source: liacs/MIR2010/Sample/cximage/xmemfile.cpp@ 93

Last change on this file since 93 was 93, checked in by Rick van der Zwet, 15 years ago

Sample implementation of professor
File size: 4.9 KB
RevLine 
[93]1#include "xmemfile.h"
2
3//////////////////////////////////////////////////////////
4CxMemFile::CxMemFile(BYTE* pBuffer, DWORD size)
5{
6 m_pBuffer = pBuffer;
7 m_Position = 0;
8 m_Size = m_Edge = size;
9 m_bFreeOnClose = (bool)(pBuffer==0);
10}
11//////////////////////////////////////////////////////////
12CxMemFile::~CxMemFile()
13{
14 Close();
15}
16//////////////////////////////////////////////////////////
17bool CxMemFile::Close()
18{
19 if ( (m_pBuffer) && (m_bFreeOnClose) ){
20 free(m_pBuffer);
21 m_pBuffer = NULL;
22 m_Size = 0;
23 }
24 return true;
25}
26//////////////////////////////////////////////////////////
27bool CxMemFile::Open()
28{
29 if (m_pBuffer) return false; // Can't re-open without closing first
30
31 m_Position = m_Size = m_Edge = 0;
32 m_pBuffer=(BYTE*)malloc(1);
33 m_bFreeOnClose = true;
34
35 return (m_pBuffer!=0);
36}
37//////////////////////////////////////////////////////////
38BYTE* CxMemFile::GetBuffer(bool bDetachBuffer)
39{
40 //can only detach, avoid inadvertantly attaching to
41 // memory that may not be ours [Jason De Arte]
42 if( bDetachBuffer )
43 m_bFreeOnClose = false;
44 return m_pBuffer;
45}
46//////////////////////////////////////////////////////////
47size_t CxMemFile::Read(void *buffer, size_t size, size_t count)
48{
49 if (buffer==NULL) return 0;
50
51 if (m_pBuffer==NULL) return 0;
52 if (m_Position >= (long)m_Size) return 0;
53
54 long nCount = (long)(count*size);
55 if (nCount == 0) return 0;
56
57 long nRead;
58 if (m_Position + nCount > (long)m_Size)
59 nRead = (m_Size - m_Position);
60 else
61 nRead = nCount;
62
63 memcpy(buffer, m_pBuffer + m_Position, nRead);
64 m_Position += nRead;
65
66 return (size_t)(nRead/size);
67}
68//////////////////////////////////////////////////////////
69size_t CxMemFile::Write(const void *buffer, size_t size, size_t count)
70{
71 if (m_pBuffer==NULL) return 0;
72 if (buffer==NULL) return 0;
73
74 long nCount = (long)(count*size);
75 if (nCount == 0) return 0;
76
77 if (m_Position + nCount > m_Edge){
78 if (!Alloc(m_Position + nCount)){
79 return false;
80 }
81 }
82
83 memcpy(m_pBuffer + m_Position, buffer, nCount);
84
85 m_Position += nCount;
86
87 if (m_Position > (long)m_Size) m_Size = m_Position;
88
89 return count;
90}
91//////////////////////////////////////////////////////////
92bool CxMemFile::Seek(long offset, int origin)
93{
94 if (m_pBuffer==NULL) return false;
95 long lNewPos = m_Position;
96
97 if (origin == SEEK_SET) lNewPos = offset;
98 else if (origin == SEEK_CUR) lNewPos += offset;
99 else if (origin == SEEK_END) lNewPos = m_Size + offset;
100 else return false;
101
102 if (lNewPos < 0) lNewPos = 0;
103
104 m_Position = lNewPos;
105 return true;
106}
107//////////////////////////////////////////////////////////
108long CxMemFile::Tell()
109{
110 if (m_pBuffer==NULL) return -1;
111 return m_Position;
112}
113//////////////////////////////////////////////////////////
114long CxMemFile::Size()
115{
116 if (m_pBuffer==NULL) return -1;
117 return m_Size;
118}
119//////////////////////////////////////////////////////////
120bool CxMemFile::Flush()
121{
122 if (m_pBuffer==NULL) return false;
123 return true;
124}
125//////////////////////////////////////////////////////////
126bool CxMemFile::Eof()
127{
128 if (m_pBuffer==NULL) return true;
129 return (m_Position >= (long)m_Size);
130}
131//////////////////////////////////////////////////////////
132long CxMemFile::Error()
133{
134 if (m_pBuffer==NULL) return -1;
135 return (m_Position > (long)m_Size);
136}
137//////////////////////////////////////////////////////////
138bool CxMemFile::PutC(unsigned char c)
139{
140 if (m_pBuffer==NULL) return false;
141
142 if (m_Position >= m_Edge){
143 if (!Alloc(m_Position + 1)){
144 return false;
145 }
146 }
147
148 m_pBuffer[m_Position++] = c;
149
150 if (m_Position > (long)m_Size) m_Size = m_Position;
151
152 return true;
153}
154//////////////////////////////////////////////////////////
155long CxMemFile::GetC()
156{
157 if (Eof()) return EOF;
158 return *(BYTE*)((BYTE*)m_pBuffer + m_Position++);
159}
160//////////////////////////////////////////////////////////
161char * CxMemFile::GetS(char *string, int n)
162{
163 n--;
164 long c,i=0;
165 while (i<n){
166 c = GetC();
167 if (c == EOF) return 0;
168 string[i++] = (char)c;
169 if (c == '\n') break;
170 }
171 string[i] = 0;
172 return string;
173}
174//////////////////////////////////////////////////////////
175long CxMemFile::Scanf(const char *format, void* output)
176{
177 return 0;
178}
179//////////////////////////////////////////////////////////
180bool CxMemFile::Alloc(DWORD dwNewLen)
181{
182 if (dwNewLen > (DWORD)m_Edge)
183 {
184 // find new buffer size
185 DWORD dwNewBufferSize = (DWORD)(((dwNewLen>>16)+1)<<16);
186
187 // allocate new buffer
188 if (m_pBuffer == NULL) m_pBuffer = (BYTE*)malloc(dwNewBufferSize);
189 else m_pBuffer = (BYTE*)realloc(m_pBuffer, dwNewBufferSize);
190 // I own this buffer now (caller knows nothing about it)
191 m_bFreeOnClose = true;
192
193 m_Edge = dwNewBufferSize;
194 }
195 return (m_pBuffer!=0);
196}
197//////////////////////////////////////////////////////////
198void CxMemFile::Free()
199{
200 Close();
201}
202//////////////////////////////////////////////////////////
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