/* See the DRL-LICENSE file for this file's software license. */

#ifndef _DRL_CONFIG_
#define _DRL_CONFIG_

struct drl_instance;

/** Enumeration of identity types. */
enum ident_types {

    /** Type used by identities that will limit all slivers on the machine. */
    IDENT_MACHINE = 1,

    /** Type used by identities that will limit only a subset of slivers. */
    IDENT_SET = 2
};

/** Enumeration of identity member types. */
enum member_types {

    /** The member is an identifier (xid) of a single sliver. */
    MEMBER_XID = 1,

    /** The member is an identifier (guid) of another sliver-set identity. */
    MEMBER_GUID = 2
};

/**
 * Linked list node containing address information for one of the identity's
 * peers.
 */
typedef struct ident_peer {
    /** The peer's IP address. */
    in_addr_t ip;

    /** Pointer to the next peer in the list or NULL if this is the last. */
    struct ident_peer *next;
} ident_peer;

/**
 * Linked list node containing hierarchy information.  For whole-machine
 * identities, this is unnecessary.  For sliver-set identities, this specifies
 * which slivers and other sliver-sets belong in the set.
 */
typedef struct ident_member {
    /** The numerical xid or guid of the member. */
    int value;

    /** Specifies whether the value is an xid or guid. */
    enum member_types type;

    /** Pointer to the next member in the list or NULL if this is the last. */
    struct ident_member *next;
} ident_member;

/**
 * Linked list node containing identity information.
 */
typedef struct ident_config {
    /** The guid of this identity. */
    int id;

    /** The global DRL limit for this identity. */
    int limit;

    /** The communication fabric (COMM_MESH or COMM_GOSSIP) for this identity.*/
    enum commfabrics commfabric;

    /** The gossip branch factor (when commfabric is COMM_GOSSIP). */
    int branch;

    /** The flow accounting mechanism to be used by this identity. */
    enum accountings accounting;

    /** The fixed (1-second) ewma weight value for this identity. */
    double fixed_ewma_weight;

    /** The number of estimate intervals to wait between calls to estimate,
     * allocate and enforce. */
    int intervals;

    /** The type of this identity. */
    enum ident_types type;

    /** List of the identity's peers. */
    ident_peer *peers;

    /** The number of peers. */
    int peer_count;

    /** List of the identity's members (type IDENT_SET only). */
    ident_member *members;

    /** Pointer to the next ident in the list or NULL if this is the last. */
    struct ident_config *next;
} ident_config;

/**
 * Structure used to pass two lists after parsing is complete.
 */
typedef struct parsed_configs {
    /** A list of IDENT_MACHINE type identities. */
    ident_config *machines;

    /** The number of machine identities. */
    int machine_count;

    /** A list of IDENT_SET type identities. */
    ident_config *sets;

    /** The number of set identities. */
    int set_count;

    /** Pointer to the tail of the machines list. */
    ident_config *last_machine;

    /** Pointer to the tail of the sets list. */
    ident_config *last_set;
} parsed_configs;

/**
 * Frees the specified ident and all of the memory associated with it and its
 * fields.
 *
 * @param ident The ident to free.
 */
void free_ident(ident_config *ident);

/**
 * Frees the specified list of identities and all of the memory associated
 * with them.
 *
 * @param list The ident_config list to free.
 */
void free_ident_list(ident_config *list);

/**
 * Uses libxml2 to parse a DRL configuration XML file and converts the
 * information into a linked list of identities.
 *
 * @param configfile The path to the XML configuration file.
 * @param configs A parsed_configs structure to be filled in with linked list
 * of machine and set configs.
 *
 * @returns zero on success, non-zero on error.
 */
int parse_drl_config(const char *configfile, parsed_configs *configs);

/**
 * Reads /proc/virtual to get a list of viable xids.  It creates an array of
 * leaf_t structures and a map that maps xid to the leaf_t in the array with
 * the xid.
 *
 * @param instance The drl_instance_t to be filled in.  This function sets
 * the instance's leaf_map, leaves, and leaf_count fields.
 *
 * @returns zero on success, non-zero on error. (Possibly ENOMEM if memory
 * allocation fails, or 1 if the cause of the error is unclear. */
int get_eligible_leaves(struct drl_instance *instance);

#endif  /* _DRL_CONFIG_ */