type pullResult … type imagePuller … var ( _ … _ … ) type parallelImagePuller … func newParallelImagePuller(imageService kubecontainer.ImageService, maxParallelImagePulls *int32) imagePuller { … } func (pip *parallelImagePuller) pullImage(ctx context.Context, spec kubecontainer.ImageSpec, pullSecrets []v1.Secret, pullChan chan<- pullResult, podSandboxConfig *runtimeapi.PodSandboxConfig) { … } const maxImagePullRequests … type serialImagePuller … func newSerialImagePuller(imageService kubecontainer.ImageService) imagePuller { … } type imagePullRequest … func (sip *serialImagePuller) pullImage(ctx context.Context, spec kubecontainer.ImageSpec, pullSecrets []v1.Secret, pullChan chan<- pullResult, podSandboxConfig *runtimeapi.PodSandboxConfig) { … } func (sip *serialImagePuller) processImagePullRequests() { … }