1 //===- MsgPackWriter.h - Simple MsgPack writer ------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 ///  \file
10 ///  This file contains a MessagePack writer.
11 ///
12 ///  See https://github.com/msgpack/msgpack/blob/master/spec.md for the full
13 ///  specification.
14 ///
15 ///  Typical usage:
16 ///  \code
17 ///  raw_ostream output = GetOutputStream();
18 ///  msgpack::Writer MPWriter(output);
19 ///  MPWriter.writeNil();
20 ///  MPWriter.write(false);
21 ///  MPWriter.write("string");
22 ///  // ...
23 ///  \endcode
24 ///
25 ///
26 //===----------------------------------------------------------------------===//
27 
28 #ifndef LLVM_SUPPORT_MSGPACKPARSER_H
29 #define LLVM_SUPPORT_MSGPACKPARSER_H
30 
31 #include "llvm/BinaryFormat/MsgPack.h"
32 #include "llvm/Support/EndianStream.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/raw_ostream.h"
35 
36 namespace llvm {
37 namespace msgpack {
38 
39 /// Writes MessagePack objects to an output stream, one at a time.
40 class Writer {
41 public:
42   /// Construct a writer, optionally enabling "Compatibility Mode" as defined
43   /// in the MessagePack specification.
44   ///
45   /// When in \p Compatible mode, the writer will write \c Str16 formats
46   /// instead of \c Str8 formats, and will refuse to write any \c Bin formats.
47   ///
48   /// \param OS stream to output MessagePack objects to.
49   /// \param Compatible when set, write in "Compatibility Mode".
50   Writer(raw_ostream &OS, bool Compatible = false);
51 
52   Writer(const Writer &) = delete;
53   Writer &operator=(const Writer &) = delete;
54 
55   /// Write a \em Nil to the output stream.
56   ///
57   /// The output will be the \em nil format.
58   void writeNil();
59 
60   /// Write a \em Boolean to the output stream.
61   ///
62   /// The output will be a \em bool format.
63   void write(bool b);
64 
65   /// Write a signed integer to the output stream.
66   ///
67   /// The output will be in the smallest possible \em int format.
68   ///
69   /// The format chosen may be for an unsigned integer.
70   void write(int64_t i);
71 
72   /// Write an unsigned integer to the output stream.
73   ///
74   /// The output will be in the smallest possible \em int format.
75   void write(uint64_t u);
76 
77   /// Write a floating point number to the output stream.
78   ///
79   /// The output will be in the smallest possible \em float format.
80   void write(double d);
81 
82   /// Write a string to the output stream.
83   ///
84   /// The output will be in the smallest possible \em str format.
85   void write(StringRef s);
86 
87   /// Write a memory buffer to the output stream.
88   ///
89   /// The output will be in the smallest possible \em bin format.
90   ///
91   /// \warning Do not use this overload if in \c Compatible mode.
92   void write(MemoryBufferRef Buffer);
93 
94   /// Write the header for an \em Array of the given size.
95   ///
96   /// The output will be in the smallest possible \em array format.
97   //
98   /// The header contains an identifier for the \em array format used, as well
99   /// as an encoding of the size of the array.
100   ///
101   /// N.B. The caller must subsequently call \c Write an additional \p Size
102   /// times to complete the array.
103   void writeArraySize(uint32_t Size);
104 
105   /// Write the header for a \em Map of the given size.
106   ///
107   /// The output will be in the smallest possible \em map format.
108   //
109   /// The header contains an identifier for the \em map format used, as well
110   /// as an encoding of the size of the map.
111   ///
112   /// N.B. The caller must subsequently call \c Write and additional \c Size*2
113   /// times to complete the map. Each even numbered call to \c Write defines a
114   /// new key, and each odd numbered call defines the previous key's value.
115   void writeMapSize(uint32_t Size);
116 
117   /// Write a typed memory buffer (an extension type) to the output stream.
118   ///
119   /// The output will be in the smallest possible \em ext format.
120   void writeExt(int8_t Type, MemoryBufferRef Buffer);
121 
122 private:
123   support::endian::Writer EW;
124   bool Compatible;
125 };
126 
127 } // end namespace msgpack
128 } // end namespace llvm
129 
130 #endif // LLVM_SUPPORT_MSGPACKPARSER_H
131