Oihana PHP

StreamModel

Interface for models that provide document streaming.

This interface defines a method to retrieve documents from a model as a generator, allowing efficient iteration over large datasets without loading all documents into memory at once.

Tags
author

Marc Alcaraz (ekameleon)

since
1.0.0

Table of Contents

Methods

stream()  : Generator<string|int, mixed>
Streams documents from the model.

Methods

stream()

Streams documents from the model.

public stream([array<string|int, mixed> $init = [] ]) : Generator<string|int, mixed>

This method returns a generator that yields each document one at a time. It is useful for iterating over large collections efficiently, since documents are produced lazily instead of being loaded all at once like ListModel::list() does.

Parameters
$init : array<string|int, mixed> = []

Operation options scoping the stream, typically conditions with their binds, a sort clause and a batch size. An empty array streams every document.

Tags
example 
use Generator;
use oihana\models\interfaces\StreamModel;

class UserModel implements StreamModel
{
    public function stream( array $init = [] ) : Generator
    {
        foreach ( $this->store->cursor( $init[ 'conditions' ] ?? null ) as $row )
        {
            yield $row ;
        }
    }
}

$model = new UserModel() ;

foreach ( $model->stream( [ 'conditions' => 'doc.active == true' ] ) as $user )
{
    // process one user at a time, constant memory
}
Return values
Generator<string|int, mixed> —

Yields each document in the collection. The type of document depends on the model implementation.

On this page

Search results