Class: Iriq::Storage::Sqlite

Inherits:
Object
  • Object
show all
Defined in:
lib/iriq/storage/sqlite.rb

Overview

Sqlite is the incremental-write backend. Each observation translates to a handful of UPSERTs against a long-lived connection; nothing is materialized in memory beyond what reads explicitly ask for.

WAL journaling lets multiple processes observe against the same file concurrently — the writer is serialized, readers are not blocked, and the existing ‘iriq –corpus c.db <url>` pattern works without a flock at the application layer.

Constant Summary collapse

SCHEMA_VERSION = 
1
SCHEMA = 
<<~SQL.freeze
  CREATE TABLE IF NOT EXISTS meta (
    key   TEXT PRIMARY KEY,
    value TEXT
  );
  CREATE TABLE IF NOT EXISTS host_counts (
    host  TEXT PRIMARY KEY,
    count INTEGER NOT NULL
  );
  CREATE TABLE IF NOT EXISTS path_length_counts (
    length INTEGER PRIMARY KEY,
    count  INTEGER NOT NULL
  );
  CREATE TABLE IF NOT EXISTS raw_shape_counts (
    shape TEXT PRIMARY KEY,
    count INTEGER NOT NULL
  );
  CREATE TABLE IF NOT EXISTS fingerprint_counts (
    shape TEXT PRIMARY KEY,
    count INTEGER NOT NULL
  );
  CREATE TABLE IF NOT EXISTS position_stats (
    host   TEXT NOT NULL,
    prefix TEXT NOT NULL,
    total  INTEGER NOT NULL DEFAULT 0,
    PRIMARY KEY (host, prefix)
  );
  CREATE TABLE IF NOT EXISTS position_values (
    host   TEXT NOT NULL,
    prefix TEXT NOT NULL,
    value  TEXT NOT NULL,
    count  INTEGER NOT NULL,
    PRIMARY KEY (host, prefix, value)
  );
  CREATE TABLE IF NOT EXISTS position_types (
    host   TEXT NOT NULL,
    prefix TEXT NOT NULL,
    type   TEXT NOT NULL,
    count  INTEGER NOT NULL,
    PRIMARY KEY (host, prefix, type)
  );
  CREATE TABLE IF NOT EXISTS clusters (
    key    TEXT PRIMARY KEY,
    host   TEXT,
    scheme TEXT,
    shape  TEXT,
    count  INTEGER NOT NULL DEFAULT 0,
    ord    INTEGER NOT NULL
  );
  CREATE TABLE IF NOT EXISTS cluster_examples (
    cluster_key TEXT NOT NULL,
    position    INTEGER NOT NULL,
    canonical   TEXT NOT NULL,
    PRIMARY KEY (cluster_key, position)
  );
  CREATE TABLE IF NOT EXISTS cluster_segments (
    cluster_key TEXT NOT NULL,
    position    INTEGER NOT NULL,
    value       TEXT NOT NULL,
    count       INTEGER NOT NULL,
    PRIMARY KEY (cluster_key, position, value)
  );
SQL

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path:, classifier: SegmentClassifier::DEFAULT, max_values_per_position: PositionStats::DEFAULT_MAX_VALUES) ⇒ Sqlite

Returns a new instance of Sqlite.



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# File 'lib/iriq/storage/sqlite.rb', line 87

def initialize(path:, classifier: SegmentClassifier::DEFAULT,
               max_values_per_position: PositionStats::DEFAULT_MAX_VALUES)
  @path                    = path
  @classifier              = classifier
  @max_values_per_position = max_values_per_position
  @db                      = SQLite3::Database.new(path)
  # busy_timeout MUST come first: other PRAGMAs (journal_mode in
  # particular) can themselves block on the write lock under
  # concurrent open, and without busy_timeout set they fail
  # immediately with SQLITE_BUSY.
  @db.execute("PRAGMA busy_timeout = 30000")
  @db.execute("PRAGMA journal_mode = WAL")
  @db.execute("PRAGMA synchronous = NORMAL")
  @db.execute("PRAGMA foreign_keys = ON")
  @in_batch = false
end

Instance Attribute Details

#max_values_per_position ⇒ Object (readonly)

Returns the value of attribute max_values_per_position.



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# File 'lib/iriq/storage/sqlite.rb', line 80

def max_values_per_position
  @max_values_per_position
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/iriq/storage/sqlite.rb', line 80

def path
  @path
end

Class Method Details

.open(path, classifier: SegmentClassifier::DEFAULT, max_values_per_position: PositionStats::DEFAULT_MAX_VALUES) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 82

def self.open(path, classifier: SegmentClassifier::DEFAULT,
                    max_values_per_position: PositionStats::DEFAULT_MAX_VALUES)
  new(path: path, classifier: classifier, max_values_per_position: max_values_per_position).tap(&:setup!)
end

Instance Method Details

#add_to_cluster(key, host, scheme, shape, identifier) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 226

def add_to_cluster(key, host, scheme, shape, identifier)
  # Insert the cluster row if new (with a monotonic ord for stable
  # iteration), then bump its count.
  @db.execute(<<~SQL, [key, host, scheme, shape])
    INSERT INTO clusters (key, host, scheme, shape, count, ord)
    VALUES (?, ?, ?, ?, 1, (SELECT COALESCE(MAX(ord), 0) + 1 FROM clusters))
    ON CONFLICT(key) DO UPDATE SET count = count + 1
  SQL

  # Examples — capped at Cluster::MAX_EXAMPLES.
  examples_count = @db.get_first_value(
    "SELECT COUNT(*) FROM cluster_examples WHERE cluster_key = ?", [key],
  )
  if examples_count < Cluster::MAX_EXAMPLES
    @db.execute(<<~SQL, [key, examples_count, identifier.canonical])
      INSERT INTO cluster_examples (cluster_key, position, canonical)
      VALUES (?, ?, ?)
    SQL
  end

  # Per-position segment counts — uncapped.
  identifier.path_segments.each_with_index do |seg, i|
    @db.execute(<<~SQL, [key, i, seg])
      INSERT INTO cluster_segments (cluster_key, position, value, count) VALUES (?, ?, ?, 1)
      ON CONFLICT(cluster_key, position, value) DO UPDATE SET count = count + 1
    SQL
  end

  load_cluster(key)
end

#batch ⇒ Object

Wrap many observations in a single transaction. Cuts SQLite write overhead from O(observations) fsyncs to O(1).



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# File 'lib/iriq/storage/sqlite.rb', line 134

def batch
  return yield if @in_batch

  @in_batch = true
  @db.transaction
  begin
    yield
    @db.commit
  rescue
    @db.rollback rescue nil
    raise
  ensure
    @in_batch = false
  end
end

#close ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 158

def close
  # Checkpoint + truncate the WAL so the .db-wal sidecar doesn't grow
  # unbounded across long-lived `iriq --corpus c.db` sessions.
  @db.execute("PRAGMA wal_checkpoint(TRUNCATE)") rescue nil
  @db.close
end

#cluster_size ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 318

def cluster_size
  @db.get_first_value("SELECT COUNT(*) FROM clusters")
end

#clusters ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 310

def clusters
  out = []
  @db.execute("SELECT key FROM clusters ORDER BY ord") do |row|
    out << load_cluster(row[0])
  end
  out
end

#each_position_stats ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 302

def each_position_stats
  seen = []
  @db.execute("SELECT DISTINCT host, prefix FROM position_stats ORDER BY ROWID") do |row|
    seen << row
  end
  seen.each { |host, prefix| yield [host, prefix], position_stats(host, prefix) }
end

#fingerprint_counts ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 273

def fingerprint_counts
  rows_to_count_hash("fingerprint_counts", "shape")
end

#flush ⇒ Object

Saving is automatic — incremental UPSERTs hit disk on commit. flush makes that explicit; close releases the connection.



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# File 'lib/iriq/storage/sqlite.rb', line 152

def flush; end

#host_counts ⇒ Object

— Reads ————————————————————



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# File 'lib/iriq/storage/sqlite.rb', line 259

def host_counts
  rows_to_count_hash("host_counts", "host")
end

#increment_fingerprint(shape) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 187

def increment_fingerprint(shape)
  upsert_shape("fingerprint_counts", shape)
end

#increment_host(host) ⇒ Object

— Increments ——————————————————-



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# File 'lib/iriq/storage/sqlite.rb', line 167

def increment_host(host)
  return unless host

  @db.execute(<<~SQL, host)
    INSERT INTO host_counts (host, count) VALUES (?, 1)
    ON CONFLICT(host) DO UPDATE SET count = count + 1
  SQL
end

#increment_path_length(length) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 176

def increment_path_length(length)
  @db.execute(<<~SQL, length)
    INSERT INTO path_length_counts (length, count) VALUES (?, 1)
    ON CONFLICT(length) DO UPDATE SET count = count + 1
  SQL
end

#increment_raw_shape(shape) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 183

def increment_raw_shape(shape)
  upsert_shape("raw_shape_counts", shape)
end

#observe_position(host, prefix, value, type) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 191

def observe_position(host, prefix, value, type)
  host ||= ""
  @db.execute(<<~SQL, [host, prefix])
    INSERT INTO position_stats (host, prefix, total) VALUES (?, ?, 1)
    ON CONFLICT(host, prefix) DO UPDATE SET total = total + 1
  SQL

  # Type counts are unbounded — always upsert.
  @db.execute(<<~SQL, [host, prefix, type.to_s])
    INSERT INTO position_types (host, prefix, type, count) VALUES (?, ?, ?, 1)
    ON CONFLICT(host, prefix, type) DO UPDATE SET count = count + 1
  SQL

  # Value counts are capped at max_values_per_position. If the value
  # already exists, increment it; otherwise insert only when
  # cardinality is below the cap. Two-step rather than ON CONFLICT
  # because we need to enforce the cap on insert.
  @db.execute(<<~SQL, [host, prefix, value])
    UPDATE position_values SET count = count + 1
    WHERE host = ? AND prefix = ? AND value = ?
  SQL
  if @db.changes.zero?
    card = @db.get_first_value(
      "SELECT COUNT(*) FROM position_values WHERE host = ? AND prefix = ?",
      [host, prefix],
    )
    if card < @max_values_per_position
      @db.execute(
        "INSERT INTO position_values (host, prefix, value, count) VALUES (?, ?, ?, 1)",
        [host, prefix, value],
      )
    end
  end
end

#path_length_counts ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 263

def path_length_counts
  h = Hash.new(0)
  @db.execute("SELECT length, count FROM path_length_counts") { |r| h[r[0]] = r[1] }
  h
end

#position_stats(host, prefix) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 277

def position_stats(host, prefix)
  host ||= ""
  total = @db.get_first_value(
    "SELECT total FROM position_stats WHERE host = ? AND prefix = ?", [host, prefix],
  )
  return nil if total.nil?

  stats = PositionStats.new(max_values: @max_values_per_position)
  stats.instance_variable_set(:@total, total)

  vc = Hash.new(0)
  @db.execute(
    "SELECT value, count FROM position_values WHERE host = ? AND prefix = ?", [host, prefix]
  ) { |r| vc[r[0]] = r[1] }
  stats.instance_variable_set(:@value_counts, vc)

  tc = Hash.new(0)
  @db.execute(
    "SELECT type, count FROM position_types WHERE host = ? AND prefix = ?", [host, prefix]
  ) { |r| tc[r[0].to_sym] = r[1] }
  stats.instance_variable_set(:@type_counts, tc)

  stats
end

#raw_shape_counts ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 269

def raw_shape_counts
  rows_to_count_hash("raw_shape_counts", "shape")
end

#save(_path = nil) ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 154

def save(_path = nil)
  # Already persisted. Provided for parity with the JSON backend.
end

#setup! ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 104

def setup!
  @db.execute_batch(SCHEMA)
  existing = @db.get_first_value("SELECT value FROM meta WHERE key = 'schema_version'")
  if existing.nil?
    @db.execute("INSERT INTO meta (key, value) VALUES ('schema_version', ?)", SCHEMA_VERSION.to_s)
    @db.execute("INSERT INTO meta (key, value) VALUES ('max_values_per_position', ?)",
                @max_values_per_position.to_s)
  else
    @max_values_per_position = (@db.get_first_value(
      "SELECT value FROM meta WHERE key = 'max_values_per_position'"
    ) || @max_values_per_position).to_i
  end
  self
end

#transaction ⇒ Object 



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# File 'lib/iriq/storage/sqlite.rb', line 119

def transaction
  # While inside an outer batch, observe()-time transactions become
  # no-ops — the outer batch wraps everything in one txn for speed.
  return yield(self) if @in_batch

  @db.transaction
  yield self
  @db.commit
rescue
  @db.rollback rescue nil
  raise
end