/
snapshot.go
92 lines (75 loc) · 2.16 KB
/
snapshot.go
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// Copyright 2017 Quentin Machu & eco 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 snapshot
import (
"errors"
"io"
"sync"
"time"
)
var (
providers = make(map[string]Provider)
providersM sync.RWMutex
ErrNoSnapshot = errors.New("no snapshot available")
)
type Provider interface {
Configure(Config) error
Save(io.ReadCloser, *Metadata) error
Get(*Metadata) (string, bool, error)
Info() (*Metadata, error)
Purge(time.Duration) error
}
// Config represents the configuration of the snapshot provider.
type Config struct {
Interval time.Duration `yaml:"interval"`
TTL time.Duration `yaml:"ttl"`
Provider string `yaml:"provider"`
Params map[string]interface{} `yaml:",inline"`
}
// Register makes a Provider available by the provided name.
//
// If called twice with the same name, the name is blank, or if the provided
// Provider is nil, this function panics.
func Register(name string, p Provider) {
if name == "" {
panic("provider: could not register an Provider with an empty name")
}
if p == nil {
panic("provider: could not register a nil Provider")
}
providersM.Lock()
defer providersM.Unlock()
if _, dup := providers[name]; dup {
panic("provider: RegisterUpdater called twice for " + name)
}
providers[name] = p
}
// AsMap returns a map representing the registered Providers.
func AsMap() map[string]Provider {
providersM.RLock()
defer providersM.RUnlock()
ret := make(map[string]Provider)
for k, v := range providers {
ret[k] = v
}
return ret
}
// AsList returns the names of registered providers.
func AsList() []string {
r := []string{}
for u := range providers {
r = append(r, u)
}
return r
}