1 | /* |
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2 | * Shooting* Shortest path algorithm for PostgreSQL |
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3 | * |
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4 | * Copyright (c) 2007 Anton A. Patrushev, 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 <stdio.h> |
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27 | #include <stdlib.h> |
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28 | #include <search.h> |
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29 | |
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30 | #include <string.h> |
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31 | #include <time.h> |
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32 | |
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33 | #include "shooting_star.h" |
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34 | |
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35 | //------------------------------------------------------------------------- |
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36 | |
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37 | Datum shortest_path_shooting_star(PG_FUNCTION_ARGS); |
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38 | |
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39 | #undef DEBUG |
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40 | //#define DEBUG 1 |
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41 | |
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42 | #ifdef DEBUG |
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43 | #define DBG(format, arg...) \ |
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44 | elog(NOTICE, format , ## arg) |
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45 | #else |
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46 | #define DBG(format, arg...) do { ; } while (0) |
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47 | #endif |
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48 | |
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49 | // The number of tuples to fetch from the SPI cursor at each iteration |
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50 | #define TUPLIMIT 1000 |
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51 | |
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52 | static char * |
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53 | text2char(text *in) |
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54 | { |
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55 | char *out = palloc(VARSIZE(in)); |
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56 | |
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57 | memcpy(out, VARDATA(in), VARSIZE(in) - VARHDRSZ); |
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58 | out[VARSIZE(in) - VARHDRSZ] = '\0'; |
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59 | return out; |
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60 | } |
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61 | |
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62 | static int |
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63 | finish(int code, int ret) |
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64 | { |
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65 | code = SPI_finish(); |
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66 | if (code != SPI_OK_FINISH ) |
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67 | { |
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68 | elog(ERROR,"couldn't disconnect from SPI"); |
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69 | return -1 ; |
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70 | } |
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71 | |
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72 | return ret; |
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73 | } |
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74 | |
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75 | typedef struct edge_shooting_star_columns |
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76 | { |
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77 | int id; |
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78 | int source; |
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79 | int target; |
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80 | int cost; |
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81 | int reverse_cost; |
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82 | int s_x; |
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83 | int s_y; |
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84 | int t_x; |
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85 | int t_y; |
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86 | int to_cost;//cost of transit to adjacent edge |
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87 | int rule; |
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88 | } edge_shooting_star_columns_t; |
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89 | |
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90 | static int |
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91 | fetch_edge_shooting_star_columns(SPITupleTable *tuptable, |
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92 | edge_shooting_star_columns_t *edge_columns, |
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93 | bool has_reverse_cost) |
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94 | { |
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95 | edge_columns->id = SPI_fnumber(SPI_tuptable->tupdesc, "id"); |
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96 | edge_columns->source = SPI_fnumber(SPI_tuptable->tupdesc, "source"); |
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97 | edge_columns->target = SPI_fnumber(SPI_tuptable->tupdesc, "target"); |
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98 | edge_columns->cost = SPI_fnumber(SPI_tuptable->tupdesc, "cost"); |
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99 | if (edge_columns->id == SPI_ERROR_NOATTRIBUTE || |
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100 | edge_columns->source == SPI_ERROR_NOATTRIBUTE || |
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101 | edge_columns->target == SPI_ERROR_NOATTRIBUTE || |
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102 | edge_columns->cost == SPI_ERROR_NOATTRIBUTE) |
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103 | { |
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104 | elog(ERROR, "Error, query must return columns " |
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105 | "'id', 'source', 'target' and 'cost'"); |
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106 | return -1; |
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107 | } |
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108 | |
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109 | if (SPI_gettypeid(SPI_tuptable->tupdesc, |
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110 | edge_columns->source) != INT4OID || |
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111 | SPI_gettypeid(SPI_tuptable->tupdesc, |
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112 | edge_columns->target) != INT4OID || |
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113 | SPI_gettypeid(SPI_tuptable->tupdesc, edge_columns->cost) != FLOAT8OID) |
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114 | { |
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115 | elog(ERROR, "Error, columns 'source', 'target' must be of type int4, " |
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116 | "'cost' must be of type float8"); |
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117 | return -1; |
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118 | } |
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119 | |
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120 | DBG("columns: id %i source %i target %i cost %i", |
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121 | edge_columns->id, edge_columns->source, |
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122 | edge_columns->target, edge_columns->cost); |
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123 | |
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124 | if (has_reverse_cost) |
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125 | { |
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126 | edge_columns->reverse_cost = SPI_fnumber(SPI_tuptable->tupdesc, |
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127 | "reverse_cost"); |
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128 | |
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129 | if (edge_columns->reverse_cost == SPI_ERROR_NOATTRIBUTE) |
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130 | { |
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131 | elog(ERROR, "Error, reverse_cost is used, but query did't return " |
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132 | "'reverse_cost' column"); |
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133 | return -1; |
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134 | } |
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135 | |
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136 | if (SPI_gettypeid(SPI_tuptable->tupdesc, |
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137 | edge_columns->reverse_cost) != FLOAT8OID) |
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138 | { |
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139 | elog(ERROR, "Error, columns 'reverse_cost' must be of type float8"); |
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140 | return -1; |
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141 | } |
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142 | |
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143 | DBG("columns: reverse_cost cost %i", edge_columns->reverse_cost); |
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144 | } |
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145 | |
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146 | edge_columns->s_x = SPI_fnumber(SPI_tuptable->tupdesc, "x1"); |
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147 | edge_columns->s_y = SPI_fnumber(SPI_tuptable->tupdesc, "y1"); |
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148 | edge_columns->t_x = SPI_fnumber(SPI_tuptable->tupdesc, "x2"); |
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149 | edge_columns->t_y = SPI_fnumber(SPI_tuptable->tupdesc, "y2"); |
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150 | |
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151 | if (edge_columns->s_x == SPI_ERROR_NOATTRIBUTE || |
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152 | edge_columns->s_y == SPI_ERROR_NOATTRIBUTE || |
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153 | edge_columns->t_x == SPI_ERROR_NOATTRIBUTE || |
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154 | edge_columns->t_y == SPI_ERROR_NOATTRIBUTE) |
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155 | { |
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156 | elog(ERROR, "Error, query must return columns " |
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157 | "'x1', 'x2', 'y1' and 'y2'"); |
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158 | return -1; |
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159 | } |
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160 | |
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161 | DBG("columns: x1 %i y1 %i x2 %i y2 %i", |
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162 | edge_columns->s_x, edge_columns->s_y, |
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163 | edge_columns->t_x,edge_columns->t_y); |
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164 | |
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165 | |
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166 | edge_columns->to_cost = SPI_fnumber(SPI_tuptable->tupdesc, "to_cost"); |
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167 | edge_columns->rule = SPI_fnumber(SPI_tuptable->tupdesc, "rule"); |
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168 | |
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169 | if (edge_columns->to_cost == SPI_ERROR_NOATTRIBUTE || |
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170 | edge_columns->rule == SPI_ERROR_NOATTRIBUTE) |
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171 | { |
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172 | elog(ERROR, "Error, query must return columns " |
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173 | "'to_cost' and 'rule'"); |
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174 | return -1; |
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175 | } |
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176 | |
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177 | return 0; |
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178 | } |
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179 | |
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180 | //edges should be ordered by id or else we have to search for |
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181 | //existing edges every time we want to add adjacent edge |
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182 | static void |
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183 | fetch_edge_shooting_star(HeapTuple *tuple, TupleDesc *tupdesc, |
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184 | edge_shooting_star_columns_t *edge_columns, |
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185 | edge_shooting_star_t *target_edge) |
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186 | { |
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187 | Datum binval; |
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188 | bool isnull; |
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189 | int t; |
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190 | |
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191 | for(t=0; t<MAX_RULE_LENGTH;++t) |
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192 | target_edge->rule[t] = -1; |
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193 | |
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194 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->id, &isnull); |
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195 | if (isnull) |
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196 | elog(ERROR, "id contains a null value"); |
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197 | target_edge->id = DatumGetInt32(binval); |
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198 | |
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199 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->source, &isnull); |
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200 | if (isnull) |
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201 | elog(ERROR, "source contains a null value"); |
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202 | target_edge->source = DatumGetInt32(binval); |
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203 | |
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204 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->target, &isnull); |
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205 | if (isnull) |
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206 | elog(ERROR, "target contains a null value"); |
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207 | target_edge->target = DatumGetInt32(binval); |
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208 | |
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209 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->cost, &isnull); |
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210 | if (isnull) |
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211 | elog(ERROR, "cost contains a null value"); |
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212 | target_edge->cost = DatumGetFloat8(binval); |
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213 | |
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214 | if (edge_columns->reverse_cost != -1) |
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215 | { |
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216 | binval = SPI_getbinval(*tuple, *tupdesc, |
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217 | edge_columns->reverse_cost, &isnull); |
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218 | if (isnull) |
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219 | elog(ERROR, "reverse_cost contains a null value"); |
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220 | target_edge->reverse_cost = DatumGetFloat8(binval); |
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221 | } |
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222 | |
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223 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->s_x, &isnull); |
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224 | if (isnull) |
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225 | elog(ERROR, "source x contains a null value"); |
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226 | target_edge->s_x = DatumGetFloat8(binval); |
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227 | |
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228 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->s_y, &isnull); |
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229 | if (isnull) |
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230 | elog(ERROR, "source y contains a null value"); |
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231 | target_edge->s_y = DatumGetFloat8(binval); |
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232 | |
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233 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->t_x, &isnull); |
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234 | if (isnull) |
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235 | elog(ERROR, "target x contains a null value"); |
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236 | target_edge->t_x = DatumGetFloat8(binval); |
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237 | |
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238 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->t_y, &isnull); |
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239 | if (isnull) |
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240 | elog(ERROR, "target y contains a null value"); |
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241 | target_edge->t_y = DatumGetFloat8(binval); |
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242 | |
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243 | binval = SPI_getbinval(*tuple, *tupdesc, edge_columns->to_cost, &isnull); |
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244 | if (isnull) |
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245 | target_edge->to_cost = 0; |
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246 | |
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247 | else |
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248 | target_edge->to_cost = DatumGetFloat8(binval); |
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249 | |
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250 | char *str = DatumGetCString(SPI_getvalue(*tuple, *tupdesc, edge_columns->rule)); |
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251 | |
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252 | char* pch; |
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253 | int ci = MAX_RULE_LENGTH; |
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254 | |
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255 | pch = (char *)strtok (str," ,"); |
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256 | |
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257 | while (pch != NULL) |
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258 | { |
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259 | --ci; |
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260 | target_edge->rule[ci] = atoi(pch); |
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261 | pch = (char *)strtok (NULL, " ,"); |
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262 | } |
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263 | |
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264 | } |
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265 | |
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266 | |
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267 | static int compute_shortest_path_shooting_star(char* sql, int source_edge_id, |
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268 | int target_edge_id, bool directed, |
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269 | bool has_reverse_cost, |
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270 | path_element_t **path, int *path_count) |
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271 | { |
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272 | |
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273 | int SPIcode; |
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274 | void *SPIplan; |
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275 | Portal SPIportal; |
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276 | bool moredata = TRUE; |
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277 | int ntuples; |
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278 | edge_shooting_star_t *edges = NULL; |
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279 | int total_tuples = 0; |
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280 | |
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281 | // int v_max_id=0; |
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282 | // int v_min_id=INT_MAX; |
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283 | int e_max_id=0; |
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284 | int e_min_id=INT_MAX; |
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285 | |
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286 | edge_shooting_star_columns_t edge_columns = {id: -1, source: -1, target: -1, |
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287 | cost: -1, reverse_cost: -1, |
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288 | s_x: -1, s_y: -1, t_x: -1, t_y: -1, |
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289 | to_cost: -1, rule: -1}; |
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290 | char *err_msg; |
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291 | int ret = -1; |
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292 | register int z, t; |
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293 | |
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294 | int s_count=0; |
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295 | int t_count=0; |
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296 | |
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297 | DBG("start shortest_path_shooting_star\n"); |
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298 | |
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299 | SPIcode = SPI_connect(); |
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300 | if (SPIcode != SPI_OK_CONNECT) |
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301 | { |
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302 | elog(ERROR, "shortest_path_shooting_star: couldn't open a connection to SPI"); |
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303 | return -1; |
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304 | } |
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305 | |
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306 | SPIplan = SPI_prepare(sql, 0, NULL); |
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307 | if (SPIplan == NULL) |
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308 | { |
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309 | elog(ERROR, "shortest_path_shooting_star: couldn't create query plan via SPI"); |
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310 | return -1; |
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311 | } |
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312 | |
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313 | if ((SPIportal = SPI_cursor_open(NULL, SPIplan, NULL, NULL, true)) == NULL) |
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314 | { |
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315 | elog(ERROR, "shortest_path_shooting_star: SPI_cursor_open('%s') returns NULL", |
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316 | sql); |
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317 | return -1; |
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318 | } |
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319 | |
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320 | while (moredata == TRUE) |
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321 | { |
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322 | SPI_cursor_fetch(SPIportal, TRUE, TUPLIMIT); |
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323 | |
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324 | if (edge_columns.id == -1) |
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325 | { |
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326 | if (fetch_edge_shooting_star_columns(SPI_tuptable, &edge_columns, |
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327 | has_reverse_cost) == -1) |
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328 | return finish(SPIcode, ret); |
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329 | } |
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330 | |
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331 | //DBG("***%i***", ret); |
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332 | |
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333 | ntuples = SPI_processed; |
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334 | total_tuples += ntuples; |
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335 | |
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336 | if (!edges) |
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337 | edges = palloc(total_tuples * sizeof(edge_shooting_star_t)); |
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338 | else |
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339 | edges = repalloc(edges, total_tuples * sizeof(edge_shooting_star_t)); |
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340 | |
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341 | if (edges == NULL) |
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342 | { |
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343 | elog(ERROR, "Out of memory"); |
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344 | return finish(SPIcode, ret); |
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345 | } |
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346 | |
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347 | if (ntuples > 0) |
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348 | { |
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349 | int t; |
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350 | SPITupleTable *tuptable = SPI_tuptable; |
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351 | TupleDesc tupdesc = SPI_tuptable->tupdesc; |
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352 | |
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353 | for (t = 0; t < ntuples; t++) |
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354 | { |
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355 | HeapTuple tuple = tuptable->vals[t]; |
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356 | fetch_edge_shooting_star(&tuple, &tupdesc, &edge_columns, |
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357 | &edges[total_tuples - ntuples + t]); |
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358 | } |
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359 | SPI_freetuptable(tuptable); |
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360 | } |
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361 | else |
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362 | { |
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363 | moredata = FALSE; |
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364 | } |
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365 | } |
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366 | |
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367 | |
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368 | DBG("Total %i tuples", total_tuples); |
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369 | |
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370 | |
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371 | |
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372 | for(z=0; z<total_tuples; z++) |
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373 | { |
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374 | if(edges[z].id<e_min_id) |
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375 | e_min_id=edges[z].id; |
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376 | |
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377 | if(edges[z].id>e_max_id) |
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378 | e_max_id=edges[z].id; |
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379 | |
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380 | } |
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381 | |
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382 | DBG("E : %i <-> %i", e_min_id, e_max_id); |
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383 | |
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384 | for(z=0; z<total_tuples; ++z) |
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385 | { |
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386 | |
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387 | //check if edges[] contains source and target |
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388 | if(edges[z].id == source_edge_id || |
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389 | edges[z].id == source_edge_id) |
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390 | ++s_count; |
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391 | if(edges[z].id == target_edge_id || |
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392 | edges[z].id == target_edge_id) |
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393 | ++t_count; |
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394 | |
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395 | |
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396 | //edges[z].source-=v_min_id; |
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397 | //edges[z].target-=v_min_id; |
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398 | |
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399 | } |
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400 | |
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401 | DBG("Total %i tuples", total_tuples); |
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402 | |
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403 | if(s_count == 0) |
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404 | { |
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405 | elog(ERROR, "Start edge was not found."); |
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406 | return -1; |
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407 | } |
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408 | |
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409 | if(t_count == 0) |
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410 | { |
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411 | elog(ERROR, "Target edge was not found."); |
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412 | return -1; |
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413 | } |
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414 | |
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415 | DBG("Total %i tuples", total_tuples); |
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416 | |
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417 | DBG("Calling boost_shooting_star <%i>\n", total_tuples); |
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418 | |
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419 | //time_t stime = time(NULL); |
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420 | |
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421 | ret = boost_shooting_star(edges, total_tuples, source_edge_id, |
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422 | target_edge_id, |
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423 | directed, has_reverse_cost, |
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424 | path, path_count, &err_msg, e_max_id); |
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425 | |
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426 | //time_t etime = time(NULL); |
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427 | |
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428 | //DBG("Path was calculated in %f seconds. \n", difftime(etime, stime)); |
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429 | |
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430 | DBG("SIZE %i\n",*path_count); |
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431 | |
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432 | DBG("ret = %i\n",ret); |
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433 | |
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434 | |
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435 | if (ret < 0) |
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436 | { |
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437 | ereport(ERROR, (errcode(ERRCODE_E_R_E_CONTAINING_SQL_NOT_PERMITTED), |
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438 | errmsg("Error computing path: %s", err_msg))); |
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439 | } |
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440 | return finish(SPIcode, ret); |
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441 | } |
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442 | |
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443 | |
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444 | PG_FUNCTION_INFO_V1(shortest_path_shooting_star); |
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445 | Datum |
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446 | shortest_path_shooting_star(PG_FUNCTION_ARGS) |
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447 | { |
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448 | FuncCallContext *funcctx; |
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449 | int call_cntr; |
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450 | int max_calls; |
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451 | TupleDesc tuple_desc; |
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452 | path_element_t *path; |
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453 | |
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454 | /* stuff done only on the first call of the function */ |
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455 | if (SRF_IS_FIRSTCALL()) |
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456 | { |
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457 | MemoryContext oldcontext; |
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458 | int path_count = 0; |
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459 | int ret; |
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460 | |
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461 | /* create a function context for cross-call persistence */ |
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462 | funcctx = SRF_FIRSTCALL_INIT(); |
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463 | |
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464 | /* switch to memory context appropriate for multiple function calls */ |
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465 | oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx); |
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466 | |
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467 | |
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468 | ret = compute_shortest_path_shooting_star(text2char(PG_GETARG_TEXT_P(0)), |
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469 | PG_GETARG_INT32(1), |
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470 | PG_GETARG_INT32(2), |
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471 | PG_GETARG_BOOL(3), |
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472 | PG_GETARG_BOOL(4), |
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473 | &path, &path_count); |
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474 | |
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475 | #ifdef DEBUG |
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476 | DBG("Ret is %i", ret); |
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477 | if (ret >= 0) |
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478 | { |
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479 | int i; |
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480 | for (i = 0; i < path_count; i++) |
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481 | { |
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482 | DBG("Step # %i vertex_id %i ", i, path[i].vertex_id); |
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483 | DBG(" edge_id %i ", path[i].edge_id); |
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484 | DBG(" cost %f ", path[i].cost); |
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485 | } |
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486 | } |
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487 | #endif |
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488 | |
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489 | /* total number of tuples to be returned */ |
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490 | DBG("Conting tuples number\n"); |
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491 | funcctx->max_calls = path_count; |
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492 | funcctx->user_fctx = path; |
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493 | |
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494 | DBG("Path count %i", path_count); |
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495 | |
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496 | funcctx->tuple_desc = |
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497 | BlessTupleDesc(RelationNameGetTupleDesc("path_result")); |
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498 | |
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499 | MemoryContextSwitchTo(oldcontext); |
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500 | } |
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501 | |
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502 | /* stuff done on every call of the function */ |
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503 | |
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504 | funcctx = SRF_PERCALL_SETUP(); |
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505 | |
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506 | call_cntr = funcctx->call_cntr; |
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507 | max_calls = funcctx->max_calls; |
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508 | tuple_desc = funcctx->tuple_desc; |
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509 | path = (path_element_t*) funcctx->user_fctx; |
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510 | |
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511 | DBG("Trying to allocate some memory\n"); |
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512 | |
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513 | if (call_cntr < max_calls) /* do when there is more left to send */ |
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514 | { |
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515 | HeapTuple tuple; |
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516 | Datum result; |
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517 | Datum *values; |
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518 | char* nulls; |
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519 | |
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520 | values = palloc(3 * sizeof(Datum)); |
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521 | nulls = palloc(3 * sizeof(char)); |
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522 | |
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523 | values[0] = Int32GetDatum(path[call_cntr].vertex_id); |
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524 | nulls[0] = ' '; |
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525 | values[1] = Int32GetDatum(path[call_cntr].edge_id); |
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526 | nulls[1] = ' '; |
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527 | values[2] = Float8GetDatum(path[call_cntr].cost); |
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528 | nulls[2] = ' '; |
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529 | |
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530 | tuple = heap_formtuple(tuple_desc, values, nulls); |
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531 | |
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532 | /* make the tuple into a datum */ |
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533 | result = HeapTupleGetDatum(tuple); |
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534 | |
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535 | |
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536 | /* clean up (this is not really necessary) */ |
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537 | pfree(values); |
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538 | pfree(nulls); |
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539 | |
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540 | SRF_RETURN_NEXT(funcctx, result); |
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541 | } |
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542 | else /* do when there is no more left */ |
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543 | { |
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544 | SRF_RETURN_DONE(funcctx); |
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545 | } |
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546 | } |
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