1 | /* |
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2 | * Finding the Driving Distance (isochrone/isodist) for PostgreSQL |
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3 | * |
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4 | * Copyright (c) 2006 Mario H. Basa, Orkney, Inc. |
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5 | * |
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6 | * This program is free software; you can redistribute it and/or modify |
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7 | * it under the terms of the GNU General Public License as published by |
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8 | * the Free Software Foundation; either version 2 of the License, or |
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9 | * (at your option) any later version. |
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10 | * |
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11 | * This program is distributed in the hope that it will be useful, |
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12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | * GNU General Public License for more details. |
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15 | * |
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16 | * You should have received a copy of the GNU General Public License |
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17 | * along with this program; if not, write to the Free Software |
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18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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19 | * |
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20 | */ |
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21 | |
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22 | #include "postgres.h" |
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23 | #include "executor/spi.h" |
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24 | #include "funcapi.h" |
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25 | |
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26 | #include "drivedist.h" |
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27 | |
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28 | //--------------------------------------------------------------------------- |
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29 | |
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30 | /* |
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31 | * Define this to have profiling enabled |
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32 | */ |
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33 | //#define PROFILE |
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34 | |
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35 | #ifdef PROFILE |
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36 | #include <sys/time.h> |
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37 | |
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38 | struct timeval prof_dijkstra, prof_store, prof_extract, prof_total; |
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39 | long proftime[5]; |
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40 | long profipts1, profipts2, profopts; |
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41 | #define profstart(x) do { gettimeofday(&x, NULL); } while (0); |
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42 | #define profstop(n, x) do { struct timeval _profstop; \ |
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43 | long _proftime; \ |
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44 | gettimeofday(&_profstop, NULL); \ |
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45 | _proftime = ( _profstop.tv_sec*1000000+_profstop.tv_usec) - \ |
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46 | ( x.tv_sec*1000000+x.tv_usec); \ |
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47 | elog(NOTICE, \ |
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48 | "PRF(%s) %lu (%f ms)", \ |
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49 | (n), \ |
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50 | _proftime, _proftime / 1000.0); \ |
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51 | } while (0); |
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52 | |
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53 | #else |
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54 | |
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55 | #define profstart(x) do { } while (0); |
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56 | #define profstop(n, x) do { } while (0); |
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57 | |
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58 | #endif // PROFILE |
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59 | |
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60 | |
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61 | //---------------------------------------------------------------------------- |
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62 | |
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63 | Datum driving_distance(PG_FUNCTION_ARGS); |
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64 | |
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65 | #undef DEBUG |
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66 | //#define DEBUG 1 |
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67 | |
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68 | #ifdef DEBUG |
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69 | #define DBG(format, arg...) \ |
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70 | elog(NOTICE, format , ## arg) |
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71 | #else |
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72 | #define DBG(format, arg...) do { ; } while (0) |
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73 | #endif |
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74 | |
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75 | // The number of tuples to fetch from the SPI cursor at each iteration |
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76 | #define TUPLIMIT 1000 |
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77 | |
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78 | static char * |
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79 | text2char(text *in) |
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80 | { |
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81 | char *out = palloc(VARSIZE(in)); |
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82 | |
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83 | memcpy(out, VARDATA(in), VARSIZE(in) - VARHDRSZ); |
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84 | out[VARSIZE(in) - VARHDRSZ] = '\0'; |
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85 | return out; |
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86 | } |
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87 | |
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88 | static int |
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89 | finish(int code, int ret) |
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90 | { |
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91 | code = SPI_finish(); |
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92 | if (code != SPI_OK_FINISH ) |
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93 | { |
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94 | elog(ERROR,"couldn't disconnect from SPI"); |
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95 | return -1 ; |
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96 | } |
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97 | |
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98 | return ret; |
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99 | } |
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100 | |
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101 | |
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102 | typedef struct edge_columns |
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103 | { |
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104 | int id; |
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105 | int source; |
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106 | int target; |
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107 | int cost; |
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108 | int reverse_cost; |
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109 | } edge_columns_t; |
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110 | |
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111 | static int |
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112 | fetch_edge_columns(SPITupleTable *tuptable, edge_columns_t *edge_columns, |
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113 | bool has_reverse_cost) |
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114 | { |
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115 | edge_columns->id = SPI_fnumber(SPI_tuptable->tupdesc, "id"); |
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116 | edge_columns->source = SPI_fnumber(SPI_tuptable->tupdesc, "source"); |
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117 | edge_columns->target = SPI_fnumber(SPI_tuptable->tupdesc, "target"); |
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118 | edge_columns->cost = SPI_fnumber(SPI_tuptable->tupdesc, "cost"); |
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119 | |
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120 | if (edge_columns->id == SPI_ERROR_NOATTRIBUTE || |
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121 | edge_columns->source == SPI_ERROR_NOATTRIBUTE || |
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122 | edge_columns->target == SPI_ERROR_NOATTRIBUTE || |
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123 | edge_columns->cost == SPI_ERROR_NOATTRIBUTE) { |
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124 | elog(ERROR, "Error, query must return columns " |
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125 | "'id', 'source', 'target' and 'cost'"); |
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126 | return -1; |
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127 | } |
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128 | |
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129 | if (SPI_gettypeid(SPI_tuptable->tupdesc, edge_columns->source) != INT4OID || |
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130 | SPI_gettypeid(SPI_tuptable->tupdesc, edge_columns->target) != INT4OID || |
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131 | SPI_gettypeid(SPI_tuptable->tupdesc, edge_columns->cost) != FLOAT8OID) { |
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132 | elog(ERROR, "Error, columns 'source', 'target' must be of type int4, 'cost' must be of type float8"); |
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133 | return -1; |
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134 | } |
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135 | |
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136 | DBG("columns: id %i source %i target %i cost %i", |
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137 | edge_columns->id, edge_columns->source, |
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138 | edge_columns->target, edge_columns->cost); |
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139 | |
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140 | if (has_reverse_cost) { |
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141 | edge_columns->reverse_cost = SPI_fnumber(SPI_tuptable->tupdesc, |
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142 | "reverse_cost"); |
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143 | |
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144 | if (edge_columns->reverse_cost == SPI_ERROR_NOATTRIBUTE) { |
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145 | elog(ERROR, "Error, reverse_cost is used, but query did't return " |
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146 | "'reverse_cost' column"); |
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147 | return -1; |
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148 | } |
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149 | |
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150 | if (SPI_gettypeid(SPI_tuptable->tupdesc, |
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151 | edge_columns->reverse_cost) != FLOAT8OID) { |
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152 | elog(ERROR, "Error, columns 'reverse_cost' must be of type float8"); |
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153 | return -1; |
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154 | } |
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155 | |
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156 | DBG("columns: reverse_cost cost %i", edge_columns->reverse_cost); |
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157 | } |
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158 | |
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159 | return 0; |
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160 | } |
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161 | |
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162 | static void |
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163 | fetch_edge(HeapTuple *tuple, TupleDesc *tupdesc, edge_columns_t *edge_columns, |
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164 | edge_t *target_edge) |
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165 | { |
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166 | Datum binval; |
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167 | bool isnull; |
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168 | |
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169 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->id, &isnull); |
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170 | |
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171 | if (isnull) |
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172 | elog(ERROR, "id contains a null value"); |
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173 | target_edge->id = DatumGetInt32(binval); |
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174 | |
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175 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->source, &isnull); |
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176 | |
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177 | if (isnull) |
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178 | elog(ERROR, "source contains a null value"); |
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179 | |
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180 | target_edge->source = DatumGetInt32(binval); |
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181 | |
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182 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->target, &isnull); |
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183 | |
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184 | if (isnull) |
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185 | elog(ERROR, "target contains a null value"); |
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186 | |
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187 | target_edge->target = DatumGetInt32(binval); |
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188 | |
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189 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->cost, &isnull); |
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190 | |
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191 | if (isnull) |
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192 | elog(ERROR, "cost contains a null value"); |
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193 | |
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194 | target_edge->cost = DatumGetFloat8(binval); |
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195 | |
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196 | if (edge_columns->reverse_cost != -1) { |
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197 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->reverse_cost, |
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198 | &isnull); |
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199 | |
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200 | if (isnull) |
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201 | elog(ERROR, "reverse_cost contains a null value"); |
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202 | target_edge->reverse_cost = DatumGetFloat8(binval); |
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203 | } |
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204 | } |
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205 | |
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206 | |
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207 | static int compute_driving_distance(char* sql, int source_vertex_id, |
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208 | float8 distance, bool directed, |
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209 | bool has_reverse_cost, |
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210 | path_element_t **path, int *path_count) |
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211 | { |
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212 | int SPIcode; |
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213 | void *SPIplan; |
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214 | Portal SPIportal; |
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215 | bool moredata = TRUE; |
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216 | int ntuples; |
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217 | edge_t *edges = NULL; |
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218 | int total_tuples = 0; |
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219 | edge_columns_t edge_columns = {id: -1, source: -1, target: -1, |
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220 | cost: -1, reverse_cost: -1}; |
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221 | |
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222 | int v_max_id=0; |
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223 | int v_min_id=INT_MAX; |
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224 | |
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225 | char *err_msg; |
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226 | int ret = -1; |
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227 | |
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228 | int s_count = 0; |
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229 | |
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230 | register int z; |
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231 | |
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232 | DBG("start driving_distance\n"); |
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233 | |
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234 | SPIcode = SPI_connect(); |
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235 | if (SPIcode != SPI_OK_CONNECT) { |
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236 | elog(ERROR, "driving_distance: couldn't open a connection to SPI"); |
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237 | return -1; |
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238 | } |
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239 | |
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240 | SPIplan = SPI_prepare(sql, 0, NULL); |
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241 | |
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242 | if (SPIplan == NULL) { |
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243 | elog(ERROR, "driving_distance: couldn't create query plan via SPI"); |
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244 | return -1; |
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245 | } |
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246 | |
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247 | if ((SPIportal = SPI_cursor_open(NULL, SPIplan, NULL, |
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248 | NULL, true)) == NULL) { |
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249 | elog(ERROR, "driving_distance: SPI_cursor_open('%s') returns NULL", sql); |
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250 | return -1; |
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251 | } |
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252 | |
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253 | while (moredata == TRUE) { |
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254 | SPI_cursor_fetch(SPIportal, TRUE, TUPLIMIT); |
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255 | |
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256 | |
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257 | if (edge_columns.id == -1) { |
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258 | if (fetch_edge_columns(SPI_tuptable, &edge_columns, |
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259 | has_reverse_cost) == -1) |
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260 | return finish(SPIcode, ret); |
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261 | } |
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262 | |
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263 | ntuples = SPI_processed; |
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264 | total_tuples += ntuples; |
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265 | if (!edges) |
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266 | edges = palloc(total_tuples * sizeof(edge_t)); |
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267 | else |
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268 | edges = repalloc(edges, total_tuples * sizeof(edge_t)); |
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269 | |
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270 | if (edges == NULL) { |
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271 | elog(ERROR, "Out of memory"); |
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272 | return finish(SPIcode, ret); |
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273 | } |
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274 | |
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275 | if (ntuples > 0) { |
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276 | int t; |
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277 | SPITupleTable *tuptable = SPI_tuptable; |
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278 | TupleDesc tupdesc = SPI_tuptable->tupdesc; |
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279 | |
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280 | for (t = 0; t < ntuples; t++) { |
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281 | HeapTuple tuple = tuptable->vals[t]; |
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282 | fetch_edge(&tuple, &tupdesc, &edge_columns, |
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283 | &edges[total_tuples - ntuples + t]); |
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284 | } |
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285 | SPI_freetuptable(tuptable); |
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286 | } |
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287 | else { |
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288 | moredata = FALSE; |
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289 | } |
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290 | } |
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291 | |
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292 | |
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293 | //defining min and max vertex id |
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294 | |
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295 | DBG("Total %i tuples", total_tuples); |
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296 | |
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297 | for(z=0; z<total_tuples; z++) |
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298 | { |
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299 | if(edges[z].source<v_min_id) |
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300 | v_min_id=edges[z].source; |
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301 | |
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302 | if(edges[z].source>v_max_id) |
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303 | v_max_id=edges[z].source; |
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304 | |
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305 | if(edges[z].target<v_min_id) |
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306 | v_min_id=edges[z].target; |
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307 | |
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308 | if(edges[z].target>v_max_id) |
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309 | v_max_id=edges[z].target; |
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310 | |
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311 | DBG("%i <-> %i", v_min_id, v_max_id); |
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312 | |
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313 | } |
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314 | |
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315 | //:::::::::::::::::::::::::::::::::::: |
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316 | //:: reducing vertex id (renumbering) |
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317 | //:::::::::::::::::::::::::::::::::::: |
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318 | for(z=0; z<total_tuples; z++) |
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319 | { |
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320 | //check if edges[] contains source |
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321 | if(edges[z].source == source_vertex_id || |
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322 | edges[z].target == source_vertex_id) |
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323 | ++s_count; |
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324 | |
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325 | edges[z].source-=v_min_id; |
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326 | edges[z].target-=v_min_id; |
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327 | DBG("%i - %i", edges[z].source, edges[z].target); |
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328 | } |
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329 | |
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330 | if(s_count == 0) |
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331 | { |
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332 | elog(ERROR, "Start vertex was not found."); |
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333 | return -1; |
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334 | } |
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335 | |
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336 | source_vertex_id -= v_min_id; |
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337 | |
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338 | DBG("Calling boost_dijkstra\n"); |
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339 | |
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340 | profstop("extract", prof_extract); |
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341 | profstart(prof_dijkstra); |
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342 | |
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343 | ret = boost_dijkstra_dist(edges, total_tuples, source_vertex_id, |
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344 | distance, directed, has_reverse_cost, |
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345 | path, path_count, &err_msg); |
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346 | |
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347 | profstop("dijkstra", prof_dijkstra); |
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348 | profstart(prof_store); |
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349 | |
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350 | //:::::::::::::::::::::::::::::::: |
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351 | //:: restoring original vertex id |
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352 | //:::::::::::::::::::::::::::::::: |
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353 | for(z=0;z<*path_count;z++) |
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354 | { |
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355 | //DBG("vetex %i\n",(*path)[z].vertex_id); |
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356 | (*path)[z].vertex_id+=v_min_id; |
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357 | } |
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358 | |
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359 | if (ret < 0) { |
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360 | //elog(ERROR, "Error computing path: %s", err_msg); |
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361 | ereport(ERROR, (errcode(ERRCODE_E_R_E_CONTAINING_SQL_NOT_PERMITTED), |
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362 | errmsg("Error computing path: %s", err_msg))); |
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363 | } |
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364 | |
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365 | return finish(SPIcode, ret); |
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366 | } |
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367 | |
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368 | |
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369 | PG_FUNCTION_INFO_V1(driving_distance); |
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370 | Datum |
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371 | driving_distance(PG_FUNCTION_ARGS) |
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372 | { |
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373 | FuncCallContext *funcctx; |
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374 | int call_cntr; |
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375 | int max_calls; |
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376 | TupleDesc tuple_desc; |
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377 | path_element_t *path; |
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378 | |
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379 | /* stuff done only on the first call of the function */ |
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380 | if (SRF_IS_FIRSTCALL()) { |
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381 | MemoryContext oldcontext; |
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382 | int path_count = 0; |
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383 | int ret; |
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384 | |
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385 | // XXX profiling messages are not thread safe |
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386 | profstart(prof_total); |
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387 | profstart(prof_extract); |
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388 | |
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389 | /* create a function context for cross-call persistence */ |
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390 | funcctx = SRF_FIRSTCALL_INIT(); |
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391 | |
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392 | /* switch to memory context appropriate for multiple function calls */ |
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393 | oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx); |
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394 | |
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395 | ret = compute_driving_distance(text2char(PG_GETARG_TEXT_P(0)), // sql |
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396 | PG_GETARG_INT32(1), // source vertex |
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397 | PG_GETARG_FLOAT8(2), // distance or time |
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398 | PG_GETARG_BOOL(3), |
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399 | PG_GETARG_BOOL(4), &path, &path_count); |
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400 | |
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401 | #ifdef DEBUG |
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402 | DBG("Ret is %i", ret); |
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403 | if (ret >= 0) { |
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404 | int i; |
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405 | for (i = 0; i < path_count; i++) { |
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406 | DBG("Step %i vertex_id %i ", i, path[i].vertex_id); |
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407 | DBG(" edge_id %i ", path[i].edge_id); |
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408 | DBG(" cost %f ", path[i].cost); |
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409 | } |
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410 | } |
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411 | #endif |
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412 | |
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413 | /* total number of tuples to be returned */ |
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414 | funcctx->max_calls = path_count; |
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415 | funcctx->user_fctx = path; |
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416 | |
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417 | funcctx->tuple_desc = BlessTupleDesc( |
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418 | RelationNameGetTupleDesc("path_result")); |
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419 | |
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420 | MemoryContextSwitchTo(oldcontext); |
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421 | } |
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422 | |
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423 | /* stuff done on every call of the function */ |
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424 | funcctx = SRF_PERCALL_SETUP(); |
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425 | |
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426 | call_cntr = funcctx->call_cntr; |
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427 | max_calls = funcctx->max_calls; |
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428 | tuple_desc = funcctx->tuple_desc; |
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429 | path = (path_element_t*) funcctx->user_fctx; |
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430 | |
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431 | if (call_cntr < max_calls) { /* do when there is more left to send */ |
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432 | HeapTuple tuple; |
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433 | Datum result; |
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434 | Datum *values; |
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435 | char* nulls; |
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436 | |
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437 | /* This will work for some compilers. If it crashes with segfault, try to change the following block with this one |
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438 | |
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439 | values = palloc(4 * sizeof(Datum)); |
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440 | nulls = palloc(4 * sizeof(char)); |
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441 | |
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442 | values[0] = call_cntr; |
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443 | nulls[0] = ' '; |
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444 | values[1] = Int32GetDatum(path[call_cntr].vertex_id); |
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445 | nulls[1] = ' '; |
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446 | values[2] = Int32GetDatum(path[call_cntr].edge_id); |
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447 | nulls[2] = ' '; |
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448 | values[3] = Float8GetDatum(path[call_cntr].cost); |
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449 | nulls[3] = ' '; |
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450 | */ |
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451 | |
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452 | values = palloc(3 * sizeof(Datum)); |
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453 | nulls = palloc(3 * sizeof(char)); |
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454 | |
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455 | values[0] = Int32GetDatum(path[call_cntr].vertex_id); |
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456 | nulls[0] = ' '; |
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457 | values[1] = Int32GetDatum(path[call_cntr].edge_id); |
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458 | nulls[1] = ' '; |
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459 | values[2] = Float8GetDatum(path[call_cntr].cost); |
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460 | nulls[2] = ' '; |
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461 | |
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462 | tuple = heap_formtuple(tuple_desc, values, nulls); |
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463 | |
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464 | |
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465 | /* make the tuple into a datum */ |
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466 | result = HeapTupleGetDatum(tuple); |
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467 | |
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468 | /* clean up (this is not really necessary) */ |
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469 | pfree(values); |
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470 | pfree(nulls); |
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471 | |
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472 | SRF_RETURN_NEXT(funcctx, result); |
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473 | } |
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474 | else { /* do when there is no more left */ |
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475 | profstop("store", prof_store); |
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476 | profstop("total", prof_total); |
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477 | #ifdef PROFILE |
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478 | elog(NOTICE, "_________"); |
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479 | #endif |
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480 | DBG("Returning value"); |
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481 | |
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482 | SRF_RETURN_DONE(funcctx); |
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483 | } |
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484 | } |
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