First, this is best done with PHP's curl functions. See the various answers to PHP file_get_contents() returns "failed to open stream: HTTP request failed!"
If you stick with fopen() you probably need to set up the context for SSL, and it may involve installing some certificates. See file_get_contents(): SSL operation failed with code 1. And more (and note the security warning about the accepted answer)
Finally, your while(1) loop is around the fopen() (which is okay for re-starts after relatively rare failures), but you actually want it inside. Here is your code with just the minimal changes to show that:
<?php
while(1)
{
$get_stream_data = fopen('https://api.xyz.com:8100/update-stream/connect', 'r');
if($get_stream_data)while(1)
{
$stream_data = stream_get_contents($get_stream_data);
$save_stream_data = getStreamingData($stream_data);
if($save_stream_data == true)
{
continue;
}
sleep(1);
}
else
{
sleep(1);
continue;
}
}
UPDATE: The above code still nags at me: I think you want me to using fread() instead of stream_get_contents(), and use blocking instead of the sleep(1) (in the inner loop).
BTW, I'd suggest changing the outer-loop sleep(1) to be sleep(3) or sleep(5) which are typical defaults in Chrome/Firefox/etc. (Really, you should be looking for the SSE server sending a "retry" header, and using that number as the sleep.)