First attempt to write a backend-independent Pivot-Table implementation

library/Icinga/Data/PivotTable.php

@@ -0,0 +1,136 @@
+<?php
+
+namespace Icinga\Data;
+
+class PivotTable
+{
+    protected $query;
+
+    protected $verticalColumn;
+
+    protected $horizontalColumn;
+
+    protected $limit;
+    
+    protected $offset;
+
+    protected $verticalLimit;
+
+    protected $horizontalLimit;
+
+    public function __construct(QueryInterface $query, $verticalColumn, $horizontalColumn)
+    {
+        $this->query = $query;
+        $this->verticalColumn   = $verticalColumn;
+        $this->horizontalColumn = $horizontalColumn;
+    }
+
+    public function limit($limit = null, $offset = null)
+    {
+        $this->limit = $limit;
+        $this->offset = $offset;
+        return $this;
+    }
+
+    public function getLimit()
+    {
+        if ($this->limit === null) {
+            return 20;
+        }
+        return $this->limit;
+    }
+
+    public function getOffset()
+    {
+        if ($this->limit === null) {
+            return 20;
+        }
+        return $this->offset;
+    }
+
+    public function verticalLimit($limit = null, $offset = null)
+    {
+        // TODO: Trigger limit by calling $this->limit()?
+        if ($limit === null) {
+            $limit = $this->getLimit();
+        }
+        if ($offset === null) {
+            $offset = $this->getOffset();
+        }
+        $this->verticalLimit = $limit;
+        $this->verticalOffset = $offset;
+        return $this;
+    }
+
+    public function paginateVertical($limit = null, $offset = null)
+    {
+        $this->verticalLimit($limit, $offset);
+        return Paginator($this);
+    }
+
+    public function getVerticalLimit()
+    {
+        if ($this->verticalLimit === null) {
+            return 20;
+        }
+        return $this->verticalLimit;
+    }
+
+    public function getVerticalOffset()
+    {
+        if ($this->verticalLimit === null) {
+            return 20;
+        }
+        return $this->verticalOffset;
+    }
+
+    /**
+     * Fetch all columns
+     */
+    public function fetchAll()
+    {
+        $xcol = $this->horizontalColumn;
+        $ycol = $this->verticalColumn;
+        $queryX = clone($this->query);
+        $queryX->columns($xcol);
+        if ($this->limit !== null) {
+            $queryX->limit($this->getLimit(), $this->getOffset());
+        }
+        $queryX->limit(40);
+        $listX = $queryX->fetchColumn();
+        $queryY = clone($this->query);
+
+        $queryY->columns($ycol);
+        if ($this->verticalLimit !== null) {
+            $queryY->limit($this->getVerticalLimit(), $this->getVerticalOffset());
+        }
+        $queryY->limit(50);
+        $listY = $queryY->fetchColumn();
+
+        // TODO: resetOrder
+        $this->query
+            ->where($ycol, $listY)
+            ->where($xcol, $listX)
+            ->order($ycol)
+            ->order($xcol)
+            ;
+        $pivot = array();
+        $emptyrow = (object) array();
+        foreach ($this->query->listColumns() as $col) {
+            $emptyrow->$col = null;
+        }
+        foreach ($listY as $y) {
+            foreach ($listX as $x) {
+                $row = clone($emptyrow);
+                $row->$xcol = $x;
+                $row->$ycol = $y;
+                $pivot[$y][$x] = $row;
+            }
+        }
+
+        foreach ($this->query->fetchAll() as $row) {
+            $pivot[$row->$ycol][$row->$xcol] = $row;
+        }
+        return $pivot;
+    }
+}