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 #ifndef GOOGLE_PROTOBUF_UTIL_CONVERTER_OBJECT_WRITER_H__ 32 #define GOOGLE_PROTOBUF_UTIL_CONVERTER_OBJECT_WRITER_H__ 33 34 #include <google/protobuf/stubs/common.h> 35 #include <google/protobuf/stubs/stringpiece.h> 36 37 namespace google { 38 namespace protobuf { 39 namespace util { 40 namespace converter { 41 42 class DataPiece; 43 44 // An ObjectWriter is an interface for writing a stream of events 45 // representing objects and collections. Implementation of this 46 // interface can be used to write an object stream to an in-memory 47 // structure, protobufs, JSON, XML, or any other output format 48 // desired. The ObjectSource interface is typically used as the 49 // source of an object stream. 50 // 51 // See JsonObjectWriter for a sample implementation of ObjectWriter 52 // and its use. 53 // 54 // Derived classes could be thread-unsafe. 55 // 56 // TODO(xinb): seems like a prime candidate to apply the RAII paradigm 57 // and get rid the need to call EndXXX(). 58 class LIBPROTOBUF_EXPORT ObjectWriter { 59 public: ~ObjectWriter()60 virtual ~ObjectWriter() {} 61 62 // Starts an object. If the name is empty, the object will not be named. 63 virtual ObjectWriter* StartObject(StringPiece name) = 0; 64 65 // Ends an object. 66 virtual ObjectWriter* EndObject() = 0; 67 68 // Starts a list. If the name is empty, the list will not be named. 69 virtual ObjectWriter* StartList(StringPiece name) = 0; 70 71 // Ends a list. 72 virtual ObjectWriter* EndList() = 0; 73 74 // Renders a boolean value. 75 virtual ObjectWriter* RenderBool(StringPiece name, bool value) = 0; 76 77 // Renders an 32-bit integer value. 78 virtual ObjectWriter* RenderInt32(StringPiece name, int32 value) = 0; 79 80 // Renders an 32-bit unsigned integer value. 81 virtual ObjectWriter* RenderUint32(StringPiece name, uint32 value) = 0; 82 83 // Renders a 64-bit integer value. 84 virtual ObjectWriter* RenderInt64(StringPiece name, int64 value) = 0; 85 86 // Renders an 64-bit unsigned integer value. 87 virtual ObjectWriter* RenderUint64(StringPiece name, uint64 value) = 0; 88 89 // Renders a double value. 90 virtual ObjectWriter* RenderDouble(StringPiece name, double value) = 0; 91 92 // Renders a float value. 93 virtual ObjectWriter* RenderFloat(StringPiece name, float value) = 0; 94 95 // Renders a StringPiece value. This is for rendering strings. 96 virtual ObjectWriter* RenderString(StringPiece name, StringPiece value) = 0; 97 98 // Renders a bytes value. 99 virtual ObjectWriter* RenderBytes(StringPiece name, StringPiece value) = 0; 100 101 // Renders a Null value. 102 virtual ObjectWriter* RenderNull(StringPiece name) = 0; 103 104 // Renders a DataPiece object to a ObjectWriter. 105 static void RenderDataPieceTo(const DataPiece& data, StringPiece name, 106 ObjectWriter* ow); 107 108 // Indicates whether this ObjectWriter has completed writing the root message, 109 // usually this means writing of one complete object. Subclasses must override 110 // this behavior appropriately. done()111 virtual bool done() { return false; } 112 set_use_strict_base64_decoding(bool value)113 void set_use_strict_base64_decoding(bool value) { 114 use_strict_base64_decoding_ = value; 115 } 116 use_strict_base64_decoding()117 bool use_strict_base64_decoding() const { 118 return use_strict_base64_decoding_; 119 } 120 121 protected: ObjectWriter()122 ObjectWriter() : use_strict_base64_decoding_(true) {} 123 124 private: 125 // If set to true, we use the stricter version of base64 decoding for byte 126 // fields by making sure decoded version encodes back to the original string. 127 bool use_strict_base64_decoding_; 128 129 // Do not add any data members to this class. 130 GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ObjectWriter); 131 }; 132 133 } // namespace converter 134 } // namespace util 135 } // namespace protobuf 136 137 } // namespace google 138 #endif // GOOGLE_PROTOBUF_UTIL_CONVERTER_OBJECT_WRITER_H__ 139