package Ġio . lib p 2 p . pubsub Ċ Ċ class ĠMax Count Topic Subscription Filter ( ĊĠĠĠ Ġprivate Ġval Ġmax Subscriptions Per Request : ĠInt , ĊĠĠĠ Ġprivate Ġval Ġmax Sub scribed Topics : ĠInt , ĊĠĠĠ Ġprivate Ġval Ġdelegate Filter : ĠTopic Subscription Filter Ċ ) Ġ: ĠTopic Subscription Filter Ġ{ ĊĠĠĠ Ġoverride Ġfun Ġcan Subscribe ( topic : ĠTopic ): ĠBoolean Ġ= ĊĠĠĠĠĠĠĠ Ġdelegate Filter . can Subscribe ( topic ) ĊĊĠĠĠ Ġoverride Ġfun Ġfilter Incoming Subscriptions ( ĊĠĠĠĠĠĠĠ Ġsubscriptions : ĠCollection < Pub sub Subscription >, ĊĠĠĠĠĠĠĠ Ġcurrently Sub scribed Topics : ĠCollection < Topic > ĊĠĠĠ Ġ): ĠCollection < Pub sub Subscription > Ġ{ ĊĠĠĠĠĠĠĠ Ġif Ġ( subscriptions . size Ġ> Ġmax Subscriptions Per Request ) Ġ{ ĊĠĠĠĠĠĠĠĠĠĠĠ Ġthrow ĠInvalid Message Exception (" Too Ġmany Ġsubscriptions Ġper Ġrequest ") ĊĠĠĠĠĠĠĠ Ġ} ĊĠĠĠĠĠĠĠ Ġval Ġfiltered Subscriptions Ġ= ĊĠĠĠĠĠĠĠĠĠĠĠ Ġdelegate Filter . filter Incoming Subscriptions ( subscriptions , Ġcurrently Sub scribed Topics ) ĊĊĠĠĠĠĠĠĠ Ġvar Ġun subscribed Ġ= Ġ 0 ĊĠĠĠĠĠĠĠ Ġvar Ġnew Sub scribed Ġ= Ġ 0 ĊĠĠĠĠĠĠĠ Ġfiltered Subscriptions . forEach Ġ{ Ġsubscription : ĠPub sub Subscription Ġ-> ĊĠĠĠĠĠĠĠĠĠĠĠ Ġval Ġcurrently Sub scribed Ġ= Ġcurrently Sub scribed Topics . contains ( subscription . topic ) ĊĠĠĠĠĠĠĠĠĠĠĠ Ġif Ġ( subscription . subscribe Ġ&& Ġ! currently Sub scribed ) Ġnew Sub scribed ++ ĊĠĠĠĠĠĠĠĠĠĠĠ Ġif Ġ(! subscription . subscribe Ġ&& Ġcurrently Sub scribed ) Ġun subscribed ++ ĊĠĠĠĠĠĠĠ Ġ} ĊĊĠĠĠĠĠĠĠ Ġif Ġ( currently Sub scribed Topics . size Ġ+ Ġnew Sub scribed Ġ- Ġun subscribed Ġ> Ġmax Sub scribed Topics ) Ġ{ ĊĠĠĠĠĠĠĠĠĠĠĠ Ġthrow ĠInvalid Message Exception (" Too Ġmany Ġsubscribed Ġtopics ") ĊĠĠĠĠĠĠĠ Ġ} ĊĠĠĠĠĠĠĠ Ġreturn Ġfiltered Subscriptions ĊĠĠĠ Ġ} Ċ } Ċ