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5.29 libnod

5.29.1 Overview

View lcov test coverage results on http://www.gnu.org/software/liquidwar6/coverage/src/lib/nod/index.html.

5.29.2 API

— Function: void lw6nod_dyn_info_free (lw6nod_dyn_info_t * dyn_info)

dyn_info: the dyn info struct to free

Frees a dyn info object, to be used after a call to lw6nod_info_dup_dyn for instance.

Return value: none

— Function: lw6nod_info_t * lw6nod_info_new (char * program, char * version, char * codename, int stamp, u_int64_t id, char * url, char * title, char * description, char * password, int bench, int open_relay, int uptime, int idle_screenshot_size, void * idle_screenshot_data)

program: the program (normally it's liquidwar6)

version: the version

codename: the codename

stamp: the stamp

id: the node id

url: the node public url

title: the node title

description: the node description

password: the node password

bench: the node bench

open_relay: open relay or not

uptime: uptime in seconds

idle_screenshot_size: the size (bytes) of the image to display when game is idle

idle_screenshot_data: the data (jpeg) of the image to display when game is idle

Creates a node info object. The arguments correspond to the immutable node attributes, other properties such as how many players are connected or set in other functions like lw6nod_info_update which can be called later.

Return value: newly allocated object, NULL on error.

— Function: void lw6nod_info_free (lw6nod_info_t * info)

info: the node info to free

Frees a node info object.

Return value: none

— Function: int lw6nod_info_lock (lw6nod_info_t * info)

info: the node info to lock

Locks a node info object, this is usefull for some members, typically list of servers, can be accessed by separated threads, one reading, many writing, and these objects (chained lists) certainly do not want to be modified while being read.

Return value: 1 if ok, 0 if not.

— Function: int lw6nod_info_unlock (lw6nod_info_t * info)

info: the node info to unlock

Unlocks a node info object, this is the compation of the lw6nod_info_lock function.

Return value: 1 if ok, 0 if not.

— Function: void lw6nod_info_idle (lw6nod_info_t * info)

info: the node info to modify

Clears a node info object and sets all its variable attributes to NULL/default values. This is what we want when the node is idle, not playing.

Return value: none.

— Function: int lw6nod_info_update (lw6nod_info_t * info, u_int64_t community_id, int round, char * level, int required_bench, int nb_colors, int max_nb_colors, int nb_cursors, int max_nb_cursors, int nb_nodes, int max_nb_nodes, int game_screenshot_size, void * game_screenshot_data)

info: the node info to update

community_id: the id of the community the node belongs to

round: the current round (can have an offset with real round number)

level: the name of the current level (map)

required_bench: the bench required to connect

nb_colors: number of colors playing

max_nb_colors: max number of colors allowed

nb_cursors: number of cursors playing

max_nb_cursors: max number of cursors allowed

nb_nodes: number of nodes playing

max_nb_nodes: max number of nodes allowed

game_screenshot_size: size of screenshot (bytes)

game_screenshot_data: screenshot data (byte buffer, contains JPEG)

Set a node info object variable attributes. Call this whenever the node has changed some parameter. Not too often for it's not needed and some operations such as modying the screenshot, can be time consuming.

Return value: 1 if OK, 0 if error.

— Function: lw6nod_dyn_info_t * lw6nod_info_dup_dyn (lw6nod_info_t * info)

info: the node info containing the dyn info to duplicate

Extracts the dynamic part of an info struct and duplicates it, this is to avoid protection fault error when concurrent threads access this info.

Return value: newly allocated object, must be freed.

— Function: lw6sys_hash_t * lw6nod_info_new_discovered_nodes ()

Creates a new hash, to be used as a discovered nodes list. Using this function has the advantage of setting the hash options to their defaults. We use a hash to avoid having uselessly long lists containing always the same node due to multiple detections.

Return value: an empty hash

— Function: int lw6nod_info_add_discovered_node (lw6nod_info_t * info, char * public_url)

info: the node info to update

public_url: the address of the discovered node

Registers a new server, and queues it as something that should be checked later because it's interesting. We can't insert in the database all the servers we suspect to exist so network threads should use this, then main thread will process discovered servers afterwards. This is also a good way to avoid trivial DOS attacks.

Return value: 1 if OK, O if error.

— Function: lw6sys_list_t * lw6nod_info_pop_discovered_nodes (lw6nod_info_t * info)

info: the node info to query

Returns a list of all discovered nodes (their public URL) and empties the current queue as well.

Return value: a list of dynamically allocated strings.

— Function: lw6sys_list_t * lw6nod_info_new_verified_nodes ()

Creates a new list, to be filled with nodes and typically passed to lw6nod_info_set_verified_nodes. Using this function has the advantage of setting the listh options to their defaults.

Return value: an empty list

— Function: int lw6nod_info_set_verified_nodes (lw6nod_info_t * info, lw6sys_list_t * list)

info: the node info to modify

list: the list of verified nodes, will be freed by this function

Sets the list of verified nodes, that is, the list of nodes we are sure to exist, this is typically the list we will display later on a web page. We can't directly display any discovered node, one needs to filter them through main thread. Something very important about this function is that list will be freed by function, that is, if you call this, then you can (you should) forget your object, it will disappear any time soon.

Return value: 1 if OK, 0 on error.

— Function: void lw6nod_info_map_verified_nodes (lw6nod_info_t * info, lw6sys_list_callback_func_t func, void * func_data)

info: the node info concerned

func: the function to apply

func_data: arbitrary pointer holding data to pass to function

Calls lw6sys_hash_map with func on every member of the list of verified nodes. The reason there's a function for this is that it is very important that list object is locked when doing this. This function does perform a lock/unlock so it is safe.

Return value: none.

— Function: int lw6nod_test (int mode)

mode: 0 for check only, 1 for full test

Runs the nod module test suite.

Return value: 1 if test is successfull, 0 on error.