Files
kopia/cli/storage_providers.go

110 lines
3.6 KiB
Go

package cli
import (
"context"
"io"
"maps"
"slices"
"sync"
"github.com/alecthomas/kingpin/v2"
"github.com/pkg/errors"
"github.com/kopia/kopia/internal/impossible"
"github.com/kopia/kopia/repo/blob"
"github.com/kopia/kopia/repo/blob/throttling"
)
// StorageProviderServices is implemented by the cli App that allows the cli
// and tests to mutate the default storage providers.
type StorageProviderServices interface {
EnvName(s string) string
setPasswordFromToken(pwd string)
storageProviders() []StorageProvider
stdin() io.Reader
}
// StorageFlags is implemented by cli storage providers which need to support a
// particular backend. This requires the common setup and connection methods
// implemented by all the cli storage providers.
type StorageFlags interface {
Setup(sps StorageProviderServices, cmd *kingpin.CmdClause)
Connect(ctx context.Context, isCreate bool, formatVersion int) (blob.Storage, error)
}
// StorageProvider is a CLI provider for storage options and allows the CLI to
// multiplex between various provider CLI flag constructors.
type StorageProvider struct {
Name string
Description string
NewFlags func() StorageFlags
}
//nolint:gochecknoglobals
var (
registeredProvidersMu sync.Mutex
// +checklocks:registeredProvidersMu
registeredProviders = make(map[string]StorageProvider)
errStorageAlreadyRegistered = errors.New("storage provider already registered") // +checklocksignore
)
// mustRegisterStorageProvider registers a storage provider for use with the CLI repository connect command.
// It should typically be called from init() functions in storage provider packages.
// It panics if the storage provider has already been registered.
func mustRegisterStorageProvider(name, description string, newFlags func() StorageFlags) {
impossible.PanicOnError(registerStorageProvider(name, description, newFlags))
}
func registerStorageProvider(name, description string, newFlags func() StorageFlags) error {
registeredProvidersMu.Lock()
defer registeredProvidersMu.Unlock()
if _, ok := registeredProviders[name]; ok {
return errors.Wrapf(errStorageAlreadyRegistered, "%s", name)
}
registeredProviders[name] = StorageProvider{
Name: name,
Description: description,
NewFlags: newFlags,
}
return nil
}
// getRegisteredStorageProviders returns a copy of all registered storage providers.
// This is used internally by the App to build the list of available storage providers.
func getRegisteredStorageProviders() []StorageProvider {
registeredProvidersMu.Lock()
defer registeredProvidersMu.Unlock()
// Return a copy to prevent external modification
p := make([]StorageProvider, 0, len(registeredProviders))
for _, n := range slices.Sorted(maps.Keys(registeredProviders)) {
p = append(p, registeredProviders[n])
}
if len(p) != len(registeredProviders) {
panic("expected provider length mismatch")
}
return p
}
func commonThrottlingFlags(cmd *kingpin.CmdClause, limits *throttling.Limits) {
cmd.Flag("max-download-speed", "Limit the download speed.").PlaceHolder("BYTES_PER_SEC").FloatVar(&limits.DownloadBytesPerSecond)
cmd.Flag("max-upload-speed", "Limit the upload speed.").PlaceHolder("BYTES_PER_SEC").FloatVar(&limits.UploadBytesPerSecond)
}
// AddStorageProvider adds a new StorageProvider at runtime after the App has
// been initialized with the default providers. This is used in tests which
// require custom storage providers to simulate various edge cases.
func (c *App) AddStorageProvider(p StorageProvider) {
c.cliStorageProviders = append(c.cliStorageProviders, p)
}
func (c *App) storageProviders() []StorageProvider {
return c.cliStorageProviders
}