memory.c File Reference

🧠 In-memory rate limiting backend using uthash More...

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Data Structures
struct	rate_event_s
	The useful part of memory backend is in events, lock: together they describe what is pending, who owns it, and how much data is valid. Keep the object with its parent operation and use the parent cleanup path. More...
struct	memory_backend_t
	Memory backend data. More...

Macros
#define	NETWORK_RATE_LIMIT_MEMORY_KEY_BUFFER_SIZE   256
#define	RATE_LIMIT_INITIAL_EVENT_CAPACITY   100

Typedefs
typedef struct rate_event_s	rate_event_t
	The useful part of memory backend is in events, lock: together they describe what is pending, who owns it, and how much data is valid. Keep the object with its parent operation and use the parent cleanup path.

Functions
void *	memory_backend_create (void)
	Create memory backend instance.

Variables
const rate_limiter_backend_ops_t	memory_backend_ops
	Memory backend operations vtable.

Detailed Description

🧠 In-memory rate limiting backend using uthash

Thread-safe implementation for ascii-chat server where persistence is not needed.

Definition in file memory.c.

Macro Definition Documentation

NETWORK_RATE_LIMIT_MEMORY_KEY_BUFFER_SIZE

#define NETWORK_RATE_LIMIT_MEMORY_KEY_BUFFER_SIZE   256

Definition at line 9 of file memory.c.

RATE_LIMIT_INITIAL_EVENT_CAPACITY

#define RATE_LIMIT_INITIAL_EVENT_CAPACITY   100

Definition at line 12 of file memory.c.

Typedef Documentation

rate_event_t

typedef struct rate_event_s rate_event_t

The useful part of memory backend is in events, lock: together they describe what is pending, who owns it, and how much data is valid. Keep the object with its parent operation and use the parent cleanup path.

Per-address, per-event timestamp ring used by the in-memory limiter

Per-address, per-event timestamp ring used by the in-memory limiter.

key combines the client address and event type; timestamps stores the recent event times, while count, capacity, and head manage the circular window. The hash handle lets the backend find this record quickly.

Function Documentation

memory_backend_create()

void * memory_backend_create

(

void

)

Create memory backend instance.

Returns

Backend instance or NULL on failure

Definition at line 256 of file memory.c.

                                  {
  memory_backend_t *backend = SAFE_MALLOC(sizeof(memory_backend_t), memory_backend_t *);
  if (!backend) {
    log_error("Failed to allocate memory backend");
    return NULL;
  }
 
  defer_named(release_backend, SAFE_FREE(backend));
  memset(backend, 0, sizeof(*backend));
 
  if (mutex_init(&backend->lock, "rate_limiter") != 0) {
    log_error("Failed to initialize mutex");
    return NULL;
  }
 
  log_debug("Memory rate limiter backend initialized");
  defer_cancel(release_backend);
  return backend;
}

References memory_backend_t::lock, log_debug, log_error, SAFE_FREE, and SAFE_MALLOC.

Referenced by rate_limiter_create_memory().

Variable Documentation

memory_backend_ops

const rate_limiter_backend_ops_t memory_backend_ops

Initial value:

= {
    .check = memory_check,
    .record = memory_record,
    .cleanup = memory_cleanup,
    .destroy = memory_destroy,
}

Memory backend operations vtable.

Definition at line 276 of file memory.c.

                                                      {
    .check = memory_check,
    .record = memory_record,
    .cleanup = memory_cleanup,
    .destroy = memory_destroy,
};

Referenced by rate_limiter_create_memory().