forked from gravitational/teleport
/
wrap.go
154 lines (131 loc) · 4.49 KB
/
wrap.go
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/*
* Teleport
* Copyright (C) 2023 Gravitational, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package backend
import (
"context"
"sync"
"time"
"github.com/gravitational/trace"
"github.com/jonboulle/clockwork"
)
// Wrapper wraps a Backend implementation that can fail
// on demand.
type Wrapper struct {
sync.RWMutex
backend Backend
// readErr if set, will result in an error returned
// on every read operation
readErr error
}
// NewWrapper returns a new Wrapper.
func NewWrapper(backend Backend) *Wrapper {
return &Wrapper{
backend: backend,
}
}
func (s *Wrapper) GetName() string {
return s.backend.GetName()
}
// GetReadError returns error to be returned by
// read backend operations
func (s *Wrapper) GetReadError() error {
s.RLock()
defer s.RUnlock()
return s.readErr
}
// SetReadError sets error to be returned by read backend operations
func (s *Wrapper) SetReadError(err error) {
s.Lock()
defer s.Unlock()
s.readErr = err
}
// GetRange returns query range
func (s *Wrapper) GetRange(ctx context.Context, startKey []byte, endKey []byte, limit int) (*GetResult, error) {
if err := s.GetReadError(); err != nil {
return nil, trace.Wrap(err)
}
return s.backend.GetRange(ctx, startKey, endKey, limit)
}
// Create creates item if it does not exist
func (s *Wrapper) Create(ctx context.Context, i Item) (*Lease, error) {
return s.backend.Create(ctx, i)
}
// Put puts value into backend (creates if it does not
// exists, updates it otherwise)
func (s *Wrapper) Put(ctx context.Context, i Item) (*Lease, error) {
return s.backend.Put(ctx, i)
}
// Update updates value in the backend
func (s *Wrapper) Update(ctx context.Context, i Item) (*Lease, error) {
return s.backend.Update(ctx, i)
}
// ConditionalUpdate updates value in the backend if revisions match.
func (s *Wrapper) ConditionalUpdate(ctx context.Context, i Item) (*Lease, error) {
return s.backend.ConditionalUpdate(ctx, i)
}
// Get returns a single item or not found error
func (s *Wrapper) Get(ctx context.Context, key []byte) (*Item, error) {
if err := s.GetReadError(); err != nil {
return nil, trace.Wrap(err)
}
return s.backend.Get(ctx, key)
}
// CompareAndSwap compares item with existing item
// and replaces is with replaceWith item
func (s *Wrapper) CompareAndSwap(ctx context.Context, expected Item, replaceWith Item) (*Lease, error) {
return s.backend.CompareAndSwap(ctx, expected, replaceWith)
}
// Delete deletes item by key
func (s *Wrapper) Delete(ctx context.Context, key []byte) error {
return s.backend.Delete(ctx, key)
}
// ConditionalDelete deletes item by key if revisions match.
func (s *Wrapper) ConditionalDelete(ctx context.Context, key []byte, revision string) error {
return s.backend.ConditionalDelete(ctx, key, revision)
}
// DeleteRange deletes range of items
func (s *Wrapper) DeleteRange(ctx context.Context, startKey []byte, endKey []byte) error {
return s.backend.DeleteRange(ctx, startKey, endKey)
}
// KeepAlive keeps object from expiring, updates lease on the existing object,
// expires contains the new expiry to set on the lease,
// some backends may ignore expires based on the implementation
// in case if the lease managed server side
func (s *Wrapper) KeepAlive(ctx context.Context, lease Lease, expires time.Time) error {
return s.backend.KeepAlive(ctx, lease, expires)
}
// NewWatcher returns a new event watcher
func (s *Wrapper) NewWatcher(ctx context.Context, watch Watch) (Watcher, error) {
if err := s.GetReadError(); err != nil {
return nil, trace.Wrap(err)
}
return s.backend.NewWatcher(ctx, watch)
}
// Close releases the resources taken up by this backend
func (s *Wrapper) Close() error {
return s.backend.Close()
}
// CloseWatchers closes all the watchers
// without closing the backend
func (s *Wrapper) CloseWatchers() {
s.backend.CloseWatchers()
}
// Clock returns clock used by this backend
func (s *Wrapper) Clock() clockwork.Clock {
return s.backend.Clock()
}