summaryrefslogtreecommitdiff
path: root/src/buffer.cpp
blob: b54f97e91fcb141567d382606ba42bea733a8a21 (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
/*
 * Copyright (C) 2007-2011 Xagasoft, All rights reserved.
 *
 * This file is part of the libbu++ library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#include "bu/buffer.h"

Bu::Buffer::Buffer( Bu::Stream &rNext, int iBufSize ) :
	Bu::Filter( rNext ),
	sSoFar( 0 ),
	iBufSize( iBufSize ),
	sReadBuf( NULL ),
	sWriteBuf( NULL ),
	iReadBufFill( 0 ),
	iReadPos( 0 ),
	iWriteBufFill( 0 ),
	iWritePos( 0 )
{
	sReadBuf = new char[iBufSize];
	sWriteBuf = new char[iBufSize];
}

Bu::Buffer::~Buffer()
{
	delete[] sReadBuf;
	delete[] sWriteBuf;
}

void Bu::Buffer::start()
{
}

Bu::size Bu::Buffer::stop()
{
	iReadBufFill = iReadPos = iWriteBufFill = iWritePos = 0;
	return sSoFar;
}

void Bu::Buffer::fillReadBuf()
{
	if( iReadBufFill+iReadPos < iBufSize )
	{
		iReadBufFill += rNext.read(
			sReadBuf+iReadPos+iReadBufFill,
			iBufSize-iReadBufFill-iReadPos
			);
	}
}

Bu::size Bu::Buffer::read( void *pBuf, Bu::size nBytes )
{
	if( nBytes <= 0 )
	{
		fillReadBuf();
		return 0;
	}

	Bu::size nTotRead = 0;
//	fillReadBuf();

	do
	{
		int iAmnt = nBytes-nTotRead;
		if( iAmnt > iReadBufFill )
		{
			iAmnt = iReadBufFill;
		}
		if( iAmnt > 0 )
		{
			memcpy( ((char *)pBuf)+nTotRead, sReadBuf+iReadPos, iAmnt );
			iReadPos += iAmnt;
			nTotRead += iAmnt;
			iReadBufFill -= iAmnt;
		}
		if( iReadBufFill == 0 )
		{
			iReadPos = 0;
			fillReadBuf();
		}
	}
	while( nTotRead < nBytes && iReadBufFill > 0 );

	//printf("Buffer:  %db returned, %db remain in buffer.\n", nTotRead, iReadBufFill );

	return nTotRead;
}

Bu::size Bu::Buffer::write( const void *pBuf, Bu::size nBytes )
{
	Bu::size nTotWrote = 0;

	do
	{
		int iAmnt = nBytes-nTotWrote;
		if( iAmnt > iBufSize-iWritePos-iWriteBufFill )
		{
			iAmnt = iBufSize-iWritePos-iWriteBufFill;
		}
		if( iAmnt > 0 )
		{
			memcpy(
				sWriteBuf+iWritePos+iWriteBufFill,
				((char *)pBuf)+nTotWrote,
				iAmnt
				);
			nTotWrote += iAmnt;
			iWriteBufFill += iAmnt;
			//printf("Buffer: Moved %db to write buffer, %db filled now.\n",
					//iAmnt, iWriteBufFill );
		}
		while( iWritePos+iWriteBufFill == iBufSize )
		{
			//printf("iWritePos = %d\n", iWritePos );
			int iWr = rNext.write( sWriteBuf+iWritePos, iWriteBufFill );
			//printf("Buffer: Wrote %db from buffer to stream, %db filled now.\n", iWr, iWriteBufFill-iWr );
			if( iWr == 0 )
			{
				return nTotWrote;
			}
			else if( iWr == iWriteBufFill )
			{
				iWritePos = iWriteBufFill = 0;
			}
			else
			{
				iWritePos += iWr;
				iWriteBufFill -= iWr;
			}
		}
	}
	while( nTotWrote < nBytes && iWriteBufFill < iBufSize+iWritePos );

	return nTotWrote;
}

void Bu::Buffer::flush()
{
	if( iWriteBufFill > 0 )
	{
		//printf("Buffer: Flushing remaining data, %db.\n", iWriteBufFill );
		int iWr = 0;
		do
		{
			iWr = rNext.write( sWriteBuf+iWritePos, iWriteBufFill );
			//printf("Buffer: %db written to stream.\n", iWr );
			iWritePos += iWr;
			iWriteBufFill -= iWr;
		} while( iWriteBufFill > 0 && iWr > 0 );
	}
}

bool Bu::Buffer::isEos()
{
	return (iReadPos >= (iReadBufFill-1)) && (rNext.isEos());
}