ObjectStores
This package defines an abstract type, ObjectStore, and a common API for accessing object storage.
This allows you to swap storage back-ends without changing your code.
Storage back-ends include in-memory, local disk and cloud-based object storage.
What is an object store?
In an object store, data is stored as objects and objects are grouped into buckets.
Concrete examples of object stores include:
- LocalDiskObjectStores.jl, which uses the local file system to store objects (files) in buckets (directories).
- GoogleCloudObjectStores.jl, which uses Google Cloud Storage.
Permissions
An object store's access to buckets and objects is controlled using the small but flexible Authorization.jl framework. This framework allows both fine-grained access control for specific buckets and objects, as well as more coarse access control such as uniform access for all buckets and/or objects. Please read the README to understand how to access buckets and objects can be controlled.
NOTE: An ObjectStore cannot act on (create/read/delete) buckets or objects that are outside the root bucket.
Example Usage
See the examples and tests in LocalDiskObjectStores.jl and GoogleCloudObjectStores.jl, which uses the local file system as the storage back-end.
API
store = T(args...) # Constructor for some T <: ObjectStore
# Set access permissions
setpermission!(store, :bucket, Permission(false, true, false, false)) # Bucket access is cRud (read-only) without expiry
setpermission!(store, :object, Permission(false, true, false, false)) # Object access is cRud (read-only) without expiry
# Allow CRUD (read/write) access for 5 minutes to objects in the bucket called "mybucket"
setpermission!(store, r"^rootbucket/mybucket/.+", Permission(true, true, true, true, now() + Minute(5)))
# Buckets
createbucket!(store, "mybucket") # Create mybucket in the root bucket
listcontents(store, "mybucket") # List the contents of rootbucket/mybucket. Return nothing if it doesn't exist
deletebucket!(store, "mybucket") # Delete rootbucket/mybucket if it exists
# Objects
store["mybucket/myobject"] = value # Create/update. Not possible if the bucket doesn't exist.
store["mybucket/myobject"] # Read. Returns nothing if the object doesn't exist.
delete!(store, "mybucket/myobject")
# Conveniences
isbucket(store, bucketname) # True if bucketname refers to a bucket
isobject(store, objectname) # True if objectname refers to an object
# Permission queries
p = getpermission(store, bucket_or_object) # Get the permission settings for the specific bucket/object
setexpiry!(store, now() + Hour(1)) # Set an expiry for all the buckets/objects that the store has access to
haspermission(store, bucket_or_object, :create) # True if the store has :create access to the bucket/object
permissions_conflict(store, "mybucket") # True if the rules that define the store's access to "mybucket" conflict