Bulk helper

[miguelgrinberg]

Closes #1537

A bulk helper class that creates and submits chunk requests according to size or operation count limits. The application just provides an iterator or generator that feeds items one by one. Example:

use Elastic\Elasticsearch\Helper\Bulk;

function get_next_document() {
    foreach($dataset as $document) {
        yield Bulk::index_action($document)
    }
}

Bulk::bulk($client, $index, get_next_document());

[github-actions]

🔍 Preview links for changed docs

• docs/reference/bulk.md
• docs/reference/client-helpers.md

[github-actions]

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