Class: OpenASN::Snapshot

Inherits:
Object
  • Object
show all
Defined in:
lib/openasn/snapshot.rb

Overview

An immutable, fully-loaded dataset: canonical artifacts (both address families) + org names + Tier B overlays, plus the metadata to explain where it all came from. Snapshots are built off the hot path and swapped in with a single ivar assignment (see Dataset) — readers never see partial state, and there are no locks anywhere near lookups.

Defined Under Namespace

Classes: Family

Constant Summary collapse

SEED_DIR = 
File.expand_path("data/seed", __dir__)
EMPTY_OVERLAYS = 
[].freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(v4_parsed, v6_parsed, orgs, overlays, manifest, origin, store) ⇒ Snapshot

Returns a new instance of Snapshot.



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# File 'lib/openasn/snapshot.rb', line 106

def initialize(v4_parsed, v6_parsed, orgs, overlays, manifest, origin, store)
  @v4 = Family.new(base: v4_parsed[:base], vpn: v4_parsed[:vpn], dc: v4_parsed[:dc], relay: v4_parsed[:relay])
  @v6 = Family.new(base: v6_parsed[:base], vpn: v6_parsed[:vpn], dc: v6_parsed[:dc], relay: v6_parsed[:relay])
  @orgs = orgs
  @overlays = overlays.freeze
  @build_id = manifest["build_id"]
  @build_ts = v4_parsed[:build_ts]
  @loaded_at = Time.now.utc
  @origin = origin
  @record_counts = {
    base_ipv4: @v4.base.count, vpn_ipv4: @v4.vpn.count, dc_ipv4: @v4.dc.count,
    base_ipv6: @v6.base.count
  }.freeze
  @tier_b_status = build_tier_b_status(store)
  # Precomputed (family, maps_to) -> [[entry, layer], ...] index. The old
  # per-lookup filter_map was fine at 8 overlays but allocation-heavy at
  # 18+ (measured: 42us/lookup vs 15us overlay-less with 11 overlays -
  # most of the gap was these throwaway arrays, not the binary searches).
  # The snapshot is immutable, so build the index exactly once.
  @overlay_index = {}
  @overlays.each do |o|
    { ipv4: o.v4, ipv6: o.v6 }.each do |fam, layer|
      next unless layer

      (@overlay_index[[fam, o.maps_to]] ||= []) << [o, layer].freeze
    end
  end
  @overlay_index.each_value(&:freeze)
  @overlay_index.freeze
  freeze
end

Instance Attribute Details

#build_id ⇒ Object (readonly)

Returns the value of attribute build_id.



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# File 'lib/openasn/snapshot.rb', line 17

def build_id
  @build_id
end

#build_ts ⇒ Object (readonly)

Returns the value of attribute build_ts.



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# File 'lib/openasn/snapshot.rb', line 17

def build_ts
  @build_ts
end

#loaded_at ⇒ Object (readonly)

Returns the value of attribute loaded_at.



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# File 'lib/openasn/snapshot.rb', line 17

def loaded_at
  @loaded_at
end

#orgs ⇒ Object (readonly)

Returns the value of attribute orgs.



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# File 'lib/openasn/snapshot.rb', line 17

def orgs
  @orgs
end

#origin ⇒ Object (readonly)

Returns the value of attribute origin.



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# File 'lib/openasn/snapshot.rb', line 17

def origin
  @origin
end

#overlays ⇒ Object (readonly)

Returns the value of attribute overlays.



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# File 'lib/openasn/snapshot.rb', line 17

def overlays
  @overlays
end

#record_counts ⇒ Object (readonly)

Returns the value of attribute record_counts.



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# File 'lib/openasn/snapshot.rb', line 17

def record_counts
  @record_counts
end

#tier_b_status ⇒ Object (readonly)

Returns the value of attribute tier_b_status.



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# File 'lib/openasn/snapshot.rb', line 17

def tier_b_status
  @tier_b_status
end

#v4 ⇒ Object (readonly)

Returns the value of attribute v4.



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# File 'lib/openasn/snapshot.rb', line 17

def v4
  @v4
end

#v6 ⇒ Object (readonly)

Returns the value of attribute v6.



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# File 'lib/openasn/snapshot.rb', line 17

def v6
  @v6
end

Class Method Details

.build(config) ⇒ Object

Build from the best available data:

1. data_dir artifacts (downloaded by the updater) when present+valid
2. the gem's bundled seed otherwise (first boot, corrupted dir, …)

A corrupt downloaded artifact NEVER crashes boot — parsing happens INSIDE the fallback boundary (a truncated download that still reads fine must not take the app down); we log and fall back to the seed, and the next update cycle re-downloads. If the bundled seed itself fails to parse, the gem is broken and raising IS correct.



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# File 'lib/openasn/snapshot.rb', line 28

def self.build(config)
  data_dir = config.data_dir
  mode = config.memory_mode

  origin = :data_dir
  begin
    v4_bytes, v6_bytes, manifest = read_artifacts(data_dir)
    raise Errno::ENOENT, "no artifacts in data_dir" unless v4_bytes

    v4_parsed, v6_parsed = parse_pair(v4_bytes, v6_bytes, mode)
  rescue StandardError => e
    unless e.is_a?(Errno::ENOENT)
      config.logger.warn("openasn: data_dir artifacts unusable (#{e.message}); falling back to bundled seed")
    end
    origin = :seed
    v4_bytes = File.binread(File.join(SEED_DIR, "openasn-ipv4.bin"))
    v6_bytes = File.binread(File.join(SEED_DIR, "openasn-ipv6.bin"))
    manifest = JSON.parse(File.read(File.join(SEED_DIR, "manifest.json")))
    v4_parsed, v6_parsed = parse_pair(v4_bytes, v6_bytes, mode)
  end

  orgs = load_orgs(data_dir, config)
  store = OverlayStore.new(data_dir)
  overlays = store.load(config.enabled_tier_b_source_ids, mode)

  new(v4_parsed, v6_parsed, orgs, overlays, manifest, origin, store)
end

.load_orgs(data_dir, config) ⇒ Object 



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# File 'lib/openasn/snapshot.rb', line 96

def self.load_orgs(data_dir, config)
  path = File.join(data_dir, "openasn-orgs.bin")
  return nil unless File.exist?(path)

  BinaryFormat::OrgIndex.load(path)
rescue StandardError => e
  config.logger.warn("openasn: openasn-orgs.bin unusable (#{e.message}); as_org will be nil until next update")
  nil
end

.parse_pair(v4_bytes, v6_bytes, mode) ⇒ Object

Raises:



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# File 'lib/openasn/snapshot.rb', line 56

def self.parse_pair(v4_bytes, v6_bytes, mode)
  v4_parsed = BinaryFormat.parse_artifact(v4_bytes, mode: mode)
  v6_parsed = BinaryFormat.parse_artifact(v6_bytes, mode: mode)
  raise FormatError, "openasn-ipv4.bin is not an IPv4 artifact" unless v4_parsed[:family] == :ipv4
  raise FormatError, "openasn-ipv6.bin is not an IPv6 artifact" unless v6_parsed[:family] == :ipv6

  [v4_parsed, v6_parsed]
end

.read_artifacts(data_dir) ⇒ Object 



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# File 'lib/openasn/snapshot.rb', line 65

def self.read_artifacts(data_dir)
  v4 = File.join(data_dir, "openasn-ipv4.bin")
  v6 = File.join(data_dir, "openasn-ipv6.bin")
  mf = File.join(data_dir, "manifest.json")
  return nil unless File.exist?(v4) && File.exist?(v6)

  manifest = File.exist?(mf) ? JSON.parse(File.read(mf)) : {}
  verify_manifest_hashes!(manifest, "openasn-ipv4.bin" => v4, "openasn-ipv6.bin" => v6)
  [File.binread(v4), File.binread(v6), manifest]
end

.verify_manifest_hashes!(manifest, files) ⇒ Object 



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# File 'lib/openasn/snapshot.rb', line 76

def self.verify_manifest_hashes!(manifest, files)
  by_name = (manifest["files"] || []).to_h { |f| [f["name"], f] }
  return if by_name.empty? # legacy/manual installs without checksums still parse through FORMAT.md.

  files.each do |name, path|
    expected = by_name.dig(name, "sha256")
    raise IntegrityError, "manifest missing checksum for #{name}" if expected.to_s.empty?

    actual = Digest::SHA256.file(path).hexdigest
    next if actual == expected

    # Updater writes manifest.json last as the commit marker. If a
    # process dies during the final rename loop, a fresh boot can see
    # new artifact bytes next to the old manifest. Reject that mixed
    # set here and fall back to the bundled seed instead of serving a
    # cross-build IPv4/IPv6 pair.
    raise IntegrityError, "#{name} checksum does not match manifest"
  end
end

Instance Method Details

#age_seconds ⇒ Object 



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# File 'lib/openasn/snapshot.rb', line 153

def age_seconds
  Time.now.to_i - @build_ts
end

#family(fam) ⇒ Object 



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# File 'lib/openasn/snapshot.rb', line 138

def family(fam) = fam == :ipv4 ? @v4 : @v6

#org_name(asn) ⇒ Object 



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# File 'lib/openasn/snapshot.rb', line 149

def org_name(asn)
  asn && @orgs ? @orgs.name(asn) : nil
end

#overlays_for(fam, maps_to) ⇒ Object

Overlays for one family in a stable order (executor wrote them; order among same-precedence overlays doesn't affect verdicts, only which provider gets attribution on exotic multi-overlay hits).



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# File 'lib/openasn/snapshot.rb', line 145

def overlays_for(fam, maps_to)
  @overlay_index.fetch([fam, maps_to], EMPTY_OVERLAYS)
end