1<html><head><base target=k-main></head><body bgcolor=white><nobr> 2 3<font face=Helvetica size=3> 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> 11 12 13</font></dl> 14 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> 218 219 220 221 222 223 224<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" -- Dec 9, 1999 233 </td> 234 </tr> 235 236 237 238 239</table> 240 241</font></font> 242 243</nobr></body></html> 244