/*
Copyright 2016 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package cm

import (
	"k8s.io/kubernetes/pkg/api"
)

// ResourceConfig holds information about all the supported cgroup resource parameters.
type ResourceConfig struct {
	// Memory limit (in bytes).
	Memory *int64
	// CPU shares (relative weight vs. other containers).
	CpuShares *int64
	// CPU hardcap limit (in usecs). Allowed cpu time in a given period.
	CpuQuota *int64
}

// CgroupConfig holds the cgroup configuration information.
// This is common object which is used to specify
// cgroup information to both systemd and raw cgroup fs
// implementation of the Cgroup Manager interface.
type CgroupConfig struct {
	// We would expect systemd implementation to make appropriate
	// name conversion. For example, if we pass /foo/bar
	// then systemd should convert the name to something like
	// foo.slice/foo-bar.slice

	// Fully qualified name
	Name string
	// ResourceParameters contains various cgroups settings to apply.
	ResourceParameters *ResourceConfig
}

// CgroupManager allows for cgroup management.
// Supports Cgroup Creation ,Deletion and Updates.
type CgroupManager interface {
	// Create creates and applies the cgroup configurations on the cgroup.
	// It just creates the leaf cgroups.
	// It expects the parent cgroup to already exist.
	Create(*CgroupConfig) error
	// Destroys the cgroup.
	Destroy(*CgroupConfig) error
	// Update cgroup configuration.
	Update(*CgroupConfig) error
	// Exists checks if the cgroup already exists
	Exists(string) bool
}

// QOSContainersInfo stores the names of containers per qos
type QOSContainersInfo struct {
	Guaranteed string
	BestEffort string
	Burstable  string
}

// PodContainerManager stores and manages pod level containers
// The Pod workers interact with the PodContainerManager to create and destroy
// containers for the pod.
type PodContainerManager interface {
	// getPodContainerName returns the pod container's absolute name
	GetPodContainerName(*api.Pod) string

	// EnsureExists takes a pod as argument and makes sure that
	// pod cgroup exists if qos cgroup hierarchy flag is enabled.
	// If the pod cgroup doesen't already exist this method creates it.
	EnsureExists(*api.Pod) error

	Exists(*api.Pod) bool

	//Destroy takes a pod as argument and destroys the pod's container.
	Destroy(string) error
}