aboutsummaryrefslogtreecommitdiffstats
path: root/src/google/protobuf/io/printer.h
blob: 5be48543ab04c5cd136ba5b0f916ffcc059892d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Author: kenton@google.com (Kenton Varda)
//  Based on original Protocol Buffers design by
//  Sanjay Ghemawat, Jeff Dean, and others.
//
// Utility class for writing text to a ZeroCopyOutputStream.

#ifndef GOOGLE_PROTOBUF_IO_PRINTER_H__
#define GOOGLE_PROTOBUF_IO_PRINTER_H__

#include <string>
#include <map>
#include <google/protobuf/stubs/common.h>

namespace google {
namespace protobuf {
namespace io {

class ZeroCopyOutputStream;     // zero_copy_stream.h

// This simple utility class assists in code generation.  It basically
// allows the caller to define a set of variables and then output some
// text with variable substitutions.  Example usage:
//
//   Printer printer(output, '$');
//   map<string, string> vars;
//   vars["name"] = "Bob";
//   printer.Print(vars, "My name is $name$.");
//
// The above writes "My name is Bob." to the output stream.
//
// Printer aggressively enforces correct usage, crashing (with assert failures)
// in the case of undefined variables in debug builds. This helps greatly in
// debugging code which uses it.
class LIBPROTOBUF_EXPORT Printer {
 public:
  // Create a printer that writes text to the given output stream.  Use the
  // given character as the delimiter for variables.
  Printer(ZeroCopyOutputStream* output, char variable_delimiter);
  ~Printer();

  // Print some text after applying variable substitutions.  If a particular
  // variable in the text is not defined, this will crash.  Variables to be
  // substituted are identified by their names surrounded by delimiter
  // characters (as given to the constructor).  The variable bindings are
  // defined by the given map.
  void Print(const map<string, string>& variables, const char* text);

  // Like the first Print(), except the substitutions are given as parameters.
  void Print(const char* text);
  // Like the first Print(), except the substitutions are given as parameters.
  void Print(const char* text, const char* variable, const string& value);
  // Like the first Print(), except the substitutions are given as parameters.
  void Print(const char* text, const char* variable1, const string& value1,
                               const char* variable2, const string& value2);
  // Like the first Print(), except the substitutions are given as parameters.
  void Print(const char* text, const char* variable1, const string& value1,
                               const char* variable2, const string& value2,
                               const char* variable3, const string& value3);
  // TODO(kenton):  Overloaded versions with more variables?  Three seems
  //   to be enough.

  // Indent text by two spaces.  After calling Indent(), two spaces will be
  // inserted at the beginning of each line of text.  Indent() may be called
  // multiple times to produce deeper indents.
  void Indent();

  // Reduces the current indent level by two spaces, or crashes if the indent
  // level is zero.
  void Outdent();

  // Write a string to the output buffer.
  // This method does not look for newlines to add indentation.
  void PrintRaw(const string& data);

  // Write a zero-delimited string to output buffer.
  // This method does not look for newlines to add indentation.
  void PrintRaw(const char* data);

  // Write some bytes to the output buffer.
  // This method does not look for newlines to add indentation.
  void WriteRaw(const char* data, int size);

  // True if any write to the underlying stream failed.  (We don't just
  // crash in this case because this is an I/O failure, not a programming
  // error.)
  bool failed() const { return failed_; }

 private:
  const char variable_delimiter_;

  ZeroCopyOutputStream* const output_;
  char* buffer_;
  int buffer_size_;

  string indent_;
  bool at_start_of_line_;
  bool failed_;

  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Printer);
};

}  // namespace io
}  // namespace protobuf

}  // namespace google
#endif  // GOOGLE_PROTOBUF_IO_PRINTER_H__