メモリを使い果たさずに PHP で大きな JSON ファイルを効率的に処理するにはどうすればよいですか?

$reader = new JsonReader();
$reader->open("data.json");

$reader->read(); // Outer array
$depth = $reader->depth();
$reader->read(); // First object

while ($reader->next() && $reader->depth() > $depth) {
    print_r($reader->value()); // Process each object
}

$reader->close();

$reader->json($json);

while ($reader->read()) {
    if ($reader->name() !== null) {
        echo "{$reader->name()}: {$reader->value()}\n";
    }
}

$reader->close();

$json = '[{"property":"value", "property2":"value2"}, {"foo":"foo", "foo":"bar"}]';

$reader = new JsonReader();
$reader->json($json);

while ($reader->read("foo")) {
    echo "{$reader->name()}: {$reader->value()}\n";
}

$reader->close();