/
storage.go
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/
storage.go
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// Copyright The OpenTelemetry 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 storage
import (
"context"
"go.opentelemetry.io/collector/component"
"go.opentelemetry.io/collector/config"
)
// Extension is the interface that storage extensions must implement
type Extension interface {
component.Extension
// GetClient will create a client for use by the specified component.
// The component can use the client to manage state
GetClient(context.Context, component.Kind, config.ComponentID, string) (Client, error)
}
// Client is the interface that storage clients must implement
// All methods should return error only if a problem occurred.
// This mirrors the behavior of a golang map:
// - Set doesn't error if a key already exists - it just overwrites the value.
// - Get doesn't error if a key is not found - it just returns nil.
// - Delete doesn't error if the key doesn't exist - it just no-ops.
// This also provides a way to differentiate data operations
// [overwrite | not-found | no-op] from "real" problems
type Client interface {
// Get will retrieve data from storage that corresponds to the
// specified key. It should return nil, nil if not found
Get(context.Context, string) ([]byte, error)
// Set will store data. The data can be retrieved by the same
// component after a process restart, using the same key
Set(context.Context, string, []byte) error
// Delete will delete data associated with the specified key
Delete(context.Context, string) error
// Close will release any resources held by the client
Close(context.Context) error
}