Function getClientReplicationBacklogSharedUsage

src/networking.cpp:3802–3804

In the case of a replica client, writes to said replica are using data from the replication backlog * as opposed to it's own internal buffer, this number should keep track of that */

/* In the case of a replica client, writes to said replica are using data from the replication backlog
 * as opposed to it's own internal buffer, this number should keep track of that */
unsigned long getClientReplicationBacklogSharedUsage(client *c) {
    return (!(c->flags & CLIENT_SLAVE) || !c->FPendingReplicaWrite() ) ? 0 : g_pserver->master_repl_offset - c->repl_curr_off;
}

/* This function returns the number of bytes that Redis is
 * using to store the reply still not read by the client.