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4<dl><dt>
5
6  <b>class c4_Strategy</b>
7<br><br>
8
9<dd><font face=Times size=3>
10A strategy encapsulates code dealing with the I/O system interface.<br><br>
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12
13</font></dl>
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15
16  <table cellborder=0>
17    <tr>
18    <td colspan=2>
19	  <font face=Helvetica size=-1><b>Public members</b></font>
20    </td>
21	</tr>
22  
23    <tr>
24    <td valign=top align=right width=150>
25	  
26    </td>
27	<td>
28	  <nobr>
29	  <b>c4_Strategy</b> ();
30	  
31	  
32		
33	</td>
34	</tr>
35  
36    <tr>
37    <td valign=top align=right width=150>
38	  virtual 
39    </td>
40	<td>
41	  <nobr>
42	  <b>~c4_Strategy</b> ();
43	  
44	  
45		
46	</td>
47	</tr>
48  
49    <tr>
50    <td valign=top align=right width=150>
51	  virtual bool 
52    </td>
53	<td>
54	  <nobr>
55	  <b>IsValid</b> () <i>const</i>;
56	  
57	  
58		<font face=Helvetica size=-1><br>
59			True if we can do I/O with this object</font>
60	</td>
61	</tr>
62  
63    <tr>
64    <td valign=top align=right width=150>
65	  virtual void 
66    </td>
67	<td>
68	  <nobr>
69	  <b>DataSeek</b> (t4_i32 position_);
70	  
71	  
72		<font face=Helvetica size=-1><br>
73			Set file position</font>
74	</td>
75	</tr>
76  
77    <tr>
78    <td valign=top align=right width=150>
79	  virtual int 
80    </td>
81	<td>
82	  <nobr>
83	  <b>DataRead</b> (void* buffer_, int length_);
84	  
85	  
86		<font face=Helvetica size=-1><br>
87			Read a number of bytes</font>
88	</td>
89	</tr>
90  
91    <tr>
92    <td valign=top align=right width=150>
93	  void 
94    </td>
95	<td>
96	  <nobr>
97	  <b>DataLoad</b> (void* buffer_, int length_);
98	  
99	  
100		<font face=Helvetica size=-1><br>
101			Read an exact number of bytes</font>
102	</td>
103	</tr>
104  
105    <tr>
106    <td valign=top align=right width=150>
107	  virtual bool 
108    </td>
109	<td>
110	  <nobr>
111	  <b>DataWrite</b> (const void* buffer_, int length_);
112	  
113	  
114		<font face=Helvetica size=-1><br>
115			Write a number of bytes, return true if successful</font>
116	</td>
117	</tr>
118  
119    <tr>
120    <td valign=top align=right width=150>
121	  virtual void 
122    </td>
123	<td>
124	  <nobr>
125	  <b>DataCommit</b> (t4_i32 newSize_);
126	  
127	  
128		<font face=Helvetica size=-1><br>
129			Flush and truncate file</font>
130	</td>
131	</tr>
132  
133    <tr>
134    <td valign=top align=right width=150>
135	  virtual void 
136    </td>
137	<td>
138	  <nobr>
139	  <b>ResetFileMapping</b> ();
140	  
141	  
142		<font face=Helvetica size=-1><br>
143			Override to support memory-mapped files</font>
144	</td>
145	</tr>
146  
147    <tr>
148    <td valign=top align=right width=150>
149	  bool 
150    </td>
151	<td>
152	  <nobr>
153	  <b>_keepAfterCommit</b>;
154	  
155	  
156		<font face=Helvetica size=-1><br>
157			Keep data in memory after each commit (default is false)</font>
158	</td>
159	</tr>
160  
161    <tr>
162    <td valign=top align=right width=150>
163	  bool 
164    </td>
165	<td>
166	  <nobr>
167	  <b>_bytesFlipped</b>;
168	  
169	  
170		<font face=Helvetica size=-1><br>
171			True if the storage format is not native (default is false)</font>
172	</td>
173	</tr>
174  
175    <tr>
176    <td valign=top align=right width=150>
177	  int 
178    </td>
179	<td>
180	  <nobr>
181	  <b>_failure</b>;
182	  
183	  
184		<font face=Helvetica size=-1><br>
185			Error code of last failed I/O operation, zero if I/O was ok</font>
186	</td>
187	</tr>
188  
189    <tr>
190    <td valign=top align=right width=150>
191	  const t4_byte* 
192    </td>
193	<td>
194	  <nobr>
195	  <b>_mapStart</b>;
196	  
197	  
198		<font face=Helvetica size=-1><br>
199			First byte in file mapping, zero if not active</font>
200	</td>
201	</tr>
202  
203    <tr>
204    <td valign=top align=right width=150>
205	  const t4_byte* 
206    </td>
207	<td>
208	  <nobr>
209	  <b>_mapLimit</b>;
210	  
211	  
212		<font face=Helvetica size=-1><br>
213			Past last byte in file mapping, zero if not active</font>
214	</td>
215	</tr>
216  
217  </table>
218
219
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223
224<br><hr size=1 width=50 align=left>
225
226<table cellborder=0>
227    <tr>
228    <td width=150>
229	  <font face=Helvetica size=-1><b>Header file</b></font>
230    </td>
231    <td>
232	  "mk4.h" &nbsp; -- &nbsp; Dec 9, 1999
233    </td>
234	</tr>
235
236  
237
238  
239</table>
240
241</font></font>
242
243</nobr></body></html>
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