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30 
31 #ifndef GOOGLE_PROTOBUF_UTIL_CONVERTER_PROTOSTREAM_OBJECTSOURCE_H__
32 #define GOOGLE_PROTOBUF_UTIL_CONVERTER_PROTOSTREAM_OBJECTSOURCE_H__
33 
34 #include <functional>
35 #include <google/protobuf/stubs/hash.h>
36 #include <string>
37 
38 #include <google/protobuf/stubs/common.h>
39 #include <google/protobuf/type.pb.h>
40 #include <google/protobuf/util/internal/object_source.h>
41 #include <google/protobuf/util/internal/object_writer.h>
42 #include <google/protobuf/util/internal/type_info.h>
43 #include <google/protobuf/util/type_resolver.h>
44 #include <google/protobuf/stubs/stringpiece.h>
45 #include <google/protobuf/stubs/status.h>
46 #include <google/protobuf/stubs/statusor.h>
47 
48 
49 namespace google {
50 namespace protobuf {
51 class Field;
52 class Type;
53 }  // namespace protobuf
54 
55 
56 namespace protobuf {
57 namespace util {
58 namespace converter {
59 
60 class TypeInfo;
61 
62 // An ObjectSource that can parse a stream of bytes as a protocol buffer.
63 // Its WriteTo() method can be given an ObjectWriter.
64 // This implementation uses a google.protobuf.Type for tag and name lookup.
65 // The field names are converted into lower camel-case when writing to the
66 // ObjectWriter.
67 //
68 // Sample usage: (suppose input is: string proto)
69 //   ArrayInputStream arr_stream(proto.data(), proto.size());
70 //   CodedInputStream in_stream(&arr_stream);
71 //   ProtoStreamObjectSource os(&in_stream, /*ServiceTypeInfo*/ typeinfo,
72 //                              <your message google::protobuf::Type>);
73 //
74 //   Status status = os.WriteTo(<some ObjectWriter>);
75 class LIBPROTOBUF_EXPORT ProtoStreamObjectSource : public ObjectSource {
76  public:
77   ProtoStreamObjectSource(google::protobuf::io::CodedInputStream* stream,
78                           TypeResolver* type_resolver,
79                           const google::protobuf::Type& type);
80 
81   virtual ~ProtoStreamObjectSource();
82 
83   virtual util::Status NamedWriteTo(StringPiece name, ObjectWriter* ow) const;
84 
85   // Sets whether or not to use lowerCamelCase casing for enum values. If set to
86   // false, enum values are output without any case conversions.
87   //
88   // For example, if we have an enum:
89   // enum Type {
90   //   ACTION_AND_ADVENTURE = 1;
91   // }
92   // Type type = 20;
93   //
94   // And this option is set to true. Then the rendered "type" field will have
95   // the string "actionAndAdventure".
96   // {
97   //   ...
98   //   "type": "actionAndAdventure",
99   //   ...
100   // }
101   //
102   // If set to false, the rendered "type" field will have the string
103   // "ACTION_AND_ADVENTURE".
104   // {
105   //   ...
106   //   "type": "ACTION_AND_ADVENTURE",
107   //   ...
108   // }
set_use_lower_camel_for_enums(bool value)109   void set_use_lower_camel_for_enums(bool value) {
110     use_lower_camel_for_enums_ = value;
111   }
112 
113   // Sets whether to always output enums as ints, by default this is off, and
114   // enums are rendered as strings.
set_use_ints_for_enums(bool value)115   void set_use_ints_for_enums(bool value) { use_ints_for_enums_ = value; }
116 
117   // Sets whether to use original proto field names
set_preserve_proto_field_names(bool value)118   void set_preserve_proto_field_names(bool value) {
119     preserve_proto_field_names_ = value;
120   }
121 
122   // Sets the max recursion depth of proto message to be deserialized. Proto
123   // messages over this depth will fail to be deserialized.
124   // Default value is 64.
set_max_recursion_depth(int max_depth)125   void set_max_recursion_depth(int max_depth) {
126     max_recursion_depth_ = max_depth;
127   }
128 
129 
130  protected:
131   // Writes a proto2 Message to the ObjectWriter. When the given end_tag is
132   // found this method will complete, allowing it to be used for parsing both
133   // nested messages (end with 0) and nested groups (end with group end tag).
134   // The include_start_and_end parameter allows this method to be called when
135   // already inside of an object, and skip calling StartObject and EndObject.
136   virtual util::Status WriteMessage(const google::protobuf::Type& descriptor,
137                                       StringPiece name, const uint32 end_tag,
138                                       bool include_start_and_end,
139                                       ObjectWriter* ow) const;
140 
141   // Renders a repeating field (packed or unpacked).  Returns the next tag after
142   // reading all sequential repeating elements. The caller should use this tag
143   // before reading more tags from the stream.
144   virtual util::StatusOr<uint32> RenderList(
145       const google::protobuf::Field* field, StringPiece name, uint32 list_tag,
146       ObjectWriter* ow) const;
147 
148   // Looks up a field and verify its consistency with wire type in tag.
149   const google::protobuf::Field* FindAndVerifyField(
150       const google::protobuf::Type& type, uint32 tag) const;
151 
152   // Renders a field value to the ObjectWriter.
153   util::Status RenderField(const google::protobuf::Field* field,
154                              StringPiece field_name, ObjectWriter* ow) const;
155 
156   // Reads field value according to Field spec in 'field' and returns the read
157   // value as string. This only works for primitive datatypes (no message
158   // types).
159   const string ReadFieldValueAsString(
160       const google::protobuf::Field& field) const;
161 
162 
163  private:
164   ProtoStreamObjectSource(google::protobuf::io::CodedInputStream* stream,
165                           const TypeInfo* typeinfo,
166                           const google::protobuf::Type& type);
167   // Function that renders a well known type with a modified behavior.
168   typedef util::Status (*TypeRenderer)(const ProtoStreamObjectSource*,
169                                          const google::protobuf::Type&,
170                                          StringPiece, ObjectWriter*);
171 
172   // TODO(skarvaje): Mark these methods as non-const as they modify internal
173   // state (stream_).
174   //
175   // Renders a NWP map.
176   // Returns the next tag after reading all map entries. The caller should use
177   // this tag before reading more tags from the stream.
178   util::StatusOr<uint32> RenderMap(const google::protobuf::Field* field,
179                                      StringPiece name, uint32 list_tag,
180                                      ObjectWriter* ow) const;
181 
182   // Renders a packed repeating field. A packed field is stored as:
183   // {tag length item1 item2 item3} instead of the less efficient
184   // {tag item1 tag item2 tag item3}.
185   util::Status RenderPacked(const google::protobuf::Field* field,
186                               ObjectWriter* ow) const;
187 
188   // Renders a google.protobuf.Timestamp value to ObjectWriter
189   static util::Status RenderTimestamp(const ProtoStreamObjectSource* os,
190                                         const google::protobuf::Type& type,
191                                         StringPiece name, ObjectWriter* ow);
192 
193   // Renders a google.protobuf.Duration value to ObjectWriter
194   static util::Status RenderDuration(const ProtoStreamObjectSource* os,
195                                        const google::protobuf::Type& type,
196                                        StringPiece name, ObjectWriter* ow);
197 
198   // Following RenderTYPE functions render well known types in
199   // google/protobuf/wrappers.proto corresponding to TYPE.
200   static util::Status RenderDouble(const ProtoStreamObjectSource* os,
201                                      const google::protobuf::Type& type,
202                                      StringPiece name, ObjectWriter* ow);
203   static util::Status RenderFloat(const ProtoStreamObjectSource* os,
204                                     const google::protobuf::Type& type,
205                                     StringPiece name, ObjectWriter* ow);
206   static util::Status RenderInt64(const ProtoStreamObjectSource* os,
207                                     const google::protobuf::Type& type,
208                                     StringPiece name, ObjectWriter* ow);
209   static util::Status RenderUInt64(const ProtoStreamObjectSource* os,
210                                      const google::protobuf::Type& type,
211                                      StringPiece name, ObjectWriter* ow);
212   static util::Status RenderInt32(const ProtoStreamObjectSource* os,
213                                     const google::protobuf::Type& type,
214                                     StringPiece name, ObjectWriter* ow);
215   static util::Status RenderUInt32(const ProtoStreamObjectSource* os,
216                                      const google::protobuf::Type& type,
217                                      StringPiece name, ObjectWriter* ow);
218   static util::Status RenderBool(const ProtoStreamObjectSource* os,
219                                    const google::protobuf::Type& type,
220                                    StringPiece name, ObjectWriter* ow);
221   static util::Status RenderString(const ProtoStreamObjectSource* os,
222                                      const google::protobuf::Type& type,
223                                      StringPiece name, ObjectWriter* ow);
224   static util::Status RenderBytes(const ProtoStreamObjectSource* os,
225                                     const google::protobuf::Type& type,
226                                     StringPiece name, ObjectWriter* ow);
227 
228   // Renders a google.protobuf.Struct to ObjectWriter.
229   static util::Status RenderStruct(const ProtoStreamObjectSource* os,
230                                      const google::protobuf::Type& type,
231                                      StringPiece name, ObjectWriter* ow);
232 
233   // Helper to render google.protobuf.Struct's Value fields to ObjectWriter.
234   static util::Status RenderStructValue(const ProtoStreamObjectSource* os,
235                                           const google::protobuf::Type& type,
236                                           StringPiece name, ObjectWriter* ow);
237 
238   // Helper to render google.protobuf.Struct's ListValue fields to ObjectWriter.
239   static util::Status RenderStructListValue(
240       const ProtoStreamObjectSource* os, const google::protobuf::Type& type,
241       StringPiece name, ObjectWriter* ow);
242 
243   // Render the "Any" type.
244   static util::Status RenderAny(const ProtoStreamObjectSource* os,
245                                   const google::protobuf::Type& type,
246                                   StringPiece name, ObjectWriter* ow);
247 
248   // Render the "FieldMask" type.
249   static util::Status RenderFieldMask(const ProtoStreamObjectSource* os,
250                                         const google::protobuf::Type& type,
251                                         StringPiece name, ObjectWriter* ow);
252 
253   static hash_map<string, TypeRenderer>* renderers_;
254   static void InitRendererMap();
255   static void DeleteRendererMap();
256   static TypeRenderer* FindTypeRenderer(const string& type_url);
257 
258   // Same as above but renders all non-message field types. Callers don't call
259   // this function directly. They just use RenderField.
260   util::Status RenderNonMessageField(const google::protobuf::Field* field,
261                                        StringPiece field_name,
262                                        ObjectWriter* ow) const;
263 
264 
265   // Utility function to detect proto maps. The 'field' MUST be repeated.
266   bool IsMap(const google::protobuf::Field& field) const;
267 
268   // Utility to read int64 and int32 values from a message type in stream_.
269   // Used for reading google.protobuf.Timestamp and Duration messages.
270   std::pair<int64, int32> ReadSecondsAndNanos(
271       const google::protobuf::Type& type) const;
272 
273   // Helper function to check recursion depth and increment it. It will return
274   // Status::OK if the current depth is allowed. Otherwise an error is returned.
275   // type_name and field_name are used for error reporting.
276   util::Status IncrementRecursionDepth(StringPiece type_name,
277                                          StringPiece field_name) const;
278 
279   // Input stream to read from. Ownership rests with the caller.
280   google::protobuf::io::CodedInputStream* stream_;
281 
282   // Type information for all the types used in the descriptor. Used to find
283   // google::protobuf::Type of nested messages/enums.
284   const TypeInfo* typeinfo_;
285 
286   // Whether this class owns the typeinfo_ object. If true the typeinfo_ object
287   // should be deleted in the destructor.
288   bool own_typeinfo_;
289 
290   // google::protobuf::Type of the message source.
291   const google::protobuf::Type& type_;
292 
293 
294   // Whether to render enums using lowerCamelCase. Defaults to false.
295   bool use_lower_camel_for_enums_;
296 
297   // Whether to render enums as ints always. Defaults to false.
298   bool use_ints_for_enums_;
299 
300   // Whether to preserve proto field names
301   bool preserve_proto_field_names_;
302 
303   // Tracks current recursion depth.
304   mutable int recursion_depth_;
305 
306   // Maximum allowed recursion depth.
307   int max_recursion_depth_;
308 
309   // Whether to render unknown fields.
310   bool render_unknown_fields_;
311 
312   // Whether to render unknown enum values.
313   bool render_unknown_enum_values_;
314 
315   // Whether to add trailing zeros for timestamp and duration.
316   bool add_trailing_zeros_for_timestamp_and_duration_;
317 
318   GOOGLE_DISALLOW_IMPLICIT_CONSTRUCTORS(ProtoStreamObjectSource);
319 };
320 
321 }  // namespace converter
322 }  // namespace util
323 }  // namespace protobuf
324 
325 }  // namespace google
326 #endif  // GOOGLE_PROTOBUF_UTIL_CONVERTER_PROTOSTREAM_OBJECTSOURCE_H__
327