| … | |
… | |
| 88 | |
88 | |
| 89 | void |
89 | void |
| 90 | MTfile::Close() |
90 | MTfile::Close() |
| 91 | { |
91 | { |
| 92 | if(!IsOpen()) return; |
92 | if(!IsOpen()) return; |
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93 | Sync(); |
| 93 | close(fileHandle); |
94 | close(fileHandle); |
| 94 | SetOpen(0); |
95 | SetOpen(0); |
| 95 | } |
96 | } |
| 96 | |
97 | |
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98 | MTfile::~MTfile() |
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99 | { |
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100 | setcache (0); |
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101 | } |
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102 | |
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103 | void MTfile::setcache(unsigned int pages) |
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104 | { |
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105 | Sync(); |
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106 | |
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107 | if (cachesize) |
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108 | { |
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109 | for (int i = cachesize; i--; ) |
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110 | delete [] cache[i].buf; |
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111 | |
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112 | delete [] cache; |
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113 | } |
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114 | |
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115 | cachesize = pages; |
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116 | |
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117 | if (cachesize) |
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118 | { |
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119 | cache = new Page[pages]; |
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120 | for (int i = cachesize; i--; ) |
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121 | { |
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122 | cache[i].seq = 0; |
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123 | cache[i].dirty = 0; |
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124 | cache[i].page = (GiSTpage) -1; |
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125 | cache[i].buf = new char[PageSize()]; |
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126 | } |
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127 | } |
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128 | } |
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129 | |
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130 | static unsigned int seq; |
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131 | |
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132 | MTfile::Page *MTfile::newpage(GiSTpage page) |
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133 | { |
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134 | Page *p = &cache[0]; |
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135 | |
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136 | for (int i = cachesize; --i; ) { |
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137 | if (cache[i].seq < p->seq) |
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138 | p = &cache[i]; |
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139 | } |
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140 | |
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141 | if (p->dirty) |
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142 | flushpage (p); |
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143 | |
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144 | p->seq = ++seq; |
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145 | //min->dirty = 0; |
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146 | p->page = page; |
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147 | |
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148 | return p; |
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149 | } |
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150 | |
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151 | MTfile::Page *MTfile::findpage(GiSTpage page) |
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152 | { |
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153 | for (int i = cachesize; i--; ) |
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154 | if (cache[i].page == page) |
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155 | return &cache[i]; |
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156 | |
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157 | return 0; |
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158 | } |
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159 | |
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160 | void MTfile::flushpage(Page *p) |
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161 | { |
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162 | assert (IsOpen()); |
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163 | lseek (fileHandle, p->page*PageSize(), SEEK_SET); |
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164 | write (fileHandle, p->buf, PageSize()); |
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165 | p->dirty = 0; |
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166 | IOwrite++; |
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167 | } |
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168 | |
| 97 | void |
169 | void |
| 98 | MTfile::Read(GiSTpage page, char *buf) |
170 | MTfile::Read(GiSTpage page, char *buf) |
| 99 | { |
171 | { |
| 100 | if(IsOpen()) { |
172 | if(IsOpen()) { |
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173 | Page *p = findpage (page); |
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174 | |
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175 | if (p) |
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176 | { |
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177 | p->seq = ++seq; |
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178 | memcpy (buf, p->buf, PageSize ()); |
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179 | return; |
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180 | } |
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181 | |
| 101 | lseek(fileHandle, page*PageSize(), SEEK_SET); |
182 | lseek(fileHandle, page*PageSize(), SEEK_SET); |
| 102 | read(fileHandle, buf, PageSize()); |
183 | read(fileHandle, buf, PageSize()); |
| 103 | IOread++; |
184 | IOread++; |
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185 | |
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186 | p = newpage (page); |
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187 | |
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188 | memcpy (p->buf, buf, PageSize()); |
| 104 | } |
189 | } |
| 105 | } |
190 | } |
| 106 | |
191 | |
| 107 | void |
192 | void |
| 108 | MTfile::Write(GiSTpage page, const char *buf) |
193 | MTfile::Write(GiSTpage page, const char *buf) |
| 109 | { |
194 | { |
| 110 | if(IsOpen()) { |
195 | Page *p = findpage (page); |
| 111 | lseek(fileHandle, page*PageSize(), SEEK_SET); |
196 | |
| 112 | write(fileHandle, buf, PageSize()); |
197 | if (!p) |
| 113 | IOwrite++; |
198 | p = newpage (page); |
| 114 | } |
199 | |
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200 | memcpy (p->buf, buf, PageSize ()); |
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201 | p->seq = ++seq; |
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202 | p->dirty++; |
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203 | } |
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204 | |
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205 | void MTfile::Sync() |
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206 | { |
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207 | for (int i = cachesize; i--; ) |
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208 | if (cache[i].dirty) |
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209 | flushpage (&cache[i]); |
| 115 | } |
210 | } |
| 116 | |
211 | |
| 117 | GiSTpage |
212 | GiSTpage |
| 118 | MTfile::Allocate() |
213 | MTfile::Allocate() |
| 119 | { |
214 | { |
