Module: RailsTracepointStack::Truncator

Defined in:
lib/rails_tracepoint_stack/truncator.rb

Overview

Shrinks an already-serialized value so one fat argument (a big payload, a long SQL string, a loaded association) cannot dominate the output. Runs over the plain structures LogFormatter.safe_value produces, so it only ever sees strings, numbers, booleans, nil, arrays and hashes.

Constant Summary collapse

ELLIPSIS = 
"…".freeze

Class Method Summary collapse

Class Method Details

.call(value, limits) ⇒ Object 



9
10
11
12
13
14
15
16
 
# File 'lib/rails_tracepoint_stack/truncator.rb', line 9

def self.call(value, limits)
  case value
  when String then truncate_string(value, limits)
  when Array then truncate_array(value, limits)
  when Hash then truncate_hash(value, limits)
  else value
  end
end

.truncate_array(value, limits) ⇒ Object 



25
26
27
28
29
30
31
32
33
 
# File 'lib/rails_tracepoint_stack/truncator.rb', line 25

def self.truncate_array(value, limits)
  max = limits.max_collection_size
  kept = (max.nil? || value.length <= max) ? value : value.first(max)
  result = kept.map { |item| call(item, limits) }

  return result if kept.length == value.length

  result << "(+#{value.length - kept.length} more)"
end

.truncate_hash(value, limits) ⇒ Object 



35
36
37
38
39
40
41
42
43
44
45
46
47
48
 
# File 'lib/rails_tracepoint_stack/truncator.rb', line 35

def self.truncate_hash(value, limits)
  max = limits.max_collection_size
  dropped = (max.nil? || value.size <= max) ? 0 : value.size - max
  kept = dropped.zero? ? value : value.first(max).to_h

  result = kept.each_with_object({}) do |(key, item), memo|
    memo[key] = call(item, limits)
  end

  return result if dropped.zero?

  result[ELLIPSIS] = "(+#{dropped} more)"
  result
end

.truncate_string(value, limits) ⇒ Object 



18
19
20
21
22
23
 
# File 'lib/rails_tracepoint_stack/truncator.rb', line 18

def self.truncate_string(value, limits)
  max = limits.max_string_length
  return value if max.nil? || value.length <= max

  "#{value[0, max]}#{ELLIPSIS} (#{value.length} chars)"
end