Golang storage.Storage类代码示例

func GetImageDiffCache(s storage.Storage, imageID string) ([]byte, error) {
	path := storage.ImageDiffPath(imageID)
	if exists, _ := s.Exists(path); exists {
		return s.Get(storage.ImageDiffPath(imageID))
	}
	// that indicates miss/successful hit/cache error...
	// weird that we have no way of knowing that this is a cache miss outside of this function, but this is how
	// docker-registry does it so we'll follow...
	return nil, nil // nil error, because cache missed
}

func StoreChecksum(s storage.Storage, imageID string, checksums []string) error {
	for _, checksum := range checksums {
		parts := strings.Split(checksum, ":")
		if len(parts) != 2 {
			return errors.New("Invalid checksum format")
		}
	}
	content, err := json.Marshal(checksums)
	if err != nil {
		return err
	}
	return s.Put(storage.ImageChecksumPath(imageID), content)
}

// this function takes both []byte and []map[string]interface{} to shortcut in some cases.
func UpdateIndexImages(s storage.Storage, namespace, repo string, additionalBytes []byte,
	additional []map[string]interface{}) error {
	path := storage.RepoIndexImagesPath(namespace, repo)
	// get previous content
	previousData, err := s.Get(path)
	if err != nil {
		// doesn't yet exist, just put the data
		return s.Put(path, additionalBytes)
	}
	var previous []map[string]interface{}
	if err := json.Unmarshal(previousData, &previous); err != nil {
		return err
	}
	if len(previous) == 0 {
		// nothing in previous, just put the data
		return s.Put(path, additionalBytes)
	}
	// Merge existing images with the incoming images. if the image ID exists in the existing, check to see if
	// the checksum is the same. if it is just continue, if it isn't replace it with the incoming image
	newImagesMap := map[string]map[string]interface{}{}
	for _, value := range additional {
		id, ok := value["id"].(string)
		if !ok {
			// json was screwed up
			return errors.New("Invalid Data")
		}
		if imageData, ok := newImagesMap[id]; ok {
			if _, ok := imageData["checksum"]; ok {
				continue
			}
		}
		newImagesMap[id] = value
	}
	for _, value := range previous {
		id, ok := value["id"].(string)
		if !ok {
			// json was screwed up
			return errors.New("Invalid Data")
		}
		if imageData, ok := newImagesMap[id]; ok {
			if _, ok := imageData["checksum"]; ok {
				continue
			}
		}
		newImagesMap[id] = value
	}
	newImagesArr := make([]map[string]interface{}, len(newImagesMap))
	i := 0
	for _, image := range newImagesMap {
		newImagesArr[i] = image
		i++
	}
	data, err := json.Marshal(&newImagesArr)
	if err != nil {
		return err
	}
	return s.Put(path, data)
}

// return json file listing for given image id
// Download the specified layer and determine the file contents. If the cache already exists, just return it.
func GetImageFilesJson(s storage.Storage, imageID string) ([]byte, error) {
	// if the files json exists in the cache, return it
	filesJson, err := GetImageFilesCache(s, imageID)
	if err != nil {
		return filesJson, nil
	}

	// cache doesn't exist. download remote layer
	// docker-registry 0.6.5 has an lzma decompress here. it actually doesn't seem to be used so i've omitted it
	// will add it later if need be.
	tarFilesInfo := NewTarFilesInfo()
	if reader, err := s.GetReader(storage.ImageLayerPath(imageID)); err != nil {
		return nil, err
	} else if err := tarFilesInfo.Load(reader); err != nil {
		return nil, err
	}
	return tarFilesInfo.Json()
}

func GenerateAncestry(s storage.Storage, imageID, parentID string) (err error) {
	logger.Debug("[GenerateAncestry] imageID=" + imageID + " parentID=" + parentID)
	path := storage.ImageAncestryPath(imageID)
	if parentID == "" {
		return s.Put(path, []byte(`["`+imageID+`"]`))
	}
	var content []byte
	if content, err = s.Get(storage.ImageAncestryPath(parentID)); err != nil {
		return err
	}
	var ancestry []string
	if err := json.Unmarshal(content, &ancestry); err != nil {
		return err
	}
	ancestry = append([]string{imageID}, ancestry...)
	if content, err = json.Marshal(&ancestry); err != nil {
		return err
	}
	return s.Put(path, content)
}

func SetImageFilesCache(s storage.Storage, imageID string, filesJson []byte) error {
	return s.Put(storage.ImageFilesPath(imageID), filesJson)
}

func GetImageFilesCache(s storage.Storage, imageID string) ([]byte, error) {
	return s.Get(storage.ImageFilesPath(imageID))
}

func GenDiff(s storage.Storage, imageID string) {
	// Comment from docker-registry 0.6.5
	// get json describing file differences in layer
	// Calculate the diff information for the files contained within
	// the layer. Return a dictionary of lists grouped by whether they
	// were deleted, changed or created in this layer.
	// To determine what happened to a file in a layer we walk backwards
	// through the ancestry until we see the file in an older layer. Based
	// on whether the file was previously deleted or not we know whether
	// the file was created or modified. If we do not find the file in an
	// ancestor we know the file was just created.
	// - File marked as deleted by union fs tar: DELETED
	// - Ancestor contains non-deleted file:     CHANGED
	// - Ancestor contains deleted marked file:  CREATED
	// - No ancestor contains file:              CREATED

	diffJson, err := GetImageDiffCache(s, imageID)
	if err == nil && diffJson != nil {
		// cache hit, just return
		logger.Debug("[GenDiff][" + imageID + "] already exists")
		return
	}

	anPath := storage.ImageAncestryPath(imageID)
	anContent, err := s.Get(anPath)
	if err != nil {
		// error fetching ancestry, just return
		logger.Error("[GenDiff][" + imageID + "] error fetching ancestry: " + err.Error())
		return
	}
	var ancestry []string
	if err := json.Unmarshal(anContent, &ancestry); err != nil {
		// json unmarshal fail, just return
		logger.Error("[GenDiff][" + imageID + "] error unmarshalling ancestry json: " + err.Error())
		return
	}
	// get map of file infos
	infoMap, err := fileInfoMap(s, imageID)
	if err != nil {
		// error getting file info, just return
		logger.Error("[GenDiff][" + imageID + "] error getting files info: " + err.Error())
		return
	}

	deleted := map[string][]interface{}{}
	changed := map[string][]interface{}{}
	created := map[string][]interface{}{}

	for _, anID := range ancestry {
		anInfoMap, err := fileInfoMap(s, anID)
		if err != nil {
			// error getting file info, just return
			logger.Error("[GenDiff][" + imageID + "] error getting ancestor " + anID + " files info: " + err.Error())
			return
		}
		for fname, info := range infoMap {
			isDeleted, isBool := (info[1]).(bool)
			// if the file info is in a bad format (isDeleted is not a bool), we should just assume it is deleted.
			// technically isBool should never be false.
			if !isBool || isDeleted {
				if !isBool {
					logger.Error("[GenDiff][" + imageID + "] file info is in a bad format")
				}
				deleted[fname] = info
				delete(infoMap, fname)
				continue
			}
			anInfo := anInfoMap[fname]
			if err != nil || anInfo == nil {
				// doesn't exist, must be created. do nothing.
				continue
			}
			isDeleted, isBool = anInfo[1].(bool)
			if !isBool || isDeleted {
				if !isBool {
					logger.Error("[GenDiff][" + imageID + "] file info is in a bad format")
				}
				// deleted in ancestor, must be created now.
				created[fname] = info
			} else {
				// not deleted in ancestor, must have just changed now.
				changed[fname] = info
			}
			delete(infoMap, fname)
		}
	}
	// dump all created stuff from infoMap
	for fname, info := range infoMap {
		created[fname] = info
	}

	diff := map[string]map[string][]interface{}{
		"deleted": deleted,
		"changed": changed,
		"created": created,
	}
	if diffJson, err = json.Marshal(&diff); err != nil {
		// json marshal fail. just return
		logger.Error("[GenDiff][" + imageID + "] error marshalling new diff json: " + err.Error())
		return
//.........这里部分代码省略.........

func SetImageDiffCache(s storage.Storage, imageID string, diffJson []byte) error {
	return s.Put(storage.ImageDiffPath(imageID), diffJson)
}