meta

README

Meta Service

A central storage for all nodes metadata.

API

Metadata are stored JSON-serialized and associated to nodes UUID. This service is not indexed (except by node UUID). See the Search service if you need to make metadata queryable.

This service provides two handlers:

• GRPC: for internal communication
• HTTP API: for setting/reading meta from the clients.

TODO: Later should be transformed to a REST service.

Events

Meta service publishes the following NodeChange events to the topic common.TOPIC_META_CHANGES :

• NodeChangeEvent_UPDATE_META
• NodeChangeEvent_DELETE

Meta service is subscribing to the following NodeChange events on topic common.TOPIC_TREE_CHANGES

• NodeChangeEvent_CREATE : extract meta from node and store it
• NodeChangeEvent_UPDATE_PATH : same
• NodeChangeEvent_UPDATE_META : same
• NodeChangeEvent_DELETE : remove all metadata stored for this node

Storage

Storage is currently implemented in SQL, providing both MySQL and Sqlite implementations.

Documentation

Overview

Package meta provides storage for files and folders metadata.

Index

• func NewDAO(ctx context.Context, o dao.DAO) (dao.DAO, error)
• type DAO

Functions

func NewDAO

func NewDAO(ctx context.Context, o dao.DAO) (dao.DAO, error)

Types

type DAO

type DAO interface {
	dao.DAO

	SetMetadata(nodeId string, author string, metadata map[string]string) (err error)
	GetMetadata(nodeId string) (metadata map[string]string, err error)
	ListMetadata(query string) (metadataByUuid map[string]map[string]string, err error)
}