Class: Faye::Redis::SubscriptionManager

Inherits:
Object
  • Object
show all
Defined in:
lib/faye/redis/subscription_manager.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(connection, options = {}) ⇒ SubscriptionManager

Returns a new instance of SubscriptionManager.



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# File 'lib/faye/redis/subscription_manager.rb', line 6

def initialize(connection, options = {})
  @connection = connection
  @options = options
  @pattern_cache = {}  # Cache compiled regexes for pattern matching performance
end

Instance Attribute Details

#connection ⇒ Object (readonly)

Returns the value of attribute connection.



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# File 'lib/faye/redis/subscription_manager.rb', line 4

def connection
  @connection
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/faye/redis/subscription_manager.rb', line 4

def options
  @options
end

Instance Method Details

#channel_matches_pattern?(channel, pattern) ⇒ Boolean

Check if a channel matches a pattern Uses memoization to cache compiled regexes for performance

Returns:

  • (Boolean) 


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# File 'lib/faye/redis/subscription_manager.rb', line 212

def channel_matches_pattern?(channel, pattern)
  # Get or compile regex for this pattern
  regex = @pattern_cache[pattern] ||= begin
    # Escape the pattern first to handle special regex characters
    # Then replace escaped wildcards with regex patterns
    # ** matches multiple segments (including /), * matches one segment (no /)
    escaped = Regexp.escape(pattern)

    regex_pattern = escaped
      .gsub(Regexp.escape('**'), '.*')        # ** → .* (match anything)
      .gsub(Regexp.escape('*'), '[^/]+')      # * → [^/]+ (match one segment)

    Regexp.new("^#{regex_pattern}$")
  end

  !!(channel =~ regex)
rescue RegexpError => e
  log_error("Invalid pattern #{pattern}: #{e.message}")
  false
end

#cleanup_client_subscriptions(client_id) ⇒ Object

Clean up subscriptions for a client



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# File 'lib/faye/redis/subscription_manager.rb', line 234

def cleanup_client_subscriptions(client_id)
  unsubscribe_all(client_id)
end

#cleanup_orphaned_data(active_client_ids, &callback) ⇒ Object

Comprehensive cleanup of orphaned subscription data This should be called periodically during garbage collection Processes in batches to avoid blocking the connection pool



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# File 'lib/faye/redis/subscription_manager.rb', line 241

def cleanup_orphaned_data(active_client_ids, &callback)
  active_set = active_client_ids.to_set
  namespace = @options[:namespace] || 'faye'
  batch_size = @options[:cleanup_batch_size] || 50

  # Validate and clamp batch_size to safe range (1-1000)
  batch_size = [[batch_size.to_i, 1].max, 1000].min

  # Phase 1: Scan for orphaned subscriptions
  scan_orphaned_subscriptions(active_set, namespace) do |orphaned_subscriptions|
    # Phase 2: Clean up orphaned subscriptions in batches
    cleanup_orphaned_subscriptions_batched(orphaned_subscriptions, namespace, batch_size) do
      # Phase 3: Clean up orphaned message queues
      cleanup_orphaned_message_queues_async(active_set, namespace, batch_size) do
        # Phase 4: Clean up empty channels (yields between operations)
        cleanup_empty_channels_async(namespace) do
          # Phase 5: Clean up unused patterns
          cleanup_unused_patterns_async do
            callback.call if callback
          end
        end
      end
    end
  end
rescue => e
  log_error("Failed to cleanup orphaned data: #{e.message}")
  EventMachine.next_tick { callback.call } if callback
end

#get_client_subscriptions(client_id, &callback) ⇒ Object

Get all channels a client is subscribed to



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# File 'lib/faye/redis/subscription_manager.rb', line 151

def get_client_subscriptions(client_id, &callback)
  channels = @connection.with_redis do |redis|
    redis.smembers(client_subscriptions_key(client_id))
  end

  EventMachine.next_tick { callback.call(channels) } if callback
  channels
rescue => e
  log_error("Failed to get subscriptions for client #{client_id}: #{e.message}")
  EventMachine.next_tick { callback.call([]) } if callback
  []
end

#get_pattern_subscribers(channel) ⇒ Object

Get subscribers matching wildcard patterns



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# File 'lib/faye/redis/subscription_manager.rb', line 185

def get_pattern_subscribers(channel)
  patterns = @connection.with_redis do |redis|
    redis.smembers(patterns_key)
  end

  # Filter to only matching patterns first
  matching_patterns = patterns.select { |pattern| channel_matches_pattern?(channel, pattern) }
  return [] if matching_patterns.empty?

  # Use pipelining to fetch all matching pattern subscribers in one network round-trip
  results = @connection.with_redis do |redis|
    redis.pipelined do |pipeline|
      matching_patterns.each do |pattern|
        pipeline.smembers(channel_subscribers_key(pattern))
      end
    end
  end

  # Flatten and deduplicate results
  results.flatten.uniq
rescue => e
  log_error("Failed to get pattern subscribers for channel #{channel}: #{e.message}")
  []
end

#get_subscribers(channel, &callback) ⇒ Object

Get all clients subscribed to a channel



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# File 'lib/faye/redis/subscription_manager.rb', line 165

def get_subscribers(channel, &callback)
  # Get direct subscribers
  direct_subscribers = @connection.with_redis do |redis|
    redis.smembers(channel_subscribers_key(channel))
  end

  # Get pattern subscribers
  pattern_subscribers = get_pattern_subscribers(channel)

  all_subscribers = (direct_subscribers + pattern_subscribers).uniq

  EventMachine.next_tick { callback.call(all_subscribers) } if callback
  all_subscribers
rescue => e
  log_error("Failed to get subscribers for channel #{channel}: #{e.message}")
  EventMachine.next_tick { callback.call([]) } if callback
  []
end

#refresh_client_subscriptions_ttl(client_id) ⇒ Object

Refresh TTL for all subscription keys related to a client Called during ping to keep subscriptions alive as long as client is connected



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# File 'lib/faye/redis/subscription_manager.rb', line 123

def refresh_client_subscriptions_ttl(client_id)
  subscription_ttl = @options[:subscription_ttl] || 3600

  @connection.with_redis do |redis|
    # Get all channels this client is subscribed to
    channels = redis.smembers(client_subscriptions_key(client_id))
    return if channels.empty?

    # Use pipeline to refresh all TTLs efficiently
    redis.pipelined do |pipeline|
      # Refresh client's subscriptions set
      pipeline.expire(client_subscriptions_key(client_id), subscription_ttl)

      # Refresh each subscription metadata and channel subscriber set
      channels.each do |channel|
        pipeline.expire(subscription_key(client_id, channel), subscription_ttl)
        pipeline.expire(channel_subscribers_key(channel), subscription_ttl)
      end

      # Refresh patterns set if it exists
      pipeline.expire(patterns_key, subscription_ttl)
    end
  end
rescue => e
  log_error("Failed to refresh subscription TTL for client #{client_id}: #{e.message}")
end

#subscribe(client_id, channel, &callback) ⇒ Object

Subscribe a client to a channel



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# File 'lib/faye/redis/subscription_manager.rb', line 13

def subscribe(client_id, channel, &callback)
  timestamp = Time.now.to_i
  subscription_ttl = @options[:subscription_ttl] || 3600  # 1 hour default (matches message_ttl)

  client_subs_key = client_subscriptions_key(client_id)
  channel_subs_key = channel_subscribers_key(channel)
  sub_key = subscription_key(client_id, channel)

  @connection.with_redis do |redis|
    # Use Lua script to atomically add subscriptions and set TTL only if keys have no TTL
    # This prevents resetting TTL on re-subscription
    redis.eval(<<-LUA, keys: [client_subs_key, channel_subs_key, sub_key], argv: [channel, client_id, timestamp.to_s, subscription_ttl])
      -- Add channel to client's subscriptions
      redis.call('SADD', KEYS[1], ARGV[1])
      local ttl1 = redis.call('TTL', KEYS[1])
      if ttl1 == -1 then
        redis.call('EXPIRE', KEYS[1], ARGV[4])
      end

      -- Add client to channel's subscribers
      redis.call('SADD', KEYS[2], ARGV[2])
      local ttl2 = redis.call('TTL', KEYS[2])
      if ttl2 == -1 then
        redis.call('EXPIRE', KEYS[2], ARGV[4])
      end

      -- Store subscription metadata
      redis.call('HSET', KEYS[3], 'subscribed_at', ARGV[3], 'channel', ARGV[1], 'client_id', ARGV[2])
      local ttl3 = redis.call('TTL', KEYS[3])
      if ttl3 == -1 then
        redis.call('EXPIRE', KEYS[3], ARGV[4])
      end

      return 1
    LUA

    # Handle wildcard patterns separately
    if channel.include?('*')
      redis.eval(<<-LUA, keys: [patterns_key], argv: [channel, subscription_ttl])
        redis.call('SADD', KEYS[1], ARGV[1])
        local ttl = redis.call('TTL', KEYS[1])
        if ttl == -1 then
          redis.call('EXPIRE', KEYS[1], ARGV[2])
        end
        return 1
      LUA
    end
  end

  EventMachine.next_tick { callback.call(true) } if callback
rescue => e
  log_error("Failed to subscribe client #{client_id} to #{channel}: #{e.message}")
  EventMachine.next_tick { callback.call(false) } if callback
end

#unsubscribe(client_id, channel, &callback) ⇒ Object

Unsubscribe a client from a channel



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# File 'lib/faye/redis/subscription_manager.rb', line 69

def unsubscribe(client_id, channel, &callback)
  @connection.with_redis do |redis|
    redis.multi do |multi|
      # Remove channel from client's subscriptions
      multi.srem?(client_subscriptions_key(client_id), channel)

      # Remove client from channel's subscribers
      multi.srem?(channel_subscribers_key(channel), client_id)

      # Delete subscription metadata
      multi.del(subscription_key(client_id, channel))
    end
  end

  # Clean up wildcard pattern if no more subscribers
  if channel.include?('*')
    cleanup_pattern_if_unused(channel)
  end

  EventMachine.next_tick { callback.call(true) } if callback
rescue => e
  log_error("Failed to unsubscribe client #{client_id} from #{channel}: #{e.message}")
  EventMachine.next_tick { callback.call(false) } if callback
end

#unsubscribe_all(client_id, &callback) ⇒ Object

Unsubscribe a client from all channels



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# File 'lib/faye/redis/subscription_manager.rb', line 95

def unsubscribe_all(client_id, &callback)
  # Get all channels the client is subscribed to
  get_client_subscriptions(client_id) do |channels|
    if channels.empty?
      callback.call(true) if callback
    else
      # Unsubscribe from each channel
      remaining = channels.size
      callback_called = false  # Prevent race condition
      channels.each do |channel|
        unsubscribe(client_id, channel) do
          remaining -= 1
          # Check flag to prevent multiple callback invocations
          if remaining == 0 && !callback_called && callback
            callback_called = true
            callback.call(true)
          end
        end
      end
    end
  end
rescue => e
  log_error("Failed to unsubscribe client #{client_id} from all channels: #{e.message}")
  EventMachine.next_tick { callback.call(false) } if callback
end