createQuerySet method

@override QuerySet createQuerySet(QueryType type, int count)

A set of count queries of type — DeviceFeature.occlusionQuery, DeviceFeature.timestampQuery or DeviceFeature.pipelineStatisticsQuery, the feature QueryType.feature names.

A QueryType.pipelineStatistics set reports exactly the counters PipelineStatistic.values names at 1.0, in that order, for every 1.x release: the per-query stride an outside backend returns is part of the contract. A counter a later minor adds arrives as a new QueryType with its own stride, never as a sixth value here; this member cannot gain a parameter to select counters.

Implementation

@override
QuerySet createQuerySet(QueryType type, int count) {
  switch (type) {
    case QueryType.occlusion:
      features.require(DeviceFeature.occlusionQuery, backend: _backend);
    case QueryType.timestamp:
      features.require(
        DeviceFeature.timestampQuery,
        backend: _backend,
        reason: 'the adapter did not offer timestamp-query',
      );
    case QueryType.pipelineStatistics:
      // TODO(webgpu): pipeline statistics — not in the WebGPU
      // specification; a `"pipeline-statistics"` query type behind a
      // feature would unblock it.
      features.require(
        DeviceFeature.pipelineStatisticsQuery,
        backend: _backend,
        reason: 'WebGPU has no pipeline statistics queries',
      );
  }
  if (count < 1 || count > 4096) {
    throw ArgumentError.value(count, 'count', 'WebGPU takes 1 to 4096');
  }
  return wrapQuerySet(
    owner: this,
    backend: WebGpuQueries(
      _guard(
        'a query set of $count',
        () => _gpuDevice.createQuerySet(
          GPUQuerySetDescriptor(
            type: type == QueryType.occlusion ? 'occlusion' : 'timestamp',
            count: count,
            label: '${type.name} x$count',
          ),
        ),
      ),
    ),
    type: type,
    count: count,
  );
}