php - Class-to-class passing of data, optimization -

i have written file-handler-class, works this:

• __construct opens , ex-locks file, reads json-content , parses php-array, keeping property of class.
• the file still locked, in order avoid race-conditions.
• other 'worker-classes' make changes in array, in/from other scopes.
• __destruct encodes finished array, writes file, , unlocks file.

everything works fine ...

question:

is sensible keep array property of original class, or better pass array worker-classes, , let them return @ end?

perhaps there way keep array locally, , pass worker-classes reference, instead of raw data?

i mean ... question of not having duplicates, waisting memory. question of speed, not passing things unnecessarily. , question of best practices, keeping things easy understand.

actually, passing array function, having function modify array, , return other caller may or may not conduct modifications on it, in fact copying array multiple times (since invokes copy-on-write semantics in php) , definition wasting memory.

whereas keeping property of object instance, not invoking copy-on-write semantics, if caller not same instance. since passing object instance won't copy array, nor modification said instance.

not mention make easier retain state within object (assuming care validation).