Module: Shipeasy::SDK::Eval

Defined in:
lib/shipeasy/sdk/eval.rb

Defined Under Namespace

Classes: ExperimentResult

Class Method Summary collapse

Class Method Details

.enabled?(v) ⇒ Boolean

Returns:

  • (Boolean) 


10
11
12
 
# File 'lib/shipeasy/sdk/eval.rb', line 10

def self.enabled?(v)
  v == 1 || v == true
end

.eval_experiment(exp, flags_blob, exps_blob, user, exp_name: nil, sticky_store: nil) ⇒ Object

exp_name + sticky_store are optional so existing callers stay deterministic. When a sticky_store is passed, an enrolled unit whose stored salt prefix still matches skips the allocation gate (so a shrinking allocation keeps it in) and returns the stored group without re-running the pick. A fresh pick is persisted via store.set; a salt mismatch / missing stored group falls through to re-bucket + overwrite. Mirrors the TS reference (doc 20 §2). exp_name is the key under which the entry is stored.



102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
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/shipeasy/sdk/eval.rb', line 102

def self.eval_experiment(exp, flags_blob, exps_blob, user, exp_name: nil, sticky_store: nil)
  not_in = ExperimentResult.new(in_experiment: false, group: "control", params: nil)

  return not_in unless exp && exp["status"] == "running"

  targeting_gate = exp["targetingGate"]
  if targeting_gate && !targeting_gate.empty?
    gate = flags_blob&.dig("gates", targeting_gate)
    return not_in unless gate && eval_gate(gate, user)
  end

  bucket_by = exp["bucketBy"] || exp[:bucketBy]
  uid = pick_identifier(user, bucket_by)
  return not_in unless uid

  universe_name = exp["universe"]
  universe = exps_blob&.dig("universes", universe_name)
  holdout = universe&.dig("holdout_range")
  if holdout
    seg = murmur3("#{universe_name}:#{uid}") % 10000
    return not_in if seg >= holdout[0] && seg <= holdout[1]
  end

  salt          = exp["salt"]
  allocation_pct = exp["allocationPct"] || 0
  groups = exp["groups"] || []
  salt8 = (salt || "")[0, 8]

  # Sticky short-circuit: an enrolled unit whose stored salt prefix still
  # matches skips allocation and returns the stored group. If the stored
  # group no longer exists, fall through to re-bucket + overwrite.
  if sticky_store && exp_name
    entry = (sticky_store.get(uid) || {})[exp_name]
    if entry && entry["s"] == salt8
      g = groups.find { |x| x["name"] == entry["g"] }
      return ExperimentResult.new(in_experiment: true, group: g["name"], params: g["params"]) if g
    end
  end

  return not_in if murmur3("#{salt}:alloc:#{uid}") % 10000 >= allocation_pct

  group_hash = murmur3("#{salt}:group:#{uid}") % 10000
  cumulative = 0
  groups.each_with_index do |g, i|
    cumulative += g["weight"]
    if group_hash < cumulative || i == groups.length - 1
      sticky_store.set(uid, exp_name, { "g" => g["name"], "s" => salt8 }) if sticky_store && exp_name
      return ExperimentResult.new(in_experiment: true, group: g["name"], params: g["params"])
    end
  end

  not_in
end

.eval_gate(gate, user) ⇒ Object 



73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
 
# File 'lib/shipeasy/sdk/eval.rb', line 73

def self.eval_gate(gate, user)
  return false if enabled?(gate["killswitch"])
  return false unless enabled?(gate["enabled"])

  (gate["rules"] || []).each do |rule|
    return false unless match_rule(rule, user)
  end

  uid = user["user_id"] || user[:user_id] || user["anonymous_id"] || user[:anonymous_id]
  # No unit id (an unidentified request before any anon id is minted): a
  # fully-rolled gate is on for everyone, so it can be answered without
  # bucketing; a fractional rollout genuinely needs a stable unit, so deny
  # until one exists. Rules above are still checked, so targeting wins.
  # See experiment-platform/18-identity-bucketing.md.
  return (gate["rolloutPct"] || gate[:rolloutPct] || 0) >= 10000 unless uid

  salt = gate["salt"] || gate[:salt]
  murmur3("#{salt}:#{uid}") % 10000 < (gate["rolloutPct"] || gate[:rolloutPct] || 0)
end

.match_rule(rule, user) ⇒ Object 



23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
 
# File 'lib/shipeasy/sdk/eval.rb', line 23

def self.match_rule(rule, user)
  attr  = rule["attr"] || rule[:attr]
  op    = rule["op"]   || rule[:op]
  value = rule["value"] || rule[:value]
  actual = user[attr] || user[attr.to_sym]

  case op
  when "eq"       then actual == value
  when "neq"      then actual != value
  when "in"       then Array(value).include?(actual)
  when "not_in"   then !Array(value).include?(actual)
  when "contains"
    if actual.is_a?(String) && value.is_a?(String)
      actual.include?(value)
    elsif actual.is_a?(Array)
      actual.include?(value)
    else
      false
    end
  when "regex"
    actual.is_a?(String) && value.is_a?(String) &&
      Regexp.new(value).match?(actual) rescue false
  when "gt", "gte", "lt", "lte"
    a = to_num(actual)
    b = to_num(value)
    return false if a.nil? || b.nil?
    case op
    when "gt"  then a > b
    when "gte" then a >= b
    when "lt"  then a < b
    when "lte" then a <= b
    end
  else
    false
  end
end

.murmur3(key) ⇒ Object 



6
7
8
 
# File 'lib/shipeasy/sdk/eval.rb', line 6

def self.murmur3(key)
  Murmur3.hash32(key, 0)
end

.pick_identifier(user, bucket_by) ⇒ Object

Pick the bucketing identifier. When bucket_by is set and the user carries that attribute as a non-empty string (or any number, stringified), bucket on it — so a whole company/org lands on one variant. Otherwise fall back to user_id, then anonymous_id. Mirrors core’s pickIdentifier.



64
65
66
67
68
69
70
71
 
# File 'lib/shipeasy/sdk/eval.rb', line 64

def self.pick_identifier(user, bucket_by)
  if bucket_by && !bucket_by.to_s.empty?
    v = user[bucket_by] || user[bucket_by.to_sym]
    return v if v.is_a?(String) && !v.empty?
    return v.to_s if v.is_a?(Numeric)
  end
  user["user_id"] || user[:user_id] || user["anonymous_id"] || user[:anonymous_id]
end

.to_num(v) ⇒ Object 



14
15
16
17
18
19
20
21
 
# File 'lib/shipeasy/sdk/eval.rb', line 14

def self.to_num(v)
  case v
  when Numeric then v.finite? ? v : nil
  when String
    n = Float(v) rescue nil
    n&.finite? ? n : nil
  end
end