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1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 //     * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 //     * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 //     * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31 // Author: kenton@google.com (Kenton Varda)
32 //         atenasio@google.com (Chris Atenasio) (ZigZag transform)
33 //         wink@google.com (Wink Saville) (refactored from wire_format.h)
34 //  Based on original Protocol Buffers design by
35 //  Sanjay Ghemawat, Jeff Dean, and others.
36 //
37 // This header is logically internal, but is made public because it is used
38 // from protocol-compiler-generated code, which may reside in other components.
39 
40 #ifndef GOOGLE_PROTOBUF_WIRE_FORMAT_LITE_H__
41 #define GOOGLE_PROTOBUF_WIRE_FORMAT_LITE_H__
42 
43 #include <string>
44 #include <google/protobuf/stubs/common.h>
45 #include <google/protobuf/message_lite.h>
46 #include <google/protobuf/io/coded_stream.h>  // for CodedOutputStream::Varint32Size
47 
48 namespace google {
49 
50 namespace protobuf {
51   template <typename T> class RepeatedField;  // repeated_field.h
52 }
53 
54 namespace protobuf {
55 namespace internal {
56 
57 class StringPieceField;
58 
59 // This class is for internal use by the protocol buffer library and by
60 // protocol-complier-generated message classes.  It must not be called
61 // directly by clients.
62 //
63 // This class contains helpers for implementing the binary protocol buffer
64 // wire format without the need for reflection. Use WireFormat when using
65 // reflection.
66 //
67 // This class is really a namespace that contains only static methods.
68 class LIBPROTOBUF_EXPORT WireFormatLite {
69  public:
70 
71   // -----------------------------------------------------------------
72   // Helper constants and functions related to the format.  These are
73   // mostly meant for internal and generated code to use.
74 
75   // The wire format is composed of a sequence of tag/value pairs, each
76   // of which contains the value of one field (or one element of a repeated
77   // field).  Each tag is encoded as a varint.  The lower bits of the tag
78   // identify its wire type, which specifies the format of the data to follow.
79   // The rest of the bits contain the field number.  Each type of field (as
80   // declared by FieldDescriptor::Type, in descriptor.h) maps to one of
81   // these wire types.  Immediately following each tag is the field's value,
82   // encoded in the format specified by the wire type.  Because the tag
83   // identifies the encoding of this data, it is possible to skip
84   // unrecognized fields for forwards compatibility.
85 
86   enum WireType {
87     WIRETYPE_VARINT           = 0,
88     WIRETYPE_FIXED64          = 1,
89     WIRETYPE_LENGTH_DELIMITED = 2,
90     WIRETYPE_START_GROUP      = 3,
91     WIRETYPE_END_GROUP        = 4,
92     WIRETYPE_FIXED32          = 5,
93   };
94 
95   // Lite alternative to FieldDescriptor::Type.  Must be kept in sync.
96   enum FieldType {
97     TYPE_DOUBLE         = 1,
98     TYPE_FLOAT          = 2,
99     TYPE_INT64          = 3,
100     TYPE_UINT64         = 4,
101     TYPE_INT32          = 5,
102     TYPE_FIXED64        = 6,
103     TYPE_FIXED32        = 7,
104     TYPE_BOOL           = 8,
105     TYPE_STRING         = 9,
106     TYPE_GROUP          = 10,
107     TYPE_MESSAGE        = 11,
108     TYPE_BYTES          = 12,
109     TYPE_UINT32         = 13,
110     TYPE_ENUM           = 14,
111     TYPE_SFIXED32       = 15,
112     TYPE_SFIXED64       = 16,
113     TYPE_SINT32         = 17,
114     TYPE_SINT64         = 18,
115     MAX_FIELD_TYPE      = 18,
116   };
117 
118   // Lite alternative to FieldDescriptor::CppType.  Must be kept in sync.
119   enum CppType {
120     CPPTYPE_INT32       = 1,
121     CPPTYPE_INT64       = 2,
122     CPPTYPE_UINT32      = 3,
123     CPPTYPE_UINT64      = 4,
124     CPPTYPE_DOUBLE      = 5,
125     CPPTYPE_FLOAT       = 6,
126     CPPTYPE_BOOL        = 7,
127     CPPTYPE_ENUM        = 8,
128     CPPTYPE_STRING      = 9,
129     CPPTYPE_MESSAGE     = 10,
130     MAX_CPPTYPE         = 10,
131   };
132 
133   // Helper method to get the CppType for a particular Type.
134   static CppType FieldTypeToCppType(FieldType type);
135 
136   // Given a FieldSescriptor::Type return its WireType
WireTypeForFieldType(WireFormatLite::FieldType type)137   static inline WireFormatLite::WireType WireTypeForFieldType(
138       WireFormatLite::FieldType type) {
139     return kWireTypeForFieldType[type];
140   }
141 
142   // Number of bits in a tag which identify the wire type.
143   static const int kTagTypeBits = 3;
144   // Mask for those bits.
145   static const uint32 kTagTypeMask = (1 << kTagTypeBits) - 1;
146 
147   // Helper functions for encoding and decoding tags.  (Inlined below and in
148   // _inl.h)
149   //
150   // This is different from MakeTag(field->number(), field->type()) in the case
151   // of packed repeated fields.
152   static uint32 MakeTag(int field_number, WireType type);
153   static WireType GetTagWireType(uint32 tag);
154   static int GetTagFieldNumber(uint32 tag);
155 
156   // Compute the byte size of a tag.  For groups, this includes both the start
157   // and end tags.
158   static inline int TagSize(int field_number, WireFormatLite::FieldType type);
159 
160   // Skips a field value with the given tag.  The input should start
161   // positioned immediately after the tag.  Skipped values are simply discarded,
162   // not recorded anywhere.  See WireFormat::SkipField() for a version that
163   // records to an UnknownFieldSet.
164   static bool SkipField(io::CodedInputStream* input, uint32 tag);
165 
166   // Skips a field value with the given tag.  The input should start
167   // positioned immediately after the tag. Skipped values are recorded to a
168   // CodedOutputStream.
169   static bool SkipField(io::CodedInputStream* input, uint32 tag,
170                         io::CodedOutputStream* output);
171 
172   // Reads and ignores a message from the input.  Skipped values are simply
173   // discarded, not recorded anywhere.  See WireFormat::SkipMessage() for a
174   // version that records to an UnknownFieldSet.
175   static bool SkipMessage(io::CodedInputStream* input);
176 
177   // Reads and ignores a message from the input.  Skipped values are recorded
178   // to a CodedOutputStream.
179   static bool SkipMessage(io::CodedInputStream* input,
180                           io::CodedOutputStream* output);
181 
182 // This macro does the same thing as WireFormatLite::MakeTag(), but the
183 // result is usable as a compile-time constant, which makes it usable
184 // as a switch case or a template input.  WireFormatLite::MakeTag() is more
185 // type-safe, though, so prefer it if possible.
186 #define GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(FIELD_NUMBER, TYPE)                  \
187   static_cast<uint32>(                                                   \
188     ((FIELD_NUMBER) << ::google::protobuf::internal::WireFormatLite::kTagTypeBits) \
189       | (TYPE))
190 
191   // These are the tags for the old MessageSet format, which was defined as:
192   //   message MessageSet {
193   //     repeated group Item = 1 {
194   //       required int32 type_id = 2;
195   //       required string message = 3;
196   //     }
197   //   }
198   static const int kMessageSetItemNumber = 1;
199   static const int kMessageSetTypeIdNumber = 2;
200   static const int kMessageSetMessageNumber = 3;
201   static const int kMessageSetItemStartTag =
202     GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetItemNumber,
203                                 WireFormatLite::WIRETYPE_START_GROUP);
204   static const int kMessageSetItemEndTag =
205     GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetItemNumber,
206                                 WireFormatLite::WIRETYPE_END_GROUP);
207   static const int kMessageSetTypeIdTag =
208     GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetTypeIdNumber,
209                                 WireFormatLite::WIRETYPE_VARINT);
210   static const int kMessageSetMessageTag =
211     GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetMessageNumber,
212                                 WireFormatLite::WIRETYPE_LENGTH_DELIMITED);
213 
214   // Byte size of all tags of a MessageSet::Item combined.
215   static const int kMessageSetItemTagsSize;
216 
217   // Helper functions for converting between floats/doubles and IEEE-754
218   // uint32s/uint64s so that they can be written.  (Assumes your platform
219   // uses IEEE-754 floats.)
220   static uint32 EncodeFloat(float value);
221   static float DecodeFloat(uint32 value);
222   static uint64 EncodeDouble(double value);
223   static double DecodeDouble(uint64 value);
224 
225   // Helper functions for mapping signed integers to unsigned integers in
226   // such a way that numbers with small magnitudes will encode to smaller
227   // varints.  If you simply static_cast a negative number to an unsigned
228   // number and varint-encode it, it will always take 10 bytes, defeating
229   // the purpose of varint.  So, for the "sint32" and "sint64" field types,
230   // we ZigZag-encode the values.
231   static uint32 ZigZagEncode32(int32 n);
232   static int32  ZigZagDecode32(uint32 n);
233   static uint64 ZigZagEncode64(int64 n);
234   static int64  ZigZagDecode64(uint64 n);
235 
236   // =================================================================
237   // Methods for reading/writing individual field.  The implementations
238   // of these methods are defined in wire_format_lite_inl.h; you must #include
239   // that file to use these.
240 
241 // Avoid ugly line wrapping
242 #define input  io::CodedInputStream*  input_arg
243 #define output io::CodedOutputStream* output_arg
244 #define field_number int field_number_arg
245 #define INL GOOGLE_ATTRIBUTE_ALWAYS_INLINE
246 
247   // Read fields, not including tags.  The assumption is that you already
248   // read the tag to determine what field to read.
249 
250   // For primitive fields, we just use a templatized routine parameterized by
251   // the represented type and the FieldType. These are specialized with the
252   // appropriate definition for each declared type.
253   template <typename CType, enum FieldType DeclaredType> INL
254   static bool ReadPrimitive(input, CType* value);
255 
256   // Reads repeated primitive values, with optimizations for repeats.
257   // tag_size and tag should both be compile-time constants provided by the
258   // protocol compiler.
259   template <typename CType, enum FieldType DeclaredType> INL
260   static bool ReadRepeatedPrimitive(int tag_size,
261                                     uint32 tag,
262                                     input,
263                                     RepeatedField<CType>* value);
264 
265   // Identical to ReadRepeatedPrimitive, except will not inline the
266   // implementation.
267   template <typename CType, enum FieldType DeclaredType>
268   static bool ReadRepeatedPrimitiveNoInline(int tag_size,
269                                             uint32 tag,
270                                             input,
271                                             RepeatedField<CType>* value);
272 
273   // Reads a primitive value directly from the provided buffer. It returns a
274   // pointer past the segment of data that was read.
275   //
276   // This is only implemented for the types with fixed wire size, e.g.
277   // float, double, and the (s)fixed* types.
278   template <typename CType, enum FieldType DeclaredType> INL
279   static const uint8* ReadPrimitiveFromArray(const uint8* buffer, CType* value);
280 
281   // Reads a primitive packed field.
282   //
283   // This is only implemented for packable types.
284   template <typename CType, enum FieldType DeclaredType> INL
285   static bool ReadPackedPrimitive(input, RepeatedField<CType>* value);
286 
287   // Identical to ReadPackedPrimitive, except will not inline the
288   // implementation.
289   template <typename CType, enum FieldType DeclaredType>
290   static bool ReadPackedPrimitiveNoInline(input, RepeatedField<CType>* value);
291 
292   // Read a packed enum field. If the is_valid function is not NULL, values for
293   // which is_valid(value) returns false are silently dropped.
294   static bool ReadPackedEnumNoInline(input,
295                                      bool (*is_valid)(int),
296                                      RepeatedField<int>* values);
297 
298   // Read a packed enum field. If the is_valid function is not NULL, values for
299   // which is_valid(value) returns false are appended to unknown_fields_stream.
300   static bool ReadPackedEnumPreserveUnknowns(
301       input,
302       field_number,
303       bool (*is_valid)(int),
304       io::CodedOutputStream* unknown_fields_stream,
305       RepeatedField<int>* values);
306 
307   // Read a string.  ReadString(..., string* value) requires an existing string.
308   static inline bool ReadString(input, string* value);
309   // ReadString(..., string** p) is internal-only, and should only be called
310   // from generated code. It starts by setting *p to "new string"
311   // if *p == &GetEmptyStringAlreadyInited().  It then invokes
312   // ReadString(input, *p).  This is useful for reducing code size.
313   static inline bool ReadString(input, string** p);
314   // Analogous to ReadString().
315   static bool ReadBytes(input, string* value);
316   static bool ReadBytes(input, string** p);
317 
318 
319   enum Operation {
320     PARSE = 0,
321     SERIALIZE = 1,
322   };
323 
324   // Returns true if the data is valid UTF-8.
325   static bool VerifyUtf8String(const char* data, int size,
326                                Operation op,
327                                const char* field_name);
328 
329   static inline bool ReadGroup  (field_number, input, MessageLite* value);
330   static inline bool ReadMessage(input, MessageLite* value);
331 
332   // Like above, but de-virtualize the call to MergePartialFromCodedStream().
333   // The pointer must point at an instance of MessageType, *not* a subclass (or
334   // the subclass must not override MergePartialFromCodedStream()).
335   template<typename MessageType>
336   static inline bool ReadGroupNoVirtual(field_number, input,
337                                         MessageType* value);
338   template<typename MessageType>
339   static inline bool ReadMessageNoVirtual(input, MessageType* value);
340 
341   // The same, but do not modify input's recursion depth.  This is useful
342   // when reading a bunch of groups or messages in a loop, because then the
343   // recursion depth can be incremented before the loop and decremented after.
344   template<typename MessageType>
345   static inline bool ReadGroupNoVirtualNoRecursionDepth(field_number, input,
346                                                         MessageType* value);
347 
348   template<typename MessageType>
349   static inline bool ReadMessageNoVirtualNoRecursionDepth(input,
350                                                           MessageType* value);
351 
352   // Write a tag.  The Write*() functions typically include the tag, so
353   // normally there's no need to call this unless using the Write*NoTag()
354   // variants.
355   INL static void WriteTag(field_number, WireType type, output);
356 
357   // Write fields, without tags.
358   INL static void WriteInt32NoTag   (int32 value, output);
359   INL static void WriteInt64NoTag   (int64 value, output);
360   INL static void WriteUInt32NoTag  (uint32 value, output);
361   INL static void WriteUInt64NoTag  (uint64 value, output);
362   INL static void WriteSInt32NoTag  (int32 value, output);
363   INL static void WriteSInt64NoTag  (int64 value, output);
364   INL static void WriteFixed32NoTag (uint32 value, output);
365   INL static void WriteFixed64NoTag (uint64 value, output);
366   INL static void WriteSFixed32NoTag(int32 value, output);
367   INL static void WriteSFixed64NoTag(int64 value, output);
368   INL static void WriteFloatNoTag   (float value, output);
369   INL static void WriteDoubleNoTag  (double value, output);
370   INL static void WriteBoolNoTag    (bool value, output);
371   INL static void WriteEnumNoTag    (int value, output);
372 
373   // Write fields, including tags.
374   static void WriteInt32   (field_number,  int32 value, output);
375   static void WriteInt64   (field_number,  int64 value, output);
376   static void WriteUInt32  (field_number, uint32 value, output);
377   static void WriteUInt64  (field_number, uint64 value, output);
378   static void WriteSInt32  (field_number,  int32 value, output);
379   static void WriteSInt64  (field_number,  int64 value, output);
380   static void WriteFixed32 (field_number, uint32 value, output);
381   static void WriteFixed64 (field_number, uint64 value, output);
382   static void WriteSFixed32(field_number,  int32 value, output);
383   static void WriteSFixed64(field_number,  int64 value, output);
384   static void WriteFloat   (field_number,  float value, output);
385   static void WriteDouble  (field_number, double value, output);
386   static void WriteBool    (field_number,   bool value, output);
387   static void WriteEnum    (field_number,    int value, output);
388 
389   static void WriteString(field_number, const string& value, output);
390   static void WriteBytes (field_number, const string& value, output);
391   static void WriteStringMaybeAliased(
392       field_number, const string& value, output);
393   static void WriteBytesMaybeAliased(
394       field_number, const string& value, output);
395 
396   static void WriteGroup(
397     field_number, const MessageLite& value, output);
398   static void WriteMessage(
399     field_number, const MessageLite& value, output);
400   // Like above, but these will check if the output stream has enough
401   // space to write directly to a flat array.
402   static void WriteGroupMaybeToArray(
403     field_number, const MessageLite& value, output);
404   static void WriteMessageMaybeToArray(
405     field_number, const MessageLite& value, output);
406 
407   // Like above, but de-virtualize the call to SerializeWithCachedSizes().  The
408   // pointer must point at an instance of MessageType, *not* a subclass (or
409   // the subclass must not override SerializeWithCachedSizes()).
410   template<typename MessageType>
411   static inline void WriteGroupNoVirtual(
412     field_number, const MessageType& value, output);
413   template<typename MessageType>
414   static inline void WriteMessageNoVirtual(
415     field_number, const MessageType& value, output);
416 
417 #undef output
418 #define output uint8* target
419 
420   // Like above, but use only *ToArray methods of CodedOutputStream.
421   INL static uint8* WriteTagToArray(field_number, WireType type, output);
422 
423   // Write fields, without tags.
424   INL static uint8* WriteInt32NoTagToArray   (int32 value, output);
425   INL static uint8* WriteInt64NoTagToArray   (int64 value, output);
426   INL static uint8* WriteUInt32NoTagToArray  (uint32 value, output);
427   INL static uint8* WriteUInt64NoTagToArray  (uint64 value, output);
428   INL static uint8* WriteSInt32NoTagToArray  (int32 value, output);
429   INL static uint8* WriteSInt64NoTagToArray  (int64 value, output);
430   INL static uint8* WriteFixed32NoTagToArray (uint32 value, output);
431   INL static uint8* WriteFixed64NoTagToArray (uint64 value, output);
432   INL static uint8* WriteSFixed32NoTagToArray(int32 value, output);
433   INL static uint8* WriteSFixed64NoTagToArray(int64 value, output);
434   INL static uint8* WriteFloatNoTagToArray   (float value, output);
435   INL static uint8* WriteDoubleNoTagToArray  (double value, output);
436   INL static uint8* WriteBoolNoTagToArray    (bool value, output);
437   INL static uint8* WriteEnumNoTagToArray    (int value, output);
438 
439   // Write fields, including tags.
440   INL static uint8* WriteInt32ToArray(field_number, int32 value, output);
441   INL static uint8* WriteInt64ToArray(field_number, int64 value, output);
442   INL static uint8* WriteUInt32ToArray(field_number, uint32 value, output);
443   INL static uint8* WriteUInt64ToArray(field_number, uint64 value, output);
444   INL static uint8* WriteSInt32ToArray(field_number, int32 value, output);
445   INL static uint8* WriteSInt64ToArray(field_number, int64 value, output);
446   INL static uint8* WriteFixed32ToArray(field_number, uint32 value, output);
447   INL static uint8* WriteFixed64ToArray(field_number, uint64 value, output);
448   INL static uint8* WriteSFixed32ToArray(field_number, int32 value, output);
449   INL static uint8* WriteSFixed64ToArray(field_number, int64 value, output);
450   INL static uint8* WriteFloatToArray(field_number, float value, output);
451   INL static uint8* WriteDoubleToArray(field_number, double value, output);
452   INL static uint8* WriteBoolToArray(field_number, bool value, output);
453   INL static uint8* WriteEnumToArray(field_number, int value, output);
454 
455   INL static uint8* WriteStringToArray(
456     field_number, const string& value, output);
457   INL static uint8* WriteBytesToArray(
458     field_number, const string& value, output);
459 
460   // Whether to serialize deterministically (e.g., map keys are
461   // sorted) is a property of a CodedOutputStream, and in the process
462   // of serialization, the "ToArray" variants may be invoked.  But they don't
463   // have a CodedOutputStream available, so they get an additional parameter
464   // telling them whether to serialize deterministically.
465   INL static uint8* InternalWriteGroupToArray(
466       field_number, const MessageLite& value, bool deterministic, output);
467   INL static uint8* InternalWriteMessageToArray(
468       field_number, const MessageLite& value, bool deterministic, output);
469 
470   // Like above, but de-virtualize the call to SerializeWithCachedSizes().  The
471   // pointer must point at an instance of MessageType, *not* a subclass (or
472   // the subclass must not override SerializeWithCachedSizes()).
473   template<typename MessageType>
474   INL static uint8* InternalWriteGroupNoVirtualToArray(
475     field_number, const MessageType& value, bool deterministic, output);
476   template<typename MessageType>
477   INL static uint8* InternalWriteMessageNoVirtualToArray(
478     field_number, const MessageType& value, bool deterministic, output);
479 
480   // For backward-compatibility, the last four methods also have versions
481   // that are non-deterministic always.
WriteGroupToArray(field_number,const MessageLite & value,output)482   INL static uint8* WriteGroupToArray(
483       field_number, const MessageLite& value, output) {
484     return InternalWriteGroupToArray(field_number_arg, value, false, target);
485   }
WriteMessageToArray(field_number,const MessageLite & value,output)486   INL static uint8* WriteMessageToArray(
487       field_number, const MessageLite& value, output) {
488     return InternalWriteMessageToArray(field_number_arg, value, false, target);
489   }
490   template<typename MessageType>
WriteGroupNoVirtualToArray(field_number,const MessageType & value,output)491   INL static uint8* WriteGroupNoVirtualToArray(
492       field_number, const MessageType& value, output) {
493     return InternalWriteGroupNoVirtualToArray(field_number_arg, value, false,
494                                               target);
495   }
496   template<typename MessageType>
WriteMessageNoVirtualToArray(field_number,const MessageType & value,output)497   INL static uint8* WriteMessageNoVirtualToArray(
498       field_number, const MessageType& value, output) {
499     return InternalWriteMessageNoVirtualToArray(field_number_arg, value, false,
500                                                 target);
501   }
502 
503 #undef output
504 #undef input
505 #undef INL
506 
507 #undef field_number
508 
509   // Compute the byte size of a field.  The XxSize() functions do NOT include
510   // the tag, so you must also call TagSize().  (This is because, for repeated
511   // fields, you should only call TagSize() once and multiply it by the element
512   // count, but you may have to call XxSize() for each individual element.)
513   static inline int Int32Size   ( int32 value);
514   static inline int Int64Size   ( int64 value);
515   static inline int UInt32Size  (uint32 value);
516   static inline int UInt64Size  (uint64 value);
517   static inline int SInt32Size  ( int32 value);
518   static inline int SInt64Size  ( int64 value);
519   static inline int EnumSize    (   int value);
520 
521   // These types always have the same size.
522   static const int kFixed32Size  = 4;
523   static const int kFixed64Size  = 8;
524   static const int kSFixed32Size = 4;
525   static const int kSFixed64Size = 8;
526   static const int kFloatSize    = 4;
527   static const int kDoubleSize   = 8;
528   static const int kBoolSize     = 1;
529 
530   static inline int StringSize(const string& value);
531   static inline int BytesSize (const string& value);
532 
533   static inline int GroupSize  (const MessageLite& value);
534   static inline int MessageSize(const MessageLite& value);
535 
536   // Like above, but de-virtualize the call to ByteSize().  The
537   // pointer must point at an instance of MessageType, *not* a subclass (or
538   // the subclass must not override ByteSize()).
539   template<typename MessageType>
540   static inline int GroupSizeNoVirtual  (const MessageType& value);
541   template<typename MessageType>
542   static inline int MessageSizeNoVirtual(const MessageType& value);
543 
544   // Given the length of data, calculate the byte size of the data on the
545   // wire if we encode the data as a length delimited field.
546   static inline int LengthDelimitedSize(int length);
547 
548  private:
549   // A helper method for the repeated primitive reader. This method has
550   // optimizations for primitive types that have fixed size on the wire, and
551   // can be read using potentially faster paths.
552   template <typename CType, enum FieldType DeclaredType> GOOGLE_ATTRIBUTE_ALWAYS_INLINE
553   static bool ReadRepeatedFixedSizePrimitive(
554       int tag_size,
555       uint32 tag,
556       google::protobuf::io::CodedInputStream* input,
557       RepeatedField<CType>* value);
558 
559   // Like ReadRepeatedFixedSizePrimitive but for packed primitive fields.
560   template <typename CType, enum FieldType DeclaredType> GOOGLE_ATTRIBUTE_ALWAYS_INLINE
561   static bool ReadPackedFixedSizePrimitive(google::protobuf::io::CodedInputStream* input,
562                                            RepeatedField<CType>* value);
563 
564   static const CppType kFieldTypeToCppTypeMap[];
565   static const WireFormatLite::WireType kWireTypeForFieldType[];
566 
567   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(WireFormatLite);
568 };
569 
570 // A class which deals with unknown values.  The default implementation just
571 // discards them.  WireFormat defines a subclass which writes to an
572 // UnknownFieldSet.  This class is used by ExtensionSet::ParseField(), since
573 // ExtensionSet is part of the lite library but UnknownFieldSet is not.
574 class LIBPROTOBUF_EXPORT FieldSkipper {
575  public:
FieldSkipper()576   FieldSkipper() {}
~FieldSkipper()577   virtual ~FieldSkipper() {}
578 
579   // Skip a field whose tag has already been consumed.
580   virtual bool SkipField(io::CodedInputStream* input, uint32 tag);
581 
582   // Skip an entire message or group, up to an end-group tag (which is consumed)
583   // or end-of-stream.
584   virtual bool SkipMessage(io::CodedInputStream* input);
585 
586   // Deal with an already-parsed unrecognized enum value.  The default
587   // implementation does nothing, but the UnknownFieldSet-based implementation
588   // saves it as an unknown varint.
589   virtual void SkipUnknownEnum(int field_number, int value);
590 };
591 
592 // Subclass of FieldSkipper which saves skipped fields to a CodedOutputStream.
593 
594 class LIBPROTOBUF_EXPORT CodedOutputStreamFieldSkipper : public FieldSkipper {
595  public:
CodedOutputStreamFieldSkipper(io::CodedOutputStream * unknown_fields)596   explicit CodedOutputStreamFieldSkipper(io::CodedOutputStream* unknown_fields)
597       : unknown_fields_(unknown_fields) {}
~CodedOutputStreamFieldSkipper()598   virtual ~CodedOutputStreamFieldSkipper() {}
599 
600   // implements FieldSkipper -----------------------------------------
601   virtual bool SkipField(io::CodedInputStream* input, uint32 tag);
602   virtual bool SkipMessage(io::CodedInputStream* input);
603   virtual void SkipUnknownEnum(int field_number, int value);
604 
605  protected:
606   io::CodedOutputStream* unknown_fields_;
607 };
608 
609 
610 // inline methods ====================================================
611 
612 inline WireFormatLite::CppType
FieldTypeToCppType(FieldType type)613 WireFormatLite::FieldTypeToCppType(FieldType type) {
614   return kFieldTypeToCppTypeMap[type];
615 }
616 
MakeTag(int field_number,WireType type)617 inline uint32 WireFormatLite::MakeTag(int field_number, WireType type) {
618   return GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(field_number, type);
619 }
620 
GetTagWireType(uint32 tag)621 inline WireFormatLite::WireType WireFormatLite::GetTagWireType(uint32 tag) {
622   return static_cast<WireType>(tag & kTagTypeMask);
623 }
624 
GetTagFieldNumber(uint32 tag)625 inline int WireFormatLite::GetTagFieldNumber(uint32 tag) {
626   return static_cast<int>(tag >> kTagTypeBits);
627 }
628 
TagSize(int field_number,WireFormatLite::FieldType type)629 inline int WireFormatLite::TagSize(int field_number,
630                                    WireFormatLite::FieldType type) {
631   int result = io::CodedOutputStream::VarintSize32(
632     field_number << kTagTypeBits);
633   if (type == TYPE_GROUP) {
634     // Groups have both a start and an end tag.
635     return result * 2;
636   } else {
637     return result;
638   }
639 }
640 
EncodeFloat(float value)641 inline uint32 WireFormatLite::EncodeFloat(float value) {
642   union {float f; uint32 i;};
643   f = value;
644   return i;
645 }
646 
DecodeFloat(uint32 value)647 inline float WireFormatLite::DecodeFloat(uint32 value) {
648   union {float f; uint32 i;};
649   i = value;
650   return f;
651 }
652 
EncodeDouble(double value)653 inline uint64 WireFormatLite::EncodeDouble(double value) {
654   union {double f; uint64 i;};
655   f = value;
656   return i;
657 }
658 
DecodeDouble(uint64 value)659 inline double WireFormatLite::DecodeDouble(uint64 value) {
660   union {double f; uint64 i;};
661   i = value;
662   return f;
663 }
664 
665 // ZigZag Transform:  Encodes signed integers so that they can be
666 // effectively used with varint encoding.
667 //
668 // varint operates on unsigned integers, encoding smaller numbers into
669 // fewer bytes.  If you try to use it on a signed integer, it will treat
670 // this number as a very large unsigned integer, which means that even
671 // small signed numbers like -1 will take the maximum number of bytes
672 // (10) to encode.  ZigZagEncode() maps signed integers to unsigned
673 // in such a way that those with a small absolute value will have smaller
674 // encoded values, making them appropriate for encoding using varint.
675 //
676 //       int32 ->     uint32
677 // -------------------------
678 //           0 ->          0
679 //          -1 ->          1
680 //           1 ->          2
681 //          -2 ->          3
682 //         ... ->        ...
683 //  2147483647 -> 4294967294
684 // -2147483648 -> 4294967295
685 //
686 //        >> encode >>
687 //        << decode <<
688 
ZigZagEncode32(int32 n)689 inline uint32 WireFormatLite::ZigZagEncode32(int32 n) {
690   // Note:  the right-shift must be arithmetic
691   return (static_cast<uint32>(n) << 1) ^ (n >> 31);
692 }
693 
ZigZagDecode32(uint32 n)694 inline int32 WireFormatLite::ZigZagDecode32(uint32 n) {
695   return (n >> 1) ^ -static_cast<int32>(n & 1);
696 }
697 
ZigZagEncode64(int64 n)698 inline uint64 WireFormatLite::ZigZagEncode64(int64 n) {
699   // Note:  the right-shift must be arithmetic
700   return (static_cast<uint64>(n) << 1) ^ (n >> 63);
701 }
702 
ZigZagDecode64(uint64 n)703 inline int64 WireFormatLite::ZigZagDecode64(uint64 n) {
704   return (n >> 1) ^ -static_cast<int64>(n & 1);
705 }
706 
707 // String is for UTF-8 text only, but, even so, ReadString() can simply
708 // call ReadBytes().
709 
ReadString(io::CodedInputStream * input,string * value)710 inline bool WireFormatLite::ReadString(io::CodedInputStream* input,
711                                        string* value) {
712   return ReadBytes(input, value);
713 }
714 
ReadString(io::CodedInputStream * input,string ** p)715 inline bool WireFormatLite::ReadString(io::CodedInputStream* input,
716                                        string** p) {
717   return ReadBytes(input, p);
718 }
719 
720 }  // namespace internal
721 }  // namespace protobuf
722 
723 }  // namespace google
724 #endif  // GOOGLE_PROTOBUF_WIRE_FORMAT_LITE_H__
725