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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
//===-- llvm/Support/circular_raw_ostream.h - Buffered streams --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains raw_ostream implementations for streams to do circular
// buffering of their output.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_CIRCULAR_RAW_OSTREAM_H
#define LLVM_SUPPORT_CIRCULAR_RAW_OSTREAM_H
#include "llvm/Support/raw_ostream.h"
namespace llvm
{
/// circular_raw_ostream - A raw_ostream which *can* save its data
/// to a circular buffer, or can pass it through directly to an
/// underlying stream if specified with a buffer of zero.
///
class circular_raw_ostream : public raw_ostream {
public:
/// TAKE_OWNERSHIP - Tell this stream that it owns the underlying
/// stream and is responsible for cleanup, memory management
/// issues, etc.
///
static const bool TAKE_OWNERSHIP = true;
/// REFERENCE_ONLY - Tell this stream it should not manage the
/// held stream.
///
static const bool REFERENCE_ONLY = false;
private:
/// TheStream - The real stream we output to. We set it to be
/// unbuffered, since we're already doing our own buffering.
///
raw_ostream *TheStream;
/// OwnsStream - Are we responsible for managing the underlying
/// stream?
///
bool OwnsStream;
/// BufferSize - The size of the buffer in bytes.
///
size_t BufferSize;
/// BufferArray - The actual buffer storage.
///
char *BufferArray;
/// Cur - Pointer to the current output point in BufferArray.
///
char *Cur;
/// Filled - Indicate whether the buffer has been completely
/// filled. This helps avoid garbage output.
///
bool Filled;
/// Banner - A pointer to a banner to print before dumping the
/// log.
///
const char *Banner;
/// flushBuffer - Dump the contents of the buffer to Stream.
///
void flushBuffer(void) {
if (Filled)
// Write the older portion of the buffer.
TheStream->write(Cur, BufferArray + BufferSize - Cur);
// Write the newer portion of the buffer.
TheStream->write(BufferArray, Cur - BufferArray);
Cur = BufferArray;
Filled = false;
}
virtual void write_impl(const char *Ptr, size_t Size);
/// current_pos - Return the current position within the stream,
/// not counting the bytes currently in the buffer.
///
virtual uint64_t current_pos() const {
// This has the same effect as calling TheStream.current_pos(),
// but that interface is private.
return TheStream->tell() - TheStream->GetNumBytesInBuffer();
}
public:
/// circular_raw_ostream - Construct an optionally
/// circular-buffered stream, handing it an underlying stream to
/// do the "real" output.
///
/// As a side effect, if BuffSize is nonzero, the given Stream is
/// set to be Unbuffered. This is because circular_raw_ostream
/// does its own buffering, so it doesn't want another layer of
/// buffering to be happening underneath it.
///
/// "Owns" tells the circular_raw_ostream whether it is
/// responsible for managing the held stream, doing memory
/// management of it, etc.
///
circular_raw_ostream(raw_ostream &Stream, const char *Header,
size_t BuffSize = 0, bool Owns = REFERENCE_ONLY)
: raw_ostream(/*unbuffered*/true),
TheStream(0),
OwnsStream(Owns),
BufferSize(BuffSize),
BufferArray(0),
Filled(false),
Banner(Header) {
if (BufferSize != 0)
BufferArray = new char[BufferSize];
Cur = BufferArray;
setStream(Stream, Owns);
}
explicit circular_raw_ostream()
: raw_ostream(/*unbuffered*/true),
TheStream(0),
OwnsStream(REFERENCE_ONLY),
BufferArray(0),
Filled(false),
Banner("") {
Cur = BufferArray;
}
~circular_raw_ostream() {
flush();
flushBufferWithBanner();
releaseStream();
delete[] BufferArray;
}
/// setStream - Tell the circular_raw_ostream to output a
/// different stream. "Owns" tells circular_raw_ostream whether
/// it should take responsibility for managing the underlying
/// stream.
///
void setStream(raw_ostream &Stream, bool Owns = REFERENCE_ONLY) {
releaseStream();
TheStream = &Stream;
OwnsStream = Owns;
}
/// flushBufferWithBanner - Force output of the buffer along with
/// a small header.
///
void flushBufferWithBanner(void);
private:
/// releaseStream - Delete the held stream if needed. Otherwise,
/// transfer the buffer settings from this circular_raw_ostream
/// back to the underlying stream.
///
void releaseStream() {
if (!TheStream)
return;
if (OwnsStream)
delete TheStream;
}
};
} // end llvm namespace
#endif
|
