1 | <?php |
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22 | abstract class AbstractNode |
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23 | { |
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24 | /** |
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25 | * Set of keys to be aggregated by Parser while parsing results. |
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26 | * |
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27 | * @var array |
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28 | */ |
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29 | private $trackReferences = []; |
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30 | |||
31 | /** |
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32 | * Tree parts associated with reference keys and key values. |
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33 | * |
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34 | * $this->collectedReferences[id][ID_VALUE] = [ITEM1, ITEM2, ...]. |
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35 | * |
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36 | * @var array |
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37 | */ |
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38 | private $references = []; |
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39 | |||
40 | /** |
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41 | * Indicates that node data is joined to parent row. |
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42 | * |
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43 | * @var bool |
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44 | */ |
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45 | private $joined = false; |
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46 | |||
47 | /** |
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48 | * Column names to be used to hydrate based on given query rows. |
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49 | * |
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50 | * @var array |
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51 | */ |
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52 | protected $columns = []; |
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53 | |||
54 | /** |
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55 | * @var int |
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56 | */ |
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57 | private $countColumns = 0; |
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58 | |||
59 | /** |
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60 | * Declared column which must be aggregated in a parent node. i.e. Parent Key |
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61 | * |
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62 | * @var null|string |
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63 | */ |
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64 | protected $outerKey = null; |
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65 | |||
66 | /** |
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67 | * Node location in a tree. Set when node is registered. |
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68 | * |
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69 | * @invisible |
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70 | * @var string |
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71 | */ |
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72 | protected $container; |
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73 | |||
74 | /** |
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75 | * @invisible |
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76 | * @var AbstractNode |
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77 | */ |
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78 | protected $parent; |
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79 | |||
80 | /** |
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81 | * @var AbstractNode[] |
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82 | */ |
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83 | protected $nodes = []; |
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84 | |||
85 | /** |
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86 | * @param array $columns When columns are empty original line will be returned as result. |
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87 | * @param string|null $outerKey Defines column name in parent Node to be aggregated. |
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88 | */ |
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89 | public function __construct(array $columns, string $outerKey = null) |
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90 | { |
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91 | $this->columns = $columns; |
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92 | $this->countColumns = count($columns); |
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93 | $this->outerKey = $outerKey; |
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94 | } |
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95 | |||
96 | /** |
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97 | * Convert node into joined form (node will automatically parse parent row). |
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98 | * |
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99 | * @param bool $joined |
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100 | * |
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101 | * @return AbstractNode |
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102 | */ |
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103 | public function asJoined(bool $joined = true) |
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104 | { |
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105 | $node = clone $this; |
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106 | $node->joined = $joined; |
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107 | |||
108 | return $node; |
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109 | } |
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110 | |||
111 | /** |
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112 | * Get list of reference key values aggregated by parent. |
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113 | * |
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114 | * @return array |
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115 | * |
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116 | * @throws NodeException |
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117 | */ |
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118 | public function getReferences(): array |
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119 | { |
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120 | if (empty($this->parent)) { |
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121 | throw new NodeException("Unable to aggregate reference values, parent is missing"); |
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122 | } |
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123 | |||
124 | if (empty($this->parent->references[$this->outerKey])) { |
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125 | return []; |
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126 | } |
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127 | |||
128 | return array_keys($this->parent->references[$this->outerKey]); |
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129 | } |
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130 | |||
131 | /** |
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132 | * Register new node into NodeTree. Nodes used to convert flat results into tree representation |
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133 | * using reference aggregations. |
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134 | * |
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135 | * @param string $container |
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136 | * @param AbstractNode $node |
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137 | * |
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138 | * @throws NodeException |
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139 | */ |
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140 | final public function registerNode(string $container, AbstractNode $node) |
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141 | { |
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142 | $node->container = $container; |
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143 | $node->parent = $this; |
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144 | |||
145 | $this->nodes[$container] = $node; |
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146 | |||
147 | if (!empty($node->outerKey)) { |
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148 | //This will make parser to aggregate such key in order to be used in later statement |
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149 | $this->trackReference($node->outerKey); |
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150 | } |
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151 | } |
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152 | |||
153 | /** |
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154 | * Destructing. |
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155 | */ |
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156 | public function __destruct() |
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157 | { |
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158 | $this->parent = null; |
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159 | $this->nodes = []; |
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160 | $this->references = []; |
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161 | $this->trackReferences = []; |
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162 | } |
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163 | |||
164 | /** |
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165 | * Fetch sub node. |
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166 | * |
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167 | * @param string $container |
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168 | * |
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169 | * @return AbstractNode |
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170 | * |
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171 | * @throws NodeException |
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172 | */ |
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173 | final public function fetchNode(string $container): AbstractNode |
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174 | { |
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175 | if (!isset($this->nodes[$container])) { |
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176 | throw new NodeException("Undefined node {$container}"); |
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177 | } |
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178 | |||
179 | return $this->nodes[$container]; |
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180 | } |
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181 | |||
182 | /** |
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183 | * Parser result work, fetch data and mount it into parent tree. |
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184 | * |
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185 | * @param int $dataOffset |
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186 | * @param array $row |
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187 | * |
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188 | * @return int Must return number of handled columns. |
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189 | */ |
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190 | final public function parseRow(int $dataOffset, array $row): int |
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191 | { |
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192 | //Fetching Node specific data from resulted row |
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193 | $data = $this->fetchData($dataOffset, $row); |
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194 | |||
195 | if ($this->deduplicate($data)) { |
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196 | //Create reference keys |
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197 | $this->collectReferences($data); |
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198 | |||
199 | //Make sure that all nested relations are registered |
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200 | $this->ensurePlaceholders($data); |
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201 | |||
202 | //Add data into result set |
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203 | $this->pushData($data); |
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204 | } elseif (!empty($this->parent)) { |
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205 | //Registering duplicates rows in each parent row |
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206 | $this->pushData($data); |
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207 | } |
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208 | |||
209 | $innerOffset = 0; |
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210 | foreach ($this->nodes as $container => $node) { |
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211 | if ($node->joined) { |
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212 | /** |
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213 | * We are looking into branch like structure: |
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214 | * node |
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215 | * - node |
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216 | * - node |
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217 | * - node |
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218 | * node |
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219 | * |
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220 | * This means offset has to be calculated using all nested nodes |
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221 | */ |
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222 | $innerColumns = $node->parseRow($this->countColumns + $dataOffset, $row); |
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223 | |||
224 | //Counting next selection offset |
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225 | $dataOffset += $innerColumns; |
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226 | |||
227 | //Counting nested tree offset |
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228 | $innerOffset += $innerColumns; |
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229 | } |
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230 | } |
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231 | |||
232 | return $this->countColumns + $innerOffset; |
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233 | } |
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234 | |||
235 | /** |
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236 | * In many cases (for example if you have INLOAD of HAS_MANY relation) record data can be |
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237 | * replicated by many result rows (duplicated). To prevent incorrect data linking we have to |
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238 | * deduplicate such records. |
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239 | * |
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240 | * Method will return true if data is unique and handled previously or false in opposite case. |
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241 | * |
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242 | * Provided data array will be automatically linked with it's unique state using references |
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243 | * (pointer will receive different address). |
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244 | * |
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245 | * @param array $data Reference to parsed record data, reference will be pointed to valid and |
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246 | * existed data segment if such data was already parsed. |
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247 | * |
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248 | * @return bool Must return TRUE what data is unique in this selection. |
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249 | */ |
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250 | abstract protected function deduplicate(array &$data): bool; |
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251 | |||
252 | /** |
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253 | * Register data result. |
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254 | * |
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255 | * @param array $data |
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256 | */ |
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257 | abstract protected function pushData(array &$data); |
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258 | |||
259 | /** |
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260 | * Mount record data into internal data storage under specified container using reference key |
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261 | * (inner key) and reference criteria (outer key value). |
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262 | * |
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263 | * Example (default ORM Loaders): |
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264 | * $this->parent->mount('profile', 'id', 1, [ |
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265 | * 'id' => 100, |
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266 | * 'user_id' => 1, |
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267 | * ... |
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268 | * ]); |
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269 | * |
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270 | * In this example "id" argument is inner key of "user" record and it's linked to outer key |
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271 | * "user_id" in "profile" record, which defines reference criteria as 1. |
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272 | * |
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273 | * Attention, data WILL be referenced to new memory location! |
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274 | * |
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275 | * @param string $container |
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276 | * @param string $key |
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277 | * @param mixed $criteria |
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278 | * @param array $data Data must be referenced to existed set if it was registered |
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279 | * previously. |
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280 | * |
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281 | * @throws NodeException |
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282 | */ |
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283 | final protected function mount( |
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304 | |||
305 | /** |
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306 | * Mount record data into internal data storage under specified container using reference key |
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307 | * (inner key) and reference criteria (outer key value). |
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308 | * |
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309 | * Example (default ORM Loaders): |
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310 | * $this->parent->mountArray('comments', 'id', 1, [ |
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311 | * 'id' => 100, |
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312 | * 'user_id' => 1, |
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313 | * ... |
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314 | * ]); |
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315 | * |
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316 | * In this example "id" argument is inner key of "user" record and it's linked to outer key |
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317 | * "user_id" in "profile" record, which defines reference criteria as 1. |
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318 | * |
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319 | * Add added records will be added as array items. |
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320 | * |
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321 | * @param string $container |
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322 | * @param string $key |
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323 | * @param mixed $criteria |
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324 | * @param array $data Data must be referenced to existed set if it was registered |
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325 | * previously. |
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326 | * |
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327 | * @throws NodeException |
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328 | */ |
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329 | final protected function mountArray( |
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348 | |||
349 | /** |
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350 | * Fetch record columns from query row, must use data offset to slice required part of query. |
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351 | * |
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352 | * @param int $dataOffset |
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353 | * @param array $line |
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354 | * |
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355 | * @return array |
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356 | */ |
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357 | protected function fetchData(int $dataOffset, array $line): array |
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373 | |||
374 | /** |
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375 | * Create internal references cache based on requested keys. For example, if we have request for |
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376 | * "id" as reference key, every record will create following structure: |
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377 | * $this->references[id][ID_VALUE] = ITEM. |
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378 | * |
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379 | * Only deduplicated data must be collected! |
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380 | * |
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381 | * @see deduplicate() |
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382 | * |
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383 | * @param array $data |
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384 | */ |
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385 | private function collectReferences(array &$data) |
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392 | |||
393 | /** |
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394 | * Create placeholders for each of sub nodes. |
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395 | * |
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396 | * @param array $data |
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397 | */ |
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398 | private function ensurePlaceholders(array &$data) |
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405 | |||
406 | /** |
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407 | * Add key to be tracked |
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408 | * |
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409 | * @param string $key |
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410 | * |
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411 | * @throws NodeException |
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412 | */ |
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413 | private function trackReference(string $key) |
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424 | } |