basic_controller

Last updated: 2024-09-27 10:47:32.595409 File source: link on GitLab

basic_controller

Table of Contents

Specification

Description

This sub package offers a default implementation of the volume controller.

Structure and Organisation

Here is quick overview of the contents of this pacakge:

  • README: Current file which is aimed towards developers who wish to use and modify the functionality.

  • basic_controller: This file implements the methods for VolumeController interface.

  • basic_controller_test: This file contains the unit tests for the methods of VolumeController interface.

Class Diagram

The class diagram for the basic_controller sub-package is shown below.

Source file

basic_controller Class Diagram

Rendered from source file

!$rootUrlGitlab = "https://gitlab.com/nunet/device-management-service/-/raw/main"
!$packageRelativePath = "/storage/basic_controller"
!$packageUrlGitlab = $rootUrlGitlab + $packageRelativePath
 
!include $packageUrlGitlab/specs/class_diagram.puml

Functionality

NewDefaultVolumeController

  • signature: NewDefaultVolumeController(db *gorm.DB, volBasePath string, fs afero.Fs) -> (storage.basic_controller.BasicVolumeController, error)

  • input #1: local database instance of type *gorm.DB

  • input #2: base path of the volumes

  • input #3: file system instance of type afero.FS

  • output (sucess): new instance of type storage.basic_controller.BasicVolumeController

  • output (error): error

NewDefaultVolumeController returns a new instance of storage.basic_controller.BasicVolumeController struct.

BasicVolumeController is the default implementation of the VolumeController interface. It persists storage volumes information in the local database.

CreateVolume

For function signature refer to the package readme

CreateVolume creates a new storage volume given a storage source (S3, IPFS, job, etc). The creation of a storage volume effectively creates an empty directory in the local filesystem and writes a record in the database.

The directory name follows the format: <volSource> + "-" + <name> where name is random.

CreateVolume will return an error if there is a failure in

  • creation of new directory

  • creating a database entry

LockVolume

For function signature refer to the package readme

LockVolume makes the volume read-only, not only changing the field value but also changing file permissions. It should be used after all necessary data has been written to the volume. It optionally can also set the CID and mark the volume as private

LockVolume will return an error when

  • No storage volume is found at the specified

  • There is error in saving the updated volume in the database

  • There is error in updating file persmissions

DeleteVolume

For function signature refer to the package readme

DeleteVolume deletes a given storage volume record from the database. The identifier can be a path of a volume or a Content ID (CID). Therefore, records for both will be deleted.

It will return an error when

  • Input has incorrect identifier

  • There is failure in deleting the volume

  • No volume is found

ListVolumes

For function signature refer to the package readme

ListVolumes function returns a list of all storage volumes stored on the database.

It will return an error when no storage volumes exist.

GetSize

For function signature refer to the package readme

GetSize returns the size of a volume. The input can be a path or a Content ID (CID).

It will return an error if the operation fails due to:

  • error while querying database

  • volume not found for given identifier

  • unsupported identifed provided as input

  • error while caculating size of directory

Custom configuration Parameters

Both CreateVolume and LockVolume allow for custom configuration of storage volumes via optional parameters. Below is the list of available parameters that can be used:

WithPrivate() - Passing this as an input parameter designates a given volume as private. It can be used both when creating or locking a volume.

WithCID(cid string) - This can be used as an input parameter to set the CID of a given volume during the lock volume operation.

Data Types

storage.basic_controller.BasicVolumeController: This struct manages implementation of VolumeController interface methods.

// BasicVolumeController is the default implementation of the VolumeController.
// It persists storage volumes information in the local database.
type BasicVolumeController struct {
	// db is where all volumes information is stored.
	db *gorm.DB

	// basePath is the base path where volumes are stored under
	basePath string

	// file system to act upon
	fs afero.Fs
}

Refer to package readme for other data types.

Testing

The unit tests for the package functionality are defined in *_test.go file.

Proposed Functionality / Requirements

List of issues

All issues that are related to the implementation of storage package can be found below. These include any proposals for modifications to the package or new data structures needed to cover the requirements of other packages.

References

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