Class: Pgbus::Configuration::CapsuleDSL

Inherits:
Object
  • Object
show all
Defined in:
lib/pgbus/configuration/capsule_dsl.rb

Overview

Parses the capsule string DSL into the internal worker config array.

The DSL lets users describe worker thread pools (capsules) compactly:

"*: 5"                                # one capsule, all queues, 5 threads
"critical: 5; default: 10"            # two capsules
"critical, default: 5"                # one capsule, list = strict priority
"default, mailers: 10; *: 2"          # specialized + fallback wildcard
"staging_*: 3"                        # prefix wildcard

Operators:

,    queue separator within a capsule (list order = strict priority)
;    capsule separator (each becomes its own thread pool)
:N   thread count for the capsule (default 5)
*    wildcard, matches all queues
*_   trailing wildcard, prefix match (e.g. "staging_*")

Returns Array<Hash> in the same shape as the legacy workers: array, so the rest of the codebase can consume it without changes:

[{ queues: ["critical"], threads: 5 },
 { queues: ["default", "mailers"], threads: 10 }]

Validation runs at parse time. Errors include the offending input and a clear message naming the rule that was violated.

Defined Under Namespace

Classes: ParseError

Constant Summary collapse

DEFAULT_THREADS = 
5
WILDCARD = 
"*"
QUEUE_NAME_PATTERN =

Valid queue tokens accepted by the DSL:

"*"         bare wildcard (matches all queues at runtime)
"default"   bare queue name
"staging_*" prefix wildcard (matches queues by prefix at runtime)

The character class for queue names — alphanumerics and underscores only — intentionally matches Pgbus::QueueNameValidator::VALID_QUEUE_NAME_PATTERN. Hyphens, dots, and other punctuation are NOT permitted because PGMQ interpolates queue names directly into SQL identifiers (q_<name>, a_<name>) and only those characters are safe there. If you change this pattern, also update QueueNameValidator to keep them in sync.

The “*” tokens (bare and trailing) are DSL-only — they get expanded to concrete queue names at runtime before reaching QueueNameValidator.

/\A(?:\*|[a-zA-Z0-9_]+\*?)\z/
THREAD_COUNT_PATTERN = 
/\A\d+\z/

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(input) ⇒ CapsuleDSL

Returns a new instance of CapsuleDSL.



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# File 'lib/pgbus/configuration/capsule_dsl.rb', line 57

def initialize(input)
  @input = input
end

Class Method Details

.parse(input) ⇒ Object 



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# File 'lib/pgbus/configuration/capsule_dsl.rb', line 53

def self.parse(input)
  new(input).parse
end

Instance Method Details

#parse ⇒ Object 



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# File 'lib/pgbus/configuration/capsule_dsl.rb', line 61

def parse
  validate_input_type!
  validate_input_not_empty!

  # Pure tokenization: split, parse each capsule, return them in order.
  # Cross-capsule overlap rules live in Pgbus::Configuration#workers=
  # because they depend on whether the resulting capsules are named or
  # anonymous, and naming is a Configuration concern (not a parser one).
  # Within-capsule duplicate-queue checks still happen in parse_capsule.
  split_capsules(@input).map { |segment| parse_capsule(segment) }
end