1// Protocol Buffers - Google's data interchange format
2// Copyright 2008 Google Inc.  All rights reserved.
3// https://developers.google.com/protocol-buffers/
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30
31#ifndef GOOGLE_PROTOBUF_UTIL_CONVERTER_OBJECT_SOURCE_H__
32#define GOOGLE_PROTOBUF_UTIL_CONVERTER_OBJECT_SOURCE_H__
33
34#include <google/protobuf/stubs/common.h>
35#include <google/protobuf/stubs/stringpiece.h>
36#include <google/protobuf/stubs/status.h>
37
38namespace google {
39namespace protobuf {
40namespace util {
41namespace converter {
42
43class ObjectWriter;
44
45// An ObjectSource is anything that can write to an ObjectWriter.
46// Implementation of this interface typically provide constructors or
47// factory methods to create an instance based on some source data, for
48// example, a character stream, or protobuf.
49//
50// Derived classes could be thread-unsafe.
51class LIBPROTOBUF_EXPORT ObjectSource {
52 public:
53  virtual ~ObjectSource() {}
54
55  // Writes to the ObjectWriter
56  virtual util::Status WriteTo(ObjectWriter* ow) const {
57    return NamedWriteTo("", ow);
58  }
59
60  // Writes to the ObjectWriter with a custom name for the message.
61  // This is useful when you chain ObjectSource together by embedding one
62  // within another.
63  virtual util::Status NamedWriteTo(StringPiece name,
64                                      ObjectWriter* ow) const = 0;
65
66 protected:
67  ObjectSource() {}
68
69 private:
70  // Do not add any data members to this class.
71  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ObjectSource);
72};
73
74}  // namespace converter
75}  // namespace util
76}  // namespace protobuf
77
78}  // namespace google
79#endif  // GOOGLE_PROTOBUF_UTIL_CONVERTER_OBJECT_SOURCE_H__
80