1 /////////////////////////////////////////////////////////////////////////////
2 // Name: src/common/mstream.cpp
3 // Purpose: "Memory stream" classes
4 // Author: Guilhem Lavaux
5 // Modified by: VZ (23.11.00): general code review
6 // Created: 04/01/98
7 // Copyright: (c) Guilhem Lavaux
8 // Licence: wxWindows licence
9 /////////////////////////////////////////////////////////////////////////////
10
11 // ============================================================================
12 // declarations
13 // ============================================================================
14
15 // ----------------------------------------------------------------------------
16 // headers
17 // ----------------------------------------------------------------------------
18
19 // For compilers that support precompilation, includes "wx.h".
20 #include "wx/wxprec.h"
21
22
23 #if wxUSE_STREAMS
24
25 #include "wx/mstream.h"
26
27 #ifndef WX_PRECOMP
28 #include "wx/stream.h"
29 #endif //WX_PRECOMP
30
31 #include <stdlib.h>
32
33 // ============================================================================
34 // implementation
35 // ============================================================================
36
37 // ----------------------------------------------------------------------------
38 // wxMemoryInputStream
39 // ----------------------------------------------------------------------------
40
41 wxIMPLEMENT_ABSTRACT_CLASS(wxMemoryInputStream, wxInputStream);
42
wxMemoryInputStream(const void * data,size_t len)43 wxMemoryInputStream::wxMemoryInputStream(const void *data, size_t len)
44 {
45 m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
46 m_i_streambuf->SetBufferIO(const_cast<void *>(data), len);
47 m_i_streambuf->SetIntPosition(0); // seek to start pos
48 m_i_streambuf->Fixed(true);
49
50 m_length = len;
51 }
52
wxMemoryInputStream(const wxMemoryOutputStream & stream)53 wxMemoryInputStream::wxMemoryInputStream(const wxMemoryOutputStream& stream)
54 {
55 const wxFileOffset lenFile = stream.GetLength();
56 if ( lenFile == wxInvalidOffset )
57 {
58 m_i_streambuf = NULL;
59 m_lasterror = wxSTREAM_EOF;
60 return;
61 }
62
63 const size_t len = wx_truncate_cast(size_t, lenFile);
64 wxASSERT_MSG( len == lenFile + size_t(0), wxT("huge files not supported") );
65
66 m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
67 m_i_streambuf->SetBufferIO(len); // create buffer
68 stream.CopyTo(m_i_streambuf->GetBufferStart(), len);
69 m_i_streambuf->SetIntPosition(0); // seek to start pos
70 m_i_streambuf->Fixed(true);
71 m_length = len;
72 }
73
74 void
InitFromStream(wxInputStream & stream,wxFileOffset lenFile)75 wxMemoryInputStream::InitFromStream(wxInputStream& stream, wxFileOffset lenFile)
76 {
77 if ( lenFile == wxInvalidOffset )
78 lenFile = stream.GetLength();
79
80 if ( lenFile == wxInvalidOffset )
81 {
82 m_i_streambuf = NULL;
83 m_lasterror = wxSTREAM_EOF;
84 return;
85 }
86
87 const size_t len = wx_truncate_cast(size_t, lenFile);
88 wxASSERT_MSG( (wxFileOffset)len == lenFile, wxT("huge files not supported") );
89
90 m_i_streambuf = new wxStreamBuffer(wxStreamBuffer::read);
91 m_i_streambuf->SetBufferIO(len); // create buffer
92 stream.Read(m_i_streambuf->GetBufferStart(), len);
93 m_i_streambuf->SetIntPosition(0); // seek to start pos
94 m_i_streambuf->Fixed(true);
95 m_length = stream.LastRead();
96 }
97
CanRead() const98 bool wxMemoryInputStream::CanRead() const
99 {
100 return m_i_streambuf->GetIntPosition() != m_length;
101 }
102
~wxMemoryInputStream()103 wxMemoryInputStream::~wxMemoryInputStream()
104 {
105 delete m_i_streambuf;
106 }
107
Peek()108 char wxMemoryInputStream::Peek()
109 {
110 char *buf = (char *)m_i_streambuf->GetBufferStart();
111 size_t pos = m_i_streambuf->GetIntPosition();
112 if ( pos == m_length )
113 {
114 m_lasterror = wxSTREAM_READ_ERROR;
115
116 return 0;
117 }
118
119 return buf[pos];
120 }
121
OnSysRead(void * buffer,size_t nbytes)122 size_t wxMemoryInputStream::OnSysRead(void *buffer, size_t nbytes)
123 {
124 size_t pos = m_i_streambuf->GetIntPosition();
125 if ( pos == m_length )
126 {
127 m_lasterror = wxSTREAM_EOF;
128
129 return 0;
130 }
131
132 m_i_streambuf->Read(buffer, nbytes);
133 m_lasterror = wxSTREAM_NO_ERROR;
134
135 return m_i_streambuf->GetIntPosition() - pos;
136 }
137
OnSysSeek(wxFileOffset pos,wxSeekMode mode)138 wxFileOffset wxMemoryInputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
139 {
140 return m_i_streambuf->Seek(pos, mode);
141 }
142
OnSysTell() const143 wxFileOffset wxMemoryInputStream::OnSysTell() const
144 {
145 return m_i_streambuf->Tell();
146 }
147
148 // ----------------------------------------------------------------------------
149 // wxMemoryOutputStream
150 // ----------------------------------------------------------------------------
151
152 wxIMPLEMENT_DYNAMIC_CLASS(wxMemoryOutputStream, wxOutputStream);
153
wxMemoryOutputStream(void * data,size_t len)154 wxMemoryOutputStream::wxMemoryOutputStream(void *data, size_t len)
155 {
156 m_o_streambuf = new wxStreamBuffer(wxStreamBuffer::write);
157 if ( data )
158 m_o_streambuf->SetBufferIO(data, len);
159 m_o_streambuf->Fixed(false);
160 m_o_streambuf->Flushable(false);
161 }
162
~wxMemoryOutputStream()163 wxMemoryOutputStream::~wxMemoryOutputStream()
164 {
165 delete m_o_streambuf;
166 }
167
OnSysWrite(const void * buffer,size_t nbytes)168 size_t wxMemoryOutputStream::OnSysWrite(const void *buffer, size_t nbytes)
169 {
170 size_t oldpos = m_o_streambuf->GetIntPosition();
171 m_o_streambuf->Write(buffer, nbytes);
172 size_t newpos = m_o_streambuf->GetIntPosition();
173
174 // FIXME can someone please explain what this does? (VZ)
175 if ( !newpos )
176 newpos = m_o_streambuf->GetBufferSize();
177
178 return newpos - oldpos;
179 }
180
OnSysSeek(wxFileOffset pos,wxSeekMode mode)181 wxFileOffset wxMemoryOutputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
182 {
183 return m_o_streambuf->Seek(pos, mode);
184 }
185
OnSysTell() const186 wxFileOffset wxMemoryOutputStream::OnSysTell() const
187 {
188 return m_o_streambuf->Tell();
189 }
190
CopyTo(void * buffer,size_t len) const191 size_t wxMemoryOutputStream::CopyTo(void *buffer, size_t len) const
192 {
193 wxCHECK_MSG( buffer, 0, wxT("must have buffer to CopyTo") );
194
195 if ( len > GetSize() )
196 len = GetSize();
197
198 memcpy(buffer, m_o_streambuf->GetBufferStart(), len);
199
200 return len;
201 }
202
203 #endif // wxUSE_STREAMS
204