value >= 0x80)) {
913       *ptr = static_cast<uint8_t>(value | 0x80);
914       value >>= 7;
915       ++ptr;
916     }
917     *ptr++ = static_cast<uint8_t>(value);
918     return ptr;
919   }
920 
921   template <int S>
922   uint8_t* WriteRawLittleEndian(const void* data, int size, uint8_t* ptr);
923 #if !defined(ABSL_IS_LITTLE_ENDIAN) || \
924     defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST)
925   uint8_t* WriteRawLittleEndian32(const void* data, int size, uint8_t* ptr);
926   uint8_t* WriteRawLittleEndian64(const void* data, int size, uint8_t* ptr);
927 #endif
928 
929   // These methods are for CodedOutputStream. Ideally they should be private
930   // but to match current behavior of CodedOutputStream as close as possible
931   // we allow it some functionality.
932  public:
SetInitialBuffer(void * data,int size)933   uint8_t* SetInitialBuffer(void* data, int size) {
934     auto ptr = static_cast<uint8_t*>(data);
935     if (size > kSlopBytes) {
936       end_ = ptr + size - kSlopBytes;
937       buffer_end_ = nullptr;
938       return ptr;
939     } else {
940       end_ = buffer_ + size;
941       buffer_end_ = ptr;
942       return buffer_;
943     }
944   }
945 
946  private:
947   // Needed by CodedOutputStream HadError. HadError needs to flush the patch
948   // buffers to ensure there is no error as of yet.
949   uint8_t* FlushAndResetBuffer(uint8_t*);
950 
951   // The following functions mimic the old CodedOutputStream behavior as close
952   // as possible. They flush the current state to the stream, behave as
953   // the old CodedOutputStream and then return to normal operation.
954   bool Skip(int count, uint8_t** pp);
955   bool GetDirectBufferPointer(void** data, int* size, uint8_t** pp);
956   uint8_t* GetDirectBufferForNBytesAndAdvance(int size, uint8_t** pp);
957 
958   friend class CodedOutputStream;
959 };
960 
961 template <>
962 inline uint8_t* EpsCopyOutputStream::WriteRawLittleEndian<1>(const void* data,
963                                                              int size,
964                                                              uint8_t* ptr) {
965   return WriteRaw(data, size, ptr);
966 }
967 template <>
968 inline uint8_t* EpsCopyOutputStream::WriteRawLittleEndian<4>(const void* data,
969                                                              int size,
970                                                              uint8_t* ptr) {
971 #if defined(ABSL_IS_LITTLE_ENDIAN) && \
972     !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST)
973   return WriteRaw(data, size, ptr);
974 #else
975   return WriteRawLittleEndian32(data, size, ptr);
976 #endif
977 }
978 template <>
979 inline uint8_t* EpsCopyOutputStream::WriteRawLittleEndian<8>(const void* data,
980                                                              int size,
981                                                              uint8_t* ptr) {
982 #if defined(ABSL_IS_LITTLE_ENDIAN) && \
983     !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST)
984   return WriteRaw(data, size, ptr);
985 #else
986   return WriteRawLittleEndian64(data, size, ptr);
987 #endif
988 }
989 
990 // Class which encodes and writes binary data which is composed of varint-
991 // encoded integers and fixed-width pieces.  Wraps a ZeroCopyOutputStream.
992 // Most users will not need to deal with CodedOutputStream.
993 //
994 // Most methods of CodedOutputStream which return a bool return false if an
995 // underlying I/O error occurs.  Once such a failure occurs, the
996 // CodedOutputStream is broken and is no longer useful. The Write* methods do
997 // not return the stream status, but will invalidate the stream if an error
998 // occurs. The client can probe HadError() to determine the status.
999 //
1000 // Note that every method of CodedOutputStream which writes some data has
1001 // a corresponding static "ToArray" version. These versions write directly
1002 // to the provided buffer, returning a pointer past the last written byte.
1003 // They require that the buffer has sufficient capacity for the encoded data.
1004 // This allows an optimization where we check if an output stream has enough
1005 // space for an entire message before we start writing and, if there is, we
1006 // call only the ToArray methods to avoid doing bound checks for each
1007 // individual value.
1008 // i.e., in the example above:
1009 //
1010 //   CodedOutputStream* coded_output = new CodedOutputStream(raw_output);
1011 //   int magic_number = 1234;
1012 //   char text[] = "Hello world!";
1013 //
1014 //   int coded_size = sizeof(magic_number) +
1015 //                    CodedOutputStream::VarintSize32(strlen(text)) +
1016 //                    strlen(text);
1017 //
1018 //   uint8_t* buffer =
1019 //       coded_output->GetDirectBufferForNBytesAndAdvance(coded_size);
1020 //   if (buffer != nullptr) {
1021 //     // The output stream has enough space in the buffer: write directly to
1022 //     // the array.
1023 //     buffer = CodedOutputStream::WriteLittleEndian32ToArray(magic_number,
1024 //                                                            buffer);
1025 //     buffer = CodedOutputStream::WriteVarint32ToArray(strlen(text), buffer);
1026 //     buffer = CodedOutputStream::WriteRawToArray(text, strlen(text), buffer);
1027 //   } else {
1028 //     // Make bound-checked writes, which will ask the underlying stream for
1029 //     // more space as needed.
1030 //     coded_output->WriteLittleEndian32(magic_number);
1031 //     coded_output->WriteVarint32(strlen(text));
1032 //     coded_output->WriteRaw(text, strlen(text));
1033 //   }
1034 //
1035 //   delete coded_output;
1036 class PROTOBUF_EXPORT CodedOutputStream {
1037  public:
1038   // Creates a CodedOutputStream that writes to the given `stream`.
1039   // The provided stream must publicly derive from `ZeroCopyOutputStream`.
1040   template <class Stream, class = typename std::enable_if<std::is_base_of<
1041                               ZeroCopyOutputStream, Stream>::value>::type>
1042   explicit CodedOutputStream(Stream* stream);
1043 
1044   // Creates a CodedOutputStream that writes to the given `stream`, and does
1045   // an 'eager initialization' of the internal state if `eager_init` is true.
1046   // The provided stream must publicly derive from `ZeroCopyOutputStream`.
1047   template <class Stream, class = typename std::enable_if<std::is_base_of<
1048                               ZeroCopyOutputStream, Stream>::value>::type>
1049   CodedOutputStream(Stream* stream, bool eager_init);
1050   CodedOutputStream(const CodedOutputStream&) = delete;
1051   CodedOutputStream& operator=(const CodedOutputStream&) = delete;
1052 
1053   // Destroy the CodedOutputStream and position the underlying
1054   // ZeroCopyOutputStream immediately after the last byte written.
1055   ~CodedOutputStream();
1056 
1057   // Returns true if there was an underlying I/O error since this object was
1058   // created. On should call Trim before this function in order to catch all
1059   // errors.
HadError()1060   bool HadError() {
1061     cur_ = impl_.FlushAndResetBuffer(cur_);
1062     ABSL_DCHECK(cur_);
1063     return impl_.HadError();
1064   }
1065 
1066   // Trims any unused space in the underlying buffer so that its size matches
1067   // the number of bytes written by this stream. The underlying buffer will
1068   // automatically be trimmed when this stream is destroyed; this call is only
1069   // necessary if the underlying buffer is accessed *before* the stream is
1070   // destroyed.
Trim()1071   void Trim() { cur_ = impl_.Trim(cur_); }
1072 
1073   // Skips a number of bytes, leaving the bytes unmodified in the underlying
1074   // buffer.  Returns false if an underlying write error occurs.  This is
1075   // mainly useful with GetDirectBufferPointer().
1076   // Note of caution, the skipped bytes may contain uninitialized data. The
1077   // caller must make sure that the skipped bytes are properly initialized,
1078   // otherwise you might leak bytes from your heap.
Skip(int count)1079   bool Skip(int count) { return impl_.Skip(count, &cur_); }
1080 
1081   // Sets *data to point directly at the unwritten part of the
1082   // CodedOutputStream's underlying buffer, and *size to the size of that
1083   // buffer, but does not advance the stream's current position.  This will
1084   // always either produce a non-empty buffer or return false.  If the caller
1085   // writes any data to this buffer, it should then call Skip() to skip over
1086   // the consumed bytes.  This may be useful for implementing external fast
1087   // serialization routines for types of data not covered by the
1088   // CodedOutputStream interface.
GetDirectBufferPointer(void ** data,int * size)1089   bool GetDirectBufferPointer(void** data, int* size) {
1090     return impl_.GetDirectBufferPointer(data, size, &cur_);
1091   }
1092 
1093   // If there are at least "size" bytes available in the current buffer,
1094   // returns a pointer directly into the buffer and advances over these bytes.
1095   // The caller may then write directly into this buffer (e.g. using the
1096   // *ToArray static methods) rather than go through CodedOutputStream.  If
1097   // there are not enough bytes available, returns NULL.  The return pointer is
1098   // invalidated as soon as any other non-const method of CodedOutputStream
1099   // is called.
GetDirectBufferForNBytesAndAdvance(int size)1100   inline uint8_t* GetDirectBufferForNBytesAndAdvance(int size) {
1101     return impl_.GetDirectBufferForNBytesAndAdvance(size, &cur_);
1102   }
1103 
1104   // Write raw bytes, copying them from the given buffer.
WriteRaw(const void * buffer,int size)1105   void WriteRaw(const void* buffer, int size) {
1106     cur_ = impl_.WriteRaw(buffer, size, cur_);
1107   }
1108   // Like WriteRaw()  but will try to write aliased data if aliasing is
1109   // turned on.
1110   void WriteRawMaybeAliased(const void* data, int size);
1111   // Like WriteRaw()  but writing directly to the target array.
1112   // This is _not_ inlined, as the compiler often optimizes memcpy into inline
1113   // copy loops. Since this gets called by every field with string or bytes
1114   // type, inlining may lead to a significant amount of code bloat, with only a
1115   // minor performance gain.
1116   static uint8_t* WriteRawToArray(const void* buffer, int size,
1117                                   uint8_t* target);
1118 
1119   // Equivalent to WriteRaw(str.data(), str.size()).
1120   void WriteString(const std::string& str);
1121   // Like WriteString()  but writing directly to the target array.
1122   static uint8_t* WriteStringToArray(const std::string& str, uint8_t* target);
1123   // Write the varint-encoded size of str followed by str.
1124   static uint8_t* WriteStringWithSizeToArray(const std::string& str,
1125                                              uint8_t* target);
1126 
1127   // Like WriteString() but writes a Cord.
WriteCord(const absl::Cord & cord)1128   void WriteCord(const absl::Cord& cord) { cur_ = impl_.WriteCord(cord, cur_); }
1129 
1130   // Like WriteCord() but writing directly to the target array.
1131   static uint8_t* WriteCordToArray(const absl::Cord& cord, uint8_t* target);
1132 
1133 
1134   // Write a 16-bit little-endian integer.
WriteLittleEndian16(uint16_t value)1135   void WriteLittleEndian16(uint16_t value) {
1136     cur_ = impl_.EnsureSpace(cur_);
1137     SetCur(WriteLittleEndian16ToArray(value, Cur()));
1138   }
1139   // Like WriteLittleEndian16() but writing directly to the target array.
1140   static uint8_t* WriteLittleEndian16ToArray(uint16_t value, uint8_t* target);
1141   // Write a 32-bit little-endian integer.
WriteLittleEndian32(uint32_t value)1142   void WriteLittleEndian32(uint32_t value) {
1143     cur_ = impl_.EnsureSpace(cur_);
1144     SetCur(WriteLittleEndian32ToArray(value, Cur()));
1145   }
1146   // Like WriteLittleEndian32() but writing directly to the target array.
1147   static uint8_t* WriteLittleEndian32ToArray(uint32_t value, uint8_t* target);
1148   // Write a 64-bit little-endian integer.
WriteLittleEndian64(uint64_t value)1149   void WriteLittleEndian64(uint64_t value) {
1150     cur_ = impl_.EnsureSpace(cur_);
1151     SetCur(WriteLittleEndian64ToArray(value, Cur()));
1152   }
1153   // Like WriteLittleEndian64() but writing directly to the target array.
1154   static uint8_t* WriteLittleEndian64ToArray(uint64_t value, uint8_t* target);
1155 
1156   // Write an unsigned integer with Varint encoding.  Writing a 32-bit value
1157   // is equivalent to casting it to uint64_t and writing it as a 64-bit value,
1158   // but may be more efficient.
1159   void WriteVarint32(uint32_t value);
1160   // Like WriteVarint32()  but writing directly to the target array.
1161   static uint8_t* WriteVarint32ToArray(uint32_t value, uint8_t* target);
1162   // Like WriteVarint32ToArray()
1163   [[deprecated("Please use WriteVarint32ToArray() instead")]] static uint8_t*
WriteVarint32ToArrayOutOfLine(uint32_t value,uint8_t * target)1164   WriteVarint32ToArrayOutOfLine(uint32_t value, uint8_t* target) {
1165     return WriteVarint32ToArray(value, target);
1166   }
1167   // Write an unsigned integer with Varint encoding.
1168   void WriteVarint64(uint64_t value);
1169   // Like WriteVarint64()  but writing directly to the target array.
1170   static uint8_t* WriteVarint64ToArray(uint64_t value, uint8_t* target);
1171 
1172   // Equivalent to WriteVarint32() except when the value is negative,
1173   // in which case it must be sign-extended to a full 10 bytes.
1174   void WriteVarint32SignExtended(int32_t value);
1175   // Like WriteVarint32SignExtended()  but writing directly to the target array.
1176   static uint8_t* WriteVarint32SignExtendedToArray(int32_t value,
1177                                                    uint8_t* target);
1178 
1179   // This is identical to WriteVarint32(), but optimized for writing tags.
1180   // In particular, if the input is a compile-time constant, this method
1181   // compiles down to a couple instructions.
1182   // Always inline because otherwise the aforementioned optimization can't work,
1183   // but GCC by default doesn't want to inline this.
1184   void WriteTag(uint32_t value);
1185   // Like WriteTag()  but writing directly to the target array.
1186   PROTOBUF_ALWAYS_INLINE
1187   static uint8_t* WriteTagToArray(uint32_t value, uint8_t* target);
1188 
1189   // Returns the number of bytes needed to encode the given value as a varint.
1190   static size_t VarintSize32(uint32_t value);
1191   // Returns the number of bytes needed to encode the given value as a varint.
1192   static size_t VarintSize64(uint64_t value);
1193 
1194   // If negative, 10 bytes.  Otherwise, same as VarintSize32().
1195   static size_t VarintSize32SignExtended(int32_t value);
1196 
1197   // Same as above, plus one.  The additional one comes at no compute cost.
1198   static size_t VarintSize32PlusOne(uint32_t value);
1199   static size_t VarintSize64PlusOne(uint64_t value);
1200   static size_t VarintSize32SignExtendedPlusOne(int32_t value);
1201 
1202   // Compile-time equivalent of VarintSize32().
1203   template <uint32_t Value>
1204   struct StaticVarintSize32 {
1205     static const size_t value = (Value < (1 << 7))    ? 1
1206                                 : (Value < (1 << 14)) ? 2
1207                                 : (Value < (1 << 21)) ? 3
1208                                 : (Value < (1 << 28)) ? 4
1209                                                       : 5;
1210   };
1211 
1212   // Returns the total number of bytes written since this object was created.
ByteCount()1213   int ByteCount() const {
1214     return static_cast<int>(impl_.ByteCount(cur_) - start_count_);
1215   }
1216 
1217   // Instructs the CodedOutputStream to allow the underlying
1218   // ZeroCopyOutputStream to hold pointers to the original structure instead of
1219   // copying, if it supports it (i.e. output->AllowsAliasing() is true).  If the
1220   // underlying stream does not support aliasing, then enabling it has no
1221   // affect.  For now, this only affects the behavior of
1222   // WriteRawMaybeAliased().
1223   //
1224   // NOTE: It is caller's responsibility to ensure that the chunk of memory
1225   // remains live until all of the data has been consumed from the stream.
EnableAliasing(bool enabled)1226   void EnableAliasing(bool enabled) { impl_.EnableAliasing(enabled); }
1227 
1228   // Indicate to the serializer whether the user wants deterministic
1229   // serialization. The default when this is not called comes from the global
1230   // default, controlled by SetDefaultSerializationDeterministic.
1231   //
1232   // What deterministic serialization means is entirely up to the driver of the
1233   // serialization process (i.e. the caller of methods like WriteVarint32). In
1234   // the case of serializing a proto buffer message using one of the methods of
1235   // MessageLite, this means that for a given binary equal messages will always
1236   // be serialized to the same bytes. This implies:
1237   //
1238   //   * Repeated serialization of a message will return the same bytes.
1239   //
1240   //   * Different processes running the same binary (including on different
1241   //     machines) will serialize equal messages to the same bytes.
1242   //
1243   // Note that this is *not* canonical across languages. It is also unstable
1244   // across different builds with intervening message definition changes, due to
1245   // unknown fields. Users who need canonical serialization (e.g. persistent
1246   // storage in a canonical form, fingerprinting) should define their own
1247   // canonicalization specification and implement the serializer using
1248   // reflection APIs rather than relying on this API.
SetSerializationDeterministic(bool value)1249   void SetSerializationDeterministic(bool value) {
1250     impl_.SetSerializationDeterministic(value);
1251   }
1252 
1253   // Return whether the user wants deterministic serialization. See above.
IsSerializationDeterministic()1254   bool IsSerializationDeterministic() const {
1255     return impl_.IsSerializationDeterministic();
1256   }
1257 
IsDefaultSerializationDeterministic()1258   static bool IsDefaultSerializationDeterministic() {
1259     return default_serialization_deterministic_.load(
1260                std::memory_order_relaxed) != 0;
1261   }
1262 
1263   template <typename Func>
1264   void Serialize(const Func& func);
1265 
Cur()1266   uint8_t* Cur() const { return cur_; }
SetCur(uint8_t * ptr)1267   void SetCur(uint8_t* ptr) { cur_ = ptr; }
EpsCopy()1268   EpsCopyOutputStream* EpsCopy() { return &impl_; }
1269 
1270  private:
1271   template <class Stream>
1272   void InitEagerly(Stream* stream);
1273 
1274   EpsCopyOutputStream impl_;
1275   uint8_t* cur_;
1276   int64_t start_count_;
1277   static std::atomic<bool> default_serialization_deterministic_;
1278 
1279   // See above.  Other projects may use "friend" to allow them to call this.
1280   // After SetDefaultSerializationDeterministic() completes, all protocol
1281   // buffer serializations will be deterministic by default.  Thread safe.
1282   // However, the meaning of "after" is subtle here: to be safe, each thread
1283   // that wants deterministic serialization by default needs to call
1284   // SetDefaultSerializationDeterministic() or ensure on its own that another
1285   // thread has done so.
1286   friend void google::protobuf::internal::MapTestForceDeterministic();
SetDefaultSerializationDeterministic()1287   static void SetDefaultSerializationDeterministic() {
1288     default_serialization_deterministic_.store(true, std::memory_order_relaxed);
1289   }
1290 };
1291 
1292 // inline methods ====================================================
1293 // The vast majority of varints are only one byte.  These inline
1294 // methods optimize for that case.
1295 
ReadVarint32(uint32_t * value)1296 inline bool CodedInputStream::ReadVarint32(uint32_t* value) {
1297   uint32_t v = 0;
1298   if (PROTOBUF_PREDICT_TRUE(buffer_ < buffer_end_)) {
1299     v = *buffer_;
1300     if (v < 0x80) {
1301       *value = v;
1302       Advance(1);
1303       return true;
1304     }
1305   }
1306   int64_t result = ReadVarint32Fallback(v);
1307   *value = static_cast<uint32_t>(result);
1308   return result >= 0;
1309 }
1310 
ReadVarint64(uint64_t * value)1311 inline bool CodedInputStream::ReadVarint64(uint64_t* value) {
1312   if (PROTOBUF_PREDICT_TRUE(buffer_ < buffer_end_) && *buffer_ < 0x80) {
1313     *value = *buffer_;
1314     Advance(1);
1315     return true;
1316   }
1317   std::pair<uint64_t, bool> p = ReadVarint64Fallback();
1318   *value = p.first;
1319   return p.second;
1320 }
1321 
ReadVarintSizeAsInt(int * value)1322 inline bool CodedInputStream::ReadVarintSizeAsInt(int* value) {
1323   if (PROTOBUF_PREDICT_TRUE(buffer_ < buffer_end_)) {
1324     int v = *buffer_;
1325     if (v < 0x80) {
1326       *value = v;
1327       Advance(1);
1328       return true;
1329     }
1330   }
1331   *value = ReadVarintSizeAsIntFallback();
1332   return *value >= 0;
1333 }
1334 
1335 // static
ReadLittleEndian16FromArray(const uint8_t * buffer,uint16_t * value)1336 inline const uint8_t* CodedInputStream::ReadLittleEndian16FromArray(
1337     const uint8_t* buffer, uint16_t* value) {
1338   memcpy(value, buffer, sizeof(*value));
1339   *value = google::protobuf::internal::little_endian::ToHost(*value);
1340   return buffer + sizeof(*value);
1341 }
1342 // static
ReadLittleEndian32FromArray(const uint8_t * buffer,uint32_t * value)1343 inline const uint8_t* CodedInputStream::ReadLittleEndian32FromArray(
1344     const uint8_t* buffer, uint32_t* value) {
1345   memcpy(value, buffer, sizeof(*value));
1346   *value = google::protobuf::internal::little_endian::ToHost(*value);
1347   return buffer + sizeof(*value);
1348 }
1349 // static
ReadLittleEndian64FromArray(const uint8_t * buffer,uint64_t * value)1350 inline const uint8_t* CodedInputStream::ReadLittleEndian64FromArray(
1351     const uint8_t* buffer, uint64_t* value) {
1352   memcpy(value, buffer, sizeof(*value));
1353   *value = google::protobuf::internal::little_endian::ToHost(*value);
1354   return buffer + sizeof(*value);
1355 }
1356 
ReadLittleEndian16(uint16_t * value)1357 inline bool CodedInputStream::ReadLittleEndian16(uint16_t* value) {
1358   if (PROTOBUF_PREDICT_TRUE(BufferSize() >= static_cast<int>(sizeof(*value)))) {
1359     buffer_ = ReadLittleEndian16FromArray(buffer_, value);
1360     return true;
1361   } else {
1362     return ReadLittleEndian16Fallback(value);
1363   }
1364 }
1365 
ReadLittleEndian32(uint32_t * value)1366 inline bool CodedInputStream::ReadLittleEndian32(uint32_t* value) {
1367 #if defined(ABSL_IS_LITTLE_ENDIAN) && \
1368     !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST)
1369   if (PROTOBUF_PREDICT_TRUE(BufferSize() >= static_cast<int>(sizeof(*value)))) {
1370     buffer_ = ReadLittleEndian32FromArray(buffer_, value);
1371     return true;
1372   } else {
1373     return ReadLittleEndian32Fallback(value);
1374   }
1375 #else
1376   return ReadLittleEndian32Fallback(value);
1377 #endif
1378 }
1379 
ReadLittleEndian64(uint64_t * value)1380 inline bool CodedInputStream::ReadLittleEndian64(uint64_t* value) {
1381 #if defined(ABSL_IS_LITTLE_ENDIAN) && \
1382     !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST)
1383   if (PROTOBUF_PREDICT_TRUE(BufferSize() >= static_cast<int>(sizeof(*value)))) {
1384     buffer_ = ReadLittleEndian64FromArray(buffer_, value);
1385     return true;
1386   } else {
1387     return ReadLittleEndian64Fallback(value);
1388   }
1389 #else
1390   return ReadLittleEndian64Fallback(value);
1391 #endif
1392 }
1393 
ReadTagNoLastTag()1394 inline uint32_t CodedInputStream::ReadTagNoLastTag() {
1395   uint32_t v = 0;
1396   if (PROTOBUF_PREDICT_TRUE(buffer_ < buffer_end_)) {
1397     v = *buffer_;
1398     if (v < 0x80) {
1399       Advance(1);
1400       return v;
1401     }
1402   }
1403   v = ReadTagFallback(v);
1404   return v;
1405 }
1406 
ReadTagWithCutoffNoLastTag(uint32_t cutoff)1407 inline std::pair<uint32_t, bool> CodedInputStream::ReadTagWithCutoffNoLastTag(
1408     uint32_t cutoff) {
1409   // In performance-sensitive code we can expect cutoff to be a compile-time
1410   // constant, and things like "cutoff >= kMax1ByteVarint" to be evaluated at
1411   // compile time.
1412   uint32_t first_byte_or_zero = 0;
1413   if (PROTOBUF_PREDICT_TRUE(buffer_ < buffer_end_)) {
1414     // Hot case: buffer_ non_empty, buffer_[0] in [1, 128).
1415     // TODO: Is it worth rearranging this? E.g., if the number of fields
1416     // is large enough then is it better to check for the two-byte case first?
1417     first_byte_or_zero = buffer_[0];
1418     if (static_cast<int8_t>(buffer_[0]) > 0) {
1419       const uint32_t kMax1ByteVarint = 0x7f;
1420       uint32_t tag = buffer_[0];
1421       Advance(1);
1422       return std::make_pair(tag, cutoff >= kMax1ByteVarint || tag <= cutoff);
1423     }
1424     // Other hot case: cutoff >= 0x80, buffer_ has at least two bytes available,
1425     // and tag is two bytes.  The latter is tested by bitwise-and-not of the
1426     // first byte and the second byte.
1427     if (cutoff >= 0x80 && PROTOBUF_PREDICT_TRUE(buffer_ + 1 < buffer_end_) &&
1428         PROTOBUF_PREDICT_TRUE((buffer_[0] & ~buffer_[1]) >= 0x80)) {
1429       const uint32_t kMax2ByteVarint = (0x7f << 7) + 0x7f;
1430       uint32_t tag = (1u << 7) * buffer_[1] + (buffer_[0] - 0x80);
1431       Advance(2);
1432       // It might make sense to test for tag == 0 now, but it is so rare that
1433       // that we don't bother.  A varint-encoded 0 should be one byte unless
1434       // the encoder lost its mind.  The second part of the return value of
1435       // this function is allowed to be either true or false if the tag is 0,
1436       // so we don't have to check for tag == 0.  We may need to check whether
1437       // it exceeds cutoff.
1438       bool at_or_below_cutoff = cutoff >= kMax2ByteVarint || tag <= cutoff;
1439       return std::make_pair(tag, at_or_below_cutoff);
1440     }
1441   }
1442   // Slow path
1443   const uint32_t tag = ReadTagFallback(first_byte_or_zero);
1444   return std::make_pair(tag, static_cast<uint32_t>(tag - 1) < cutoff);
1445 }
1446 
LastTagWas(uint32_t expected)1447 inline bool CodedInputStream::LastTagWas(uint32_t expected) {
1448   return last_tag_ == expected;
1449 }
1450 
ConsumedEntireMessage()1451 inline bool CodedInputStream::ConsumedEntireMessage() {
1452   return legitimate_message_end_;
1453 }
1454 
ExpectTag(uint32_t expected)1455 inline bool CodedInputStream::ExpectTag(uint32_t expected) {
1456   if (expected < (1 << 7)) {
1457     if (PROTOBUF_PREDICT_TRUE(buffer_ < buffer_end_) &&
1458         buffer_[0] == expected) {
1459       Advance(1);
1460       return true;
1461     } else {
1462       return false;
1463     }
1464   } else if (expected < (1 << 14)) {
1465     if (PROTOBUF_PREDICT_TRUE(BufferSize() >= 2) &&
1466         buffer_[0] == static_cast<uint8_t>(expected | 0x80) &&
1467         buffer_[1] == static_cast<uint8_t>(expected >> 7)) {
1468       Advance(2);
1469       return true;
1470     } else {
1471       return false;
1472     }
1473   } else {
1474     // Don't bother optimizing for larger values.
1475     return false;
1476   }
1477 }
1478 
ExpectTagFromArray(const uint8_t * buffer,uint32_t expected)1479 inline const uint8_t* CodedInputStream::ExpectTagFromArray(
1480     const uint8_t* buffer, uint32_t expected) {
1481   if (expected < (1 << 7)) {
1482     if (buffer[0] == expected) {
1483       return buffer + 1;
1484     }
1485   } else if (expected < (1 << 14)) {
1486     if (buffer[0] == static_cast<uint8_t>(expected | 0x80) &&
1487         buffer[1] == static_cast<uint8_t>(expected >> 7)) {
1488       return buffer + 2;
1489     }
1490   }
1491   return nullptr;
1492 }
1493 
GetDirectBufferPointerInline(const void ** data,int * size)1494 inline void CodedInputStream::GetDirectBufferPointerInline(const void** data,
1495                                                            int* size) {
1496   *data = buffer_;
1497   *size = static_cast<int>(buffer_end_ - buffer_);
1498 }
1499 
ExpectAtEnd()1500 inline bool CodedInputStream::ExpectAtEnd() {
1501   // If we are at a limit we know no more bytes can be read.  Otherwise, it's
1502   // hard to say without calling Refresh(), and we'd rather not do that.
1503 
1504   if (buffer_ == buffer_end_ && ((buffer_size_after_limit_ != 0) ||
1505                                  (total_bytes_read_ == current_limit_))) {
1506     last_tag_ = 0;                   // Pretend we called ReadTag()...
1507     legitimate_message_end_ = true;  // ... and it hit EOF.
1508     return true;
1509   } else {
1510     return false;
1511   }
1512 }
1513 
CurrentPosition()1514 inline int CodedInputStream::CurrentPosition() const {
1515   return total_bytes_read_ - (BufferSize() + buffer_size_after_limit_);
1516 }
1517 
Advance(int amount)1518 inline void CodedInputStream::Advance(int amount) { buffer_ += amount; }
1519 
SetRecursionLimit(int limit)1520 inline void CodedInputStream::SetRecursionLimit(int limit) {
1521   recursion_budget_ += limit - recursion_limit_;
1522   recursion_limit_ = limit;
1523 }
1524 
IncrementRecursionDepth()1525 inline bool CodedInputStream::IncrementRecursionDepth() {
1526   --recursion_budget_;
1527   return recursion_budget_ >= 0;
1528 }
1529 
DecrementRecursionDepth()1530 inline void CodedInputStream::DecrementRecursionDepth() {
1531   if (recursion_budget_ < recursion_limit_) ++recursion_budget_;
1532 }
1533 
UnsafeDecrementRecursionDepth()1534 inline void CodedInputStream::UnsafeDecrementRecursionDepth() {
1535   assert(recursion_budget_ < recursion_limit_);
1536   ++recursion_budget_;
1537 }
1538 
SetExtensionRegistry(const DescriptorPool * pool,MessageFactory * factory)1539 inline void CodedInputStream::SetExtensionRegistry(const DescriptorPool* pool,
1540                                                    MessageFactory* factory) {
1541   extension_pool_ = pool;
1542   extension_factory_ = factory;
1543 }
1544 
GetExtensionPool()1545 inline const DescriptorPool* CodedInputStream::GetExtensionPool() {
1546   return extension_pool_;
1547 }
1548 
GetExtensionFactory()1549 inline MessageFactory* CodedInputStream::GetExtensionFactory() {
1550   return extension_factory_;
1551 }
1552 
BufferSize()1553 inline int CodedInputStream::BufferSize() const {
1554   return static_cast<int>(buffer_end_ - buffer_);
1555 }
1556 
CodedInputStream(ZeroCopyInputStream * input)1557 inline CodedInputStream::CodedInputStream(ZeroCopyInputStream* input)
1558     : buffer_(nullptr),
1559       buffer_end_(nullptr),
1560       input_(input),
1561       total_bytes_read_(0),
1562       overflow_bytes_(0),
1563       last_tag_(0),
1564       legitimate_message_end_(false),
1565       aliasing_enabled_(false),
1566       force_eager_parsing_(false),
1567       current_limit_(std::numeric_limits<int32_t>::max()),
1568       buffer_size_after_limit_(0),
1569       total_bytes_limit_(kDefaultTotalBytesLimit),
1570       recursion_budget_(default_recursion_limit_),
1571       recursion_limit_(default_recursion_limit_),
1572       extension_pool_(nullptr),
1573       extension_factory_(nullptr) {
1574   // Eagerly Refresh() so buffer space is immediately available.
1575   Refresh();
1576 }
1577 
CodedInputStream(const uint8_t * buffer,int size)1578 inline CodedInputStream::CodedInputStream(const uint8_t* buffer, int size)
1579     : buffer_(buffer),
1580       buffer_end_(buffer + size),
1581       input_(nullptr),
1582       total_bytes_read_(size),
1583       overflow_bytes_(0),
1584       last_tag_(0),
1585       legitimate_message_end_(false),
1586       aliasing_enabled_(false),
1587       force_eager_parsing_(false),
1588       current_limit_(size),
1589       buffer_size_after_limit_(0),
1590       total_bytes_limit_(kDefaultTotalBytesLimit),
1591       recursion_budget_(default_recursion_limit_),
1592       recursion_limit_(default_recursion_limit_),
1593       extension_pool_(nullptr),
1594       extension_factory_(nullptr) {
1595   // Note that setting current_limit_ == size is important to prevent some
1596   // code paths from trying to access input_ and segfaulting.
1597 }
1598 
IsFlat()1599 inline bool CodedInputStream::IsFlat() const { return input_ == nullptr; }
1600 
Skip(int count)1601 inline bool CodedInputStream::Skip(int count) {
1602   if (count < 0) return false;  // security: count is often user-supplied
1603 
1604   const int original_buffer_size = BufferSize();
1605 
1606   if (count <= original_buffer_size) {
1607     // Just skipping within the current buffer.  Easy.
1608     Advance(count);
1609     return true;
1610   }
1611 
1612   return SkipFallback(count, original_buffer_size);
1613 }
1614 
1615 template <class Stream, class>
CodedOutputStream(Stream * stream)1616 inline CodedOutputStream::CodedOutputStream(Stream* stream)
1617     : impl_(stream, IsDefaultSerializationDeterministic(), &cur_),
1618       start_count_(stream->ByteCount()) {
1619   InitEagerly(stream);
1620 }
1621 
1622 template <class Stream, class>
CodedOutputStream(Stream * stream,bool eager_init)1623 inline CodedOutputStream::CodedOutputStream(Stream* stream, bool eager_init)
1624     : impl_(stream, IsDefaultSerializationDeterministic(), &cur_),
1625       start_count_(stream->ByteCount()) {
1626   if (eager_init) {
1627     InitEagerly(stream);
1628   }
1629 }
1630 
1631 template <class Stream>
InitEagerly(Stream * stream)1632 inline void CodedOutputStream::InitEagerly(Stream* stream) {
1633   void* data;
1634   int size;
1635   if (PROTOBUF_PREDICT_TRUE(stream->Next(&data, &size) && size > 0)) {
1636     cur_ = impl_.SetInitialBuffer(data, size);
1637   }
1638 }
1639 
WriteVarint32ToArray(uint32_t value,uint8_t * target)1640 inline uint8_t* CodedOutputStream::WriteVarint32ToArray(uint32_t value,
1641                                                         uint8_t* target) {
1642   return EpsCopyOutputStream::UnsafeVarint(value, target);
1643 }
1644 
WriteVarint64ToArray(uint64_t value,uint8_t * target)1645 inline uint8_t* CodedOutputStream::WriteVarint64ToArray(uint64_t value,
1646                                                         uint8_t* target) {
1647   return EpsCopyOutputStream::UnsafeVarint(value, target);
1648 }
1649 
WriteVarint32SignExtended(int32_t value)1650 inline void CodedOutputStream::WriteVarint32SignExtended(int32_t value) {
1651   WriteVarint64(static_cast<uint64_t>(value));
1652 }
1653 
WriteVarint32SignExtendedToArray(int32_t value,uint8_t * target)1654 inline uint8_t* CodedOutputStream::WriteVarint32SignExtendedToArray(
1655     int32_t value, uint8_t* target) {
1656   return WriteVarint64ToArray(static_cast<uint64_t>(value), target);
1657 }
1658 
WriteLittleEndian16ToArray(uint16_t value,uint8_t * target)1659 inline uint8_t* CodedOutputStream::WriteLittleEndian16ToArray(uint16_t value,
1660                                                               uint8_t* target) {
1661   uint16_t little_endian_value = google::protobuf::internal::little_endian::ToHost(value);
1662   memcpy(target, &little_endian_value, sizeof(value));
1663   return target + sizeof(value);
1664 }
1665 
WriteLittleEndian32ToArray(uint32_t value,uint8_t * target)1666 inline uint8_t* CodedOutputStream::WriteLittleEndian32ToArray(uint32_t value,
1667                                                               uint8_t* target) {
1668 #if defined(ABSL_IS_LITTLE_ENDIAN) && \
1669     !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST)
1670   memcpy(target, &value, sizeof(value));
1671 #else
1672   target[0] = static_cast<uint8_t>(value);
1673   target[1] = static_cast<uint8_t>(value >> 8);
1674   target[2] = static_cast<uint8_t>(value >> 16);
1675   target[3] = static_cast<uint8_t>(value >> 24);
1676 #endif
1677   return target + sizeof(value);
1678 }
1679 
WriteLittleEndian64ToArray(uint64_t value,uint8_t * target)1680 inline uint8_t* CodedOutputStream::WriteLittleEndian64ToArray(uint64_t value,
1681                                                               uint8_t* target) {
1682 #if defined(ABSL_IS_LITTLE_ENDIAN) && \
1683     !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST)
1684   memcpy(target, &value, sizeof(value));
1685 #else
1686   uint32_t part0 = static_cast<uint32_t>(value);
1687   uint32_t part1 = static_cast<uint32_t>(value >> 32);
1688 
1689   target[0] = static_cast<uint8_t>(part0);
1690   target[1] = static_cast<uint8_t>(part0 >> 8);
1691   target[2] = static_cast<uint8_t>(part0 >> 16);
1692   target[3] = static_cast<uint8_t>(part0 >> 24);
1693   target[4] = static_cast<uint8_t>(part1);
1694   target[5] = static_cast<uint8_t>(part1 >> 8);
1695   target[6] = static_cast<uint8_t>(part1 >> 16);
1696   target[7] = static_cast<uint8_t>(part1 >> 24);
1697 #endif
1698   return target + sizeof(value);
1699 }
1700 
WriteVarint32(uint32_t value)1701 inline void CodedOutputStream::WriteVarint32(uint32_t value) {
1702   cur_ = impl_.EnsureSpace(cur_);
1703   SetCur(WriteVarint32ToArray(value, Cur()));
1704 }
1705 
WriteVarint64(uint64_t value)1706 inline void CodedOutputStream::WriteVarint64(uint64_t value) {
1707   cur_ = impl_.EnsureSpace(cur_);
1708   SetCur(WriteVarint64ToArray(value, Cur()));
1709 }
1710 
WriteTag(uint32_t value)1711 inline void CodedOutputStream::WriteTag(uint32_t value) {
1712   WriteVarint32(value);
1713 }
1714 
WriteTagToArray(uint32_t value,uint8_t * target)1715 inline uint8_t* CodedOutputStream::WriteTagToArray(uint32_t value,
1716                                                    uint8_t* target) {
1717   return WriteVarint32ToArray(value, target);
1718 }
1719 
1720 #if (defined(__x86__) || defined(__x86_64__) || defined(_M_IX86) || \
1721      defined(_M_X64)) &&                                            \
1722     !(defined(__LZCNT__) || defined(__AVX2__))
1723 // X86 CPUs lacking the lzcnt instruction are faster with the bsr-based
1724 // implementation. MSVC does not define __LZCNT__, the nearest option that
1725 // it interprets as lzcnt availability is __AVX2__.
1726 #define PROTOBUF_CODED_STREAM_H_PREFER_BSR 1
1727 #else
1728 #define PROTOBUF_CODED_STREAM_H_PREFER_BSR 0
1729 #endif
VarintSize32(uint32_t value)1730 inline size_t CodedOutputStream::VarintSize32(uint32_t value) {
1731 #if PROTOBUF_CODED_STREAM_H_PREFER_BSR
1732   // Explicit OR 0x1 to avoid calling absl::countl_zero(0), which
1733   // requires a branch to check for on platforms without a clz instruction.
1734   uint32_t log2value = (std::numeric_limits<uint32_t>::digits - 1) -
1735                        absl::countl_zero(value | 0x1);
1736   return static_cast<size_t>((log2value * 9 + (64 + 9)) / 64);
1737 #else
1738   uint32_t clz = absl::countl_zero(value);
1739   return static_cast<size_t>(
1740       ((std::numeric_limits<uint32_t>::digits * 9 + 64) - (clz * 9)) / 64);
1741 #endif
1742 }
1743 
VarintSize32PlusOne(uint32_t value)1744 inline size_t CodedOutputStream::VarintSize32PlusOne(uint32_t value) {
1745   // Same as above, but one more.
1746 #if PROTOBUF_CODED_STREAM_H_PREFER_BSR
1747   uint32_t log2value = (std::numeric_limits<uint32_t>::digits - 1) -
1748                        absl::countl_zero(value | 0x1);
1749   return static_cast<size_t>((log2value * 9 + (64 + 9) + 64) / 64);
1750 #else
1751   uint32_t clz = absl::countl_zero(value);
1752   return static_cast<size_t>(
1753       ((std::numeric_limits<uint32_t>::digits * 9 + 64 + 64) - (clz * 9)) / 64);
1754 #endif
1755 }
1756 
VarintSize64(uint64_t value)1757 inline size_t CodedOutputStream::VarintSize64(uint64_t value) {
1758 #if PROTOBUF_CODED_STREAM_H_PREFER_BSR
1759   // Explicit OR 0x1 to avoid calling absl::countl_zero(0), which
1760   // requires a branch to check for on platforms without a clz instruction.
1761   uint32_t log2value = (std::numeric_limits<uint64_t>::digits - 1) -
1762                        absl::countl_zero(value | 0x1);
1763   return static_cast<size_t>((log2value * 9 + (64 + 9)) / 64);
1764 #else
1765   uint32_t clz = absl::countl_zero(value);
1766   return static_cast<size_t>(
1767       ((std::numeric_limits<uint64_t>::digits * 9 + 64) - (clz * 9)) / 64);
1768 #endif
1769 }
1770 
VarintSize64PlusOne(uint64_t value)1771 inline size_t CodedOutputStream::VarintSize64PlusOne(uint64_t value) {
1772   // Same as above, but one more.
1773 #if PROTOBUF_CODED_STREAM_H_PREFER_BSR
1774   uint32_t log2value = (std::numeric_limits<uint64_t>::digits - 1) -
1775                        absl::countl_zero(value | 0x1);
1776   return static_cast<size_t>((log2value * 9 + (64 + 9) + 64) / 64);
1777 #else
1778   uint32_t clz = absl::countl_zero(value);
1779   return static_cast<size_t>(
1780       ((std::numeric_limits<uint64_t>::digits * 9 + 64 + 64) - (clz * 9)) / 64);
1781 #endif
1782 }
1783 
VarintSize32SignExtended(int32_t value)1784 inline size_t CodedOutputStream::VarintSize32SignExtended(int32_t value) {
1785   return VarintSize64(static_cast<uint64_t>(int64_t{value}));
1786 }
1787 
VarintSize32SignExtendedPlusOne(int32_t value)1788 inline size_t CodedOutputStream::VarintSize32SignExtendedPlusOne(
1789     int32_t value) {
1790   return VarintSize64PlusOne(static_cast<uint64_t>(int64_t{value}));
1791 }
1792 #undef PROTOBUF_CODED_STREAM_H_PREFER_BSR
1793 
WriteString(const std::string & str)1794 inline void CodedOutputStream::WriteString(const std::string& str) {
1795   WriteRaw(str.data(), static_cast<int>(str.size()));
1796 }
1797 
WriteRawMaybeAliased(const void * data,int size)1798 inline void CodedOutputStream::WriteRawMaybeAliased(const void* data,
1799                                                     int size) {
1800   cur_ = impl_.WriteRawMaybeAliased(data, size, cur_);
1801 }
1802 
WriteRawToArray(const void * data,int size,uint8_t * target)1803 inline uint8_t* CodedOutputStream::WriteRawToArray(const void* data, int size,
1804                                                    uint8_t* target) {
1805   memcpy(target, data, static_cast<unsigned int>(size));
1806   return target + size;
1807 }
1808 
WriteStringToArray(const std::string & str,uint8_t * target)1809 inline uint8_t* CodedOutputStream::WriteStringToArray(const std::string& str,
1810                                                       uint8_t* target) {
1811   return WriteRawToArray(str.data(), static_cast<int>(str.size()), target);
1812 }
1813 
1814 }  // namespace io
1815 }  // namespace protobuf
1816 }  // namespace google
1817 
1818 #if defined(_MSC_VER) && _MSC_VER >= 1300 && !defined(__INTEL_COMPILER)
1819 #pragma runtime_checks("c", restore)
1820 #endif  // _MSC_VER && !defined(__INTEL_COMPILER)
1821 
1822 #include "google/protobuf/port_undef.inc"
1823 
1824 #endif  // GOOGLE_PROTOBUF_IO_CODED_STREAM_H__
1825