/*
    Copyright (c)  2013 IOnU Security Inc. All rights reserved
    Created October 2013 by Kendrick Webster
    
    K2Daemon/ClientMap.h - header for client map module
    
    This module facilitates efficient (hashed) bidirectional mapping
    of client device URN strings to/from numeric IDs.
 
    The outside world (CloudGuard and the client devices themselves) use
    device URN strings as unique client identifiers.  Internally this
    daemon uses client ID numbers for efficiency.
*/
#pragma once

namespace ClientMap
{
    typedef uint64_t id_t;
    
    // valid IDs are non-zero
    static const id_t NULL_ID = 0;
    
    // get URN from ID
    // returns NULL if the client is not mapped
    // CAUTION: the returned pointer will become invalid (must be discarded) if the client is later unmapped
    const char* UrnFromId(id_t id);
    
    // get ID from URN
    // returns NULL_ID if the client is not mapped
    id_t IdFromUrn(const char* urn);
    
    // get ID from URN
    // adds client to map if it isn't already mapped
    id_t Map(const char* urn);
    
    // remove client from map
    void Unmap(const char* urn);
    
    // returns the number of connected (mapped) clients
    unsigned int Count(void);
}