1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
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30 
31 // Author: kenton@google.com (Kenton Varda)
32 //         atenasio@google.com (Chris Atenasio) (ZigZag transform)
33 //  Based on original Protocol Buffers design by
34 //  Sanjay Ghemawat, Jeff Dean, and others.
35 //
36 // This header is logically internal, but is made public because it is used
37 // from protocol-compiler-generated code, which may reside in other components.
38 
39 #ifndef GOOGLE_PROTOBUF_WIRE_FORMAT_H__
40 #define GOOGLE_PROTOBUF_WIRE_FORMAT_H__
41 
42 #include <string>
43 #include <google/protobuf/stubs/common.h>
44 #include <google/protobuf/descriptor.pb.h>
45 #include <google/protobuf/descriptor.h>
46 #include <google/protobuf/message.h>
47 #include <google/protobuf/wire_format_lite.h>
48 
49 // Do UTF-8 validation on string type in Debug build only
50 #ifndef NDEBUG
51 #define GOOGLE_PROTOBUF_UTF8_VALIDATION_ENABLED
52 #endif
53 
54 namespace google {
55 namespace protobuf {
56   namespace io {
57     class CodedInputStream;      // coded_stream.h
58     class CodedOutputStream;     // coded_stream.h
59   }
60   class UnknownFieldSet;         // unknown_field_set.h
61 }
62 
63 namespace protobuf {
64 namespace internal {
65 
66 // This class is for internal use by the protocol buffer library and by
67 // protocol-complier-generated message classes.  It must not be called
68 // directly by clients.
69 //
70 // This class contains code for implementing the binary protocol buffer
71 // wire format via reflection.  The WireFormatLite class implements the
72 // non-reflection based routines.
73 //
74 // This class is really a namespace that contains only static methods
75 class LIBPROTOBUF_EXPORT WireFormat {
76  public:
77 
78   // Given a field return its WireType
79   static inline WireFormatLite::WireType WireTypeForField(
80       const FieldDescriptor* field);
81 
82   // Given a FieldDescriptor::Type return its WireType
83   static inline WireFormatLite::WireType WireTypeForFieldType(
84       FieldDescriptor::Type type);
85 
86   // Compute the byte size of a tag.  For groups, this includes both the start
87   // and end tags.
88   static inline int TagSize(int field_number, FieldDescriptor::Type type);
89 
90   // These procedures can be used to implement the methods of Message which
91   // handle parsing and serialization of the protocol buffer wire format
92   // using only the Reflection interface.  When you ask the protocol
93   // compiler to optimize for code size rather than speed, it will implement
94   // those methods in terms of these procedures.  Of course, these are much
95   // slower than the specialized implementations which the protocol compiler
96   // generates when told to optimize for speed.
97 
98   // Read a message in protocol buffer wire format.
99   //
100   // This procedure reads either to the end of the input stream or through
101   // a WIRETYPE_END_GROUP tag ending the message, whichever comes first.
102   // It returns false if the input is invalid.
103   //
104   // Required fields are NOT checked by this method.  You must call
105   // IsInitialized() on the resulting message yourself.
106   static bool ParseAndMergePartial(io::CodedInputStream* input,
107                                    Message* message);
108 
109   // Serialize a message in protocol buffer wire format.
110   //
111   // Any embedded messages within the message must have their correct sizes
112   // cached.  However, the top-level message need not; its size is passed as
113   // a parameter to this procedure.
114   //
115   // These return false iff the underlying stream returns a write error.
116   static void SerializeWithCachedSizes(
117       const Message& message,
118       int size, io::CodedOutputStream* output);
119 
120   // Implements Message::ByteSize() via reflection.  WARNING:  The result
121   // of this method is *not* cached anywhere.  However, all embedded messages
122   // will have their ByteSize() methods called, so their sizes will be cached.
123   // Therefore, calling this method is sufficient to allow you to call
124   // WireFormat::SerializeWithCachedSizes() on the same object.
125   static int ByteSize(const Message& message);
126 
127   // -----------------------------------------------------------------
128   // Helpers for dealing with unknown fields
129 
130   // Skips a field value of the given WireType.  The input should start
131   // positioned immediately after the tag.  If unknown_fields is non-NULL,
132   // the contents of the field will be added to it.
133   static bool SkipField(io::CodedInputStream* input, uint32 tag,
134                         UnknownFieldSet* unknown_fields);
135 
136   // Reads and ignores a message from the input.  If unknown_fields is non-NULL,
137   // the contents will be added to it.
138   static bool SkipMessage(io::CodedInputStream* input,
139                           UnknownFieldSet* unknown_fields);
140 
141   // Write the contents of an UnknownFieldSet to the output.
142   static void SerializeUnknownFields(const UnknownFieldSet& unknown_fields,
143                                      io::CodedOutputStream* output);
144   // Same as above, except writing directly to the provided buffer.
145   // Requires that the buffer have sufficient capacity for
146   // ComputeUnknownFieldsSize(unknown_fields).
147   //
148   // Returns a pointer past the last written byte.
149   static uint8* SerializeUnknownFieldsToArray(
150       const UnknownFieldSet& unknown_fields,
151       uint8* target);
152 
153   // Same thing except for messages that have the message_set_wire_format
154   // option.
155   static void SerializeUnknownMessageSetItems(
156       const UnknownFieldSet& unknown_fields,
157       io::CodedOutputStream* output);
158   // Same as above, except writing directly to the provided buffer.
159   // Requires that the buffer have sufficient capacity for
160   // ComputeUnknownMessageSetItemsSize(unknown_fields).
161   //
162   // Returns a pointer past the last written byte.
163   static uint8* SerializeUnknownMessageSetItemsToArray(
164       const UnknownFieldSet& unknown_fields,
165       uint8* target);
166 
167   // Compute the size of the UnknownFieldSet on the wire.
168   static int ComputeUnknownFieldsSize(const UnknownFieldSet& unknown_fields);
169 
170   // Same thing except for messages that have the message_set_wire_format
171   // option.
172   static int ComputeUnknownMessageSetItemsSize(
173       const UnknownFieldSet& unknown_fields);
174 
175 
176   // Helper functions for encoding and decoding tags.  (Inlined below and in
177   // _inl.h)
178   //
179   // This is different from MakeTag(field->number(), field->type()) in the case
180   // of packed repeated fields.
181   static uint32 MakeTag(const FieldDescriptor* field);
182 
183   // Parse a single field.  The input should start out positioned immediately
184   // after the tag.
185   static bool ParseAndMergeField(
186       uint32 tag,
187       const FieldDescriptor* field,        // May be NULL for unknown
188       Message* message,
189       io::CodedInputStream* input);
190 
191   // Serialize a single field.
192   static void SerializeFieldWithCachedSizes(
193       const FieldDescriptor* field,        // Cannot be NULL
194       const Message& message,
195       io::CodedOutputStream* output);
196 
197   // Compute size of a single field.  If the field is a message type, this
198   // will call ByteSize() for the embedded message, insuring that it caches
199   // its size.
200   static int FieldByteSize(
201       const FieldDescriptor* field,        // Cannot be NULL
202       const Message& message);
203 
204   // Parse/serialize a MessageSet::Item group.  Used with messages that use
205   // opion message_set_wire_format = true.
206   static bool ParseAndMergeMessageSetItem(
207       io::CodedInputStream* input,
208       Message* message);
209   static void SerializeMessageSetItemWithCachedSizes(
210       const FieldDescriptor* field,
211       const Message& message,
212       io::CodedOutputStream* output);
213   static int MessageSetItemByteSize(
214       const FieldDescriptor* field,
215       const Message& message);
216 
217   // Computes the byte size of a field, excluding tags. For packed fields, it
218   // only includes the size of the raw data, and not the size of the total
219   // length, but for other length-delimited types, the size of the length is
220   // included.
221   static int FieldDataOnlyByteSize(
222       const FieldDescriptor* field,        // Cannot be NULL
223       const Message& message);
224 
225   enum Operation {
226     PARSE,
227     SERIALIZE,
228   };
229 
230   // Verifies that a string field is valid UTF8, logging an error if not.
231   // This function will not be called by newly generated protobuf code
232   // but remains present to support existing code.
233   static void VerifyUTF8String(const char* data, int size, Operation op);
234   // The NamedField variant takes a field name in order to produce an
235   // informative error message if verification fails.
236   static void VerifyUTF8StringNamedField(const char* data,
237                                          int size,
238                                          Operation op,
239                                          const char* field_name);
240 
241  private:
242   // Verifies that a string field is valid UTF8, logging an error if not.
243   static void VerifyUTF8StringFallback(
244       const char* data,
245       int size,
246       Operation op,
247       const char* field_name);
248 
249   // Skip a MessageSet field.
250   static bool SkipMessageSetField(io::CodedInputStream* input,
251                                   uint32 field_number,
252                                   UnknownFieldSet* unknown_fields);
253 
254   // Parse a MessageSet field.
255   static bool ParseAndMergeMessageSetField(uint32 field_number,
256                                            const FieldDescriptor* field,
257                                            Message* message,
258                                            io::CodedInputStream* input);
259 
260 
261 
262   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(WireFormat);
263 };
264 
265 // Subclass of FieldSkipper which saves skipped fields to an UnknownFieldSet.
266 class LIBPROTOBUF_EXPORT UnknownFieldSetFieldSkipper : public FieldSkipper {
267  public:
UnknownFieldSetFieldSkipper(UnknownFieldSet * unknown_fields)268   UnknownFieldSetFieldSkipper(UnknownFieldSet* unknown_fields)
269       : unknown_fields_(unknown_fields) {}
~UnknownFieldSetFieldSkipper()270   virtual ~UnknownFieldSetFieldSkipper() {}
271 
272   // implements FieldSkipper -----------------------------------------
273   virtual bool SkipField(io::CodedInputStream* input, uint32 tag);
274   virtual bool SkipMessage(io::CodedInputStream* input);
275   virtual void SkipUnknownEnum(int field_number, int value);
276 
277  protected:
278   UnknownFieldSet* unknown_fields_;
279 };
280 
281 // inline methods ====================================================
282 
WireTypeForField(const FieldDescriptor * field)283 inline WireFormatLite::WireType WireFormat::WireTypeForField(
284     const FieldDescriptor* field) {
285   if (field->options().packed()) {
286     return WireFormatLite::WIRETYPE_LENGTH_DELIMITED;
287   } else {
288     return WireTypeForFieldType(field->type());
289   }
290 }
291 
WireTypeForFieldType(FieldDescriptor::Type type)292 inline WireFormatLite::WireType WireFormat::WireTypeForFieldType(
293     FieldDescriptor::Type type) {
294   // Some compilers don't like enum -> enum casts, so we implicit_cast to
295   // int first.
296   return WireFormatLite::WireTypeForFieldType(
297       static_cast<WireFormatLite::FieldType>(
298         implicit_cast<int>(type)));
299 }
300 
MakeTag(const FieldDescriptor * field)301 inline uint32 WireFormat::MakeTag(const FieldDescriptor* field) {
302   return WireFormatLite::MakeTag(field->number(), WireTypeForField(field));
303 }
304 
TagSize(int field_number,FieldDescriptor::Type type)305 inline int WireFormat::TagSize(int field_number, FieldDescriptor::Type type) {
306   // Some compilers don't like enum -> enum casts, so we implicit_cast to
307   // int first.
308   return WireFormatLite::TagSize(field_number,
309       static_cast<WireFormatLite::FieldType>(
310         implicit_cast<int>(type)));
311 }
312 
VerifyUTF8String(const char * data,int size,WireFormat::Operation op)313 inline void WireFormat::VerifyUTF8String(const char* data, int size,
314     WireFormat::Operation op) {
315 #ifdef GOOGLE_PROTOBUF_UTF8_VALIDATION_ENABLED
316   WireFormat::VerifyUTF8StringFallback(data, size, op, NULL);
317 #else
318   // Avoid the compiler warning about unsued variables.
319   (void)data; (void)size; (void)op;
320 #endif
321 }
322 
VerifyUTF8StringNamedField(const char * data,int size,WireFormat::Operation op,const char * field_name)323 inline void WireFormat::VerifyUTF8StringNamedField(
324     const char* data, int size, WireFormat::Operation op,
325     const char* field_name) {
326 #ifdef GOOGLE_PROTOBUF_UTF8_VALIDATION_ENABLED
327   WireFormat::VerifyUTF8StringFallback(data, size, op, field_name);
328 #endif
329 }
330 
331 
332 }  // namespace internal
333 }  // namespace protobuf
334 
335 }  // namespace google
336 #endif  // GOOGLE_PROTOBUF_WIRE_FORMAT_H__
337