Ratelimiting

Enforce ratelimiting per the official Discord Documentation. More...

Collaboration diagram for Ratelimiting:

Data Structures
struct	discord_ratelimiter
	The ratelimiter struct for handling ratelimiting. More...
struct	discord_bucket
	The Discord bucket for handling per-group ratelimits. More...

Macros
#define	DISCORD_BUCKET_TIMEOUT   (void *)(0xf)
	Value assigned to discord_bucket busy_req field in case it's being timed-out. More...

Functions
void	discord_ratelimiter_init (struct discord_ratelimiter *rl, struct logconf *conf)
	Initialize ratelimiter handle. More...
void	discord_ratelimiter_cleanup (struct discord_ratelimiter *rl)
	Cleanup all buckets that have been discovered. More...
void	discord_ratelimiter_build_key (enum http_method method, char key[256], const char endpoint_fmt[], va_list args)
	Build unique key formed from the HTTP method and endpoint. More...
void	discord_ratelimiter_build (struct discord_ratelimiter *rl, struct discord_bucket *bucket, const char key[], struct ua_info *info)
	Update the bucket with response header data. More...
void	discord_ratelimiter_set_global_timeout (struct discord_ratelimiter *rl, struct discord_bucket *bucket, u64unix_ms wait_ms)
	Update global ratelimiting value. More...
void	discord_bucket_set_timeout (struct discord_bucket *bucket, u64unix_ms wait_ms)
	Set bucket timeout. More...
struct discord_bucket *	discord_bucket_get (struct discord_ratelimiter *rl, const char key[])
	Get a struct discord_bucket assigned to key More...
void	discord_bucket_insert (struct discord_ratelimiter *rl, struct discord_bucket *b, struct discord_request *req, bool high_priority)
	Insert into bucket's next requests queue. More...
void	discord_bucket_request_selector (struct discord_ratelimiter *rl, void *data, void(*iter)(void *data, struct discord_request *req))
	Iterate and select next requests. More...
void	discord_bucket_request_unselect (struct discord_ratelimiter *rl, struct discord_bucket *b, struct discord_request *req)
	Unselect a request provided at discord_ratelimiter_request_selector() More...

Detailed Description

Enforce ratelimiting per the official Discord Documentation.

Macro Definition Documentation

DISCORD_BUCKET_TIMEOUT

#define DISCORD_BUCKET_TIMEOUT   (void *)(0xf)

Value assigned to discord_bucket busy_req field in case it's being timed-out.

Function Documentation

discord_ratelimiter_init()

void discord_ratelimiter_init	(	struct discord_ratelimiter *	rl,
		struct logconf *	conf
	)

Initialize ratelimiter handle.

A hashtable shall be used for storage and retrieval of discovered buckets

Parameters

rl	the ratelimiter handle to be initialized
conf	pointer to discord_rest logging module

discord_ratelimiter_cleanup()

void discord_ratelimiter_cleanup

(

struct discord_ratelimiter *

rl

)

Cleanup all buckets that have been discovered.

Note

pending requests will be moved to rest.queues->recycling

Parameters

rl	the handle initialized with discord_ratelimiter_init()

discord_ratelimiter_build_key()

void discord_ratelimiter_build_key	(	enum http_method	method,
		char	key[256],
		const char	endpoint_fmt[],
		va_list	args
	)

Build unique key formed from the HTTP method and endpoint.

See also

https://discord.com/developers/docs/topics/rate-limits

Parameters

[in]	method	the request method
[out]	key	unique key for matching to buckets
[in]	endpoint_fmt	the printf-like endpoint formatting string
[in]	args	variadic arguments matched to endpoint_fmt

discord_ratelimiter_build()

void discord_ratelimiter_build	(	struct discord_ratelimiter *	rl,
		struct discord_bucket *	bucket,
		const char	key[],
		struct ua_info *	info
	)

Update the bucket with response header data.

Parameters

rl	the handle initialized with discord_ratelimiter_init()
bucket	NULL when bucket is first discovered
key	obtained from discord_ratelimiter_build_key()
info	informational struct containing details on the current transfer

Note

If the bucket was just discovered it will be created here.

discord_ratelimiter_set_global_timeout()

void discord_ratelimiter_set_global_timeout	(	struct discord_ratelimiter *	rl,
		struct discord_bucket *	bucket,
		u64unix_ms	wait_ms
	)

Update global ratelimiting value.

Todo:

check if all pending buckets must be unset

Parameters

rl	the handle initialized with discord_ratelimiter_init()
bucket	bucket that received the global ratelimiting notice
wait_ms	the amount of time that all buckets should wait for

discord_bucket_set_timeout()

void discord_bucket_set_timeout	(	struct discord_bucket *	bucket,
		u64unix_ms	wait_ms
	)

Set bucket timeout.

Parameters

bucket	the bucket to be checked for time out
wait_ms	how long the bucket should wait for

discord_bucket_get()

struct discord_bucket * discord_bucket_get	(	struct discord_ratelimiter *	rl,
		const char	key[]
	)

Get a struct discord_bucket assigned to key

Parameters

rl	the handle initialized with discord_ratelimiter_init()
key	obtained from discord_ratelimiter_build_key()

Returns

bucket matched to key

discord_bucket_insert()

void discord_bucket_insert	(	struct discord_ratelimiter *	rl,
		struct discord_bucket *	b,
		struct discord_request *	req,
		bool	high_priority
	)

Insert into bucket's next requests queue.

Parameters

rl	the handle initialized with discord_ratelimiter_init()
b	the bucket to insert the request to
req	the request to be inserted to bucket
high_priority	if high priority then request shall be prioritized over already enqueued requests

discord_bucket_request_selector()

void discord_bucket_request_selector	(	struct discord_ratelimiter *	rl,
		void *	data,
		void(*)(void *data, struct discord_request *req)	iter
	)

Iterate and select next requests.

Note

discord_bucket_unselect() must be called once bucket's current request is done and its next one should be selected

Parameters

rl	the handle initialized with discord_ratelimiter_init()
data	user arbitrary data
iter	the user callback to be called per bucket

discord_bucket_request_unselect()

void discord_bucket_request_unselect	(	struct discord_ratelimiter *	rl,
		struct discord_bucket *	b,
		struct discord_request *	req
	)

Unselect a request provided at discord_ratelimiter_request_selector()

Note

counterpart to discord_ratelimiter_request_selector()

Parameters

rl	the handle initialized with discord_ratelimiter_init()
b	the request's bucket
req	the request to unslect