* Efficiently run operations on batches of results for any function
* that supports an options array.
*
- * This is usually used with elgg_get_entities() and friends, elgg_get_annotations()
- * and elgg_get_metadata().
+ * This is usually used with elgg_get_entities() and friends,
+ * elgg_get_annotations(), and elgg_get_metadata().
*
- * If you pass a valid PHP callback, all results will be run through that callback.
- * You can still foreach() through the result set after. Valid PHP callbacks
- * can be a string, an array, or a closure.
+ * If you pass a valid PHP callback, all results will be run through that
+ * callback. You can still foreach() through the result set after. Valid
+ * PHP callbacks can be a string, an array, or a closure.
* {@link http://php.net/manual/en/language.pseudo-types.php}
*
- * The callback function must accept 3 arguments: an entity, the getter used, and the options used.
+ * The callback function must accept 3 arguments: an entity, the getter
+ * used, and the options used.
*
- * Results from the callback are stored in callbackResult.
- * If the callback returns only booleans, callbackResults will be the combined
- * result of all calls.
+ * Results from the callback are stored in callbackResult. If the callback
+ * returns only booleans, callbackResults will be the combined result of
+ * all calls.
*
- * If the callback returns anything else, callbackresult will be an indexed array
- * of whatever the callback returns. If returning error handling information,
- * you should include enough information to determine which result you're referring
- * to.
+ * If the callback returns anything else, callbackresult will be an indexed
+ * array of whatever the callback returns. If returning error handling
+ * information, you should include enough information to determine which
+ * result you're referring to.
*
* Don't combine returning bools and returning something else.
*
* Note that returning false will not stop the foreach.
*
+ * @warning If your callback or foreach loop deletes or disable entities
+ * you MUST call setIncrementOffset(false) or set that when instantiating.
+ * This forces the offset to stay what it was in the $options array.
+ *
* @example
* <code>
+ * // using foreach
* $batch = new ElggBatch('elgg_get_entities', array());
+ * $batch->setIncrementOffset(false);
*
* foreach ($batch as $entity) {
* $entity->disable();
* }
*
+ * // using both a callback
* $callback = function($result, $getter, $options) {
- * var_dump("Going to delete annotation id: $result->id");
+ * var_dump("Looking at annotation id: $result->id");
* return true;
* }
*
* $batch = new ElggBatch('elgg_get_annotations', array('guid' => 2), $callback);
- *
- * foreach ($batch as $annotation) {
- * $annotation->delete();
- * }
* </code>
*
* @package Elgg.Core
*/
public $callbackResult = null;
+ /**
+ * If false, offset will not be incremented. This is used for callbacks/loops that delete.
+ *
+ * @var bool
+ */
+ private $incrementOffset = true;
+
/**
* Batches operations on any elgg_get_*() or compatible function that supports
* an options array.
* @param int $chunk_size The number of entities to pull in before requesting more.
* You have to balance this between running out of memory in PHP
* and hitting the db server too often.
+ * @param bool $inc_offset Increment the offset on each fetch. This must be false for
+ * callbacks that delete rows. You can set this after the
+ * object is created with {@see ElggBatch::setIncrementOffset()}.
*/
- public function __construct($getter, $options, $callback = null, $chunk_size = 25) {
+ public function __construct($getter, $options, $callback = null, $chunk_size = 25,
+ $inc_offset = true) {
+
$this->getter = $getter;
$this->options = $options;
$this->callback = $callback;
$this->chunkSize = $chunk_size;
+ $this->setIncrementOffset($inc_offset);
if ($this->chunkSize <= 0) {
$this->chunkSize = 25;
// if passed a callback, create a new ElggBatch with the same options
// and pass each to the callback.
if ($callback && is_callable($callback)) {
- $batch = new ElggBatch($getter, $options, null, $chunk_size);
+ $batch = new ElggBatch($getter, $options, null, $chunk_size, $inc_offset);
$all_results = null;
}
}
+ if ($this->incrementOffset) {
+ $offset = $this->offset + $this->retrievedResults;
+ } else {
+ $offset = $this->offset;
+ }
+
$current_options = array(
'limit' => $limit,
- 'offset' => $this->offset + $this->retrievedResults
+ 'offset' => $offset
);
$options = array_merge($this->options, $current_options);
}
}
+ /**
+ * Increment the offset from the original options array? Setting to
+ * false is required for callbacks that delete rows.
+ *
+ * @param bool $increment
+ */
+ public function setIncrementOffset($increment = true) {
+ $this->incrementOffset = (bool) $increment;
+ }
+
/**
* Implements Iterator
*/
$this->assertIdentical($elements_sorted_string, $test_elements);
}
+
+ // see http://trac.elgg.org/ticket/4288
+ public function testElggBatchIncOffset() {
+ // normal increment
+ $options = array(
+ 'offset' => 0,
+ 'limit' => 11
+ );
+ $batch = new ElggBatch(array('ElggCoreHelpersTest', 'test_elgg_batch_callback'), $options,
+ null, 5);
+ $j = 0;
+ foreach ($batch as $e) {
+ $offset = floor($j / 5) * 5;
+ $this->assertEqual($offset, $e['offset']);
+ $this->assertEqual($j + 1, $e['index']);
+ $j++;
+ }
+
+ $this->assertEqual(11, $j);
+
+ // no increment, 0 start
+ ElggCoreHelpersTest::test_elgg_batch_callback(array(), true);
+ $options = array(
+ 'offset' => 0,
+ 'limit' => 11
+ );
+ $batch = new ElggBatch(array('ElggCoreHelpersTest', 'test_elgg_batch_callback'), $options,
+ null, 5);
+ $batch->setIncrementOffset(false);
+
+ $j = 0;
+ foreach ($batch as $e) {
+ $this->assertEqual(0, $e['offset']);
+ // should always be the same 5
+ $this->assertEqual($e['index'], $j + 1 - (floor($j / 5) * 5));
+ $j++;
+ }
+ $this->assertEqual(11, $j);
+
+ // no increment, 3 start
+ ElggCoreHelpersTest::test_elgg_batch_callback(array(), true);
+ $options = array(
+ 'offset' => 3,
+ 'limit' => 11
+ );
+ $batch = new ElggBatch(array('ElggCoreHelpersTest', 'test_elgg_batch_callback'), $options,
+ null, 5);
+ $batch->setIncrementOffset(false);
+
+ $j = 0;
+ foreach ($batch as $e) {
+ $this->assertEqual(3, $e['offset']);
+ // same 5 results
+ $this->assertEqual($e['index'], $j + 4 - (floor($j / 5) * 5));
+ $j++;
+ }
+
+ $this->assertEqual(11, $j);
+ }
+
+ static function test_elgg_batch_callback($options, $reset = false) {
+ static $count = 1;
+
+ if ($reset) {
+ $count = 1;
+ return true;
+ }
+
+ if ($count > 20) {
+ return false;
+ }
+
+ for ($j = 0; ($options['limit'] < 5) ? $j < $options['limit'] : $j < 5; $j++) {
+ $return[] = array(
+ 'offset' => $options['offset'],
+ 'limit' => $options['limit'],
+ 'count' => $count++,
+ 'index' => 1 + $options['offset'] + $j
+ );
+ }
+
+ return $return;
+ }
}
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projects / lorea / elgg.git / commitdiff