summaryrefslogtreecommitdiff
path: root/indra/llmessage/llbufferstream.cpp
blob: 684548b4088c2a320ad2a4b9db13a062695ca046 (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
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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
/** 
 * @file llbufferstream.cpp
 * @author Phoenix
 * @date 2005-10-10
 * @brief Implementation of the buffer iostream classes
 *
 * Copyright (c) 2005-$CurrentYear$, Linden Research, Inc.
 * $License$
 */

#include "linden_common.h"
#include "llbufferstream.h"

#include "llbuffer.h"
#include "llmemtype.h"

static const S32 DEFAULT_OUTPUT_SEGMENT_SIZE = 1024 * 4;

/*
 * LLBufferStreamBuf
 */
LLBufferStreamBuf::LLBufferStreamBuf(
	const LLChannelDescriptors& channels,
	LLBufferArray* buffer) :
	mChannels(channels),
	mBuffer(buffer)
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
}

LLBufferStreamBuf::~LLBufferStreamBuf()
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
	sync();
}

// virtual
int LLBufferStreamBuf::underflow()
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
	//lldebugs << "LLBufferStreamBuf::underflow()" << llendl;
	if(!mBuffer)
	{
		return EOF;
	}
	LLSegment segment;
	LLBufferArray::segment_iterator_t it;
	U8* last_pos = (U8*)gptr();
	if(last_pos) --last_pos;
	
	LLBufferArray::segment_iterator_t end = mBuffer->endSegment();

	// Get iterator to full segment containing last_pos
	// and construct sub-segment starting at last_pos.
	// Note: segment may != *it at this point
	it = mBuffer->constructSegmentAfter(last_pos, segment);
	if(it == end)
	{
		return EOF;
	}
	
	// Iterate through segments to find a non-empty segment on input channel.
	while((!segment.isOnChannel(mChannels.in()) || (segment.size() == 0)))
	{
		++it;
		if(it == end)
		{
			return EOF;
		}

		segment = *it;
	}
	
	char* start = (char*)segment.data();
	setg(start, start, start + segment.size());
	return *gptr();
}

// virtual
int LLBufferStreamBuf::overflow(int c)
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
	if(!mBuffer)
	{
		return EOF;
	}
	if(EOF == c)
	{
		// if someone puts an EOF, I suppose we should sync and return
		// success.
		if(0 == sync())
		{
			return 1;
		}
		else
		{
			return EOF;
		}
	}

	// since we got here, we have a buffer, and we have a character to
	// put on it.
	LLBufferArray::segment_iterator_t it;
	it = mBuffer->makeSegment(mChannels.out(), DEFAULT_OUTPUT_SEGMENT_SIZE);
	if(it != mBuffer->endSegment())
	{
		char* start = (char*)(*it).data();
		(*start) = (char)(c);
		setp(start + 1, start + (*it).size());
		return c;
	}
	else
	{
		return EOF;
	}
}

// virtual
int LLBufferStreamBuf::sync()
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
	int return_value = -1;
	if(!mBuffer)
	{
		return return_value;
	}

	// set the put pointer so that we force an overflow on the next
	// write.
	U8* address = (U8*)pptr();
	setp(NULL, NULL);

	// *NOTE: I bet we could just --address. Need to think about that.
	address = mBuffer->seek(mChannels.out(), address, -1);
	if(address)
	{
		LLBufferArray::segment_iterator_t it;
		it = mBuffer->splitAfter(address);
		LLBufferArray::segment_iterator_t end = mBuffer->endSegment();
		if(it != end)
		{
			++it;
			if(it != end)
			{
				mBuffer->eraseSegment(it);
			}
			return_value = 0;
		}
	}
	else
	{
		// nothing was put on the buffer, so the sync() is a no-op.
		return_value = 0;
	}
	return return_value;
}

// virtual
#if( LL_WINDOWS || __GNUC__ > 2)
LLBufferStreamBuf::pos_type LLBufferStreamBuf::seekoff(
	LLBufferStreamBuf::off_type off,
	std::ios::seekdir way,
	std::ios::openmode which)
#else
streampos LLBufferStreamBuf::seekoff(
	streamoff off,
	std::ios::seekdir way,
	std::ios::openmode which)
#endif
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
	if(!mBuffer
	   || ((way == std::ios::beg) && (off < 0))
	   || ((way == std::ios::end) && (off > 0)))
	{
		return -1;
	}
	U8* address = NULL;
	if(which & std::ios::in)
	{
		U8* base_addr = NULL;
		switch(way)
		{
		case std::ios::end:
			base_addr = (U8*)LLBufferArray::npos;
			break;
		case std::ios::cur:
			// get the current get pointer and adjust it for buffer
			// array semantics.
			base_addr = (U8*)gptr();
			break;
		case std::ios::beg:
		default:
			// NULL is fine
			break;
		}
		address = mBuffer->seek(mChannels.in(), base_addr, off);
		if(address)
		{
			LLBufferArray::segment_iterator_t iter;
			iter = mBuffer->getSegment(address);
			char* start = (char*)(*iter).data();
			setg(start, (char*)address, start + (*iter).size());
		}
		else
		{
			address = (U8*)(-1);
		}
	}
	if(which & std::ios::out)
	{
		U8* base_addr = NULL;
		switch(way)
		{
		case std::ios::end:
			base_addr = (U8*)LLBufferArray::npos;
			break;
		case std::ios::cur:
			// get the current put pointer and adjust it for buffer
			// array semantics.
			base_addr = (U8*)pptr();
			break;
		case std::ios::beg:
		default:
			// NULL is fine
			break;
		}
		address = mBuffer->seek(mChannels.out(), base_addr, off);
		if(address)
		{
			LLBufferArray::segment_iterator_t iter;
			iter = mBuffer->getSegment(address);
			setp((char*)address, (char*)(*iter).data() + (*iter).size());
		}
		else
		{
			address = (U8*)(-1);
		}
	}

#if( LL_WINDOWS || __GNUC__ > 2 )
	S32 rv = (S32)(intptr_t)address;
	return (pos_type)rv;
#else
	return (streampos)address;
#endif
}


/*
 * LLBufferStream
 */
LLBufferStream::LLBufferStream(
	const LLChannelDescriptors& channels,
	LLBufferArray* buffer) :
	std::iostream(&mStreamBuf),
	mStreamBuf(channels, buffer)
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
}

LLBufferStream::~LLBufferStream()
{
	LLMemType m1(LLMemType::MTYPE_IO_BUFFER);
}