Class: PostHog::Rails::Logs::RateLimiter Private

Inherits:
Object
  • Object
show all
Defined in:
lib/posthog/rails/logs/rate_limiter.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Fixed-window rate limiter protecting the PostHog Logs ingestion quota from runaway log volume (PostHog Logs bills by data ingested).

Thread-safe: the counter is the one piece of shared mutable state in the logs pipeline, guarded by a mutex scoped to a counter bump.

Constant Summary collapse

WINDOW_SECONDS =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

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Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(limit) ⇒ RateLimiter

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of RateLimiter.

Parameters:

  • limit (Integer) —

    Maximum records allowed per WINDOW_SECONDS window.



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# File 'lib/posthog/rails/logs/rate_limiter.rb', line 20

def initialize(limit)
  @limit = limit
  @mutex = Mutex.new
  @window = nil
  @count = 0
end

Instance Attribute Details

#limit ⇒ Integer (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns Maximum records allowed per window.

Returns:

  • (Integer) —

    Maximum records allowed per window.



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# File 'lib/posthog/rails/logs/rate_limiter.rb', line 17

def limit
  @limit
end

Instance Method Details

#record ⇒ Symbol

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Records one attempt and returns the verdict.

Returns:

  • (Symbol) —

    :allow when under the cap, :reject_first for the first rejection of a window (callers may emit a single notice), :reject thereafter.



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# File 'lib/posthog/rails/logs/rate_limiter.rb', line 32

def record
  @mutex.synchronize do
    window = Process.clock_gettime(Process::CLOCK_MONOTONIC).to_i / WINDOW_SECONDS
    if window != @window
      @window = window
      @count = 0
    end
    @count += 1
    next :allow if @count <= @limit

    @count == @limit + 1 ? :reject_first : :reject
  end
end