client/gapir/discovery.go

// Copyright (C) 2016 The Android Open Source Project
//
// 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 gapir

import (
	"sync"

	"android.googlesource.com/platform/tools/gpu/framework/id"
	"android.googlesource.com/platform/tools/gpu/framework/log"
)

// Discovery is used to find replay devices on the local machine and connected
// Android devices.
type Discovery struct {
	sync.Mutex
	devices []Device
}

// Device looks up the device with the specified identifier.
// If no device with the specified identifier was registered with the Discovery
// then nil is returned.
func (d *Discovery) Device(id id.ID) Device {
	d.Lock()
	defer d.Unlock()
	for _, d := range d.devices {
		if d.ID() == id {
			return d
		}
	}
	return nil
}

// Devices returns the list of devices registered with the Discovery.
func (d *Discovery) Devices() []Device {
	d.Lock()
	defer d.Unlock()

	return append([]Device{}, d.devices...)
}

// DefaultDevice returns the first device registered with the Discovery.
func (d *Discovery) DefaultDevice() Device {
	d.Lock()
	defer d.Unlock()
	if len(d.devices) == 0 {
		return nil
	}
	return d.devices[0]
}

// AddDevice registers the device dev with the Discovery.
func (d *Discovery) AddDevice(ctx log.Context, dev Device) {
	if dev != nil {
		d.Lock()
		defer d.Unlock()
		for _, t := range d.devices {
			if t == dev {
				return // already added
			}
		}
		ctx.Info().Log("Adding new device")
		d.devices = append(d.devices, dev)
	}
}

// RemoveDevice unregisters the device dev with the Discovery.
func (d *Discovery) RemoveDevice(ctx log.Context, dev Device) {
	if dev != nil {
		d.Lock()
		defer d.Unlock()
		for i, t := range d.devices {
			if t == dev {
				ctx.Info().Log("Removing existing device")
				copy(d.devices[i:], d.devices[i+1:])
				d.devices = d.devices[:len(d.devices)-1]
			}
		}
	}
}