Exemplo
pool 1.5.2: Run at most N async operations at once in Dart with package:pool, keep the results lined up with the inputs, and know what the timeout actually guards
Amostra verificada para pub pool 1.5.2: Run at most N async operations at once in Dart with package:pool, keep the results lined up with the inputs, and know…
sha256:16a15d010dc0f1c9e1ee0824cafd5bd1ed1eb32530f108bc856e8cc348fa9179
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MIT-0
Evidência de execução
O ambiente declarado e as execuções assinadas ficam separados, para você ver exatamente o que esta amostra executou e onde.
- Base da evidência
- Contrato assinado aprovado
- Recibos de verificação
- 1
- Chaves de assinatura que o compilaram
- 1
Ambiente declarado
dart 3 linux x64 dart 3 dart pub
Ambientes das execuções de verificação
| Ambiente | Contrato | Etapas | Execução |
|---|---|---|---|
| dart 3 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · pub@1 |
2026-08-14 |
Caso
HOW- Objetivo
- Run at most N async operations at once in Dart with package:pool, keep the results lined up with the inputs, and know what the timeout actually guards
- Pacotes
- Símbolos
-
- Pool
- Pool.withResource
- Pool.request
- Pool.forEach
- Pool.close
- Pool.done
- Pool.isClosed
- PoolResource
- PoolResource.release
- PoolResource.allowRelease
- TimeoutException
- Ambiente
- dart 3
- Criado
- 2026-08-14T20:09:50Z
Contrato
- assert a Pool of two runs at most two bodies at once, and that a withResource body that throws still releases its slot, so the high-water mark afterwards is two and not one
- assert pool.forEach emits results in completion order rather than input order, so its list is a permutation of the inputs, while Future.wait over withResource keeps every result in position
- assert forEach holds every resource in the pool for the whole run, so an unrelated request on the same pool is blocked outright rather than throttled alongside it
- assert the default onError adds the error to the stream and carries on, and that returning false only drops the error, with all six elements processed either way
- assert toList on a forEach stream completes with the first error, discards the values already emitted and cancels the iteration, so the remaining elements are never attempted
- assert an error thrown while iterating the elements bypasses onError entirely and lands on the stream even when onError returns false
- assert the timeout is a pool-wide inactivity alarm that any request or release resets, so a starved caller waits nearly three times it, that it then fails every pending request at once with a TimeoutException carrying the configured duration, and that it never fires again for the life of the pool
- assert request() throws StateError synchronously on a closed pool while withResource puts the identical error into its returned future instead, and that close() is memoized to one future
- assert done completes only once the resources handed out before close are released
- assert allowRelease spends the resource token so a following release() throws StateError, that its callback runs only when the slot is wanted, and that a callback which throws completes the next caller's request() with that error and leaves the pool one usable resource short forever
- assert queued requests are answered in request order even when it is a later allowRelease callback that frees the slot
- assert Pool(0) and a negative limit throw ArgumentError from the constructor, and that queued waiters are served first in, first out
Arquivos
- csx.json
- lib/throttle.dart
- pubspec.lock
- pubspec.yaml
- test/contract_test.dart