Module: DeadBro::MemoryDetails

Defined in:
lib/dead_bro/memory_details.rb

Constant Summary collapse

OBJECT_TYPE_NAMES =

Maps Ruby internal ObjectSpace type codes to human-readable names. Types omitted here are filtered out (internal noise).

{
  T_STRING: "String",
  T_ARRAY: "Array",
  T_HASH: "Hash",
  T_OBJECT: "Object",
  T_DATA: "C Extension",
  T_CLASS: "Class",
  T_MODULE: "Module",
  T_STRUCT: "Struct",
  T_MATCH: "MatchData",
  T_REGEXP: "Regexp",
  T_SYMBOL: "Symbol",
  T_FLOAT: "Float",
  T_FILE: "File",
  T_BIGNUM: "Integer (big)"
}.freeze
SKIP_TYPES =

Noise types never shown to users.

%i[FREE T_IMEMO TOTAL T_NODE T_ICLASS T_ZOMBIE T_MOVED].freeze

Class Method Summary collapse

Class Method Details

.build(gc_before:, gc_after:, memory_before_mb:, memory_after_mb:, object_counts_before:, object_counts_after:, large_objects:) ⇒ Object 



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# File 'lib/dead_bro/memory_details.rb', line 38

def self.build(gc_before:, gc_after:, memory_before_mb:, memory_after_mb:,
               object_counts_before:, object_counts_after:, large_objects:)
  memory_delta_mb = (memory_after_mb - memory_before_mb).round(2)
  gc_collections = (gc_after[:count] || 0) - (gc_before[:count] || 0)
  heap_pages_added = (gc_after[:heap_allocated_pages] || 0) - (gc_before[:heap_allocated_pages] || 0)
  new_objects = (gc_after[:total_allocated_objects] || 0) - (gc_before[:total_allocated_objects] || 0)

  raw_deltas = {}
  if object_counts_before.any? && object_counts_after.any?
    keys = (object_counts_before.keys + object_counts_after.keys).uniq
    keys.each do |k|
      diff = (object_counts_after[k] || 0) - (object_counts_before[k] || 0)
      raw_deltas[k] = diff unless diff.zero?
    end
    raw_deltas = raw_deltas.sort_by { |_, v| -v.abs }.first(20).to_h
  end

  warnings = []
  warnings << "Memory grew #{memory_delta_mb}MB — possible leak or large allocation" if memory_delta_mb > 20
  warnings << "GC ran #{gc_collections} times — many short-lived objects being created" if gc_collections > 5
  warnings << "Heap grew by #{heap_pages_added} pages — Ruby needed more memory from the OS" if heap_pages_added > 10
  warnings << "#{large_objects.length} object(s) over 1MB found in memory" if large_objects.any?

  {
    gc_collections: gc_collections,
    heap_pages_added: heap_pages_added,
    new_objects: new_objects,
    object_breakdown: format_object_breakdown(raw_deltas),
    large_objects: large_objects,
    warnings: warnings
  }
end

.format_object_breakdown(deltas) ⇒ Object 



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# File 'lib/dead_bro/memory_details.rb', line 27

def self.format_object_breakdown(deltas)
  result = {}
  deltas.each do |type, count|
    next if SKIP_TYPES.include?(type)
    next unless count.positive?
    name = OBJECT_TYPE_NAMES[type] || type.to_s.sub(/\AT_/, "")
    result[name] = count
  end
  result.sort_by { |_, v| -v }.to_h
end