Objects represent items stored within a container. These are subject to the permissions of the container being the most relaxed possible permissions that can be applied to an object. It is possible using Session/Bearer Tokens to restrict permissions further on objects within a container however
Please note actions on objects are restricted by the permissions on the container AND the permissions of the token used to access the functions.
Before uploading an object, you will need
filepath)cli)Attributes are key value pairs (string:string) that are attached to the metadata of objects. You can specify anything as an attribute, however there are a couple of reserved ones
var attributes []*object.Attribute
timeStampAttr := new(object.Attribute)
timeStampAttr.SetKey(object.AttributeTimestamp) // AttributeTimestamp key is like a 'created at' attribute
timeStampAttr.SetValue(strconv.FormatInt(time.Now().Unix(), 10))
fileNameAttr := new(object.Attribute)
fileNameAttr.SetKey(object.AttributeFileName) // AttributeFileName key is the filename to be associated with the object.
fileNameAttr.SetValue(path.Base(filepath)) //path.Base(filepath) returns the last element of a file path (usually the filename)
expirationEpochAttr := new(object.Attribute)
expirationEpochAttr.SetKey("__NEOFS__EXPIRATION_EPOCH") // Reserved case for when the life of the object should expire
expirationEpochAttr.SetValue(strconv.Itoa(epoch))) //The epoch at which the object will expire
attributes = append(attributes, []*object.Attribute{timeStampAttr, fileNameAttr, expirationEpochAttr}...)
print("please help by opening a Pull Request and filling in these code snippets!")
Console.WriteLine("please help by opening a Pull Request and filling in these code snippets!");
If you have set the FileName attribute, you can also refer to the object by its filename, i.e https://http.testnet.fs.neo.org/CONTAINER_ID/upload.png when its uploaded, (see acl permissions)
See tokens for how to create a session token
var obj = object.NewRaw()
obj.SetContainerID(containerID)
obj.SetOwnerID(ownerID)
obj.SetAttributes(attributes...)
// use an io.Reader (e.g from a file) to get the data to upload
var putParams = new(client.PutObjectParams)
putParams.WithObject(obj.Object())
putParams.WithPayloadReader(*reader)
response, err := cli.PutObject(ctx, putParams, client.WithBearer(bearerToken), client.WithSession(sessionToken))
if err != nil {
return fmt.Errorf(err)
}
//the object ID is stored in response.ID()
print("please help by opening a Pull Request and filling in these code snippets!")
Console.WriteLine("please help by opening a Pull Request and filling in these code snippets!");
Depending on your container’s permissions you should now be able to view the file you uploaded at:
https://http.testnet.fs.neo.org/CONTAINER_ID/OBJECT_ID
Once you have uploaded objects to a container, you will want to list them out. Listing is a special case of searching within a container. To search for specific objects, you add filters to the search. By setting the only filter as a root filter, it will list everything within the container
var searchParams = new (client.SearchObjectParams)
var filters = object.SearchFilters{}
filters.AddRootFilter()
searchParams.WithContainerID(containerID)
searchParams.WithSearchFilters(filters)
res, err := cli.SearchObjects(ctx, searchParams, client.WithSession(sessionToken))
if err != nil {
return fmt.Errorf(err)
}
fmt.Printf("list objects %+v\n", res.IDList())
print("please help by opening a Pull Request and filling in these code snippets!")
Console.WriteLine("please help by opening a Pull Request and filling in these code snippets!");
Once you have the ID of an object, you can download it.
You will need
To generate an object address from the string forms of a containerID and an objectID:
contID := cid.New()
contID.Parse(containerID)
objID := obj.NewID()
objID.Parse(objectID)
objAddress := obj.NewAddress()
objAddress.SetObjectID(objID)
objAddress.SetContainerID(contID)
print("please help by opening a Pull Request and filling in these code snippets!")
Console.WriteLine("please help by opening a Pull Request and filling in these code snippets!");
so now you can retrieve the object
var getParams = new(client.GetObjectParams)
getParams.WithAddress(objectAddress)
getParams.WithPayloadWriter(*writer)
o, err := cli.GetObject(ctx, getParams, client.WithSession(sessionToken))
if err != nil {
return fmt.Errorf(err)
}
// payload is in bytes []bytes
payload := o.Object().Payload()
}
print("please help by opening a Pull Request and filling in these code snippets!")
Console.WriteLine("please help by opening a Pull Request and filling in these code snippets!");
Sometimes you want information about an object, without actually downloading the entire object, for instance the size of an object
From a container, you can find out storage policies, owners and any other meta information about the container itself. This is very similar to retrieving the object
var headParams = new(client.ObjectHeaderParams)
headParams.WithAddress(objectAddress)
headObject, err := cli.HeadObject(ctx, headParams, client.WithSession(sessionToken))
if err != nil {
return fmt.Errorf(err)
}
size := headObject.Object().PayloadSize()
print("please help by opening a Pull Request and filling in these code snippets!")
Console.WriteLine("please help by opening a Pull Request and filling in these code snippets!");
You may wish to delete an object for a container
var deleteParams = new (client.DeleteObjectParams)
deleteParams.WithAddress(objectAddress)
_, err := cli.DeleteObject(ctx, deleteParams, client.WithSession(sessionToken))
if err != nil {
return fmt.Errorf(err)
}
print("please help by opening a Pull Request and filling in these code snippets!")
Console.WriteLine("please help by opening a Pull Request and filling in these code snippets!");