Index PDFs embedded with pdfjs-viewer

relevanssi_index_embedded_pdf.php

<?php

add_filter( 'relevanssi_content_to_index', 'rlv_pdfjs_content', 10, 2 );
function rlv_pdfjs_content( $content, $post ) {
	$m = preg_match_all( '/\[pdfjs-viewer url="(.*)"/', $post->post_content, $matches );
	if ( $m ) {
		global $wpdb;
		$upload_dir = wp_upload_dir();
		foreach ( $matches[1] as $pdf ) {
			$pdf_url     = ltrim( str_replace( $upload_dir['baseurl'], '', urldecode( $pdf ) ), '/' );
			$pdf_content = $wpdb->get_var( $wpdb->prepare( "SELECT meta_value FROM $wpdb->postmeta WHERE meta_key = '_relevanssi_pdf_content' AND post_id IN ( SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_wp_attached_file' AND meta_value = %s )", $pdf_url ) );
			$content    .= $pdf_content;
		}
	}
	return $content;
}