Class: Magick::PerformanceMetrics

Inherits:
Object
  • Object
show all
Defined in:
lib/magick/performance_metrics.rb

Defined Under Namespace

Classes: Metric

Constant Summary collapse

METRICS_RING_CAP = 
1_000

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(batch_size: 100, flush_interval: 60, redis_enabled: nil) ⇒ PerformanceMetrics

Returns a new instance of PerformanceMetrics.



29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
 
# File 'lib/magick/performance_metrics.rb', line 29

def initialize(batch_size: 100, flush_interval: 60, redis_enabled: nil)
  @metrics = []
  @mutex = Mutex.new
  @usage_count = Hash.new(0) # Memory-only counts (reset on each process boot)
  @pending_updates = Hash.new(0) # For Redis batching (reset on each process boot)
  @flushed_counts = Hash.new(0) # Track counts that have been flushed to Redis (to avoid double-counting)
  @batch_size = batch_size
  @flush_interval = flush_interval
  @last_flush = Time.now
  # If redis_enabled is explicitly set, use it; otherwise default to false
  # It will be enabled later via enable_redis_tracking if Redis adapter is available
  @redis_enabled = redis_enabled.nil? ? false : redis_enabled
  # Cache expensive checks for performance
  @_rails_events_enabled = defined?(Magick::Rails::Events) && Magick::Rails::Events.rails8?
  @_adapter_available = nil # Will be cached on first check
  @_redis_available = nil # Will be cached on first check

  # Async recording queue for non-blocking metrics
  @async_queue = Queue.new
  @async_thread = nil
  @async_enabled = true # Enable async by default for performance
  @owner_pid = Process.pid
  start_async_processor
end

Instance Attribute Details

#redis_enabled ⇒ Object (readonly)

Public accessor for redis_enabled



73
74
75
 
# File 'lib/magick/performance_metrics.rb', line 73

def redis_enabled
  @redis_enabled
end

Instance Method Details

#average_duration(feature_name: nil, operation: nil) ⇒ Object 



249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
 
# File 'lib/magick/performance_metrics.rb', line 249

def average_duration(feature_name: nil, operation: nil)
  # Calculate from memory metrics (current process, not yet flushed).
  # Read under the mutex - the async processor appends to and evicts from
  # @metrics concurrently.
  memory_sum, memory_count = @mutex.synchronize do
    filtered = @metrics.select do |m|
      (feature_name.nil? || m.feature_name == feature_name.to_s) &&
        (operation.nil? || m.operation == operation.to_s) &&
        m.success
    end

    [filtered.sum(&:duration), filtered.length]
  end

  # Also get from Redis if available (persisted across processes)
  redis_sum = 0.0
  redis_count = 0
  begin
    redis = stats_redis_client
    if redis
      if feature_name && operation
        # Specific feature and operation
        sum_key = "magick:duration:sum:#{feature_name}:#{operation}"
        count_key = "magick:duration:count:#{feature_name}:#{operation}"
        redis_sum = redis.get(sum_key).to_f
        redis_count = redis.get(count_key).to_i
      elsif feature_name
        # All operations for this feature
        prefix = "magick:duration:sum:#{feature_name}:"
        scan_stats_keys(redis, "#{prefix}*").each do |sum_key|
          op = sum_key.to_s.sub(prefix, '')
          count_key = "magick:duration:count:#{feature_name}:#{op}"
          redis_sum += redis.get(sum_key).to_f
          redis_count += redis.get(count_key).to_i
        end
      else
        # All features and operations (not recommended, but supported)
        scan_stats_keys(redis, 'magick:duration:sum:*').each do |sum_key|
          count_key = sum_key.to_s.sub(':sum:', ':count:')
          redis_sum += redis.get(sum_key).to_f
          redis_count += redis.get(count_key).to_i
        end
      end
    end
  rescue StandardError
    # Silently fail
  end

  total_sum = memory_sum + redis_sum
  total_count = memory_count + redis_count

  return 0.0 if total_count == 0

  total_sum / total_count.to_f
end

#clear! ⇒ Object 



357
358
359
360
361
362
363
364
 
# File 'lib/magick/performance_metrics.rb', line 357

def clear!
  @mutex.synchronize do
    @metrics.clear
    @usage_count.clear
    @pending_updates.clear
    @flushed_counts.clear
  end
end

#enable_redis_tracking(enable: true) ⇒ Object 



225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
 
# File 'lib/magick/performance_metrics.rb', line 225

def enable_redis_tracking(enable: true)
  old_value = @redis_enabled
  @redis_enabled = enable

  # Flush any pending updates when enabling
  if enable && !@mutex.synchronize { @pending_updates.empty? }
    begin
      flush_to_redis
    rescue StandardError => e
      # Don't fail if flush fails - the flag is still set
      if defined?(::Rails) && ::Rails.env.development?
        warn "Magick: Failed to flush stats when enabling Redis tracking: #{e.message}"
      end
    end
  end

  # Verify the value was set (for debugging)
  if !(@redis_enabled == enable) && defined?(::Rails) && ::Rails.env.development?
    warn "Magick: Failed to set redis_enabled to #{enable}, current value: #{@redis_enabled}"
  end

  true
end

#ensure_async_processor! ⇒ Object

Restart the async processor after a fork. Child processes inherit a dead thread reference + a queue that was populated in the parent; both must be recreated. The inherited thread (if alive in the parent's address space at fork time) is killed so it cannot keep polling a detached queue.



58
59
60
61
62
63
64
65
66
67
68
69
70
 
# File 'lib/magick/performance_metrics.rb', line 58

def ensure_async_processor!
  return if @owner_pid == Process.pid

  stale_thread = @async_thread
  stale_queue = @async_queue
  @async_queue = Queue.new
  @async_thread = nil
  @owner_pid = Process.pid
  start_async_processor

  stale_queue&.close if stale_queue.respond_to?(:close)
  stale_thread&.kill
end

#flush_to_redis ⇒ Object 



186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
 
# File 'lib/magick/performance_metrics.rb', line 186

def flush_to_redis
  return if @mutex.synchronize { @pending_updates.empty? }

  # Never drain pending state when there is nowhere to write it. Without
  # this guard a deployment with no Redis credits @flushed_counts for
  # updates that were never persisted, and usage_count reads back zero.
  redis = stats_redis_client
  return if redis.nil?

  updates_to_flush = nil
  duration_stats_to_flush = {}
  @mutex.synchronize do
    return if @pending_updates.empty?

    updates_to_flush = @pending_updates.dup
    flushed_feature_names = updates_to_flush.keys.to_set
    @pending_updates.clear

    # Collect duration stats for flushed features
    # Group metrics by feature_name and operation, sum durations and count occurrences.
    # Each group carries its own metric objects so that only samples we
    # actually persist get dropped from memory afterwards.
    @metrics.each do |metric|
      next unless flushed_feature_names.include?(metric.feature_name) && metric.success

      key = "#{metric.feature_name}:#{metric.operation}"
      duration_stats_to_flush[key] ||= { sum: 0.0, count: 0, feature_name: metric.feature_name,
                                         operation: metric.operation, metrics: [] }
      duration_stats_to_flush[key][:sum] += metric.duration
      duration_stats_to_flush[key][:count] += 1
      duration_stats_to_flush[key][:metrics] << metric
    end
  end

  return if updates_to_flush.nil? || updates_to_flush.empty?

  write_flush_to_redis(redis, updates_to_flush, duration_stats_to_flush)
end

#flush_to_redis_if_needed ⇒ Object 



156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
 
# File 'lib/magick/performance_metrics.rb', line 156

def flush_to_redis_if_needed
  # Cache adapter availability check (expensive)
  if @_adapter_available.nil?
    adapter = Magick.adapter_registry || Magick.default_adapter_registry
    @_adapter_available = adapter
    @_redis_available = adapter.is_a?(Magick::Adapters::Registry) && adapter.redis_available? if adapter
  end

  return unless @_adapter_available
  return unless @_redis_available || @redis_enabled

  should_flush = false
  @mutex.synchronize do
    next if @pending_updates.empty?

    # Flush if we have enough pending updates (sum of all counts) or enough time has passed
    # Check total count of pending updates, not just number of keys
    total_pending_count = @pending_updates.values.sum
    should_flush = true if total_pending_count >= @batch_size || (Time.now - @last_flush) >= @flush_interval
  end

  flush_to_redis if should_flush
end

#force_flush_to_redis ⇒ Object

Force flush pending updates to Redis immediately Useful when you need up-to-date stats across processes



182
183
184
 
# File 'lib/magick/performance_metrics.rb', line 182

def force_flush_to_redis
  flush_to_redis
end

#most_used_features(limit: 10) ⇒ Object 



333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
 
# File 'lib/magick/performance_metrics.rb', line 333

def most_used_features(limit: 10)
  # Combine memory and Redis counts. The memory side is read under the
  # mutex because the async processor writes @usage_count.
  combined_counts = @mutex.synchronize { @usage_count.dup }

  # Always check Redis if adapter is available (not just if @redis_enabled)
  # This ensures we get the full count even if redis_enabled flag wasn't set correctly
  begin
    redis = stats_redis_client
    if redis
      # Get all stats keys
      scan_stats_keys(redis, 'magick:stats:*').each do |key|
        feature_name = key.to_s.sub('magick:stats:', '')
        redis_count = redis.get(key).to_i
        combined_counts[feature_name] = (combined_counts[feature_name] || 0) + redis_count
      end
    end
  rescue StandardError
    # Silently fail
  end

  combined_counts.sort_by { |_name, count| -count }.first(limit).to_h
end

#process_async_record(feature_name_str, operation_str, duration, success) ⇒ Object

Internal: Process metrics from async queue (runs in background thread)



93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
 
# File 'lib/magick/performance_metrics.rb', line 93

def process_async_record(feature_name_str, operation_str, duration, success)
  # Minimize mutex lock time - only update counters
  pending_count = nil
  total_pending = nil
  @mutex.synchronize do
    # Ring buffer: append, then evict oldest. Capping by refusing new
    # samples would freeze @metrics on the first METRICS_RING_CAP entries
    # whenever there is no Redis to drain it, so averages would report
    # boot-time behaviour forever.
    @metrics << Metric.new(feature_name_str, operation_str, duration, success: success)
    @metrics.shift while @metrics.length > METRICS_RING_CAP
    @usage_count[feature_name_str] += 1
    @pending_updates[feature_name_str] += 1
    pending_count = @pending_updates[feature_name_str]
    total_pending = @pending_updates.values.sum
  end

  # Rails 8+ event for usage tracking (cached check)
  if @_rails_events_enabled
    Magick::Rails::Events.usage_tracked(feature_name_str, operation: operation_str, duration: duration,
                                                          success: success)
  end

  # Batch flush check - only if we're close to batch size
  flush_to_redis_if_needed if pending_count >= @batch_size || total_pending >= @batch_size
end

#record(feature_name, operation, duration, success: true) ⇒ Object 



75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
 
# File 'lib/magick/performance_metrics.rb', line 75

def record(feature_name, operation, duration, success: true)
  # Fast path: push to async queue (non-blocking, zero overhead in hot path)
  # Queue#<< is thread-safe and lock-free - extremely fast!
  return unless @async_enabled

  # Push to async queue - this is lock-free and extremely fast
  # Use non-blocking push (will raise if queue is full, but our queue is unbounded)
  begin
    @async_queue << [feature_name.to_s, operation.to_s, duration, success]
  rescue ThreadError, ClosedQueueError
    # Queue is closed or thread died, disable async
    @async_enabled = false
  end

  nil
end

#start_async_processor ⇒ Object

Start background thread to process async metrics



121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
 
# File 'lib/magick/performance_metrics.rb', line 121

def start_async_processor
  return if @async_thread&.alive?

  @async_thread = Thread.new do
    last_flush_check = Time.now
    loop do
      # Wait for metrics with timeout to allow periodic flush checks
      # Queue#pop with timeout returns nil on timeout, raises on closed queue
      begin
        data = @async_queue.pop(timeout: 1.0)
      rescue ThreadError => e
        # Queue closed or thread interrupted
        break if e.message.include?('queue closed')

        raise
      end

      if data
        feature_name_str, operation_str, duration, success = data
        process_async_record(feature_name_str, operation_str, duration, success)
        last_flush_check = Time.now
      elsif Time.now - last_flush_check >= 1.0
        # Timeout - check if we need to flush based on time (every second)
        flush_to_redis_if_needed
        last_flush_check = Time.now
      end
    rescue StandardError => e
      # Log error but continue processing
      warn "Magick: Error in async metrics processor: #{e.message}" if defined?(::Rails) && ::Rails.env.development?
      sleep 0.1 # Brief pause on error
    end
  end
  @async_thread.abort_on_exception = false
end

#stop_async_processor ⇒ Object

Stop async processor (for cleanup)



367
368
369
370
371
372
 
# File 'lib/magick/performance_metrics.rb', line 367

def stop_async_processor
  @async_enabled = false
  @async_queue.close if @async_queue.respond_to?(:close)
  @async_thread&.kill
  @async_thread = nil
end

#usage_count(feature_name) ⇒ Object 



305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
 
# File 'lib/magick/performance_metrics.rb', line 305

def usage_count(feature_name)
  feature_name_str = feature_name.to_s

  # Force flush any pending updates for this feature before reading to ensure accuracy
  # This ensures stats are synced across processes immediately.
  # With no Redis configured the flush is a no-op and the counts stay in memory.
  force_flush_to_redis if @mutex.synchronize { @pending_updates[feature_name_str] }.positive?

  # Memory count = total counts in current process minus what we've already flushed
  # This avoids double-counting with Redis
  memory_count = @mutex.synchronize do
    (@usage_count[feature_name_str] || 0) - (@flushed_counts[feature_name_str] || 0)
  end
  memory_count = 0 if memory_count.negative? # Safety check

  # Redis count = total counts from all processes (including this process's flushed counts)
  redis_count = 0
  begin
    redis = stats_redis_client
    redis_count = redis.get("magick:stats:#{feature_name_str}").to_i if redis
  rescue StandardError
    # Silently fail
  end

  # Total = Redis (all processes, all time) + memory (current process, not yet flushed)
  redis_count + memory_count
end