Adds ability to unwrap ipc errors into their original type

This only works for a specific whitelist of error types, which is
currently all errors in the storagedriver package.

Also improves storagedriver tests to enforce proper error types are
returned
This commit is contained in:
Brian Bland 2014-11-18 17:41:48 -08:00
parent 1e8f0ce50a
commit a3481c5f1c
5 changed files with 85 additions and 21 deletions

View file

@ -84,7 +84,7 @@ func (d *Driver) PutContent(subPath string, contents []byte) error {
func (d *Driver) ReadStream(path string, offset uint64) (io.ReadCloser, error) { func (d *Driver) ReadStream(path string, offset uint64) (io.ReadCloser, error) {
file, err := os.OpenFile(d.subPath(path), os.O_RDONLY, 0644) file, err := os.OpenFile(d.subPath(path), os.O_RDONLY, 0644)
if err != nil { if err != nil {
return nil, err return nil, storagedriver.PathNotFoundError{Path: path}
} }
seekPos, err := file.Seek(int64(offset), os.SEEK_SET) seekPos, err := file.Seek(int64(offset), os.SEEK_SET)
@ -201,7 +201,14 @@ func (d *Driver) List(subPath string) ([]string, error) {
// Move moves an object stored at sourcePath to destPath, removing the original // Move moves an object stored at sourcePath to destPath, removing the original
// object. // object.
func (d *Driver) Move(sourcePath string, destPath string) error { func (d *Driver) Move(sourcePath string, destPath string) error {
err := os.Rename(d.subPath(sourcePath), d.subPath(destPath)) source := d.subPath(sourcePath)
dest := d.subPath(destPath)
if _, err := os.Stat(source); os.IsNotExist(err) {
return storagedriver.PathNotFoundError{Path: sourcePath}
}
err := os.Rename(source, dest)
return err return err
} }

View file

@ -126,7 +126,7 @@ func (driver *StorageDriverClient) Start() error {
} }
if response.Error != nil { if response.Error != nil {
return response.Error return response.Error.Unwrap()
} }
driver.version = response.Version driver.version = response.Version
@ -194,7 +194,7 @@ func (driver *StorageDriverClient) GetContent(path string) ([]byte, error) {
} }
if response.Error != nil { if response.Error != nil {
return nil, response.Error return nil, response.Error.Unwrap()
} }
defer response.Reader.Close() defer response.Reader.Close()
@ -226,7 +226,7 @@ func (driver *StorageDriverClient) PutContent(path string, contents []byte) erro
} }
if response.Error != nil { if response.Error != nil {
return response.Error return response.Error.Unwrap()
} }
return nil return nil
@ -253,7 +253,7 @@ func (driver *StorageDriverClient) ReadStream(path string, offset uint64) (io.Re
} }
if response.Error != nil { if response.Error != nil {
return nil, response.Error return nil, response.Error.Unwrap()
} }
return response.Reader, nil return response.Reader, nil
@ -280,7 +280,7 @@ func (driver *StorageDriverClient) WriteStream(path string, offset, size uint64,
} }
if response.Error != nil { if response.Error != nil {
return response.Error return response.Error.Unwrap()
} }
return nil return nil
@ -307,7 +307,7 @@ func (driver *StorageDriverClient) CurrentSize(path string) (uint64, error) {
} }
if response.Error != nil { if response.Error != nil {
return 0, response.Error return 0, response.Error.Unwrap()
} }
return response.Position, nil return response.Position, nil
@ -334,7 +334,7 @@ func (driver *StorageDriverClient) List(path string) ([]string, error) {
} }
if response.Error != nil { if response.Error != nil {
return nil, response.Error return nil, response.Error.Unwrap()
} }
return response.Keys, nil return response.Keys, nil
@ -361,7 +361,7 @@ func (driver *StorageDriverClient) Move(sourcePath string, destPath string) erro
} }
if response.Error != nil { if response.Error != nil {
return response.Error return response.Error.Unwrap()
} }
return nil return nil
@ -387,7 +387,7 @@ func (driver *StorageDriverClient) Delete(path string) error {
} }
if response.Error != nil { if response.Error != nil {
return response.Error return response.Error.Unwrap()
} }
return nil return nil

View file

@ -37,9 +37,13 @@ type Request struct {
} }
// ResponseError is a serializable error type. // ResponseError is a serializable error type.
// The Type and Parameters may be used to reconstruct the same error on the
// client side, falling back to using the Type and Message if this cannot be
// done.
type ResponseError struct { type ResponseError struct {
Type string Type string
Message string Message string
Parameters map[string]interface{}
} }
// WrapError wraps an error in a serializable struct containing the error's type // WrapError wraps an error in a serializable struct containing the error's type
@ -48,10 +52,52 @@ func WrapError(err error) *ResponseError {
if err == nil { if err == nil {
return nil return nil
} }
return &ResponseError{ v := reflect.ValueOf(err)
Type: reflect.TypeOf(err).String(), re := ResponseError{
Type: v.Type().String(),
Message: err.Error(), Message: err.Error(),
} }
if v.Kind() == reflect.Struct {
re.Parameters = make(map[string]interface{})
for i := 0; i < v.NumField(); i++ {
field := v.Type().Field(i)
re.Parameters[field.Name] = v.Field(i).Interface()
}
}
return &re
}
// Unwrap returns the underlying error if it can be reconstructed, or the
// original ResponseError otherwise.
func (err *ResponseError) Unwrap() error {
var errVal reflect.Value
var zeroVal reflect.Value
switch err.Type {
case "storagedriver.PathNotFoundError":
errVal = reflect.ValueOf(&storagedriver.PathNotFoundError{})
case "storagedriver.InvalidOffsetError":
errVal = reflect.ValueOf(&storagedriver.InvalidOffsetError{})
}
if errVal == zeroVal {
return err
}
for k, v := range err.Parameters {
fieldVal := errVal.Elem().FieldByName(k)
if fieldVal == zeroVal {
return err
}
fieldVal.Set(reflect.ValueOf(v))
}
if unwrapped, ok := errVal.Elem().Interface().(error); ok {
return unwrapped
}
return err
} }
func (err *ResponseError) Error() string { func (err *ResponseError) Error() string {

View file

@ -106,7 +106,11 @@ func New(accessKey string, secretKey string, region aws.Region, encrypt bool, bu
// GetContent retrieves the content stored at "path" as a []byte. // GetContent retrieves the content stored at "path" as a []byte.
func (d *Driver) GetContent(path string) ([]byte, error) { func (d *Driver) GetContent(path string) ([]byte, error) {
return d.Bucket.Get(path) content, err := d.Bucket.Get(path)
if err != nil {
return nil, storagedriver.PathNotFoundError{Path: path}
}
return content, nil
} }
// PutContent stores the []byte content at a location designated by "path". // PutContent stores the []byte content at a location designated by "path".
@ -121,11 +125,10 @@ func (d *Driver) ReadStream(path string, offset uint64) (io.ReadCloser, error) {
headers.Add("Range", "bytes="+strconv.FormatUint(offset, 10)+"-") headers.Add("Range", "bytes="+strconv.FormatUint(offset, 10)+"-")
resp, err := d.Bucket.GetResponseWithHeaders(path, headers) resp, err := d.Bucket.GetResponseWithHeaders(path, headers)
if resp != nil { if err != nil {
return resp.Body, err return nil, storagedriver.PathNotFoundError{Path: path}
} }
return resp.Body, nil
return nil, err
} }
// WriteStream stores the contents of the provided io.ReadCloser at a location // WriteStream stores the contents of the provided io.ReadCloser at a location
@ -242,7 +245,7 @@ func (d *Driver) Move(sourcePath string, destPath string) error {
s3.CopyOptions{Options: d.getOptions(), MetadataDirective: "", ContentType: d.getContentType()}, s3.CopyOptions{Options: d.getOptions(), MetadataDirective: "", ContentType: d.getContentType()},
d.Bucket.Name+"/"+sourcePath) d.Bucket.Name+"/"+sourcePath)
if err != nil { if err != nil {
return err return storagedriver.PathNotFoundError{Path: sourcePath}
} }
return d.Delete(sourcePath) return d.Delete(sourcePath)

View file

@ -126,6 +126,7 @@ func (suite *DriverSuite) TestReadNonexistent(c *check.C) {
filename := randomString(32) filename := randomString(32)
_, err := suite.StorageDriver.GetContent(filename) _, err := suite.StorageDriver.GetContent(filename)
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
} }
// TestWriteReadStreams1 tests a simple write-read streaming workflow // TestWriteReadStreams1 tests a simple write-read streaming workflow
@ -247,6 +248,7 @@ func (suite *DriverSuite) TestReadNonexistentStream(c *check.C) {
filename := randomString(32) filename := randomString(32)
_, err := suite.StorageDriver.ReadStream(filename, 0) _, err := suite.StorageDriver.ReadStream(filename, 0)
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
} }
// TestList checks the returned list of keys after populating a directory tree // TestList checks the returned list of keys after populating a directory tree
@ -297,6 +299,7 @@ func (suite *DriverSuite) TestMove(c *check.C) {
_, err = suite.StorageDriver.GetContent(sourcePath) _, err = suite.StorageDriver.GetContent(sourcePath)
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
} }
// TestMoveNonexistent checks that moving a nonexistent key fails // TestMoveNonexistent checks that moving a nonexistent key fails
@ -306,6 +309,7 @@ func (suite *DriverSuite) TestMoveNonexistent(c *check.C) {
err := suite.StorageDriver.Move(sourcePath, destPath) err := suite.StorageDriver.Move(sourcePath, destPath)
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
} }
// TestDelete checks that the delete operation removes data from the storage // TestDelete checks that the delete operation removes data from the storage
@ -324,6 +328,7 @@ func (suite *DriverSuite) TestDelete(c *check.C) {
_, err = suite.StorageDriver.GetContent(filename) _, err = suite.StorageDriver.GetContent(filename)
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
} }
// TestDeleteNonexistent checks that removing a nonexistent key fails // TestDeleteNonexistent checks that removing a nonexistent key fails
@ -331,6 +336,7 @@ func (suite *DriverSuite) TestDeleteNonexistent(c *check.C) {
filename := randomString(32) filename := randomString(32)
err := suite.StorageDriver.Delete(filename) err := suite.StorageDriver.Delete(filename)
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
} }
// TestDeleteFolder checks that deleting a folder removes all child elements // TestDeleteFolder checks that deleting a folder removes all child elements
@ -354,9 +360,11 @@ func (suite *DriverSuite) TestDeleteFolder(c *check.C) {
_, err = suite.StorageDriver.GetContent(path.Join(dirname, filename1)) _, err = suite.StorageDriver.GetContent(path.Join(dirname, filename1))
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
_, err = suite.StorageDriver.GetContent(path.Join(dirname, filename2)) _, err = suite.StorageDriver.GetContent(path.Join(dirname, filename2))
c.Assert(err, check.NotNil) c.Assert(err, check.NotNil)
c.Assert(err, check.FitsTypeOf, storagedriver.PathNotFoundError{})
} }
func (suite *DriverSuite) writeReadCompare(c *check.C, filename string, contents, expected []byte) { func (suite *DriverSuite) writeReadCompare(c *check.C, filename string, contents, expected []byte) {