Module: Rigor::ModuleGraph::Stats

Defined in:
lib/rigor/module_graph/stats.rb

Overview

Computes per-namespace dependency metrics over an edge list.

Five numbers per namespace:

nodes

number of distinct constants in the namespace

fan_out

edges whose from is in the namespace and to is outside it

fan_in

edges whose to is in the namespace and from is outside it

internal

edges where both endpoints sit in the namespace

total

fan_out + internal — every edge originating in the namespace

Grouping is by top-level namespace by default (+Billing::Invoice+ → Billing). Pass depth: N for a deeper split (+Billing::Invoice::Line+ at depth 2 → Billing::Invoice). Names without enough segments at the requested depth bucket under the special label "(top-level)" so they stay visible in the report.

Defined Under Namespace

Classes: NamespaceMetrics

Constant Summary collapse

TOP_LEVEL_BUCKET = 
"(top-level)"

Class Method Summary collapse

Class Method Details

.bucket_for_normalised(name, depth) ⇒ Object

Like bucket_for, but skips the split allocation when the name has more segments than depth. Walks index once per :: separator and slices once at the boundary.



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# File 'lib/rigor/module_graph/stats.rb', line 87

def bucket_for_normalised(name, depth)
  cursor = -2
  depth.times do
    cursor = name.index("::", cursor + 2)
    return TOP_LEVEL_BUCKET unless cursor
  end
  name[0...cursor]
end

.compute(edges, depth: 1) ⇒ Array<NamespaceMetrics>

Returns sorted by fan_out desc, then namespace asc; deterministic output.

Parameters:

  • edges (Array<Edge>)
  • depth (Integer) (defaults to: 1) —

    number of leading :: segments to keep when grouping

Returns:

  • (Array<NamespaceMetrics>) —

    sorted by fan_out desc, then namespace asc; deterministic output.



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# File 'lib/rigor/module_graph/stats.rb', line 34

def compute(edges, depth: 1)
  # Single pass over edges. For each edge we resolve both
  # endpoints to a normalised name (cached), then to a
  # bucket (cached), then update the bucket's mutable
  # `[nodes_set, fan_out, fan_in, internal]` counter array.
  # Allocating one immutable `NamespaceMetrics` per edge via
  # `Data#with` is what made the old implementation slow.
  normalised = {}
  groups = {}
  counters = Hash.new { |h, k| h[k] = [{}, 0, 0, 0] }

  edges.each do |edge|
    from = (normalised[edge.from] ||= fast_normalise(edge.from))
    to = (normalised[edge.to] ||= fast_normalise(edge.to))

    from_group = (groups[from] ||= bucket_for_normalised(from, depth))
    to_group = (groups[to] ||= bucket_for_normalised(to, depth))

    from_counter = counters[from_group]
    to_counter = counters[to_group]
    from_counter[0][from] = true
    to_counter[0][to] = true

    if from_group == to_group
      from_counter[3] += 1
    else
      from_counter[1] += 1
      to_counter[2] += 1
    end
  end

  metrics = counters.map do |namespace, counter|
    NamespaceMetrics.new(
      namespace: namespace,
      nodes: counter[0].size,
      fan_out: counter[1],
      fan_in: counter[2],
      internal: counter[3]
    )
  end
  metrics.sort_by { |m| [-m.fan_out, m.namespace] }
end

.fast_normalise(name) ⇒ Object

Strip leading "::" so absolute and relative names share the same bucket / node identity — they refer to the same constant either way.



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# File 'lib/rigor/module_graph/stats.rb', line 80

def fast_normalise(name)
  name.start_with?("::") ? name[2..] : name
end