distribution/registry/storage/driver/testdriver/testdriver.go

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package testdriver
import (
"context"
storagedriver "github.com/docker/distribution/registry/storage/driver"
"github.com/docker/distribution/registry/storage/driver/factory"
"github.com/docker/distribution/registry/storage/driver/inmemory"
)
const driverName = "testdriver"
func init() {
factory.Register(driverName, &testDriverFactory{})
}
// testDriverFactory implements the factory.StorageDriverFactory interface.
type testDriverFactory struct{}
func (factory *testDriverFactory) Create(parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
return New(), nil
}
// TestDriver is a StorageDriver for testing purposes. The Writer returned by this driver
// simulates the case where Write operations are buffered. This causes the value returned by Size to lag
// behind until Close (or Commit, or Cancel) is called.
type TestDriver struct {
storagedriver.StorageDriver
}
type testFileWriter struct {
storagedriver.FileWriter
prevchunk []byte
}
var _ storagedriver.StorageDriver = &TestDriver{}
// New constructs a new StorageDriver for testing purposes. The Writer returned by this driver
// simulates the case where Write operations are buffered. This causes the value returned by Size to lag
// behind until Close (or Commit, or Cancel) is called.
func New() *TestDriver {
return &TestDriver{StorageDriver: inmemory.New()}
}
// Writer returns a FileWriter which will store the content written to it
// at the location designated by "path" after the call to Commit.
func (td *TestDriver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
fw, err := td.StorageDriver.Writer(ctx, path, append)
return &testFileWriter{FileWriter: fw}, err
}
func (tfw *testFileWriter) Write(p []byte) (int, error) {
_, err := tfw.FileWriter.Write(tfw.prevchunk)
tfw.prevchunk = make([]byte, len(p))
copy(tfw.prevchunk, p)
return len(p), err
}
func (tfw *testFileWriter) Close() error {
tfw.Write(nil)
return tfw.FileWriter.Close()
}
func (tfw *testFileWriter) Cancel() error {
tfw.Write(nil)
return tfw.FileWriter.Cancel()
}
func (tfw *testFileWriter) Commit() error {
tfw.Write(nil)
return tfw.FileWriter.Commit()
}