Class: Tina4::RateLimiterMiddleware

Inherits:
Object
  • Object
show all
Defined in:
lib/tina4/middleware.rb

Overview

RateLimiterMiddleware -- tracks requests per IP, returns 429 when exceeded. Config via env: TINA4_RATE_LIMIT (default 100), TINA4_RATE_WINDOW (default 60s).

Class Method Summary collapse

Class Method Details

.before_rate_limit(request, response) ⇒ Object 



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# File 'lib/tina4/middleware.rb', line 447

def before_rate_limit(request, response)
  limit  = (ENV["TINA4_RATE_LIMIT"]  || 100).to_i
  window = (ENV["TINA4_RATE_WINDOW"] || 60).to_i
  ip = request.ip || "unknown"
  now = Time.now

  cleanup_if_needed(now, window)

  @mutex.synchronize do
    @store[ip] ||= []
    entries = @store[ip]

    # Sliding window -- drop expired timestamps
    cutoff = now - window
    entries.reject! { |t| t < cutoff }

    if entries.length >= limit
      oldest = entries.first
      retry_after = [(oldest + window - now).ceil, 1].max

      response.headers["X-RateLimit-Limit"]     = limit.to_s
      response.headers["X-RateLimit-Remaining"]  = "0"
      response.headers["X-RateLimit-Reset"]      = (oldest + window).to_i.to_s
      response.headers["Retry-After"]            = retry_after.to_s
      response.json({ error: "Too Many Requests", retry_after: retry_after }, 429)

      return [request, response]
    end

    entries << now

    response.headers["X-RateLimit-Limit"]     = limit.to_s
    response.headers["X-RateLimit-Remaining"]  = (limit - entries.length).to_s
    response.headers["X-RateLimit-Reset"]      = (now + window).to_i.to_s
  end

  [request, response]
end

.check(ip) ⇒ Object 



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# File 'lib/tina4/middleware.rb', line 486

def check(ip)
  limit  = (ENV["TINA4_RATE_LIMIT"]  || 100).to_i
  window = (ENV["TINA4_RATE_WINDOW"] || 60).to_i
  now = Time.now

  @mutex.synchronize do
    @store[ip] ||= []
    entries = @store[ip]
    entries.reject! { |t| t < now - window }

    remaining = [limit - entries.length, 0].max
    reset_at  = entries.empty? ? window : (entries.first + window - now).ceil

    if entries.length >= limit
      return [false, { limit: limit, remaining: 0, reset: reset_at, window: window }]
    end

    entries << now
    [true, { limit: limit, remaining: remaining - 1, reset: window, window: window }]
  end
end

.reset! ⇒ Object

Allow resetting state (useful in tests)



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# File 'lib/tina4/middleware.rb', line 509

def reset!
  @mutex.synchronize { @store.clear }
end