WP - Block all http requests

The HTTP requests made by the premium plugins are really a huge pain. While I understand the purpose, I still don't get why they need to happen so often.

I have been struggling during a long time with this issue. Woo plugins, affiliate, etc. they all send requests even on page, post or custom posts pages. When their server is loaded, sit can easily take between 500ms to 2s.

Puneet, the only way to fix this has been to block all http request on specific pages by adding a filter 'pre_http_request'.
Here is a sample code: http://pastebin.com/5bji3rQG 
This is not pretty but this should give you a starting point.

Before experimenting with this, you can always test by adding 
define( 'WP_HTTP_BLOCK_EXTERNAL', TRUE ); 
in your wp-config. This will block ALL external HTTP requests on ALL pages. This should tell you if you're on a good track before going any further.

On a side note, WP_HTTP_BLOCK_EXTERNAL can be also be customized this way:

// block external requests except the white-list hosts
define('WP_HTTP_BLOCK_EXTERNAL', true); 
// allow external requests
define('WP_HTTP_BLOCK_EXTERNAL', false); 
// white-list hosts comma separated
define('WP_ACCESSIBLE_HOSTS', 'api.wordpress.org '); 

Remember this one will affect all pages. While it's good for specific purpose, it didn't do the trick for me/

Source:
https://www.facebook.com/groups/advancedwp/permalink/885292874866261/?comment_id=885456564849892&offset=0&total_comments=74

wp_http_request_block

function block_api_calls() {		
		global $pagenow;
		if (( $pagenow == 'plugins.php' ) || 
		( $pagenow == 'plugin-install.php' ) || 
		( $pagenow == 'themes.php' ) || 
		( $pagenow == 'update.php' ) || 
		( $pagenow == 'index.php' ) || 
		( $pagenow == 'admin.php' ) || 
		( $pagenow == 'update-core.php' )){
			 add_filter( 'pre_http_request', '__return_false', 100 );
		}
		else{
			 add_filter( 'pre_http_request', '__return_true', 100 );
		}		
	}
add_action( 'admin_init', 'block_api_calls', 1 );