Page MenuHomeWickedGov Phorge
Files F5989490

BatchRowUpdate.php
No OneTemporary
Actions

Size
2 KB
Referenced Files
None
Subscribers
None

BatchRowUpdate.php
View Options

<?php
/**
* @license GPL-2.0-or-later
*/
/**
* Ties together the batch update components to provide a composable
* method of batch updating rows in a database. To use create a class
* implementing the RowUpdateGenerator interface and configure the
* BatchRowIterator and BatchRowWriter for access to the correct table.
* The components will handle reading, writing, and waiting for replica DBs
* while the generator implementation handles generating update arrays
* for singular rows.
*
* Instantiate:
* $updater = new BatchRowUpdate(
* new BatchRowIterator( $dbr, 'some_table', 'primary_key_column', 500 ),
* new BatchRowWriter( $dbw, 'some_table', 'clusterName' ),
* new MyImplementationOfRowUpdateGenerator
* );
*
* Run:
* $updater->execute();
*
* An example maintenance script utilizing the BatchRowUpdate can be
* located in the Echo extension file maintenance/updateSchema.php
*
* @ingroup Maintenance
*/
class BatchRowUpdate {
/**
* @var BatchRowIterator Iterator that returns an array of
* database rows
*/
protected $reader;
/**
* @var BatchRowWriter Writer capable of pushing row updates
* to the database
*/
protected $writer;
/**
* @var RowUpdateGenerator Generates single row updates
* based on the rows content
*/
protected $generator;
/**
* @var callable Output callback
*/
protected $output;
/**
* @param BatchRowIterator $reader Iterator that returns an
* array of database rows
* @param BatchRowWriter $writer Writer capable of pushing
* row updates to the database
* @param RowUpdateGenerator $generator Generates single row updates
* based on the rows content
*/
public function __construct(
BatchRowIterator $reader, BatchRowWriter $writer, RowUpdateGenerator $generator
) {
$this->reader = $reader;
$this->writer = $writer;
$this->generator = $generator;
$this->output = static function ( $text ) {
}; // nop
}
/**
* Runs the batch update process
*/
public function execute() {
foreach ( $this->reader as $rows ) {
$updates = [];
foreach ( $rows as $row ) {
$update = $this->generator->update( $row );
if ( $update ) {
$updates[] = [
'primaryKey' => $this->reader->extractPrimaryKeys( $row ),
'changes' => $update,
];
}
}
if ( $updates ) {
$this->output( "Processing " . count( $updates ) . " rows\n" );
$this->writer->write( $updates );
}
}
$this->output( "Completed\n" );
}
/**
* Accepts a callable which will receive a single parameter
* containing string status updates
*
* @param callable $output A callback taking a single string
* parameter to output
*/
public function setOutput( callable $output ) {
$this->output = $output;
}
/**
* Write out a status update
*
* @param string $text The value to print
*/
protected function output( $text ) {
( $this->output )( $text );
}
}

File Metadata

Mime Type
text/x-php
Expires
Sun, Oct 4, 01:09 (3 w, 4 d ago)
Storage Engine
local-disk
Storage Format
Raw Data
Storage Handle
9e/48/11e331fdd539f7d8fd8d2ea36b67
Default Alt Text
BatchRowUpdate.php (2 KB)

Event Timeline